source report

jhh19970724

2016_Book_EnergyTransportationAndGlobalW.pdf

Home >English homework help >Article writing homework help >source report

Green Energy and Technology

Panagiotis Grammelis Editor

Energy, Transportation and Global Warming

Green Energy and Technology

More information about this series at http://www.springer.com/series/8059

Panagiotis Grammelis

Editor

Energy, Transportation and Global Warming

Editor Panagiotis Grammelis Chemical Process and Energy Resources Institute Centre for Research and Technology Hellas Athens, Greece

ISSN 1865-3529 ISSN 1865-3537 (electronic) Green Energy and Technology ISBN 978-3-319-30126-6 ISBN 978-3-319-30127-3 (eBook) DOI 10.1007/978-3-319-30127-3

Library of Congress Control Number: 2016933773

© Springer International Publishing Switzerland 2016 This work is subject to copyright. All rights are reserved by the Publisher, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilms or in any other physical way, and transmission or information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed. The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. The publisher, the authors and the editors are safe to assume that the advice and information in this book are believed to be true and accurate at the date of publication. Neither the publisher nor the authors or the editors give a warranty, express or implied, with respect to the material contained herein or for any errors or omissions that may have been made.

Printed on acid-free paper

This Springer imprint is published by Springer Nature The registered company is Springer International Publishing AG Switzerland

Preface

This book is associated with the Global Conference on Global Warming: Focus on

Energy-Transport-Greenhouse Effects, held in Athens on May 24–27, 2015. Objec-

tives are in accordance with the conference’s presentations and mainly concern the exchange of technical information, dissemination of high-quality research results

and presentation of new policy and scientific developments, while promoting future

priorities for a more sustainable development and energy security.

In particular, energy-related issues in all engineering disciplines for a wide area

of applications in the renewables and fossil fuels sectors are described, incorporat-

ing cross-cutting effects. It includes main aspects of transportation discipline with

emphasis on the elimination of the impact on greenhouse effects.

High-quality technical knowledge and research results from specific test cases

around the world are being analysed, providing a holistic view in the main aspects

of the Global Warming issue. The latter also concern current policies and emissions

from air and maritime transport, in addition to the fossil fuel applications. Novel

technologies such as Carbon Capture and Storage are investigated along with

process/systems analysis and optimization for mitigating CO2 emissions. Water

resources management and waste water treatment as well as waste management

issues are also tackled. Biomass, hydrogen and solar energy technologies are

presented along with an insight on green buildings.

The utmost scope of this book is to contribute to the scientific community, since

it includes scientific approaches from many organisations around the globe,

presenting key issues, challenges and research results in a variety of scientific

areas that relate to the Global Warming effects.

Athens, Greece Panagiotis Grammelis

Contents

Part I Global Warming and Climate Change:

General Issues and Challenges

General Aspects of Global Warming, Current Policies

and Challenges Policies and General Aspects of Global

Warming with Focus on Specific Examples

1 Urban Development Policy and Urban Sprawl

in Turkey . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Münevver Özge Balta

2 Perspectives on the Implementation of Climate Change Public Policies in Brazil . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Rommel de Santana Freire, Monica Carvalho,

Charles Ulises de Montreuil Carmona, and

Alexandre Magno Vieira Gonçalves de Brito

3 30 Years Air Temperature Data Analysis in Athens

and Thessaloniki, Greece . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

T. Slini and K.T. Papakostas

4 Mitigation and Adaptation Policies Related to Climate

Change in Greece . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

I. Sebos, A. Progiou, L. Kallinikos, P. Eleni, I. Katsavou,

K. Mangouta, and I. Ziomas

5 Assessing Air Quality in the Urban Environment:

the Gender Gap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

Theodora Slini and Fotini-Niovi Pavlidou

vii

6 Promotion of Sustainability by Quantifying

and Reducing the Carbon Footprint:

New Practices for Organizations . . . . . . . . . . . . . . . . . . . . . . . . . . . 61

Monica Carvalho, Rommel de Santana Freire,

and Alexandre Magno Vieira Gonçalves de Brito

Part II Global Warming and Climate Change:

General Issues and Challenges

Climate Change Mitigation Measures and Prospects

7 Group Comparison, Trends and Cluster Analysis

to Understand Historical Precipitation . . . . . . . . . . . . . . . . . . . . . . 77

Raphael Abrah~ao

8 Ground Response to Global Warming . . . . . . . . . . . . . . . . . . . . . . 89

Mohamad Kharseh and Mohammed Al-Khawaja

9 Specific Case: Regional Estimates of Global Climate Change: A Dynamical Downscaling Approach to Southeast Europe . . . . . . . 99

Rafaella-Eleni P. Sotiropoulou, Efthimios Tagaris,

Andreas Sotiropoulos, Ioannis Spanos, Panagiotis Milonas,

and Antonios Michaelakis

Part III Global Warming and Climate Change:

General Issues and Challenges

Climate Change Observatory

10 Drought Conditions in Turkey Between 2004 and 2013

Via Drought Indices Derived from Remotely Sensed Data . . . . . . . 113

Nazila Molavizadeh, Elif Sertel, and Hande Demirel

11 Carbon Foot Print of a Passanger Aircraft Engine

at Landing and Take-Off Cycle . . . . . . . . . . . . . . . . . . . . . . . . . . . 123

Yasin Ş€ohret and T. Hikmet Karakoç

12 Greenhouse Gas Emissions Trends from Waste in Greece . . . . . . . 131

L. Kallinikos, I. Sebos, A. Progiou, P. Eleni, I. Katsavou,

K. Mangouta, and I. Ziomas

Part IV Global Warming and Climate Change:

General Issues and Challenges

Climate Prediction Tools

13 Development of Models for the Estimation of Global

Solar Radiation Over Selected Stations in India . . . . . . . . . . . . . . . 149

M. Maroof Khan, M. Jamil Ahmad, and Basharat Jamil

viii Contents

14 Effect of Gap Between Absorber Plate and Condenser

Cover on the Performance of a Solar Still . . . . . . . . . . . . . . . . . . . . 161

Basharat Jamil and Naiem Akhtar

15 Solar Assisted Organic Rankine Cycle for Power Generation: A Comparative Analysis for Natural Working Fluids . . . . . . . . . . . 175

Önder Kizilkan, Sandro Nižetić, and Gamze Yildirim

16 Rainfall Trend Analysis in the Region of Curitiba

Using Regional Climate Model Scenarios . . . . . . . . . . . . . . . . . . . . 193 Robinson Ploszai and Miriam Rita Moro Mine

17 Modelling of Wind Speed Using Artificial Neural Networks

for University Campus of Burdur (Turkey) . . . . . . . . . . . . . . . . . . 209 Alper Kerem, Önder Kizilkan, and Serdar Salman

18 Cultural Landscapes as a Means of Energy Reduction

at Global Warming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 223

Afroditi Venetsanou, Alexandros-Theodoros Venetsanos,

and Lena Mantziou

Part V Energy Technologies and Their Effect

on Global Warming

Solar Energy

19 Solar-Driven Continuous Methane Reforming Reactor . . . . . . . . . 249

M. Lange, J. Lapp, R. Rieping, L. de Oliveira, M. Roeb,

and C. Sattler

20 Specific Applications/Examples: Use of Solar Energy

in Fishing: Community Initiatives . . . . . . . . . . . . . . . . . . . . . . . . . . 257 J. Vincent Jain and Satish Babu

21 Diagnostic of Sensors for Induction Machine Powered

by Photovoltaic Generator Based on Fuzzy Logic Techniques . . . . 269

A. Amrane, A. Larabi, and A. Hamzaoui

22 Air Conditioning Based on Hydroxides with Solar Driving

for Low GHG Emissions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 285

R.J. Romero, S. Silva-Sotelo, Y.R. Galindo-Luna,

C.V. Valdéz-Morales, J. Ibarra-Bahena, A. Hdz-Jasso,

and A. Rodrı́guez-Martı́nez

23 Life Cycle Analysis as a Decision Criterion

for the Implementation of Solar Photovoltaic Panels in as Northeast Brazil Hospital . . . . . . . . . . . . . . . . . . . . . . . . . . . . 295

Monica Carvalho, Danielle Bandeira de Mello Delgado,

and Ricardo Chacartegui

Contents ix

Part VI Energy Technologies and Their Effect

on Global Warming

Green Buildings Technology

24 Energy Conservation Through Sunrays Reflecting Coating

on Buildings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 315

Imre Benk€o

25 Comparison of Heating and Cooling Loads of a Typical

Building with TRNSYS and eQUEST . . . . . . . . . . . . . . . . . . . . . . . 327

E. Bellos, C. Tzivanidis, A. Kouvari, and K.A. Antonopoulos

26 Optimum Insulation Thickness for Cooling Applications

Through Exergy Analysis and Environmental Methods . . . . . . . . . 339

Beyza Nur Daldal, İbrahim Sarıo�glu, Gülcan Özel Erol, Emin Açıkkalp, and Hasan Yamık

27 Novel Tungsten Bronze Nanoparticles for Shielding

Near Infrared Ray and Decreasing CO2 Emission . . . . . . . . . . . . . 349

Tsugio Sato, Chong-shen Guo, and Shu Yin

28 Modelling of a Solar Assisted Floor Heating System

with TRNSYS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 355

E. Bellos, C. Tzivanidis, A. Prassas, and K.A. Antonopoulos

Part VII Energy Technologies and Their Effect

on Global Warming

Bioenergy–Biofuel Technologies

29 Biogas Production from Napier Grass at Various

Cutting Intervals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 375

Nusara Sinbuathong, Yuwadee Sangsil, and Suriya Sawanon

30 Sustainability Assessment of Fuels Production

via Hydrotreating Waste Lipids and Co-processing

Waste Lipids with Petroleum Fractions . . . . . . . . . . . . . . . . . . . . . 387

Stella Bezergianni and Loukia P. Chrysikou

Part VIII Energy Technologies and Their Effect on Global Warming

Hydrogen Energy and Technologies

31 Spark-Ignition Engine Fueled with Methane-Hydrogen

Blends . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 405

G.M. Kosmadakis, F. Moreno, J. Arroyo, M. Mu~noz, and C.D. Rakopoulos

x Contents

32 Hydrogen Fueled Airplanes, Test Case: Aviation in Libya . . . . . . . 421

Satya P. Bindra, Ali Alwafi, Ashour Saasi, Elbahlul Musa Abogrean,

Mohsen Masaud A. Maatugh, and Khaled Khalifa

33 Perspectives of Hydrogen Automotive Applications in Croatia . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 433

Ankica Ðukić, Ivan Güttler, and Robert Pašičko

Part IX Energy Technologies and Their Effect

on Global Warming

Fossil Fuels and Climate Change

34 Contribution to Multi-Criteria Evaluation of the Impacts of Air Pollution: Case of Cement Plant

(Ain Touta-ALGERIA) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 451

Lylia Bahmed, Samia Daas, Mourad Chebila,

and Loubna Khadoudja Aggabou

35 Environmental Impact Assessment of Electricity

Production, A Case Study of Turkey . . . . . . . . . . . . . . . . . . . . . . . . 463

Fatih Yılmaz, M. Tolga Balta, Reşat Selbaş,

and Do�gan Demiral

36 Hybridization of Parabolic Trough Power Plants

with Natural Gas Through Integration of Industrial

Gas Turbines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 475

Tobias Vogel, Gerd Oeljeklaus, and Klaus G€orner

Part X Energy Technologies and Their Effect

on Global Warming

Thermodynamic System Analysis and Optimization

37 Performance Analyses of CO2-N2O Cascade System

for Cooling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 499

Fatih Yılmaz, Reşat Selbaş, Arif Emre Özgür,

and M. Tolga Balta

38 Comparison of Thermal Repowering Alternatives

for Thermal Power Plants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 513

M. Zeki Yilmazoglu

39 Experimental Study of Heat Transfer for a Non-Newtonian

Fluid in a Heated Cylindrical Pipe . . . . . . . . . . . . . . . . . . . . . . . . . 527

Mounir Mellal, Hacina Abchiche, and Sabrina Ait Ouazzou

40 The SOC Estimation of LCO Battery Based on BP Neural

Network . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 543

Sy-Ruen Huang, Yen-Huai Ma, Jheng-Shyun Li,

and Jun-Han Chan

Contents xi

41 Investigating the Effect of Different Refrigerants

on the Performance of a Supercritical Organic

Rankine Cycle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 553

Duygu Melek Çakıcı and Can Özgür Çolpan

Part XI Environmental Technologies Related

to Global Warming

Carbon Capture and Storage (CCS)

and Geotechnology Issues

42 CaO-Based Sorbents for Post Combustion CO2 Capture

via Carbonate Looping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 571

Zinovia Skoufa, Andy Antzara, Ioannis Milios, Eleni Heracleous,

and Angeliki A. Lemonidou

43 Kinetics of CO2 Capture by Carbon Dioxide Binding

Organic Liquids . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 591

Ozge Yuksel Orhan, Hakan Kayi, and Erdogan Alper

44 Flue Gas CO2 Sequestration by Turkish Coal Fly Ashes

and Anatolian Geothermal Hot Waters . . . . . . . . . . . . . . . . . . . . . 605

Yıldırım İsmail Tosun

45 Geo.: Gas Production in Offshore Reservoirs in Brazil’s Pre-salt Region . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 617

Isabella Vaz Leal da Costa, Pedro Rochedo, Mariana Império,

Alexandre Salem Szklo, and Roberto Schaeffer

Part XII Environmental Technologies Related

to Global Warming

Water Resources and Management Issues

46 Spatial and Temporal Patterns of the Water Quality

in the Hammam Boughrara Reservoir in Algeria . . . . . . . . . . . . . . 635

Belkheir DJELITA, Souaad Bouzid-Lagha,

and Kheira Camellia NEHAR

47 Natural Tracers for Identifying Causes of the Quality

Reduction in Groundwater Emerging Along the Aegean

Volcanic Arc (Greece) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 655

E. Dotsika and P. Chantzi

48 Experimental Study of Longitudinal Dispersion

on Trapezoidal Open Channel . . . . . . . . . . . . . . . . . . . . . . . . . . . . 667

Ali Mansour Lagoun and Salim Benziada

xii Contents

49 Mygdonia Basin (N. Greece) in the View of Isotope

Geochemistry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 677

P. Chantzi and E. Dotsika

50 Sustainable Management of Sewage Sludge Conditioning and Valorization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 685

S. Igoud, F. Souahi, and C.-E. Chitour

51 Photocatalytic Degradation of Tylosin and Spiramycin

in Water by Using TiO2 and ZnO Catalysts Under UV Radiation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 695

D. Tassalit, N. Chekir, O. Benhabiles, F. Bentahar,

and N.A. Laoufi

52 Comparison Between the Photocatalytic Degradation

of a Textile Dye Under Sun Light and Artificial Irradiation . . . . . . 707

N. Sahraoui, N. Chekir, and D. Tassalit

53 Vulnerability and Impact of Climate Change Processes on Water Resource in Semi-Arid Areas: In Essaouira

Basin (Morocco) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 719

Salah Ouhamdouch, Mohammed Bahir, Abdellatif Souhel,

and Carreira Paula

Part XIII Environmental Technologies Related

to Global Warming

Waste Management

54 Experimental Study of Transverse Mixing

of Pollutants in Trapezoidal Open Channel . . . . . . . . . . . . . . . . . . 741

Ali Mansour Lagoun and Salim Benziada

55 Elimination of Micropollutent Lysine Acetylsalicylate

by Adsorption on Natural and Synthetical Supports . . . . . . . . . . . . 755

Amel Djouadi and Fatiha Bentahar

56 Integrated System for Optimized Data Collection

and processing of End of Life Tires: Case of Greece . . . . . . . . . . . . 759

Panagiotis Vounatsos, John Vournas, George Mavrias,

and Panagiotis Grammelis

57 Smart Recovery of Materials and Upgrade of Organic

Compost and RDF in Existing Mechanical Biological

Treatment Plants by Using NIR Technology . . . . . . . . . . . . . . . . . . 771

Dimitrios-Sotirios Kourkoumpas, Georgios Kontopoulos,

Ioannis Vournas, Dimitrios Koulocheris, Panagiotis Grammelis,

and Emmanouel Kakaras

Contents xiii

Part XIV Securing Sustainable Mobility to Mitigate

Climate Change

Transport Operation and Resilience Issues

58 Road Transport Induced GHG Emissions Calculation

for Urban Transportation Networks: The Case of Athens

and Thessaloniki in Greece . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 783

Christos Samaras, Iraklis Stamos, Leonidas Ntziachristos,

Evangelos Mitsakis, Zissis Samaras, and Georgia Ayfantopoulou

59 The Effect of Parameter Selection on Fume Formation Rate

in SMAW of AH36 Shipbuilding Steel and Analysis

with ANOVA Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 795 Tolga Mert, Levent Bilgili, Kutsi Mert Senoz,

U�gur Bu�gra Çelebi, and Serkan Ekinci

60 An Online Visualization Tool for Assessing the Robustness

of Multimodal Transport Networks in Case of Extreme Weather Events and Natural Hazards . . . . . . . . . . . . . . . . . . . . . . 803

Iraklis Stamos, Evangelos Mitsakis, and Georgia Aifadopoulou

Part XV Securing Sustainable Mobility to Mitigate

Climate Change

Climate Impact Effects of Air and Maritime Transport

61 Manmade Changes in Cirrus Clouds from 1984 to 2007: A Preliminary Study . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 827

Kostas Eleftheratos, Gunnar Myhre, Patrick Minnis,

Ioannis Kapsomenakis, and Christos Zerefos

62 Emission Routing in Maritime Transportation . . . . . . . . . . . . . . . . 837

Levent Bilgili and Ugur Bugra Celebi

63 Pollution Effects Onboard and Its Generated Solution

for Minimized Pollution Effect . . . . . . . . . . . . . . . . . . . . . . . . . . . . 851 Munir Suner and Tankut Yildiz

64 Carbon-Mitigating Air Transport: Analysis

of Current Policy Instruments . . . . . . . . . . . . . . . . . . . . . . . . . . . . 867 Ioanna Pagoni and Voula Psaraki-Kalouptsidi

65 Ship Life Cycle Greenhouse Gas Emissions . . . . . . . . . . . . . . . . . . 883

Stefanos Chatzinikolaou, Nikolaos Ventikos, Levent Bilgili,

and Ugur Bugra Celebi

xiv Contents

Part I

Global Warming and Climate Change: General Issues and Challenges

General Aspects of Global Warming, Current Policies and Challenges Policies and General Aspects of Global Warming

with Focus on Specific Examples

Chapter 1

Urban Development Policy and Urban Sprawl in Turkey

Münevver €Ozge Balta

Introduction

Metropolitan areas are rapidly changing in response to urban development dynam-

ics. Urban sprawl is defined as a form of urbanization which inefficient,

low-density, suburban development around the periphery. Sprawl is a leading

process at the edges of urban growth and implies deficient and weak planning

control on land policy.

Since the beginning of twentieth century, the world population has increased

dramatically, and especially metropolitan areas have undergone diverse structural

changes. As many other developing countries, Turkey was faced with the fast

urbanization which necessitated immediate formulation of new planning policies

in metropolitan areas. Metropolitan development areas have spread out into rural

areas, so planning policies supposedly regulate this new pattern of development.

In Turkey, local governments frequently use partial plans with a tendency for

discontinuity for urban fringe areas. In actuality, the urban space is patchy and the

applications can be different from the plan decisions. Partial plans may completely

change the urban settlement character. Since 1980, urban development in metro-

politan areas in Turkey has been especially piecemeal, rather than holistic. So, in

the process, urban development planning has tended to be piecemeal, resulting

urban sprawl.

M.Ö. Balta (*) Department of Architecture, Faculty of Architecture and Design, Aksaray University,

68100 Aksaray, Turkey

e-mail: [email protected]

mailto:[email protected]

This paper is concerned with the notion of urban sprawl, particularly planning

policies in metropolitan areas. It aims to discuss the impacts of planning tools and

regulations for urban sprawl. The paper also investigates a research problem that

could show the characteristic of metropolitan development and planning procedure

in Turkey.

Urban Sprawl

“Urban sprawl” is used to describe low-density, inefficient, suburban development

around the periphery. Sprawl is defined as a form of urbanization distinguished by

leapfrog development, commercial strips, low density, separated land uses, auto-

mobile dominance and a minimum of public open space (Table 1.1).

Squires (2002) defines sprawl as “a pattern of urban and metropolitan growth that

reflects low density, automobile-dependent, exclusionary new development on the

fringe of settled areas often surrounding a deteriorating city”. Urban sprawl is a

consequence of many factors, such as the need for industrial establishment for larger

and less expensive locations which force them to move out of the city centre where

they were previously settled, the increasing mobility of middle and high income

groups due to private car ownership and changing socio economic value systems.

Urban sprawl is a consequence of many factors, such as the need for industrial

establishment for larger and less expensive locations which force them to move out

of the city centre where they were previously settled, the increasing mobility of

middle and high income groups due to private car ownership and changing socio

economic value systems (Balta and Eke 2011).

European Environment Agency defines the stimulants of urban sprawl as macro

economic factors, micro-economic factors, demographic factors, housing prefer-

ences, inner city problems, transportation and regulatory frameworks (Table 1.2).

Sprawl is the leading edge of urban growth and implies deficient and weak planning

control on land subdivision.

Table 1.1 Characteristics of sprawl (Ewing 1997)

Leapfrog or scattered

development

It means subdivisions shopping centers and office parks widely

spread apart

Commercial strip

development

It is characterized by huge roads with shopping centres,

gas-stations, fast-food restaurants, banks, parking lots, etc.

Low density Suburban buildings are often single-story and widely spaced,

with intervening parking lots and roadways

Large expanses of single-use

development

Housing consist predominantly of single-family homes on indi-

vidual lots

Poor accessibility (Automo-

bile dominance)

The longer distances between activities

Lack of public open space In suburban area, public open space can be difficult to find

except school yard

6 M.Ö. Balta

In summary, some scholars (Beauregard 2006; Gillette 2005; Teaford 2006) thus

conclude that urban sprawl should be accepted as one of the forms of metropolitan

growth while others (Burchell et al. 1998; Cox and Utt 2004; Ewing et al. 2002;

Snyder and Bird 1998) condemn urban sprawl because of its detrimental affects

such as social segregation, upheave and change or economic prosperity; urban

sprawl is one of the evitable spatial attributes of metropolitan development (Balta

and Eke 2011).

There are two main reasons of urban sprawl. First reason is lack of laws and

regulations supporting planning, second, reason is lack of goodwill and determina-

tion of local authorities to keep the urban macroform as planned.

Urban Sprawl and Energy Consumption

In the last years, cities have gone through problems as global climate change.

Together with the urban growth, greenhouse gases (GHGs) are receiving increas-

ingly more attention (Glicksman 2007). The rise in population and individual car

ownership is mainly attributed to urban sprawl. Suburban areas is often believed to

Table 1.2 Stimulants of urban sprawl (EEA 2006)

Economic factors Macro-economic Globalization

Economic development

Integration

Micro-economic Quality of life

Land value

Land availability

Competition between local governments

Demographic factors Population growth

Increase in household formation

Physical factors Housing Housing preferences

More space per person

Urban problems Poor air quality

Small houses

Noise

Unsafe urban environment

Lack of open and green areas

Poor quality of schools

Transportation Private car ownership

Roads accessibility

Fuel cost

Lack of public transportation

Urban planning Weak land use planning

Lack of enforcement of existing plans

Lack of coordination and organization

1 Urban Development Policy and Urban Sprawl in Turkey 7

be less energy efficient than urban core. Overall energy consumption of a territory,

especially as far as travel energy consumption is concerned with urban sprawl

(Ewing 1994).

Urban sprawl is a consequence of many factors, such as the need for industrial

establishment for larger and less expensive locations which force them to move out

of the city centre where they were previously settled, the increasing mobility of

middle and high income groups due to private car ownership and changing socio

economic value systems.

Urban sprawl has many effects on urban environment as unplanned expansion of

the city may not coordinate with the public transportation system which brings loss

of time in journeys towards the city centre, increased energy consumption and

increased traffic congestion. Motorization has increased energy demand.

Urban Development Policy in Turkey

Metropolitan growth of Turkey is due to fast urbanization and results in urban

sprawl. The formulation and implementation of urban development plans in Turkey

is guided by the statutory provisions of the country’s planning system. The multiple

plans are lack of determined policies and the multiplicity of speculative market

forces and their heavy demands in Turkey. Thus, metropolitan growth was

transformed into an oil-spill form in most of the Turkish cities.

Metropolitan areas have been attracting a large population from rural areas since

the 1960s. Although the rate of migration has slowed down in the last two decades,

it has caused a considerable increase in the population of the metropolitan areas of

Turkey (Erkip 2005). Turkey was urbanizing fast, changing from an agriculture to

an urban-based economy. Two major steps were taken in 1960s. A new ministry of

planning was established to deal with planning, housing and infrastructural issues,

being responsible to draw urban development strategies, to undertake housing

programmes and improvement of squatter housing, and above all to approve all

plans prepared and adopted in local municipal councils (Balta and Eke 2011).

The new value systems, procedures and concepts brought to the era by global-

ization, privatization and neoliberalism affected Turkey as well. Two major reforms

were undertaken in the Turkish planning system in 1984. Besides the classical

municipal administration for cities, metropolitan municipalities were established

responsible for larger cities to plan and control the metropolitan region and the

municipalities in that area, the Metropolitan Planning Offices being joined to the

metropolitan municipalities. Metropolitan planning offices were established in

large cities with the collaboration of both local and central authorities which had

the aim of formulating new policies, models and methods to confront the negative

consequences of metropolitanism. The second major reform was the decentraliza-

tion of several administrative powers including planning. The local authorities were

now responsible for all the stages of planning practice, several administrative

powers including approval (Balta and Eke 2011).

8 M.Ö. Balta

In Turkey, local municipalities is flexible regulation of urban development. Cities

can be changed by partial plans or planning decisions (Ozuduru and Varol 2009).

This process has led to piecemeal implementation through partial plans and plan

amendments in metropolitan areas.

As many other developing countries Turkey was faced with the problem of fast

urban growth. However, the globalisation trends coupled with the decentralization

demands of the age which also affected Turkey caused the abolishment of the

planning units, leaving the ground to local authorities which could not stand against

the pressures of market forces so easily and urban sprawl has been occurred.

In Turkey, urban development plans are detailed end-state blueprint plans,

which envision that a time would come and the spatial development of any city

would be completed in the specific planning period. The allegation of the planning

system is to control every detail during urban development. Development plans, of

which structure and content are defined in planning legislation, are the main

planning control tools in the Turkish system. Urban Development Law (3194),

issued in 1985, exists at the very center of this legislation and is the main law

directly related to production of the urban built environment (Ünlü 2005).

Urban planning in Turkey are guided by the statutory provisions of the country’s

planning system. In metropolitan cities, master plans are prepared by metropolitan

municipalities, and implementation plans by county municipalities, and are then

approved. The process stimulates the development of entities’ individual behavior,

and individual acts come to the foreground primarily through piecemeal

implementations as partial plans and plan amendments. Local governments fre-

quently use partial plans for the purpose of steering the public benefit. In actuality,

the urban space is broken into pieces and is privatized through these plans, and

public spaces are turned over to the private sector through urban projects/partial

plans. To allay reactions that the public may put forth, local governments define the

plans in planning regulations and apply the procedures anticipated by the law

predominantly in a stylistic manner, thereby rendering the applications different

from the plan decisions. Partial plans may completely change the urban settlement

character as urban sprawl. Since 1980, urban development in metropolitan areas in

Turkey has been primarily incremental rather than holistic. In the process, urban

development planning has tended to be piecemeal, resulting in the fragmentation of

the urban built environment (Balta et al. 2012).

In 1980s, after the legal arrangements, the central government’s role in planning

has diminished, and authority has been decentralized to local governments. How-

ever, in metropolitan areas, the limited capacity and experience of local govern-

ments resulted in urban space to be developed through the private sector. So, urban

fringe faced partial developments. The holes in planning legislation and the popu-

larity of partial plans resulted in a urban sprawl in metropolitan areas.

The rapid growth in metropolitan areas resulted in infrastructure, environment,

and housing problems. In contrast, density increments and land use changes in

urban environment have been realized through plan modifications.

1 Urban Development Policy and Urban Sprawl in Turkey 9

Conclusion

In the twentieth century due to rapid growth, the structure of urban settlements has

changed dramatically. Metropolitan areas were mostly affected by increasing

population. Metropolitan growth will either concentrate within the city boundaries,

increasing the density, but most likely the city will expand on the periphery of the

city through decentralization. The detrimental consequences of urban sprawl can be

solved through planned decentralization. The diverse existing urban systems must

be coordinated with the new development areas in order to establish the integrity of

the macroform.

The new value systems, procedures and concepts brought to the era by global-

ization affected Turkey as well. Turkey is also similar to other developing countries

where metropolitan growth is due to fast population growth and results in urban

sprawl. The multiple plans were not effectively implemented due to lack of policies

because of speculative market forces and their heavy demands in Turkey.

Consequently, partial plans have resulted in uncontrolled development and

metropolitan growth was transformed into an oil-spill form in Turkey. Such devel-

opment increases infrastructure costs and burdens local authorities. Urban sprawl

creates problems, such as incongruity of functions, environmental problems, and

higher of public services cost, increased energy consumption. To overcome these

problems, the uncontrolled growth should be stopped and development policies that

address both public and private sectors should be addressed.

References

Balta, M. Ö., & Eke, F. (2011). Spatial reflection of urban planning in metropolitan areas and

urban rent: A case study of Cayyolu, Ankara. European Planning Studies (SSCI), 19(10), 1817–1838.

Balta, M. Ö., Tekel, A., & Tekel, İ. (2012). Urban development process of built environments in

metropolitan areas in Turkey: A case study of Angora Settlement, Ankara. Journal of Urban Planning and Development-ASCE (SCI), 138(1), 70–77.

Beauregard, R. A. (2006). When America became suburban. Minneapolis: University of Minne- sota Press.

Burchell, R., Shad, N. A., Listokin, D., Phillips, H., Downs, A., Seskin, S., Davis, J. S., Moore, T.,

Helton, D., & Gall, M. (1998). The costs of sprawl, revisited. Transportation research board (pp. 1–40). Washington, DC: National Research Council.

Cox, W., & Utt, J. (2004). The costs of sprawl reconsidered: What the data really show (pp. 1–18). Unpublished paper. The Heritage Foundation. Retrieved May 12, 2009, from http://www.

heritage.org/research/smartgrowth/.

EEA. 2006. Urban sprawl in Europe—The Ignored Challenge EEA Report No.: 10/2006.

Retrieved May 12, 2009, from http://reports.eea.europa.eu/eea_report_2006_10/en/eea_

report_10_2006.pdf.

Erkip, F. (2005). The rise of the shopping mall in Turkey: The use and appeal of a mall in Ankara.

Cities, 22(2), 89–108. Ewing, R.H. (1994). Characteristics, causes and effects of sprawl: A literature review.Environmental

and Urban Studies, 21, 1–15.

10 M.Ö. Balta

http://reports.eea.europa.eu/eea_report_2006_10/en/eea_report_10_2006.pdf

http://www.heritage.org/research/smartgrowth/

Ewing, R. (1997). Is Los Angeles—Style sprawl desirable? Journal of the American Planning Association, 63(1), 2–4.

Ewing, R., Pendall, R., & Chen, D. (2002). Measuring sprawl and its impact (pp. 1–31). Washington, DC: Smart Growth America.

Gillette, H. (2005). Camden after the fall: Decline and renewal in a post-industrial city. Phila- delphia: University of Pennsylvania Press.

Glicksman, L. R. (2007). Editorial: The energy crisis—The need for more balanced solutions.

HVAC&R Research Journal, 13(4), 521–523. Ozuduru, B. H, & Varol, C. (2009). Global restructuring of the marketplace: Local and regional

impacts on the spatial distribution of retail activity in Turkey. In 23rd congress of the Association of European Schools of Planning (AESOP), Liverpool, İngiltere.

Snyder, K., & Bird, L. (1998). Paying the Costs of Sprawl: Using Fair-Share Costing to Control Sprawl. Washington, DC: U.S. Department of Energy.

Squires, G. D. (2002).Urban sprawl: Causes, consequences & policy responses. Washington, DC: The Urban Institute Press.

Teaford, J. C. (2006). The metropolitan revolution: The rise of post-urban America. New York: Columbia University Press.

Ünlü, T. (2005). Plan modifications within the contexts of planning control mechanisms Mersin case. Unpublished PhD thesis, School of Natural and Applied Sciences of Middle East Technical University, Ankara

1 Urban Development Policy and Urban Sprawl in Turkey 11

Chapter 2

Perspectives on the Implementation of Climate Change Public Policies in Brazil

Rommel de Santana Freire, Monica Carvalho,

Charles Ulises de Montreuil Carmona,

and Alexandre Magno Vieira Gonçalves de Brito

Introduction

As a developing country, Brazil plays an important role in the global scenario for

the reduction of greenhouse gas (GHG) emissions. Several public policies have

been created towards the reduction of pollution levels. Brazil’s participation in international agreements and the creation of a positive agenda for the development

of new regulations for environmental presentation direct the country to the con-

struction of a cleaner scenario.

Brazil participates in the Kyoto Protocol (largest international agreement signed

for the reduction of GHG emissions), but still does not count with established

mandatory reduction levels. However, the country already acts in a pro-active way

through the creation of several sectional plans for mitigation and adaptation

R. de Santana Freire (*) Department of Accountancy and Finances, Center of Applied Social Sciences, Federal

University of Paraı́ba (UFPB), Cidade Universitária, Jo~ao Pessoa, 58051-900 Paraı́ba, Brazil e-mail: [email protected]

M. Carvalho

Department of Renewable Energy Engineering, Center of Alternative and Renewable Energy,

Federal University of Paraı́ba (UFPB), Caixa Postal 5115, Cidade Universitária, Jo~ao Pessoa, 58051-900 Paraı́ba, Brazil

e-mail: [email protected]

C.U. de Montreuil Carmona

Department of Management Science, Center of Applied Social Sciences, Federal University of

Pernambuco (UFPE), Cidade Universitária, Recife, 50670-901 Pernambuco, Brazil

e-mail: [email protected]

A.M.V.G. de Brito

Department of Mechanical Engineering, Center of Technology, Federal University of Paraı́ba

(UFPB), Cidade Universitária, Jo~ao Pessoa, 58051-900 Paraı́ba, Brazil e-mail: [email protected]

mailto:[email protected]

(Brasil 2011). These plans contemplate strategic areas (forests, energy in agricul-

ture, urban mobility) and industry intensive sectors (metallurgy, mining, transfor-

mation). The focus is to reduce the levels of pollution and at the same time, improve

the performance and competitiveness of companies. The process of implementing

these regulations is slow, as several bureaucratic and cultural barriers still remain,

which hinders the obtainment of better results.

A positive point that helps the country to maintain acceptable levels of pollution

is the constitution of its energy matrix, which is mainly constituted of hydroelectric

plants and therefore presents lower levels of pollution. Incentives to energy gener-

ation utilizing renewable sources is still very limited. In a different direction, in

2013 in the European Union it was observed that the energy generation sector was

responsible for the largest share of CO2 emissions—70% of these companies were

located in Germany and England (Carbon Market Data 2014).

Despite the existence of policies directed to the strengthening of energy gener-

ation from renewable sources, implementation is still expensive and complex,

hindering its application for the majority of the population. Developing countries,

such as China and India, count with greater incentives for the installation of

residential equipment that better utilize renewable energy sources (World Bank

2014). Regarding the logic of reduction of emissions, the European Union created

the European Union Emission Trading Scheme (EU ETS), responsible for regulat-

ing the operation of the market for reduction of carbon emissions, establishing goals

for the reduction of pollution and distributing the allowance quotas for carbon

emissions (European Emission Allowances, EUA) among the members of the

European community (Freire 2014).

Currently, the European Union is the largest negotiator of EUAs in the world,

also gathering the largest number of companies that follow the determinations of

the Kyoto Protocol. Globally, this new active (EUA) has been widely negotiated

since the mid-2000s, mainly in stock markets that deal with energy-related con-

tracts, taking advantage of the already existent structure and know-how (Knox-

Hayes 2009). The EUA market has grown substantially in the recent years, and can

reach the position of being one of the largest commodity markets in the world in the

next decades (Pirrong 2011).

However, after the drop in value of EUA’s during the 2006 and 2007 crisis and re-establishment of carbon markets, similar methodologies to EU ETS have been

applied to several countries, such as Japan, Canada, New Zealand, Australia and

United Kingdom—the U.S.A. (especially the state of California) and China deserve

special mention (Perdan and Azapagic 2011).

The creation of these new markets shows the directions of public policies that

aim at finding a way to reduce levels of emission of pollutants as well as contrib-

uting to energy and operational efficiencies of companies, creating therefore a new

entrepreneurial culture that is directly related to the wellbeing of the society.

A companion paper on the promotion of sustainability by quantifying and reducing

the carbon footprint lays the foundation for environmental awareness in consumers

(Carvalho et al. 2015).

14 R. de Santana Freire et al.

On the basis of an agreement with the United Nations, Brazil established

voluntary actions for the mitigation of GHG, with the objective of reducing

between 36.1% and 38.9% until 2020, fostering national policies on climate

change. Among these actions, the development of a Brazilian Market for Reduction

of Emissions is stimulated. The possibility of creating a nation-wide carbon market,

with its own regulation and interconnection with other markets in the world, can

bring positive contributions from economic and environmental viewpoints. This

manuscript aims to deepen the discussion on the subject, highlighting the benefits

and opportunities than can be generated by the implementation of public policies, as

well as the creation of new supplementary regulations.

Public Policies

The oil crisis, in the beginning of the 1970s, led the Brazilian government to create

its first study group on alternative sources of energy, being the first step towards the

creation of public policies regarding energy efficiency. After crystallization of the

first research efforts on conservation of energy, the first national program on

conservation of energy was launched in 1985. In the early 1990s, the first programs

that aimed at rational production and use of energy were created, along with

programs for better use of oil and natural gas derivatives. These programs

represented a milestone for environmental and energy efficiency policies.

In the following decades, Brazil continued to create and improve its national

policies on climate change, involving different production sectors and governmen-

tal organs. The objective is to create synergy between the involved areas, and the

main expected result is the sustainable development of the country, balancing

economic growth with environmental preservation. The current economic moment

presents low growth, hindering therefore the implementation of environmental

regulations that entail excessive costs. Laws that stimulate investments in new

equipment, processes or green products, through tributary incentives or for the

generation of green revenues, are seen as possible solutions for the mitigation of

climate change.

Politic guidelines lead the path to be followed by companies and society in

general, in the form of incentives such as tax reductions for the companies that

reduce their emissions or apply resources to efficiency energy researches. The

creation of new mechanisms to this kind of development and GHG control,

especially in the most polluting sectors is fundamental to implement a new culture

of environmental preservation. In this new environment, the organizations will be

required to optimize its processes/products in order to mitigate the effects of

pollution generated.

The Brazilian National Policy of Climate Change (PNMC) was established in

2009, through the adoption of Law 12.187 (Lude~na and Netto 2011). PNMC pursues voluntary actions for the mitigation of GHG emissions, including reduction

in deforestation (Amazon and Cerrado), reduction in energy consumption (energy

2 Perspectives on the Implementation of Climate Change Public Policies in Brazil 15

efficiency, alternative energy sources, etc.), stabilization of the share of renewable

energy sources in the energy matrix, and increased use of biofuels, among others.

Brazil’s GHG emissions are calculated every 5 years, and Fig. 2.1 shows the reduction of emissions through the implementation of PNMC, a non-mandatory

policy. These data represent the first results after its implementation.

The Brazilian legislation aims equalize sustainable development with economic

growth, eradicating poverty and reducing social inequalities. This new

interconnected vision drives the country to build a wide platform of emission

reduction alternatives. The Brazilian law also encourages the development of a

national market of reduce emissions, which in practice is not yet operational,

however the main focus is economic and social development compatibility with

the protection of the climate system (Brasil 2009, 2010).

The changes in the carbon market could modify the pollution levels defined by

the legislation (Montgomery 1972), resulting in greater control of the most pollut-

ing activities. The restrictions imposed on companies that exceed the pollution

limits could be seen as barriers to competitiveness, which would affect those that

pollute more (Perdan and Azapagic 2011).

Several countries are adapting theirs energy and climate policies to impose a

new behavior to the companies, one that focuses on cost optimization and reduc-

tions of GHG emissions, representing a new era for sustainable development. This

represents a new view that economy growth is inextricable from environmental

preservation.

The conclusions of the European Council in 2011 (CO EUR 2 CONCL 1 2011)

highlight the direction taken by the European Union regarding much necessary

environmental policies, with emphasis on sustainable growth, energy efficiency and

the necessity of creating policies that are capable of providing more investments in

research, development and innovation (Freire 2014). These three pillars are united

to create a more modern, safe, sustainable and low carbon energy system (European

Council 2011). In 2014, the European Council ratified the relevance to improve the

500.000

1.000.000

1.500.000

2.000.000

2.500.000

3.000.000

1990 1995 2.000 2005 2010

Carbon Equivalent Emissions (1000 tonnes)

Carbon Equivalent Emissions (1.000 t)

Fig. 2.1 Overall carbon emissions for Brazil (Brasil 2015)

16 R. de Santana Freire et al.

economic growth through the use of energy efficiency and the improvement of

competitiveness, maintaining the targets of greenhouse gas emission reduction

(CO EUR 2 CONCL 1 2014). Using similar strategy, China has created its own

ETS in seven regions of the country. The system will be in adaptation stage until the

end of 2015, when the emission reduction plan will be in force for the entire country

(Zhang et al. 2014).

Under a regulated market, managers will be enforced to create a new vision of

company, using threats as opportunities in the carbon market, creating competitive

advantage aims to maximize the shareholders’ wealth on behalf of other stake- holders (society and government). Cleary the news ETS needs changes to adapt

local/regional issues, but implementation is the first step for developing countries

and shows the government provides good conditions for the carbon market start up.

Brazil could follow the same path of other countries, but first needs to implement

the existing legislation and adapt/create complementary rules to improve the

creation of its own ETS, to create a positive chain between companies-govern-

ment-society.

Perspectives and Opportunities for Mitigation

Until recently, environment and sustainable development were considered prob-

lems and risk factors: however nowadays, these “problems” are seen as opportuni-

ties, as possibilities for growth and efficiency improvement (Carvalho et al. 2015).

Building upon the work of Carvalho and Freire (2014), mitigation of climate

change involves serious reduction in emissions, which can be achieved through

the better utilization of natural resources (energy efficiency concept). Obviously, if

the same amount of product can be obtained with reduced consumption of

resources, lower production costs are also achieved, which is a win-win situation

for managers and entrepreneurs.

The rise of new technologies and its learning curve costs contributes to a

reduction of transaction costs of organizations (Williamson 1994, 1995), as well

to reductions of pollutants gases (Blyth et al. 2009). R&D investments in produc-

tion models more “clean” and efficient, linked with new environmental policies rise

as option to improve energy efficiency consumption in companies, specially to

pollution reduction (Gans 2012).

Important opportunity for mitigation of climate change in Brazil include defor-

estation (Lude~na and Netto 2011) and energy-related carbon emissions (Melo et al. 2013). These mitigation efforts are translated into challenges at federal,

state and municipal levels, for both public and private sectors in Brazil.

The reduction of GHG emissions from deforestation and forest degradation is

now an important strategy for mitigating climate change, particularly in developing

countries with large forests, such as Brazil (Arima et al. 2014). National forest

policies designed to slow deforestation on public lands in developing countries

have had mixed success. However, there have been successful experiences (IPCC

2 Perspectives on the Implementation of Climate Change Public Policies in Brazil 17

2007): due to severe environmental and public health consequences, China, the

Philippines and Thailand have considerably reduced deforestation rates; in India,

there has been effective partnering with communities to reduce forest degradation.

The implementation of effective public policies needs backup from government

institutions and the general public. Considering the Brazilian scenario of limited

budgets, divergent interests and legal obligations, decision makers in Brazil face

multiple difficulties in the process of searching for adequate and reliable solutions

for the mitigation of GHG emissions (Melo et al. 2013).

In Brazil, buildings were responsible for 48% of the total electricity consumed

in the country in 2010 (Brasil 2011); this important share of electricity consumption

could obviously benefit from energy efficiency and conservation strategies aimed at

the reduction of energy-related GHG emissions. It is expected that the demand for

electricity will increase in Brazil in the next years–there is little wiggle room for

hydroelectric power plants to produce more, and therefore thermoelectric power

plants based on coal and natural gas will have to increase their contributions to the

energy mix. This will lead to higher environmental loads associated with the

consumption of electricity, and more overall environmental loads being disposed

of into the atmosphere—this figure will definitively be higher than what was

predicted in the Brazilian Energy Plan 2030 (Melo et al. 2013). Therefore any

decrease in environmental loads will be the result of dissemination efforts of energy

efficiency technologies, most probably through public policy mechanisms.

According to Lucon et al. (2014), energy efficiency technologies have been

developed at the same time as existing energy efficiency opportunities have been

taken up, and therefore the potential for cost-effective energy efficiency improve-

ment is increasing. However, there are barriers to the market uptake of these

opportunities, and large potentials will remain untapped without appropriate poli-

cies (Lucon et al. 2014): in addition to technologies and architecture, behavior,

lifestyle, and culture have a major effect on energy use.

A very promising energy efficiency scenario is linked to the establishment of

public policies that highlight well-defined priorities, goals and action plans. A

sensitive point involves the education for the development of a collective con-

science towards the preservation of the environment. The responsible agencies

should widen the education, research and development actions for new technolo-

gies and establish partnerships with the private and public sectors. Changes in

energy consumers’ behavior and practices can lead to considerable reductions in energy demands, which present positives effects on climate-change issues (e.g.,

reduction of carbon emissions). Conscious energy behavior can be achieved

through educational interventions, and by combining interventions with incentives,

substantial reductions in energy use can be produced (Kirby et al. 2015).

There is growing acknowledgement on the importance of changing the energy-

related behavior of people. Multiple research efforts have been directed to the

subject of pro-environmental behavior change (of which energy-related behavior

is a component) (Energy Saving Trust 2007). If more consumers agree to a shift

towards a more energy-savvy behavior, important reductions in environmental

loads will be achieved. Energy-education could help change current and future

18 R. de Santana Freire et al.

common routines to save energy, and also encourage consumers to promote similar

behavior. One of the main incentives that propel energy users to adopt energy-

savvy behaviors and practices is the reduction in consumption, accompanied by the

reduction in costs.

Final Remarks

The main conclusion of La Rovere et al. (2014) is that Brazil is in a good position to

meet its mitigation goals until 2020. However, after 2020, Brazil will be challenged

to combine economic development with low carbon energy-related emissions.

The creation of a system for trading GHG emissions in Brazil would encourage

Brazilian companies to reduce their emissions and trade these in a regulated market,

achieving double benefits: reduction of emissions (less consumption of resources,

lower costs) and benefits realized through the trade of emissions. This model is

similar to the model established by the Kyoto Protocol and reproduced internally in

many countries.

New environmental policies combined with financial incentives lead company

managers to promote the reduction of GHG emissions through innovation/adapta-

tion of processes and products. This action would foster economic development that

focuses on environmental preservation, promoting the development of a new

culture, where people would vigorously demand the implementation of green

policies by companies. Brazil has the potential to maintain sustainable economic

growth through the implementation of existing policies and the creation of new

mechanisms, permitting the creation of an internal carbon market, which can also

be connected to other markets already consolidated in the world.

Acknowledgments The authors wish to acknowledge the support of the Institute for the Devel- opment of Paraı́ba (IDEP-UFPB) and of the National Council for Scientific and Technological

Development (CNPq), through project n� 475879/2013-9.

References

Arima, E. Y., Barreto, P., Araújo, E., & Soares-Filho, B. (2014). Public policies can reduce

tropical deforestation: Lessons and challenges from Brazil. Land Use Policy, 41, 465–473. Blyth, W., Bunn, D., Kettunen, J., & Wilson, T. (2009). Policy interactions, risk and price

formation in carbon markets. Energy Policy, 37, 5192–5207. Brasil. Law n� 12.187, of December 29 2009. Institutes the National Policy on Climate Change—

PNMC. Official Diary of the Federative Republic of Brazil (in Portuguese).

Brasil. Decree n� 7.390, of December 9 2010. Provides regulations on paragraphs 6, 11 and 12 of Law 12.187, of December 29 2010, which instituted the National Policy on Climate Change—

PNMC. Official Diary of the Federative Republic of Brazil (in Portuguese).

Brasil, Ministry of Environment. Gas emissions. Retrieved April 11, 2015, from http://mma.gov. br/mma-em-numeros/emiss%C3%B5es-de-gee.

2 Perspectives on the Implementation of Climate Change Public Policies in Brazil 19

http://mma.gov.br/mma-em-numeros/emiss%C3%B5es-de-gee

Carbon Market Data. Retrieved April 11, 2015, from www.carbonmarketdata.com.

Carvalho, M., & Freire, R. S. (2014) Quantificar, reduzir, evidenciar: uma nova prática para

empresas sustentáveis. In ENCONTRO INTERNACIONAL SOBRE GEST ~AO EMPRESARIAL E MEIO AMBIENTE, 16, 2014, S~ao Paulo. Anais. . . S~ao Paulo: FEA-USP (in Portuguese).

Carvalho, M., Freire, R. S., & Brito, A. M. V. G. (2015) Promotion of sustainability by quantifying

and reducing the carbon footprint: New practices for organizations. In Global conference on global warming, Athens, 2015.

Energy Saving Trust. (2007). Retrieved April 7, 2015, from http://www.teachshare.org.uk/

ExtFiles/EnergyTrust-TheRoleOfEducationAndSchools.pdf.

European Council. CO EUR 2 CONCL 1, February 01, 2011. Brussels, March 8 2011.

European Council. CO EUR 2 CONCL 1, July 01, 2014. Brussels, March 21, 2014.

Freire, R. S. (2014). Essays on the permissions for carbon emissions (EUA). PhD thesis, Graduate Programe in Management (PROPAD), Federal University of Pernambuco (UFPE), Brazil.

Gans, J. S. (2012). Innovation and climate change policy. American Economic Journal: Economic Policy, 4(4), 125–145.

IPCC. (2007). Climate change 2007: Working group III: Mitigation of climate change. 9.6.1

Policies aimed at reducing deforestation. Retrieved April 7, 2015, from http://www.ipcc.ch/

publications_and_data/ar4/wg3/en/ch9s9-6-1.html.

Kirby, S. D., Guin, A., & Langham, L. (2015). Energy education incentives: Evaluating the impact

of consumer energy kits. Journal of Extension, 53(1), 10. Knox-Hayes, J. (2009). The developing carbon financial service industry: Expertise, adaptation

and complementarity in London and New York. Journal of Economic Geography, 9, 749–777. La Rovere, E. L., Júnior, A. O. P., Dubeux, C. B. S., & Wills, W. (2014). Climate change

mitigation in Brazil. Climate and Development, 6, 25–33. Lucon, O., Ürge-Vorsatz, D., Zain Ahmed, A., Akbari, H., Bertoldi, P., Cabeza, L. F., Eyre, N.,

Gadgil, A., Harvey, L. D. D., Jiang, Y., Liphoto, E., Mirasgedis, S., Murakami, S., Parikh, J.,

Pyke, C., & Vilari~no, M. V. (2014). Buildings. In O. Edenhofer, R. Pichs-Madruga, Y. Sokona, E. Farahani, S. Kadner, K. Seyboth, A. Adler, I. Baum, S. Brunner, P. Eickemeier,

B. Kriemann, J. Savolainen, S. Schl€omer, C. von Stechow, T. Zwickel, & J. C. Minx (Eds.), Climate change 2014: Mitigation of climate change. Contribution of Working Group III to the fifth assessment report of the intergovernmental panel on climate change. Cambridge/New York, NY: Cambridge University Press.

Lude~na, C., & Netto, M. (2011). Brazil: Mitigation and adaptation to climate change. Inter- American Development Bank. Technical note IDB TN 622.

Melo, C. A., Januzzi, G. M., & Tripodia, A. F. (2013). Evaluating public policy mechanisms for

climate change mitigation in Brazilian buildings sector. Energy Policy, 61, 1200–1211. Montgomery, W. D. (1972). Markets in licenses and efficient pollution control programs. Journal

of Economic Theory, 5, 395–418. Perdan, S., & Azapagic, A. (2011). Carbon trading: Current schemes and future developments.

Energy Policy, 39, 6040–6054. Pirrong, C. (2011). Commodity price dynamics: A structural approach. Cambridge: Cambridge

University Press.

Williamson, O. E. (1994). Strategizing, economizing, and economic organization. In R. Rumelt,

D. Schendel, & D. Teece (Eds.), Fundamental issues in strategy: A research agenda. Boston: Harvard Business School Press.

Williamson, O. E. (1995). Transaction cost economics and organization theory. In O. E.

Williamson (Ed.), Organization theory: From Chester Barnard to the present and beyond. New York: Oxford University Press.

World Bank. (2014). State and trends of carbon pricing 2014. Washington, DC: World Bank. Zhang, D., Karplus, V. J., Cassisa, C., & Zhang, X. (2014). Emissions trading in China: Progress

and prospects. Energy Policy, 75, 9–16.

20 R. de Santana Freire et al.

http://www.ipcc.ch/publications_and_data/ar4/wg3/en/ch9s9-6-1.html

http://www.teachshare.org.uk/ExtFiles/EnergyTrust-TheRoleOfEducationAndSchools.pdf

http://www.carbonmarketdata.com/

Chapter 3

30 Years Air Temperature Data Analysis in Athens and Thessaloniki, Greece

T. Slini and K.T. Papakostas

Introduction

The topic of climate change has attracted widespread attention in recent years and is

an issue that numerous scientists study on various time and space scales. The

reasons for climate change are complex and generate extensive discussion and

dispute in the scientific community. The main cause is the greenhouse gas emis-

sions produced by anthropogenic activities, e.g. industry, agriculture, transport. In

all these human activities, energy comes mainly from non-renewable sources

(liquid, gas and solid fuels) producing emissions that trigger the global warming.

It is widely accepted that increasing concentrations of greenhouse gases in the

atmosphere is the dominant driver of global warming and climate change. Climate

change and its impact are met with various ways: increasing temperature, changing

the distribution of rainfall floods, desertification and reduction of water resources,

forest fires, shrinking glaciers, rising sea levels.

Over the past 100 years the increase in global average temperature was about

0.74 �C and 11 out of the 12 years in the period 1995–2006 are listed among the top warmest years with reference to the historic beginning of recorded measurements

by scientific instruments, i.e. 1880 (IPCC 2007). Moreover, according to recent data

(NOAA 2014), on a global scale, the decade 2001–2010 was the warmest ever

recorded. Consequently, global warming is projected to persist, if greenhouse gases

T. Slini (*) Department of Mechanical Engineering, Laboratory of Heat Transfer and Environmental

Engineering, Aristotle University of Thessaloniki, Box 483, 54124 Thessaloniki, Greece

e-mail: [email protected]

K.T. Papakostas

Department of Mechanical Engineering, Laboratory of Process Equipment Design, Aristotle

University of Thessaloniki, 54124 Thessaloniki, Greece

e-mail: [email protected]

mailto:[email protected]

will continue to be emitted at the same rate. It is estimated that surface air warming

in the twenty-first century for a “low emission scenario” will be 1.8 �C, with a likely range of 1.1–2.9 �C, while in a “high emissions scenario”, it will be an increase of 4.0 �C with a likely range from 2.4 to 6.4 �C. A temperature increase of 0.1 �C per decade would be expected for the next two decades, even if concentrations of

greenhouse gases and aerosols were kept at the levels of the year 2000 (IPCC

2013). In particular, the average global temperature increased after 1978 with an

average rate of 0.14 �C per decade, while the average global temperature over land and sea surface reached the record highest temperature (14.47 �C) in April 2010, which is an increase of 0.77 �C as compared to the average of the twentieth century (13.7 �C). This event was characterised as one of the greatest climate anomalies at global scale based on NOAA data (URL 1). According to the same data, the global

average temperature in April 2014 over land was 9.45 �C that is 1.35 �C above the average of the twentieth century (8.1 �C), while the average global temperature of April 2014 in the sea was 16.55 �C that is 0.55 �C above the average of the twentieth century (16 �C).

Regarding Greece, according to a report conducted by the Climate Change

Impacts Study Committee (Climate Change Impacts Study Committee 2011) and

the National Observatory of Athens (WWF 2009), urban centres (e.g., Thessaloniki,

Patras, Larissa and Lamia) are expected to face annually a rise at the number of

days with maximum temperature above 35 �C, and at the number of “hot” nights, during which the temperature is maintained above 20 �C, with the period 1961–1990 as a reference.

In addition, in recent decades the frequency of occurrence of lower temperature

decreases while the frequency of occurrence of higher temperature increases

(Papakostas et al. 2013, 2014) and at the same time, the urban heat island effect

(Urban Heat Island) is observed in several Greek cities (Santamouris et al. 2001;

Kolokotsa et al. 2009; Giannaros and Melas 2012; Vardoulakis et al. 2013;

Giannopoulou et al. 2011; Livada et al. 2002). The effects of climate change are

of particular interest, as even a slight temperature change is reflected directly in

socio-economic sectors such as tourism, agriculture, mining industry, transport,

built environment, quality of life and health (Giannakopoulos et al. 2011) as well as

in energy consumption in buildings (Papakostas et al. 2010, 2013, 2014;

Santamouris et al. 2001).

According to the World Meteorological Organization (WMO) the current offi-

cial baseline for meteorological models is the 30-year time period from 1961 to

1990. At the same time this reference time period is under review for the “adjusted”

evaluation of the latest meteorological data (URL 2). The new proposed baseline is

the period 1981–2010, which is already used by several meteorological organiza-

tions so as to provide more updated and reliable services for both citizens and policy

makers regarding issues such as energy and peak load, civil protection planning and

strategic recommendations.

Based on the above, the purpose of this work is to analyze the ambient air

temperature in Athens and Thessaloniki for 30 years, namely the period 1983–2012,

in order to identify the statistically significant changes and evaluate the current

trends in urban sites in Greece.

22 T. Slini and K.T. Papakostas

Methodology

The hourly time series of outdoor air temperature of three decades (1983–2012) for

the cities of Athens and Thessaloniki are thoroughly analysed in the frame of the

current study. The measurement data are obtained from the meteorological station

of the National Observatory of Athens (NOA) (NOA Climatological Bulletin)

located on a small hill near the Acropolis (with coordinates 37�580N, 23�430E and altitude 107 m), and respectively from the station maintained by the Institute of

Meteorology and Climatology of the Aristotle University of Thessaloniki

(IMC/AUTh) (Department of Meteorology and Climatology) within the university

campus (with coordinates 40�370N, 22�570E and altitude 31 m). The measurements were checked for homogeneity (Founda et al. 2009) and the missing values were

negligible and did not affect the reliability and quality of results. Specifically, for

the Athens area recorded about 1077 out of 263,424 observations (percentage of

0.4%) and Thessaloniki about 567 in total of 263,520 (percentage of 0.2%).

For the need of the study descriptive statistics indicators were estimated such as

the mean, the standard deviation, the frequency, and quartiles in hourly, daily,

monthly, annual and decadal scale. Graphic representation of the data was

performed in order to detect and capture any evident trend, seasonality or outlier.

The average for the period 1961–1990 was employed as a benchmark for the

identification of outliers and deviations from the “normal” values. Furthermore,

according to the Intergovernmental Panel on Climate Change (IPCC), the change in

indicators is mainly expressed as deviations from the average or normal mode. The

current study adopted the indicators used in the reports of IPCC (IPCC 2007) and

the Joint Research Center (2008). In this view, the number of days with daily

average of more than 25 �C and daily maximum temperature above 35 �C were estimated.

Finally statistical tests were carried out in order to identify any statistically

significant changes in temperature at a significance level of 0.05.

Results

The main results of the analysis are presented in the following graphs exhibiting the

average minimum, mean and average maximum monthly values of temperature

(�C), the number of days with daily average temperature above 25 �C, the number of days with a maximum value greater than or equal to 35 �C, and the cumulative frequency curves of temperature per decade for the two areas under study. It is

noteworthy to point out the intense temperature variations between the decades

1983–1992 and 2003–2012 in all graphs especially during the summer months.

More specifically, there is a gradual increase in average minimum, mean and

maximum average monthly values of temperature from decade to decade (Fig. 3.1).

Note that in Athens, the differentiation between the temperature per decade is

3 30 Years Air Temperature Data Analysis in Athens and Thessaloniki, Greece 23

statistically significant both in annual scale and individually throughout the summer

months, based on the non-parametric Kruskal-Wallis (p< 0.05) test, indicating that this variation is not due to a random effect. Respectively the results for Thessaloniki

prove that there is a statistically significant difference to both the minimum and

Fig. 3.1 Average minimum, mean, and average maximum monthly temperatures per decade, in Athens (a, c, e) and Thessaloniki (b, d, f): period 1983–2012

24 T. Slini and K.T. Papakostas

maximum values. In particular regarding the variation between the first decade,

1983–1992, and the third decade, 2003–2012, the average minimum monthly

temperatures in Athens ranged from 0.1 �C (month of January) to 2.94 �C (month of September), the average monthly temperatures range from 0.04 �C (month of January) to 2.25 �C (month of August), while the average maximum temperatures range from 0.15 �C (month of February) to 2.26 �C (month of August). In Thessaloniki, the change in mean minimum monthly temperatures range from

0.24 �C (month of April) to 1.90 �C (month of August), the average monthly temperatures range from 0.13 �C (month of April) to 1.66 �C (month of August), while the average maximum temperatures ranging from 0.16 �C (month of January) to 2.02 �C (month of August). Moreover, it was observed that the major increase occurred in Athens from the first (1983–1992) to the second decade (1993–2002),

while the differentiation of temperatures was much lower from the second to the

third decade. Instead, in Thessaloniki greater changes observed between the second

and third decade, with the exception of mean minimum temperatures in August,

September and October.

Regarding the number of days with daily average temperature above 25 �C, as depicted in the diagrams of Fig. 3.2, a rising trend is exhibited in the number of days

for both areas. In detail, there were 717 days in the first decade, 906 in the second

and 934 in the third decade in Athens (at least in the measuring range). That is the

increase of days with average daily temperature above 25 �C from the first to the third decade was about 30% and from the first to the second about 26%. Similarly,

in Thessaloniki area (at least in the measurement range), there were 494 days during

the first decade, 596 during the second and 748 days in the third decade wherein the

increasing tendency was about 51% from the first to third and 25% from the first to

second decade respectively (Table 3.1).

Higher temperatures increase the amount of moisture that evaporates from land

and water, leading to drought in many areas. Generally, lands and cities are affected

by drought since they become more vulnerable to flooding once rain falls.

Fig. 3.2 Number of days with daily average temperature above 25 �C per decade (a) in Athens and (b) in Thessaloniki: period 1983–2012

3 30 Years Air Temperature Data Analysis in Athens and Thessaloniki, Greece 25

Temperature changes may as well increase the spread of infectious diseases, mainly

because warmer temperatures allow disease-carrying insects. On the other hand

temperature rise favours the touristic attractiveness during spring and autumn,

especially in areas where tourism is an important economic sector.

Regarding the number of the days with a maximum temperature value equal or

exceeding the limit of 35 �C, the analysis of data is presented in the graphs of Fig. 3.3 and the conclusions are similar. In the Athens area, the number of days with

maximum temperature above or equal to 35 �C was estimated at 79, 217 and 287 respectively for each decade (up 175% in the second decade and 263% in

the third, relative to the first), while in Thessaloniki on 56, 70 and 141 (an increase

of 25% in the second decade and 152% in the third, as compared to the first). The

most days with this characteristic were monitored during the third decade

(2003–2012) as presented in Table 3.2, while their distribution is varying signifi-

cantly within the three decades only in the Athens area (non-parametric Kruskal-

Wallis test).

Table 3.1 Number of days with average daily temperature above 25 �C in Athens and Thessaloniki: period 1983–2012

Athens May June July August September October Total

1983–1992 9 126 259 248 71 4 717

1993–2002 24 205 286 279 107 5 906

2003–2012 28 181 300 307 115 3 934

Total 61 512 845 834 293 12 2557

Thessaloniki May June July August September October Total

1983–1992 1 75 211 186 21 0 494

1993–2002 10 107 238 217 24 0 596

2003–2012 11 138 275 273 49 2 748

Total 22 320 724 676 94 2 1838

Fig. 3.3 Number of days with maximum temperature equal or greater than 35 �C per decade (a) in Athens and (b) in Thessaloniki: period 1983–2012

26 T. Slini and K.T. Papakostas

Extreme high temperatures perhaps are the most direct effect of climate change

on humans. High air temperatures in combination with high humidity on a given

day increase the death danger to people with heart and respiratory problems. Higher

air temperature also increases the concentration of ozone at ground level. In the

lower atmosphere, ozone is a harmful pollutant. It damages lung tissues and causes

problems for people with asthma and other lung diseases. Climate change would

increase cardio-respiratory morbidity and mortality associated with ground-level

ozone. Length, frequency and intensity of high temperatures affects also social life,

limits the exposure to open spaces, causes problems to transportation and creates

less favorable conditions for tourism in summer. Hot temperatures and dry condi-

tions also increase the likelihood of forest fires, especially in the conifer forests.

Furthermore based on the cumulative frequency temperature curves in Athens

(Fig. 3.4a) and Thessaloniki (Fig. 3.4b), it is also evident that the frequency of

occurrence of low temperatures decreases, while the frequency of occurrence of

high temperatures increases from decade to decade. This has a positive effect on the

coefficient of performance of heat pumps (with air as the heating source) in winter,

while it has a negative effect on the performance of heat pumps and air-cooled

chillers during the summer. Particular analysis is required in order to investigate

these deviations in efficiency rates (instantaneous and annual) both in winter and in

summer periods. The decrease of low temperatures frequency helps additionally to

reduce the demand of buildings for heating while the rise of high temperature

frequency increase energy demands for cooling, which may further exacerbate

peaks in electricity supply in the summer period. The net local impact of these

two effects depends on the current climate in a particular area. From the temper-

ature frequency curves in Fig. 3.4 it is concluded again that the strongest temper-

ature alterations in Athens are monitored from the first to the second decade while

in Thessaloniki a smoother change from decade to decade was observed.

Table 3.3 shows the number of weeks per decade, in which days with a

maximum temperature value equal or exceeding the limit of 35 �C are observed. The graphs in Fig. 3.5a and b display these weeks during the three decades as well

as the number of days per week, in which the temperature is equal to or greater than

Table 3.2 Number of days with maximum hourly temperature equal or above 35 �C in Athens and Thessaloniki: period 1983–2012

Athens May June July August September October Total

1983–1992 0 3 48 23 4 1 79

1993–2002 3 32 97 77 7 1 217

2003–2012 2 40 125 111 9 0 287

Total 5 75 270 211 20 2 583

Thessaloniki May June July August September October Total

1983–1992 0 5 31 16 4 0 56

1993–2002 0 9 34 25 2 0 70

2003–2012 0 26 50 60 5 0 141

Total 0 40 115 101 11 0 267

3 30 Years Air Temperature Data Analysis in Athens and Thessaloniki, Greece 27

Fig. 3.4 Cumulative frequency curves of the temperature (a) in Athens and (b) in Thessaloniki for the decades 1983–1992, 1993–2002 and 2003–2012

Table 3.3 Number of weeks with daily maximum

temperature equal or above

35 �C in Athens and Thessaloniki for the period

1983–2012

Athens Thessaloniki

1983–1992 79 56

1993–2002 217 70

2003–2012 287 141

Total 583 267

Fig. 3.5 Number of days per week in which the maximum temperature is equal to or exceeds the limit of 35 �C (a) in Athens and (b) in Thessaloniki for the period 1983–2012

3 30 Years Air Temperature Data Analysis in Athens and Thessaloniki, Greece 29

this limit. Obviously, both the number of weeks and the number of days per week

with high temperatures above 35 �C are increasing from decade to decade. The frequency of these events increased in Athens more from the first to the second

decade, while in Thessaloniki mainly from the second to the third decade. The

number of hours with temperature values equal or exceeding the limit of 35 �C are shown in Tables 3.4 and 3.5 and for Athens and Thessaloniki respectively.

Figure 3.6 illustrates the temperature fluctuations on a daily scale, in both cities,

for a winter and a summer month during the three recent decades. The months of

December and July are selected and the average hourly temperature curves are

shown in Fig. 3.6a and b for Athens and in Fig. 3.6c and d for Thessaloniki. It is

apparent that temperature is increasing from decade to decade, with the greater

differences to be observed at lower temperatures of the year, recorded in December.

More specifically in Athens, from the decade 1983–1992 to the decade 2003–2012

the rise monitored in average hourly temperatures ranged from 1.3 �C (16:00) to 1.9 �C (24.00) in December and from 1.6 �C (18:00) to 2.3 �C (11.00) in July. Respectively in Thessaloniki, the rise in the average hourly temperatures ranged

from 1.4 �C (23:00) to 2.0 �C (8:00) in December and from 1.1 �C (at 9:00) to 1.8 �C (17:00) in July. The significant differences in the hour of appearance of maximum temperatures in the two areas are probably due to the urban heat island

effect and the sea breeze, since the monitoring stations are located in different built-

up urban environment. The NOA station is located in a more densely built-up area,

5 m from the sea, while the IMC/AUTh station is in a green area only 1 km from the

sea.

Of particular interest is the fact that the results, the correlations and the varia-

tions of the temperature distribution in the three decades reflected in the graphs are

confirmed by the non-parametric Kruskal-Wallis test, with the only exception of the

number of days with maximum temperature above 35 �C in Thessaloniki area (Table 3.6).

Table 3.4 Number of hours per month, which the temperature is equal to or exceeds the limit of 35 �C. Athens: period 1983–2012

Athens May June July August September October Total

1983–1992 0 9 217 66 15 1 308

1993–2002 5 122 507 362 16 1 1013

2003–2012 5 203 634 529 25 0 1396

Total 10 334 1358 957 56 2 2717

Table 3.5 Number of hours per month, which the temperature is equal to or exceeds the limit of 35 �C. Thessaloniki: period 1983–2012

Thessaloniki May June July August September October Total

1983–1992 0 6 137 61 16 0 220

1993–2002 0 37 139 108 2 0 286

2003–2012 0 105 244 231 10 0 590

Total 0 148 520 400 28 0 1096

30 T. Slini and K.T. Papakostas

Fig. 3.6 Average hourly temperature for December and July for the period 1983–2012 per decade (a, b) in Athens and (c, d) in Thessaloniki respectively

Table 3.6 Results of the Kruskal–Wallis test for the distribution of the studied parameters over the three decades

Athens Thessaloniki

Minimum temperatures ** **

Maximum temperatures ** **

Number of days with daily temperature above 25oC ** **

Number of days with maximum temperature equal or above 35oC ** –

Mean daily temperature of December ** **

Mean daily temperature of July ** **

Statistically significant differences marked with **, at significance level of 0.05

3 30 Years Air Temperature Data Analysis in Athens and Thessaloniki, Greece 31

Conclusions

Climate change is happening and influences life in cities. Current observations as

well as projected changes suggest an increase of the annual mean temperature, a

change of precipitation patterns, a rise of sea level, an increase of the number,

intensity and duration of heatwaves, as well as an increase of extreme precipitation

events and drought. Cities and towns will be affected by the impacts of climate

change. The impacts are direct, such as health problems, damages to infrastructure,

lower crop productivity, fire risks, decrease in water availability, and indirect such

as lower productivity in work, reduction in the use of public spaces, social life

restriction, affection to tourism industry, effects on energy consumption and risks in

energy supplies. All these impacts are extremely important, their analysis is com-

plex and requires different data. In this work, an analysis of the dry-bulb temper-

ature of the ambient air in Athens and Thessaloniki for the 30 years period

1983–2012, based on hourly measurements of meteorological stations of the

National Observatory of Athens and the Aristotle University of Thessaloniki, was

performed. The results show a strong and statistically significant upward trend of

the temperature values in both cities. More specifically, there is a gradual increase

in average minimum, mean and maximum monthly values of air temperature from

decade to decade. The differentiation between the temperatures through the decades

was demonstrated as statistically significant, based on the non-parametric Kruskal-

Wallis test (p< 0.05), suggesting the non-randomness of this variation. The cumu- lative frequency curves of temperature show that the occurrence of low tempera-

tures decreases, whereas the frequency of the high temperatures is increased

through the examined period. Specifically an upward trend is shown in the number

of days with daily mean temperature above 25 �C and the number of days with maximum value equal to or exceeding 35 �C, for both areas, and suggest a slight shift of the warmest days from July to August. In addition, both the number of

weeks and the number of days per week with high temperatures above 35 �C are increasing from decade to decade. Finally, the daily fluctuation in temperature

reveals a distinct temperature rise from decade to decade, throughout the day,

while at the same time the increase was recorded particularly in low temperatures

in winter and in high temperatures in summer. The data that this work presents, may

be helpful to support policy development and decision making in urban and built

environment design.

References

Climate Change Impacts Study Committee. (2011). The environmental, economic and social impacts of climate change in Greece. Athens: Bank of Greece. ISBN 978-960-7032-58-4.

Department of Meteorology and Climatology, Aristotle University of Thessaloniki, Greece.

Meteorological observations of Thessaloniki station (1983–2012). Annual edition of Institute

of Meteorology and Climatology of the Aristotle University of Thessaloniki (in Greek).

32 T. Slini and K.T. Papakostas

Founda, D., Kambezidis, H. D., Petrakis, M., Zanis, P., & Zerefos, C. (2009). A correction of the

recent air-temperature record at the historical meteorological station of the National Observa-

tory of Athens (NOA) due to instrument change. Theoretical and Applied Climatology, 97, 385–389.

Giannakopoulos, C., Kostopoulou, E., Varotsos, K., Tziotziou, K., & Plitharas, A. (2011). An

integrated assessment of climate change impacts for Greece in the near future. Regional Environmental Change, 11(4), 829–843.

Giannaros, T. M., & Melas, D. (2012). Study of the urban heat island in a coastal Mediterranean

City: The case study of Thessaloniki, Greece. Atmospheric Research, 118, 103–120. Giannopoulou, K., Livada, I., Santamouris, M., Saliari, M., Assimakopoulos, M., & Caouris, Y. G.

(2011). On the characteristics of the summer urban heat island in Athens, Greece. Sustainable Cities and Society, 1, 16–18.

IPCC—Intergovernmental Panel on Climate Change. (2007). Climate change 2007: The fourth assessment report. Cambridge: Cambridge University Press.

IPCC—Intergovernmental Panel on Climate Change. (2013). Climate change 2013—The fifth assessment report. Cambridge: Cambridge University Press.

Joint Research Center. (2008). Extreme temperatures and precipitation in Europe: Analysis of a high-resolution climate change scenario. Institute for Environment and Sustainability, European Commission. JRC 44124, EUR 23291 EN, SSN 1018-5593.

Kolokotsa, D., Psomas, A., & Karapidakis, E. (2009). Urban heat island in southern Europe: The

case study of Hania, Crete. Solar Energy, 83, 1871–1883. Livada, I., Santamouris, M., Niachou, K., Papanikolaou, N., & Mihalakakou, G. (2002). Deter-

mination of places in the great Athens area where the heat island effect is observed. Theoretical and Applied Climatology, 71, 219–230.

NOA—National Observatory of Athens. Climatological bulletin (1983–2012). Institute of Mete- orology and Physics of the Atmospheric Environment, Athens (in Greek).

NOAA—National Oceanic and Atmospheric Administration. (2014). U.S. climate extremes index. Retrieved March 24, 2015, from http://www.ncdc.noaa.gov/extremes/cei/.

Papakostas, K., Mavromatis, T., & Kyriakis, N. (2010). Impact of the ambient temperature rise on

the energy consumption for heating and cooling in residential buildings of Greece. Renewable Energy, 35, 1376–1379.

Papakostas, K. T., Michopoulos, A., Mavromatis, T., & Kyriakis, N. (2013). Changes of temper-

ature data for energy studies over time and their impact on energy consumption and CO2 emissions. The case of Athens and Thessaloniki—Greece. International Journal of Energy and Environment, 4(1), 59–72.

Papakostas, K. T., Zagana-Papavasileiou, P., & Mavromatis, T. (2014). Analysis of three decades

temperature data for Athens and Thessaloniki, Greece—Impact of temperature changes on

energy consumption for heating and cooling of buildings. In International conference ADAPTtoCLIMATE, Nicosia, Cyprus, 27–28 March.

Santamouris, M., Papanikolaou, N., Livada, I., Koronakis, I., Georgakis, C., Argiriou, A., &

Assimakopoulos, D. N. (2001). On the impact of urban climate to the energy consumption of

buildings. Solar Energy, 70(3), 201–216. URL 1. Retrieved March 24, 2015, from http://www.ncdc.noaa.gov/cag/.

URL 2. Retrieved March 24, 2015, from http://www.wmo.int/pages/mediacentre/press_releases/

pr_997_en.html.

Vardoulakis, E., Karamanis, D., Fotiadi, A., & Mihalakakou, G. (2013). The urban heat island

effect in a small Mediterranean city of high summer temperatures and cooling energy demands.

Solar Energy, 70, 128–144. WWF Greece. (2009). Climate change impacts in Greece in the near future. Athens.

3 30 Years Air Temperature Data Analysis in Athens and Thessaloniki, Greece 33

http://www.wmo.int/pages/mediacentre/press_releases/pr_997_en.html

http://www.ncdc.noaa.gov/cag/

http://www.ncdc.noaa.gov/extremes/cei/

Chapter 4

Mitigation and Adaptation Policies Related to Climate Change in Greece

I. Sebos, A. Progiou, L. Kallinikos, P. Eleni, I. Katsavou, K. Mangouta,

and I. Ziomas

Introduction

In response to the emerging evidence that climate change could have a major global

impact, the United Nations Framework Convention on Climate Change (henceforth

the Convention) was adopted on 9May 1992 and was opened for signature in Rio de

Janeiro in June 1992. Greece signed the Convention in Rio and ratified it in 1994

(Law 2205/94) (Ministry of Environment Energy and Climate Change (MEECC)

2014a).

In that framework, the third meeting of the Conference of the Parties (COP) to

the Convention, held in Kyoto (1–11 December 1997), finalised the negotiations

related to the establishment of a legal instrument; the Kyoto Protocol on Climate

Change. The Kyoto Protocol runs in two commitment periods; the first one started

in 2008 and ended in 2012 (United Nations Framework Convention on Climate

Change (UNFCCC) 1998), whereas the second started in 2013 and will end in 2020

(European Environment Agency (EEA) 2014). The Protocol provides a foundation

upon which future action can be intensified and introduced, for the first time, legally

binding commitments for developed countries to reduce emissions of greenhouse

gases. The Protocol entered into force on 16 February 2005, after its ratification

from 141 Parties (with the exception of USA and Australia—Australia finally

ratified the 1997 Kyoto protocol in 2007) including developed countries with a

contribution of more than 55% to global CO2 emissions in 1990. The detailed rules

for the implementation of the Protocol were adopted at COP 7 in Marrakesh,

Morocco, in 2001, and are referred to as the “Marrakesh Accords.” In Doha,

I. Sebos (*) • A. Progiou • L. Kallinikos • P. Eleni • I. Katsavou • K. Mangouta • I. Ziomas Department of Chemical Engineering, National Technical University of Athens,

Zografou Campus, 9 Heroon Polytechniou Street, 15780 Zografou, Greece

e-mail: [email protected]; [email protected]; [email protected]; peleni@central.

ntua.gr; [email protected]; [email protected]; [email protected]

mailto:[email protected]

Qatar, on 8 December 2012, the “Doha Amendment to the Kyoto Protocol” was

adopted (United Nations Framework Convention on Climate Change (UNFCCC)

1998; United Nations Framework Convention on Climate Change (UNFCCC)

2015), and sets new commitments for Annex I Parties to the Kyoto Protocol who

agreed to take on commitments in a second commitment period from 1 January

2013 to 31 December 2020.

With respect to the EU target under the first commitment period of the Kyoto

Protocol (i.e. reduction of emissions at 8% for the period 2008–2012 comparing to

1990 levels), EU has stated that this will be achieved jointly by EU Member-States

under the provisions of Article 4 of the Protocol. The Burden-Sharing agreement

between all Member States was finalized during the Environment Council in June

1998 and entered into force with Decision 2002/358/EC concerning the approval,

on behalf of the European Community, of the Kyoto Protocol. According to this

agreement, Greece is committed to limit its GHG emissions increase for the period

2008–2012 to þ25% compared to base year emissions (1990 for CO2, CH4 and N2O emissions—1995 for F-gases). Since the base year emissions of Greece were

106,987,169 t CO2 eq. (United Nations Framework Convention on Climate Change

(UNFCCC) 2007), the assigned amount was calculated to be 668,669,806 t CO2 eq. (5 * 1.25 * base year emissions). Greece ratified the Kyoto Protocol in 2002

(Law 3017/2002) and adopted a National Programme for achieving its commitment

by a decision of the Council of Ministers (DCM5/2003).

Concerning the second period of the Kyoto Protocol, legally binding target

trajectories for the period 2013–2020 are enshrined in both the Emissions Trading

System (EU-ETS) Directive (Directive 2003/87/EC and respective amendments)

and the Effort Sharing Decision (Decision No 406/2009/EC). At the same time the

European Union (EU) has set its climate change mitigation objective for 2020,

committing itself to reducing its emissions by at least 20% compared to 1990 levels

(30% subject to the conclusion of a comprehensive international climate change

agreement) (Official Journal of the European Union 2013) in the context of the EU

Climate and Energy Package, which adopted in 2009. These legally binding

trajectories not only result in a 20% GHG reduction in 2020 compared to 1990

but also define the EU’s annual target pathway to reduce EU GHG emissions from 2013 to 2020. The EU has also committed to increase to 20% the share of

renewable energies in the EU final energy consumption (with a minimum 10%

share in the transport sector) and to save 20% of the EU’s energy consumption through increased energy efficiency (“20-20-20” objective) (European Environ-

ment Agency (EEA) 2014; European Commission/DG Climate Action/ European

Environment Agency 2014).

The EU ETS is the key tool for cutting industrial greenhouse gas emissions most

cost-effectively. The climate and energy package includes a comprehensive revi-

sion and strengthening of the legislation which underpins the EU ETS, the Emis-

sions Trading Directive. The revision applies from 2013, the start of the third

trading period of the EU ETS. Major changes include the introduction of a single

36 I. Sebos et al.

EU-wide cap on emission allowances in place of the existing system of national

caps. Thus, the emission reduction to be achieved from the sectors covered by the

EU ETS will be 21% below 2005 emission levels. In specific, the allowed GHG

emissions will start by the mean value of the period 2008–2010 for industries that

are included in the ETS and will be decreased by 1.74% annually until 2020.

The effort to reduce emissions not covered by the EU-ETS, shared between

the EU-28 Member States through differentiated annual national GHG targets

under the Effort Sharing Decision (ESD). The Effort Sharing Decision sets

annual national emission targets for all Member States for the period 2013–2020

for those sectors not covered by the EU-ETS, expressed as percentage changes

from 2005 levels. In March 2013, the Commission formally adopted the national

annual limits throughout the period for each Member State. By 2020, the

national targets will collectively deliver a reduction of around 10% in total

EU emissions from the sectors covered compared with 2005 levels. The national

target of Greece for emissions not included in the ETS (non-ETS) is a 4%

reduction of emissions by 2020 compared to 2005. According to European

Commission Decision 2013/162/EU, 4% reduction of emissions by 2020 for

Greece is account for 63,028,265 t CO2 eq., based on the global warming

potential values from the fourth IPCC assessment report (European Environment

Agency (EEA) 2014).

National Greenhouse Gas Emissions

Figure 4.1 presents the emissions of greenhouse gases (carbon dioxide, methane,

nitrous oxide, HFCs, PFCs), for the years 1990–2012, expressed in carbon dioxide

equivalent (Mt CO2 eq.), while the Land Use, Land Use Change and Forestry

(LULUCF) sector is not included (Ministry of Environment Energy and Climate

Change (MEECC) 2013).

It should be noted that because the sector Land Use, Land Use Change and

Forestry (LULUCF), was a sink of greenhouse gases in 1990 (as in the whole period

from 1990 to 2012), emissions from this sector are not taken into account for the

calculation of emissions base.

Total emissions of greenhouse gases (without LULUCF) in 2012 amounted to

110.98 Mt CO2 eq., showing an increase of 5.77% compared to base year over

emissions. Since the objective of the country for the first commitment period of the

Kyoto Protocol is to limit the increase of GHG emissions at þ25%, it is obvious that the country not only achieves its goal, but also has surplus of emission

allowances (Fig. 4.2).

The contribution of each sector in total emissions is shown in Fig. 4.3. As it is

evident from this figure, emissions from the energy sector (emissions from

4 Mitigation and Adaptation Policies Related to Climate Change in Greece 37

combustion of fossil fuels and fugitive emissions) accounted for 78.61% of the total

emissions for the year 2012.

The key findings are summarized below:

2. Industrial Processes

8.66%

1. Energy 78.61%

3. Solvent and Other Product

Use 0.29%

4. Agriculture 8.18%

5. Waste 4.27%

Fig. 4.2 Contribution of each sector to total GHG emissions for 2012

160

140

130

120

110

100

120

100

Mt CO2eq

Total emissions Change to 1990

19 90

19 91

19 92

19 93

19 94

19 95

19 96

19 97

19 98

19 99

20 00

20 01

20 02

20 03

20 04

20 05

20 06

20 07

20 08

20 09

20 10

20 11

20 12

Fig. 4.1 Total GHG emissions time series in Greece in Mt CO2 eq

38 I. Sebos et al.

Emissions from Energy in 2012 accounted for 78.61% of total GHG emissions

(without LULUCF) and increased by approximately 13.73% compared to 1990

levels.

The living standards improvement, due to the economic growth, the important

growth of the services sector and the introduction of natural gas in the Greek energy

system represent the basic factors affecting emissions trends from Energy for the

period 1990–2007. The decreasing trend of emissions in all sectors of energy of the

years 2008–2012 is attributed among others (i.e. RES, energy efficiency measures,

road infrastructure and public transportation improvements, etc.) to the economic

recession that the country is facing.

At the same time it should be mentioned that the availability of hydropower has a

significant effect to emissions trends. For instance, the significant increase of

electricity demand in 1999 was not followed by a similar increase of emissions

because of the penetration of natural gas and the high availability of hydropower.

The majority of GHG emissions (64.12%) in 2012 derived from energy indus-

tries, while the contribution of transport, manufacturing industries and construction

and other sectors is estimated at 18.63%, 6.47% and 10.78%, respectively. The

rest 0.01% of total GHG emissions from Energy derived from fugitive emissions

from fuels. Within the fuel combustion activities, the sector with the greatest

increase of emissions for the years 1990–2008 is transport, showing an average

rate of increase of 2.48%. However, for years 2009–2012 a decrease was observed

with an average rate of decrease equal to �6.81%. In addition, energy industries and other sectors (i.e. residential, tertiary and agriculture sectors) presented 1.16%

and 0.94% average annual rate of increase, respectively. Finally, missions from

Fig. 4.3 GHG emissions between 1990 and 2012 by sector

4 Mitigation and Adaptation Policies Related to Climate Change in Greece 39

manufacturing industries and construction emissions had a mean annual rate of

decrease of 1.87%.

Emissions from Industrial Processes in 2012 accounted for 8.66% of the total

emissions (excluding LULUCF) and decreased by 9.42% compared to 1990 levels.

In 2012 mineral products production has continued the decreasing trend of the

previous years, following the decrease of all the subcategories of the sector, mainly

due to the effects of the economic recession. There is an increase in emissions since

2011 (20.07%), which followed the intense decrease of 2011 (�36.74% between 2011 and 2010). Emissions from chemical industry have decreased by 23.67%

since 2011. Emissions from metal production slightly increased with regards to

2011 by 1.05%, due to the increased production of aluminum and nickel. As

regards to fluorinated greenhouse gases (f-gases) emissions, have been increased

compared to 2011 (14.48%). The general increasing trend during the last years of

the time-series depicts the continuous substitution of CFCs in the context of the

protocol of Montreal.

The contribution of the Solvents and other products use sector to total GHG

emissions is minor (0.29% of the total emissions) and has increased by 3.29%

compared to 1990 level of emissions.

Emissions from Agriculture that accounted for 8.18% of total emissions in 2012

(without LULUCF), decreased by approximately 20.44% compared to 1990 levels.

Emissions reduction is mainly due to the reduction of Ν2Ο emissions from agri- cultural soils, because of the reduction in the use of synthetic nitrogen fertilizers.

The decrease in the use of synthetic nitrogen fertilizers is attributed to the increase

of organic farming, the high price of fertilizers and the impact of initiatives to

promote good practice in fertilizer use. The changes of the rest determining

parameters of GHG emissions from the sector (e.g. animal population, crops

production etc.) have a minor effect on GHG emissions trend.

Emissions from the Waste Sector (4.27% of the total emissions, without

LULUCF), decreased by approximately 19.58% from 1990. Living standards

improvement resulted in an increase of the generated waste and thus of emissions.

However, the increase of recycling along with the exploitation of the biogas

produced limits the increase of methane emissions. At the same time, emissions

from wastewater handling have considerably decreased, due to the continuous

increase of the population served by aerobic wastewater handling facilities.

GHG Time Series Trend Assessment

In order to evaluate the trends of GHG emissions time series the indicators

presented in Fig. 4.4 were used. Figures present the variation of the indices

compared to the base year (base year index value¼ 100). The base year is 1990 or 2000, respectively, depending on the availability of data (Project: ODYSSEE-

MURE 2012).

40 I. Sebos et al.

Figure 4.4 presents two indices of GHG emissions in relation to the country’s economic development and population, respectively. As shown in the Figure, both

the total, and the energy related index have decreased significantly compared to

2000 (approximately 17.1% and 14.7%, respectively). Thus, the increase in the

GDP for the period 2000–2008 was not accompanied by a respective increase of

GHG emissions. The entry of natural gas and renewable energy in the energy mix,

and other policies and measures, such as energy saving are significant contributions

to the above reduction. The increase of the indicators in recent years compared to

previous years is probably due to the abrupt decrease in GDP (denominator) due to

the economic crisis of recent years.

Figure 4.5 presents two power generation related indicators. Both indicators

have decreased significantly compared with 1990 (about 27.6% in terms of CO2 specific emissions of public and auto producer power plants and 28.6% for the

electricity carbon intensity of total power generation). The reduction of GHG

emissions compared to the generated electricity is the result of policies and mea-

sures such as the admission of natural gas in the energy mix, the use of renewable

energy sources (RES), the modernization of power plants in combination with

energy saving measures etc. The index of total generation presents a lower value

because it includes the production of electricity from RES.

Figure 4.6 shows the industry assessment index relative to its growth (gross

value added—GVA). The index referring to industry presents a decrement by

27.6% compared to 2000. Thus, the development of industry (the period

2000–2007, as after 2008 GVA reduced) was not accompanied by a corresponding

increase of GHG emissions.

Finally, in Fig. 4.7 the indicators for the residential and tertiary sectors are

presented. For households an increase in GHG emissions per household for the

100

60 2000 2005 2010

Total CO2 intensity of GDP

Total CO2 intensity of inhabitant

Energy related CO2 intensity GDP

105

110 Index 2000=100

Fig. 4.4 Carbon intensity of GDP and population

4 Mitigation and Adaptation Policies Related to Climate Change in Greece 41

period 2000–2003 occurs, which is explained by the improvement of living stan-

dards due to the economic growth of the period. Then, the index decreases despite

the continued economic growth, mainly due to the gradual replacement of heating

diesel by natural gas and the implementation of energy saving measures. Respective

conclusions result from the tertiary sector. It should be noted that the above

indicators roughly reflect the GHG emissions from burning fossil fuels for heating

needs for each home or building in the tertiary sector, so they are strongly

influenced by the climatic conditions during winter period of each year (i.e. how

hot or cold the winter was every year).

20001990 2010

Specific CO2 emissions of public and autoproducer power plants

Carbon intensity of total power generation

100

105 Index 1990=100

Fig. 4.5 Carbon intensity of power generation

2000 2005 2010

Specific CO2 emissions of households

CO2 intensity of the commercial and institutional sector

180

160

140

120

100

Index 2000=100

Fig. 4.6 Evaluation indicator of industry (based on gross value added)

42 I. Sebos et al.

Level of Achievement of the National Commitment Under the KP

The GHG emission projections presented in this paper are based on the latest

official energy projection scenarios approved by the Ministry of Environment,

Energy and Climate Change. In Fig. 4.8 the evolution of GHG emissions and

their projections till year 2020, along with the assigned amount of Greece for the

first commitment period of Kyoto Protocol are presented.

The fulfillment of the Kyoto Protocol target (first commitment period) is eval-

uated through a comparison between the total GHG emissions of the years

2008–2012, and the Assigned Amount of Greece for the same period

(668,669,806 t CO2 eq). As it is obvious (Fig. 4.8), Greece achieves Kyoto Protocol

target for the first commitment period, on the basis of the domestic policies and

measures implemented; and there was a surplus of allowances of GHG emissions of

approximately 44 million AAUs.

The presented progress of the country in achieving the emission reduction

targets for the period 2013–2020, concerns only the case of non-ETS sectors,

since the emissions of sectors covered by the ETS will be regulated by the

Emissions Trading System (ETS). Thus, projected emissions from non-ETS sectors

and annual emissions allocation for the years 2013–2020, are presented in Fig. 4.9.

Comparing the annual emissions allocation for the years 2013–2020 (Annex 1 of

2013/634/EU), which reflect the non-ETS target of Greece pursuant to European

legislation (2013/162/EU and its amendment 2013/634/EU), with the projected

emissions from non-ETS sectors, it is concluded that Greece will meet this target,

on the basis of the domestic policies and measures. It should be mentioned that this

conclusion is based on the comparison of projections and annual emissions

Energy related CO2 intensity of gross value added of industry

2000 2005 2010

100

110

Index 2000=100

Fig. 4.7 Evaluation indicators of the residential and commercial sectors

4 Mitigation and Adaptation Policies Related to Climate Change in Greece 43

allocation calculated by applying global warming potential values from the second

IPCC assessment report. However, the same conclusion would result if global

warming potential values from the fourth IPCC assessment report were considered

(Ministry of Environment Energy and Climate Change (MEECC) 2014a; European

Commission 2014).

1985 1990

140,000.00

130,000.00

120,000.00

110,000.00

100,000.00

90,000.00

80,000.00 1995 2000 2005 2010 2015 2020 2025

Fig. 4.8 GHG emissions projections

2013

65000

Kt CO2 eq. Assigned Amount Units (AAUs) for

non-ETS sectors

Level of achievement of the national

commitment for the years 2013-2020 for

non-ETS sectors 60000

55000

50000

45000

40000 2014 2015 2016 2017 2018 2019 2020 2013 2014 2015 2016 2017 2018 2019 2020

Fig. 4.9 Projected emissions from non-ETS sectors and annual emissions allocation for the years 2013–2020—level of achievement of the national commitment for the period 2013–2020

44 I. Sebos et al.

Effect of GHG Mitigation Policies

The most important policies related with the implementation of measures for the

mitigation of GHG emissions in Greece are (Ministry of Environment Energy and

Climate Change (MEECC) 2014a):

• The National Renewable Energy Action Plan, which sets out Greece’ national targets for the share of energy from renewable sources consumed in transport,

electricity and heating and cooling in 2020, taking into account the effects of

other policy measures relating to energy efficiency on final consumption of

energy, and adequate measures to be taken to achieve those national overall

targets (raising the share of EU energy consumption produced from renewable

resources to 20%).

• The National Energy Efficiency Action Plans, which covers significant energy

efficiency improvement measures and expected and/ or achieved energy savings,

including those in the supply, transmission and distribution of energy as well as

energy end-use. (Measures for the improvement of energy efficiency.)

• The continuous development of the transmission and distribution network of

natural gas, and the promotion of its use.

• The European emissions trading scheme (Directive 2003/87/EC) the operation

of which started in 2005. In Greece, the trading system for the period 2008–2012

comprises 140 industrial installations (power plants, refineries, cement plants,

etc.). An allowance reserve is also created which is intended to cover possible

unknown new entrants in the period. In 2013, the EU ETS is now in its third

phase, running from 2013 to 2020. A major revision in order to strengthen the

system means the third phase is significantly different from phases one and two

and is based on rules which are far more harmonized across EU than before.

• The fiscal measures that support policies and measures that reduce GHG

emissions, such as the tax regime of energy products, the registration tax of

vehicles, the Motor vehicle circulation fee (road tax), the income taxation—

relief and exemptions.

The total realistic GHG emissions reduction potential from the

implemented and adopted policies and measures was estimated to be 33.3 Mt CO2 eq. for 2015 and 41.0 Mt CO2 eq. for 2020. The possible interferences

between these implemented/adopted measures, which may restrict the estimated

GHG emissions reduction potential, were taken into account. Thus, it is obvious

that the application of the already implemented and adopted measures for

the mitigation of GHG emissions contributes considerably in the restriction of the

augmentative trend of emissions (besides the economic recession), leading to the

achievement of the 2020 target, exclusively with domestic measures and actions.

4 Mitigation and Adaptation Policies Related to Climate Change in Greece 45

Adaptation Measures for Climate Change

Adaptation may include both national and regional strategies as well as measures

at community level or by individuals. Although an over-arching adaptation strategy

is not yet available in Greece, adaptation measures are currently under implemen-

tation as part of a broader network of measures that apply to the specific areas of

identified vulnerabilities. It is worth noting that the Overall National Strategy for

Adaptation is ongoing and is a key priority of the country (Ministry of Environment

Energy and Climate Change (MEECC) 2014a; Bank of Greece 2013).

Greece already has a National Biodiversity Strategy and Action Plan for its

implementation, based on a project that started in 1999 and was completed in 2014

(Ministry of Environment Energy and Climate Change (MEECC) 2014b). The aim

of the strategy is to stop the loss of biodiversity and degradation of the ecosystems

in Greece until 2026, as well as the promotion of biodiversity as a national issue.

Aiming to the adaptation of the country concerning the agricultural sector

Greece is participated in the Project ADAGIO—ADAptation of AGriculture in

European RegIOns at Environmental Risk under Climate Change. The project is

focusing on improving awareness and user-orientation of adaptation strategies,

improving local representation and considering the main vulnerable regions to

Climate Change in Europe. In addition, the National Action Plan for Combating

Desertification (2001) sets as an objective to combat efficiently the desertification

trends in the 35% of the whole Greek territory that is under direct threat and to

prevent the desertification process elsewhere. The main issues in relation to agri-

culture are erosion of soils and drought problems.

The national strategy concerning forest ecosystems is implemented via the

Program of Rural Development (RDP) 2007–2013 “Aleksandros Mpaltatzis”

(MRDF), under which 69 projects have been implemented by the Forestry Services,

aiming at the enhancement of forest fires prevention and restoring of forest burnt

area, along with anti-erosion, anti-flood works for prevention of flooding in the

lowlands and for restoration of forest burnt areas. In addition, a Lifeþ project “Adaptation of forest management to climate change in Greece (AdaptFor)” was

implemented, aiming at enhancing the capacity of forest services to adapt forest

management to climate change and to disseminate the need for adaptation of forest

management to other stakeholders and to the general public. Natura 2000 network

has also a key role in protecting and enhancing our natural capital. In addition to

safeguarding nature’s intrinsic value, investing in Natura 2000 provides multiple benefits to society and the economy at the local, regional, national and EU level.

Finally, The National Action Plan for Combating Desertification was approved

in 2001 and includes measures to reduce the frequency and decrease the spread of

forest fires.

The Greek Operational Programme “FISHERIES 2007–2013” was approved by the European Commission, with a strategic objective focusing on

“Measures for the adaptation of the fishing fleet”. Concerning aquacultures,

46 I. Sebos et al.

possible adaptation measures to climate change include institutional measures,

policy measures and action planning which are summarized as follows:

(a) Insurance aquaculture, (b) Technology transfer and research,

installation and monitoring of aquacultures.

In the water resources sector, according to the National Action Plan for

Combating Desertification, the suggested measures include: reduction of water

loss through the improvement of irrigation efficiency, reduction of water losses and

demand in urban and industrial use and increase of water supply through funding of

programs for water recycling and reuse, etc. In addition, the MEDROPLAN

Project: “Mediterranean Drought Preparedness and Mitigation Planning” focuses

on developing Guidelines for drought preparedness plans and to setting up a

Network for drought preparedness in Mediterranean countries. The Guidelines

provide an integrated approach to face droughts from a risk management perspec-

tive and therefore minimizing the impacts of drought in the population and

resources.

Concerning coastal zones the General National Framework for Spatial

Planning and Sustainable Development includes priorities that avoid the expan-

sion of existing settlements, especially along the coast; encourage expansion in the

areas where population density permits it; protect beaches and natural coastal areas,

assure public access etc.

The following measures promoted by the tourism sector and especially the

Greek National Tourism Organization include adaptation of an appropriate mar-

keting strategy aiming at diversification through the development of new tourism

product and distinctive destination brands, promotion of sustainable tourism (eco-

tourism, nature based tourism, rural tourism), promotion of Green Destinations,

encouragement of sustainable business practices, providing tools and guidance to

the tourism industry and investors and new technologies to improve energy

efficiency.

The National Action Plan for the ‘Response of Environmental Hazards Threatening Health’ for 2008–2012 included a special action dedicated to the ‘Exploring of Climate Change Impacts on Health’, primarily referring to the identification, research and documentation of the impacts. At the national level,

the governments of Europe have been developing actions to address the impacts of

climate change: (1) The national health ministries have launched actions to ensure

equal access to health services and social justice for all victims of climate change.

(2) The national health ministries will also need to design special action plans to

address the public health problems. (3) Hospitals will also need proper infrastruc-

ture and equipment. (4) Healthcare personnel will need to receive training in

environmental epidemiology and the health implications of climate change, etc.

In addition the General Framework of Spatial Planning and Sustainable

Development has the following specific objectives:

• Constant care for energy-saving;

• Promotion of alternative, and in particular renewable, energy sources;

4 Mitigation and Adaptation Policies Related to Climate Change in Greece 47

• Protection and enhancement of natural processes;

• Adaptation to new climate change conditions and mitigation of their conse-

quences (fires, floods, erosion, drought, water salinization, desertification etc.),

by putting in place mitigation mechanisms, appropriate infrastructures and plans

for action.

The proposed policies and specific policy measures for coping with the impacts

on the transport system include:

• Development of monitoring systems for crucial infrastructure and use of ‘smart’ decision-making, risk management and disaster management systems, etc.

• Use of new materials, more resilient to extreme weather conditions.

• Policy measures aimed at reducing transport demand, e.g. carpooling, mobility

management, school transport, etc.

• Promotion and support of eco-driving.

• Use of ‘smart’ technologies and systems with a view to improving freight transport and maximizing capacity use of all means of transport (target: zero

empty routes), etc.

References

Bank of Greece. (2013). Environmental, economic and social impacts of climate change in Greece.

European Commission. (2014). European Union transaction log. http://ec.europa.eu/environment/ ets/.

European Commission/DG Climate Action/ European Environment Agency. (2014). The 2020 climate and energy package. http://ec.europa.eu/clima/policies/package/index_en.htm.

European Environment Agency (EEA). (2014). Total greenhouse gas (GHG) emission trends and projections (CSI 010/CLIM 050). Assessment published November 2014.

European Environment Information and Observation Network (EIONET). (2014). Central data repository. http://cdr.eionet.europa.eu/gr.

Ministry of Environment Energy and Climate Change (MEECC). (2013). Annual inventory submission of Greece under the convention and the Kyoto protocol for greenhouse and other gases for the years 1990–2012.

Ministry of Environment Energy and Climate Change (MEECC). (2014a). Sixth national commu- nication and 1st biennial report under the United Nations framework convention on climate change.

Ministry of Environment Energy and Climate Change (MEECC). (2014b). National strategy & action plan for biodiversity.

Official Journal of the European Union. (2013). COMMISSION IMPLEMENTING DECISION of 31 October 2013 on the adjustments to Member States’ annual emission allocations for the period from 2013 to 2020 pursuant to Decision No. 406/2009/EC of the European Parliament and of the Council (2013/634/EU).

Project: ODYSSEE-MURE. (2012). Key indicators, final energy intensity. http://www.indicators. odyssee-mure.eu/online-indicators.html.

United Nations Framework Convention on Climate Change (UNFCCC). (1998). Kyoto protocol to the United Nations framework convention on climate change.

48 I. Sebos et al.

http://www.indicators.odyssee-mure.eu/online-indicators.html

http://cdr.eionet.europa.eu/gr

http://ec.europa.eu/clima/policies/package/index_en.htm

http://ec.europa.eu/environment/ets/

United Nations Framework Convention on Climate Change (UNFCCC). (2007). Report of the review of the initial report of Greece.

United Nations Framework Convention on Climate Change (UNFCCC). (2015). Doha amendment to the Kyoto protocol.

4 Mitigation and Adaptation Policies Related to Climate Change in Greece 49

Chapter 5

Assessing Air Quality in the Urban Environment: the Gender Gap

Theodora Slini and Fotini-Niovi Pavlidou

Introduction

Gender Priorities in the European Union

Climate change affects both women’s and men’s living conditions, welfare and wellbeing, however due to gender roles, women do not affect the environment in

the same way as men, and in many countries women’s access to resources, and hence their opportunities to manage conditions and adapt are quite limited

(IPCC 2014).

At the same time, environmental policies are characterized by lack of sensitivity

to women’s different economic and social status and needs, having as a result women to be directly and disproportionally affected from environmental degrada-

tion. While consumption and lifestyle patterns still differ between two genders,

with women to consume less and being more environmentally conscious, “women

are clearly under-represented in environmental negotiations, budget deliberations

and decisions on achieving a green, sustainable economy” (EC 2012). According to

‘Gender aspects of the economic downturn and financial crisis European Parliament resolution of 17 June 2010 on gender aspects of the economic downturn and

financial crisis (2009/2204(INI))’, the European Parliament “urges the need to

T. Slini (*) Laboratory of Heat Transfer and Environmental Engineering, Centre of Space, Technology

and Gender, School of Engineering, Aristotle University of Thessaloniki, Box 483, 54124

Thessaloniki, Greece

e-mail: [email protected]

F.-N. Pavlidou

Department of Electrical and Computer Engineering, Centre of Space, Technology and

Gender, School of Engineering, Aristotle University of Thessaloniki, Box 489, 54124

Thessaloniki, Greece

e-mail: [email protected]

mailto:[email protected]

encourage women in local entrepreneurial initiatives in green economy”. The

European Parliament (2012) resolution of 11 September 2012 ‘on the role of women in the green economy (2012/2035(INI))’ “calls on the Commission and the Member State to introduce gender equality into all environmental policy areas”

and introduce gender equality into all environmental policy areas, and at all levels

of economic decision-making. On 14 November 2012 the European Commission

published its proposal for a Gender Diversity Directive for improving gender

balance on company boards, obliging companies with less than 40% of women

non-executive directors to make significant efforts to make appointments in the

next 7 years to reach this target.

Furthermore, the Opinion of the European Economic and Social Committee on

‘The gender dimension in the Europe 2020 Strategy’ 2013/C 76/02 (EU Legislation 2013), the Commission is “highlighting the essential role played by women in

sustainable development”, while “women can have a key influence on decision-

making concerning the environment, particularly with regard to climate change

policy. This is a new opportunity for women, who can play a key role and improve

their personal and financial situation by getting involved with the new and emerging

green economy, which is a crucial sector for development and job creation”. After

all “women’s activism was critical in getting the conversation started,” according to historian David Stradling, author of “Smokestacks and Progressives: Environmen-

talists, Engineers and Air Quality in America, 1881–1951.”

In response to these requirements a gender perspective is a critical assumption

towards a sustainable environment and a green economy in terms of the ecosystem,

consumption, food, growth, transport, energy and citizen welfare.

Gender Priorities in Greece

According to the National Strategic Reference Framework (NSRF) for 2014–2020,

the main tools for the implementation of gender policy will be integration of equal

opportunities between men and women in all institutions, policies and actions

(gender mainstreaming) and the assumption of certain specific activities in the

following areas:

• equal participation women in the labor market,

• the participation of women outdoor activities aimed at local development,

• promotion of inclusion of women, prevention and control of female poverty and

all forms of gender-based violence,

• mainstreaming of gender issues in social protection and health,

• support family,

• equal participation of women in public life and processes of political, social and

economic decisions,

• combat discrimination based on sex and gender stereotypes and

• the integration of gender equality in public policies, monitoring and evaluation.

52 T. Slini and F.-N. Pavlidou

However, the Greek Legislation does not include the gender perspective as a

critical parameter through its development and implementation and in many cases it

is characterized as neutral or negative, according to a report by the General

Secretariat for Gender Equality (2013). For example,

1. The Law 4067/2012 (OG A79/9-3-2012) the “New Construction Regulation”

that includes a number of provisions on accessibility of buildings and built

environment. Regarding the motivation for environmental enhancement and

the improvement of quality of life in densely populated urban areas, which

gender neutral with no comment on specific needs.

2. The master plan for urban planning and environmental protection of the greater

Thessaloniki area (L. 1561/1985) refers to the daily needs of citizens ignoring

the gender matters. Special requirements due to diverse living habits and rou-

tines as well as the different ways in which environment is perceived and used

between men and women should be considered for the optimum urban planning

and city upgrading.

The most recent L. 3653/2008 on Research and Technology establishes the

minimum proportion of male/female participation in national committees of

research and development, that is at least 1/3 of each gender, as long the candidates

are equally qualified.

Results and Discussion

Gender, Air Quality and Global Warming

Despite it is widely accepted that balanced participation of men and women in

decision-making is a prerequisite for improving the operation of democracy and

society, the ongoing under-representation of women in political and economic

decision-making reflects a basic democratic deficit in Europe and the broader

international context. At the same time it is important to highlight that the female

population is more vulnerable in effects of environmental degradetation and poor

air quality (UN 2014; Fouillet et al. 2007). Furthermore, as suggested by Druckman

(2012), the investigation of the concept of carbon footprint as a potential marker for

social justice, a higher proportion of an average man’s carbon footprint is due to leisure than an average woman’s.

There are several studies that prove that poor air pollution conditions can

generate negative effects in the female population in both rural and urban sites

(Xu et al. 2013; Huisman et al. 2005; Oiamo and Luginaah 2013; Künzli

et al. 2010). The proportion of women and young children is mainly affected as

these groups of population spend most of their time indoors where solid fuels, fire

places and cooking stoves are in extensive use. According to WHO (2014), around

three billion people cook and heat their homes using open fireplaces and stoves

5 Assessing Air Quality in the Urban Environment: the Gender Gap 53

using various burning materials. These materials are not always the appropriate

ones, causing the death of over four million people prematurely from illness due to

the poor indoor air quality. The mortality of premature deaths among children under

5 attributed to household air pollution is also extremely high.

Additionally according to The European environment—state and outlook 2010

(EEA 2010), vulnerable population groups (e.g. pregnant women) are more threat-

ened by the bio-accumulation of organic persistent pollutants such as mercury.

Chen et al. (2005) and Miller et al. (2007), the associations of PM2.5 and cardio-

vascular morbidity and mortality were greater in women above 60 and at the same

time Xu et al. (2013) states that air pollution (referring to air pollutants such as NO2,

SO2, PM2.5, O3 and CO) increases risk for hypertension in pregnant women during

early pregnancy and the full gestational period.

Ambient air pollution has stronger effects on females partly due to autoimmune

disorders. Females were more likely to report cardinal symptoms after controlling

for income, age and chronic diseases (Oiamo and Luginaah 2013). As Bakke

et al. (2007) suggests female gender has reported health symptoms more often

than did men and complained more about physical but not psychosocial factors

gender, psychosocial, and physical environment factors were related to symptoms

and perceived indoor climate. Female gender seems to be highly associated with the

sick building syndrome and the symptom of atopia (Magnavita 2015).

Several studies have linked air pollution exposure to autism, including the Volk

et al. (2011) study in Environmental Health Perspectives that looked at children in Los

Angeles who lived near freeways and the Hallmayer et al. (2011) study that analysed

traffic-related air pollution exposure data among pregnant women. The main conclu-

sion of the studies was that a large proportion of the variance in liability can be

explained by shared environmental factors in addition to moderate genetic heritability.

In general, studies suggest that health responses to air pollutionmay differ between

women and men, however it is still unclear, whether observed modification is a result

of sex-linked biological differences or gender differences in activity patterns or

exposure measurement accuracy (Clougherty 2010). Cautious consideration of gen-

der effects and examination in environmental epidemiology may provide critical

information on other social factors that can affect population response to air pollution.

In addition, in countries that face the severity of current financial crisis, struc-

tural changes occur in European members states as well, including migration and

changing of household structures due to energy poverty. For example, in Greece, an

exponential increase of wood and pellet employment is monitored primarily for

heating purposes (Slini et al. 2014; Santamouris et al. 2013), posing major concern

especially for women health (Fig. 5.1), based on the results of a survey conducted in

Northern Greece by the Department of Mechanical Engineering, Aristotle Univer-

sity of Thessaloniki (AUTh).

In Greece, due to the economic situation the consumption of oil products, which

are the main fuel that is used by the household sector, decreased already by 25.7%

between 2007 and 2010. What is impressive is the exponential increase in the use of

wood and pellets, a trend that has begun to have its first implications in matters of

air quality, both indoor and outdoor, but also in an enhanced deforestation, with

54 T. Slini and F.-N. Pavlidou

major field studies being currently carried out on those matters (Slini et al. 2014).

Towards this direction many countries in Europe are adopting policies and effective

precautionary measures in order to reduce the exposure of vulnerable population

groups in toxic environments (EEA—European Environment Agency 2015).

At the same time, research on gender-related disparities are mainly focused on

energy consumption profiles and transport use. As pointed out at the Report on

Gender Equality and Climate Change (EIGE 2012a), the most significant gendered

differences in energy consumption were monitored in Greece and Sweden, with

men energy consumption reaching a proportion of 39% and 22% more than

women, respectively. Moreover, it is suggested that women use the public transport

or other sustainable means of travel more often than men.

Gender Balance in Environmental Decision Making

As global warming is a multi-fold issue and the abatement policy (e.g. GHG

emissions, legislation, and limit values) requires an interdisciplinary approach

conducted within environmental authorities. Thus, the gender distribution in

authorities responsible for climate change adaptation/mitigation measures is sub-

stantial (genderSTE 2014).

According to EU data, concerning environmental governing positions in

European States, such as senior and junior ministers in environment, energy and

transport at national governments, the women participation was slightly increased

Electricity Woodc d

2000

1500

1000

500

0 2011 2012

−31.5%

Oila lt

3000

2000

1000

0 2011 2012

−2.5%

kW h

1000 800 600 400 200

0 2011 2012

+325%

N m

−21%

2011 2012

Natural gas

800

600

400

200

Fig. 5.1 The average annual fuel and electricity consumption for the years 2011–2012 by type: (a) oil in litres, (b) natural gas in N m3, (c) electricity in kilowatt-hours and (d) wood in kilograms

5 Assessing Air Quality in the Urban Environment: the Gender Gap 55

from 20% to 27% during the last 3 years (2012–2014), a proportion that is still

significantly lower than male proportion (Fig. 5.2). In Greece during the same

period there was no female representation.

However, the national administration positions show a slightly improved distri-

bution with the female proportion increasing from 33% to 36% between 2012 and

2014. In Greece the data are considerably more balanced compared to the European

figures, though decreased from 48% to 45% from 2012 to 2014 (Fig. 5.3).

It is noteworthy to mention that in a broader approach the representation of

women in boards of large listed companies is also discouraging, with major gaps

and little progress on women representation and career evolution, as presented in

Fig. 5.4, in both the European Member States and Greece. More recently, and

specifically in October 2014, Greece stands for the proportion of 8.9% of women in

highly ranked position with a European average of 20.2% (EC 2015).

Having the aforementioned facts under consideration, the European Commis-

sion has established a set of indicators in order to determine and evaluate the

women’s participation in decision making on climate change (EIGE 2012b), that is the following:

• Proportion of women in climate change decision-making bodies at the national

level in EU Member State.

• Proportion of women in climate change decision-making bodies at the EU level.

• Proportion of women in climate change decision-making bodies at the interna-

tional level.

• Proportion of women tertiary graduates of total graduates in natural sciences and

technologies at the EU and Member State level.

Fig. 5.2 The proportion of men and women in environmental ministers (senior and junior) in European Member States for the period 2012–2014

56 T. Slini and F.-N. Pavlidou

The development and collection of such data will support the study of gender-

climate change issues and may provide the benchmark for the development of new

indicators about the correlation between gender, environment and social welfare

and justice.

Conclusions

The current study unveil the relations and links between gender and global warming

at national and European level. It is proven that there are dissimilarities between

males and females regarding global warming attitudes, contributions and capabil-

ities of adaptation in the mitigation measures and the socio-economic impacts of

climate change policies. As little progress is achieved, it comes without saying that

gender perspective is a critical assumption towards a sustainable environment and a

green economy in terms of the ecosystem, consumption, food, growth, transport,

Fig. 5.3 The gender distribution of environmental national administrators (a) in the European Member States and (b) in Greece for the period 2012–2014

Fig. 5.4 Representation of women and men (absolute numbers) on boards of high listed compa- nies (a) in the European Member States and (b) in Greece for the period 2003–2010

5 Assessing Air Quality in the Urban Environment: the Gender Gap 57

energy and citizen welfare. As the engendering of decision making on climate

change will reinforce and will improve the efficiency of the suggested policies, the

systematic research and monitoring of gender equality data and development of

awareness initiatives are on the top of the agenda of policy recommendations.

Quantitative targets and strong commitment on gender equality on environment

and global warming by national governments, international institutes and authori-

ties are critical areas of concern towards sustainable social development.

References

Bakke, J. V., Moen, B. E., Wieslander, G., & Norbäck, D. (2007). Gender and the physical and

psychosocial work environments are related to indoor air symptoms. Journal of Occupational and Environmental Medicine, 49(6), 641–650.

Chen, L. H., Knutsen, S. F., Shavlik, D., Beeson, W. L., Petersen, F., Ghamsary, M., et al. (2005).

The association between fatal coronary heart disease and ambient particulate air pollution: Are

females at greater risk? Environmental Health Perspectives, 113(12), 1723–1729. Clougherty, J. E. (2010). A growing role for gender analysis in air pollution epidemiology.

Environmental Health Perspectives, 118, 167–176. Druckman, A., Buck, I., Hayward, B., & Jackson, T. (2012). Time, gender and carbon: A study of

the carbon implications of British adults’ use of time. Ecological Economics, 84, 153–163. EC—European Commission. (2012, March). Special Eurobarometer 376 “Women in decision-

making positions”. Conducted by TNS Opinion & Social at the request of Directorate-General

Justice.

EC—European Commission. (2014). Report on equality between women and men 2014.

EC—European Commission. (2015, January). Factsheet March 2015: Gender balance on corpo- rate boards—Europe is cracking the glass ceiling.

EEA—European Environment Agency. (2010). The European environment—state and outlook 2010 (SOER 2010).

EEA—European Environment Agency. (2015). The European environment—state and outlook 2015 (SOER 2015).

EIGE—European Institute for Gender Equality. (2012a). Gender equality and climate change. ISBN 978-92-9218-126-0.

EIGE—European Institute for Gender Equality. (2012b). Review of the implementation in the EU of area K of the Beijing platform for action: Women and the environment gender equality and climate change. ISBN 978-92-9218-026-3.

EU Legislation. (2013). Opinion of the European Economic and Social Committee on ‘The gender dimension in the Europe 2020 Strategy’ (own-initiative opinion) 2013/C 76/02. Retrieved March 26, 2015, from http://eur-lex.europa.eu/legal-content/EN/TXT/?

uri¼CELEX:52012IE1734&qid¼1410262659773. European Parliament. (2012). Resolution of 11 September 2012 on the role of women in the green

economy (2012/2035(INI)). Retrieved March 26, 2015.

Fouillet, A., Rey, G., Jougla, E., Frayssinet, P., Bessemoulin, P., & Hemon D. (2007). A predictive

model relating daily fluctuation in summer temperatures and mortality rates. BMC Public

Health 7, 114.

genderSTE: A policy-driven targeted network funded by COST (European Cooperation in Science

and Technology). Retrieved March 26, 2015, from http://www.genderste.eu/index.php.

General Secretariat. (2013). Gender impact assessment of 100 laws and regulations. Retrieved March 26, 2015, from http://www.genderimpact.gr/.

58 T. Slini and F.-N. Pavlidou

http://www.genderimpact.gr/

http://www.genderste.eu/index.php

http://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:52012IE1734&qid=1410262659773

Hallmayer, J., Cleveland, S., Torres, A., Phillips, J., Cohen, B., Torigoe. T., et al. (2011). Genetic

heritability and shared environmental factors among twin pairs with autism. Archives of General Psychiatry, 68(11), 1095–1102.

Huisman, M., Kunst, A. E., Bopp, M., Borgan, J. K., Borrell, C., Costa, G., et al. (2005).

Educational inequalities in cause-specific mortality in middle-aged and older men and

women in eight western European populations. Lancet, 365(9458), 493–500. IPCC - Intergovernal Panel on Climate Change. (2014). Climate Change 2014: Impacts, Adapta-

tion, and Vulnerability. Part A: Global and Sectoral Aspects. Contribution of Working Group II

to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge

University Press, Cambridge, United Kingdom and New York, NY, USA, pp.709–754.

Künzli, N., Jerrett, M., Garcia-Esteban, R., Basagana, X., Beckermann, B., et al. (2010). Ambient

air pollution and the progression of atherosclerosis in adults. PLoS ONE, 5, e9096. doi:10. 1371/journal.pone.0009096.

Magnavita, N. (2015). Work-related symptoms in indoor environments: A puzzling problem for

the occupational physician. International Archives of Occupational and Environmental Health, 88(2), 185–196. doi:10.1007/s00420-014-0952-7.

Miller, K. A., Siscovick, D. S., Sheppard, L., Shepherd, K., Sullivan, J. H., Anderson, G. L.,

et al. (2007). Long-term exposure to air pollution and incidence of cardiovascular events in

women. New England Journal of Medicine, 356, 447–458. Oiamo, T. H., & Luginaah, I. N. (2013). Extricating sex and gender in air pollution research: A

community-based study on cardinal symptoms of exposure. International Journal of Environ- mental Research and Public Health, 10, 3801–3817.

Santamouris, M., Paravantis, J. A., Founda, D., Kolokotsa, D., Michalakakou, P., Papadopoulos,

A. M., et al. (2013). Financial crisis and energy consumption: A household survey in Greece.

Energy and Buildings, 65, 477–487. Slini, T., Giama, E., & Papadopoulos, A. M. (2014). The impact of economic recession on

domestic energy consumption. International Journal of Sustainable Energy, 34, 259–270. doi:10.1080/14786451.2014.882335.

UN—United Nations. (2014). Prototype global sustainable development report. Online unedited

edition. New York: United Nations Department of Economic and Social Affairs, Division for

Sustainable Development, 1 July 2014.

Volk, H. E., Hertz-Picciotto, I., Delwiche, L., Lurmann, F., & McConnell, R. (2011). Residential

proximity to freeways and autism in the CHARGE study. Environmental Health Perspectives, 119(6), 873–877.

WHO—World Health Organisation. (2014, March). Household air pollution and health. Fact sheet

N�292. Xu, X., Hu, H., Ha, S., & Roth, J. (2013). Ambient air pollution and hypertensive disorder of

pregnancy. Journal of Epidemiology & Community Health, 68(1), 13.

5 Assessing Air Quality in the Urban Environment: the Gender Gap 59

http://dx.doi.org/10.1080/14786451.2014.882335

http://dx.doi.org/10.1007/s00420-014-0952-7

http://dx.doi.org/10.1371/journal.pone.0009096

Chapter 6

Promotion of Sustainability by Quantifying and Reducing the Carbon Footprint: New Practices for Organizations

Monica Carvalho, Rommel de Santana Freire, and Alexandre Magno Vieira Gonçalves de Brito

Introduction

Until recently, companies and organizations had the opinion that the environment

and sustainable development were problems and risk factors. However, the pro-

gressive development of a generalized, global environmental conscience created a

demand for products (processes, services) that are more environmentally-friendly

(with less associated impacts), for which there are great advances and developments

in the application of eco-efficiency principles by industries and designers.

Nowadays, these “problems” are seen as opportunities, as possibilities for

growth and efficiency improvement. According to the World Business Council

for Sustainable Development (WBCSD 2000), eco-efficiency is basically the art of

doing more with less: better production, with the consumption of less resources. But

eco-efficiency is not only defined as the search for energy efficiency, it also

stimulates creativity and innovation in the search for the best way to do things

(WBCSD 2000). Achieving eco-efficiency does not mean the complete elimination

of environmental impacts caused by man, rather lowering these impacts to levels

M. Carvalho (*) Department of Renewable Energy Engineering, Center of Alternative and Renewable Energy,

Federal University of Paraı́ba, Caixa Postal 5115, Cidade Universitária, Jo~ao Pessoa 58051- 900, Paraı́ba, Brazil

e-mail: [email protected]

R. de Santana Freire

Department of Accountancy and Finances, Center of Applied Social Sciences, Federal

University of Paraı́ba, Cidade Universitária, Jo~ao Pessoa 58051-900, Paraı́ba, Brazil e-mail: [email protected]

A.M.V.G. de Brito

Department of Mechanical Engineering, Center of Technology, Federal University of Paraı́ba,

Cidade Universitária, Jo~ao Pessoa 58051-900, Paraı́ba, Brazil e-mail: [email protected]

mailto:[email protected]

that are more compatible to the current degree of environmental conscience.

According to Silva (2010), the environmental impacts caused by human activities

are also studied in parallel with the development of solutions to increase

eco-efficiency, to allow for the perception of solutions.

According to Ribeiro (2011), the oil crisis in the 1970s sparked the concern of

society with the depletion of fossil fuel reserves, and as a consequence, the first

environmental analyses were carried out. The interest in these analyses was not

constant throughout the years, and was rekindled in the 1990s with the creation of

the ISO 14040 norms and increase in environmental discussions. In 2006, Lima

et al. (2006) mentioned that there was a progressive interest of industry, as well as

of environmental specialists, authorities, consumer associations, environmental

associations and general public, in the environmental quality of production pro-

cesses and products.

In this current scenario where emphasis is on the minimization of dependency in

fossil fuels along with the integration of alternative energies (progressively increas-

ing participation of renewable energies), quantification of environmental impacts

has been established as a powerful tool that creates awareness. Some studies go a

step further by searching not only for the optimal solution from an environmental

viewpoint (Carvalho et al. 2011a, b), but for a balance or equilibrium between

different points of view (environmental and economic perspectives: Carvalho

et al. 2011a, b; Buoro et al. 2013). Quantification of environmental impacts have

been utilized by developed countries for many years, and the European Union

(EU) has even declared Life Cycle Assessment to be a state-of-the-art methodology

and included related aspects in the 6th Environmental Action Programme, to assure

that environmental legislation is adopted to attack most of the environmental

challenges in the EU (EIONET 2003).

Modern companies and institutions have aimed at a balance situation between

the expansion of businesses and preservation of the environment, where sustainable

growth is the fundamental point for the efficient management of resources. Accu-

rate knowledge on productive processes is essential for the organizations to mea-

sure costs and risks; when not measured or correctly controlled, revenue can be

significantly decreased to the point of non-viable business in some cases. Correct

quantification of the environmental loads of a specific process, or sector, helps the

company optimize costs and reduce risks, avoiding future liabilities in function of

environmental damages caused. In this way, from the a priori knowledge on the

amount of environmental loads generated, companies can establish targets for

reduction/mitigation of pollution levels and promote the results to society in a

clear manner. The company will publicize the reduction in the pollution generated

by its activities as a contribution to the sustainable development of its surroundings.

The reduction in environmental loads can be achieved through improvements in

processes and products, installation of new equipment, capture and treatment of

generated residues for posterior discharge or even sale. Companies can generate

non-operational revenues, which can add up to relevant volumes, from the negoti-

ation of processed/treated residues and also from the sale of carbon credits, gener-

ated from the elaboration of Clean Development Mechanism (CDM) projects. In

62 M. Carvalho et al.

these projects, the volume of reduced emissions can be converted into a commodity,

and negotiated in the financial market, which has been increasing substantially in

recent years (Pirrong 2011). Therefore, the reduction in the levels of emissions

brings, besides the environmental benefits, also financial benefits, allowing for the

sustainable growth of organizations.

Brazil should, as always, accompany the global trends of environmental con-

science. The objective of this manuscript is to explore the relationship between the

environmental loads generated by companies, with society and governments. This

relationship is based on the tripod QUANTIFY-REDUCE-PROMOTE and can be

extended to assess what society itself emits. The idea supporting this project is that

the social perception of companies developing studies for the quantification of

environmental impacts will be improved. It is important to highlight that the

quantification study is the first step: then, points are identified where improvements

can be introduced for posterior reduction of emissions. The next step is to promote,

disseminate these results, which returns to the initial idea: improvement of social

perception and popularity of the company. If the consumers or clients perceive that

the company is concerned with the environment, they are more inclined to be loyal

to the brand.

Diagnosis and Analysis of the Situation

Due to the progressive development of environmental conscience by the society,

along with ever-increasing pressure to reduce environmental loads, emerges the

necessity of considering the environment as an additional criterion at the time of

designing or building products and processes (Carvalho et al. 2012). Therefore, the

evaluation of the performance of products, processes or services depends less on

economic criteria and starts to include, progressively, environmental components.

Developed countries committed to reducing their greenhouse gas (GHG) emis-

sions through the Kyoto Protocol, at the end of the 1990s. This commitment is

mandatory only for developed countries, reflecting the international consensus that

industrialized countries must lead the process of mitigation of climate change (Baer

et al. 2000). Developed countries should not only reduce their emissions, but also

produce technology and means to help developing countries (Baer et al. 2000;

Ashton and Wang 2003). Developing countries insist that the solution for climate

change cannot be achieved at the expense of their development (Yale 2014).

According to Yale (2014), it is obvious that a reduction in emissions should also

be the goal of developing countries, but economic growth and decrease of poverty

are connected to the lack of access to energy services. Development seems to be

linked, therefore, to an unavoidable increase in the use of fossil fuels and conse-

quently, of GHG emissions. Apart from the multiple schemes for allocation of

emissions, the United Nations Framework Convention on Climate Change has

already recognized that the global nature of climate change requires the broadest

collaboration possible from all countries, and their united participation in an

6 Promotion of Sustainability by Quantifying and Reducing the Carbon Footprint. . . 63

adequate international response, following a common but differentiated responsi-

bility according to the capacity of each country (UNFCCC 2014).

There are also technical-operational arrangements, regulated by the Kyoto

Protocol, that can be utilized by companies or countries. These arrangements

offer different routes for the countries to achieve emission reduction limits and

goals. There are three “flexibilization” mechanisms (United Nations 2014): emis-

sion trading (countries that have reduced emissions even beyond the established

limit can transfer their reduction excess to another country that has not achieved its

limit); CDM, and joint implementation (GHG emission reduction projects in

countries that have set goals in the ambit of the Protocol). Only CDM is currently

applicable to Brazil. The regulation concerning CDM and carbon credits remains

underexplored in Brazil, but even without adequate regulation, in 2007 the first

auction sale of carbon credits took place in S~ao Paulo, corresponding to a volume of more than 800 thousand tonners of CO2-equivalent (CDM from a landfill project)

(Perera 2010).

Although GHG emissions are part of the development process of countries, the

increasing current environmental conscience demands that environmental impacts

are at least diminished (since they cannot be completely eliminated) in the search

for eco-efficiency (Carvalho and Freire 2014). During the 2009 United Nations

Climate Change Conference, Brazil voluntarily committed to reduce its GHG

emissions between 36.1% and 38.9% until 2020 (Marques et al. 2010). More

recently, in December 2014, during the Conference of the United Nations in

Peru, the text “The Lima call for Climate Action” (UNFCCC Newsroom 2014)

was announced. Countries can establish their own goals for the reduction of

emissions (Intended Nationally Determined Contributions), which, according to

Brasil (2014) represent the intended contribution of each country to the global effort

of mitigating climate change.

However these reduction efforts should not be limited to mitigation only,

including also efforts for adaptation, funding, technology transfer and training

(Brasil 2014). Although the word “intended” appears to indicate a non-binding

connotation, Brazil defends that the reduction targets should be juridically binding

(Brasil 2014). The Lima Call maintains the line that there is differentiated content

for developed and developing countries, according to the aforementioned principle

of common, but differentiated responsibilities.

Following the idea of sustainable development, consumers can already choose

which product to purchase based on the information shown on ecological tags or

labels. Ecological labels provide a measure of the environmental performance of

the product, informing the consumer about the environmental impacts. The con-

sumer is therefore enpowered, and this action reverberates in the market, as other

similar products will suffer pressure to adopt ecological labels; those that already

count with this label will also suffer pressure to minimize even more their impacts.

In a study carried out in France between 2004 and 2006, it was concluded that the

percentage of more selective consumers increased from 15% to 32% (Perera 2010).

64 M. Carvalho et al.

Still according to Perera (2010), more than 85% of French citizens believe they

play a crucial role in environmental matters, almost 90% prefer products and

brands that are environmentally correct, and 95% intended to research more on

the environmental impacts of consumer products. Ecological labels build on the

added value of environmental quality to the consumer (Csutora and Zs�oka 2012). The importance of providing environmental information to support more sustain-

able consumption has been repeatedly highlighted in policy reports and declarations

such as UN Agenda 21 United Nations, the EU Sustainable Consumption and

Production Action Plan and the UK Sustainable Development Report (Upham

et al. 2011).

The Blue Angel (Blaue Engel) was the pioneer in the labeling of products and

services, and was instituted in Germany in 1977 (Blaue Engel 2014). The European

Ecological Label was created in 1992, and has been raining awareness in companies

and consumers ever since (Spain 2014). In a parallel line of thinking, since 1993

Brazil counts with a seal from the National Program for the Conservation of

Electrical Energy, which is a simple way of informing the consumer on the

efficiency level and consumption of electricity of domestic appliances and equip-

ment (CBIEE 2006). This program was created by the Brazilian Government and

although limited, it is evident that Brazil attempts to follow the efforts of other

countries.

Entrepreneurship, which can be translated into the search for business opportu-

nities, might appear to be in the opposite direction of sustainability perspectives at

the long term—however, maybe because entrepreneurs present the unique ability to

combine, in an innovative manner, the individual viewpoint and the circumstances,

researchers already start to explore entrepreneurship as a potential mechanism for

sustainable development (Kosgaard and Anderson 2010). Despite the increasing

interest in this connection between sustainability and entrepreneurship, this rela-

tionship is still young but, according to York and Venkataraman (2010), entrepre-

neurs can contribute to the solution of environmental issues through the creation of

more sustainable products or services. From the moment a company or institution

manages to concentrate efforts to decrease consumption of energy or increase the

efficiency of a process, it provides some “relief” to the environment. The perception

of the consumer is positive, returning to the aforementioned environmental con-

science process. By giving preference to this product or service, the consumer

encourages the competition to decrease their own environmental impacts, closing

the cycle: less consumption of resources; less cost with resources; less environ-

mental impact. Gaining commitment and buy-in from the company is crucial. It is

also important to highlight the reductions achieved to promote the company as an

environmentally-friendly organization. This vision embraces the entrepreneur’s potential to supplement: (1) legislation; (2) social corporative responsibility; and

(3) activism in the solution of environmental issues (York and Venkataraman

2010).

6 Promotion of Sustainability by Quantifying and Reducing the Carbon Footprint. . . 65

The Quantify-Reduce-Promote (QRP) Proposal

The overarching intention of the proposal is to implement the concept of

eco-efficiency, which involves the extraction of the maximum potential of materials

and energy (efficient use), with the consequent minimization of environmental

loads and monetary costs (better use of resources means to use less and emit less,

with lower costs). International concern about climate change is beginning to

positively influence Brazilians, leading to evergrowing interest in the greenhouse

gas emissions involved in products, processes and services. The calculation of these

emissions is starting to become common in academic environments, however

actions directed to reduction and mitigation actions are still in an initial stage.

The reduction of environmental loads can only be confirmed after adequate

quantification, and in recent decades, different techniques for global environmental

assessment have been developed (e.g., ecological footprint, water footprint, carbon

footprint, Life Cycle Assessment—LCA, LEED-NH, to name a few). According to

Curran (1999), LCA is one of the most adequate tools to reach objectives directed

towards sustainability and is already an internationally accepted and recognized

tool, that evaluates the consequences of building and utilizing products and ser-

vices, through the identification and accounting of material used and disposal of

residues into the environment. However, sometimes due to limited resources and

data, companies carry out analysis based on simplified LCA approaches or apply

the general principals of Life Cycle Thinking (LCT) to specific aspects of the

productive system (De Benedetto and Klemeš 2009). LCT takes into consideration

all environmental and toxicological impacts associated with a product, process or

service, throughout its lifetime.

The first step in the proposal presented herein is to solidify LCT as a method-

ology applied not only to the quantification of environmental impacts of a product,

process or service, but also for the comparison of different alternatives, helping

decide on which option is better from an environmental viewpoint. In the light of

the above, the necessity of carrying out this project is justified, to pursue

eco-efficiency with support from the LCT/LCA methodology, which will help

decision makers make informed decisions from an environmental perspective, or

even find a commitment between economic and environmental perspectives. With

the information generated, it will be possible to establish internal environmental

policies that enable maximization of economic-financial results in equilibrium with

the preservation of the environment.

Along with the improvement of operational and economic results, there is a

concomitant improvement in the image of the company to society, created in

function of the reduction in the pollution/emissions generated. This type of public-

ity (promotion) is already utilized by large companies, especially those that have

titles being negotiated in the stock market. In Brazil, the Efficient Carbon Index

(ICO2) has sparked the interest of investors worried with environmental issues as

well as with revenue expectancy (BM&FBOVESPA 2011). The companies that

participate in this index are obligated to publish, in annual reports, the emission of

66 M. Carvalho et al.

GHG. However, small and medium sized enterprises do not present any interaction

with society, and therefore the existence of a great niche is confirmed for the

implementation of this project, especially in energy-intensive industries. In a

proactive and positive manner, good practices in environmental education will be

stimulated at the same time that environmental conscience is built in a responsible

way. Investments in green, positive marketing are important to increase market

share.

The traditional saying ‘what gets measured gets managed’ launches Phase 1, which starts with the QUANTIFICATION of environmental impacts through a

comprehensive, detailed environmental analysis. This analysis will allows for the

identification of the products, processes and services that are least aggressive to the

environment and will help quantify (and identify) critical aspects and even those

deserving special attention. This assessment can be extended to comprehend dif-

ferent products, processes or services. Another target for this Phase is the identifi-

cation of the configurations/options that are most adequate, through the

introduction of the environmental component as explicit decision element in syn-

thesis, design or operation stages.

Phase 2 of this project is the REDUCTION of environmental impacts, which

occurs after exhaustive analysis of the results of the QUANTIFICATION Phase.

This could lead to the formulation of an environmental strategy that could signal a

step change in environmental management for the studied company. Opportunities

for the REDUCTION of environmental loads can be identified, a priori, in energy

efficiency, introduction of renewable energy sources, and minimization of waste

(maximization of reuse and recycle). REDUCTION can be extended (but not

limited) to supplies and contracts (procurement), transport, construction and tem-

porary activities, and use of water. According to the Ministry for the Environment

of New Zealand (2015), these aspects are initially selected because they likely to

have the highest environmental impacts, are the most commonly addressed by other

major international organisms, and addressing them is consistent with international

government environmental policy priorities.

Phase 3 of this project is the PROMOTE, the dissemination of the results. The

dissemination, the advertising of the results is essential and therefore a specific

Phase of the project is dedicated to this activity, which includes analysis of results,

synthesis, conclusions, publicity and dissemination of results. The integration of the

previous results will provide a panoramic vision, much more complex and rich than

the simple addition of results: environmental evaluation, identification of opportu-

nities and innovative aspects to which R&D efforts must be directed, and recom-

mendations. Due to the high volume of information and data presented in Phases

1 and 2, a great effort of synthesis and creation will be necessary. Phase 3 will

influence consumers even when the cost of products is higher (in comparison with

competition or similar products). For example, Csutora and Zs�oka (2012) remark that hybrid cars are expensive (when the energy saved is accounted for, no cost

payback can be expected) but these vehicles still represent prestige or environmen-

tal value for some environmentally-conscious consumers and have achieved pre-

mium price position and small, but considerable market share.

6 Promotion of Sustainability by Quantifying and Reducing the Carbon Footprint. . . 67

The company involved in the project will be analyzed from different perspec-

tives, integrating, within an environmental focus, the productive sector with the

economic-financial management of the organization. A new focus will be therefore

created, generating wealth with an environmentally-responsible basis. Phase 1 is

not a simple activity, as it requires the mobilization of a significant amount of data

as well as a high consumption of time and computational effort. The product

(process, or service) must be described in detail, including inputs (material, energy)

and outputs (product, service, residues).

Special care is necessary to avoid any comparisons or relationships with green-

washing claims. Greenwashing is a type of deceptive marketing, used to provide the

image that a product is “green”. When combined with inexistent or ineffective

legislation, greenwashing could decrease the potential of the consumer to drive

companies in the direction of better solutions (Dahl 2010). The idea defended

herein is that good eco-labeling helps prevent greenwashing, and reduces consumer

skepticism.

Opportunities and Advantages

Some of the opportunities identified for the company that adopts the QRP proposal

are the development of a more strategic environmental approach, which will

position the company to better respond to customer needs, legislative requirements,

market changes and stakeholder expectations. Businesses and institutions aim at

respectability and need to build a good image, a good reputation and there are two

route to achieve these aspects: (1) lead the way, being the pioneer in building this

positive, environmentally-conscious image; or (2) be close to whom is a reference,

and follow their steps into achieving a good consumer perception.

Regarding the technological-social contribution of the project, it satisfies the

priorities of research, development and demonstration of new concepts and tech-

nologies to improve energy efficiency and reduce the final consumption of primary

energy. The minimization of environmental impacts is a benefit for all Brazilian

citizens. This project also presents a strong social bias, as the information on the

environmental loads embedded in a product, process or service provides decision

power to the consumer, who will be able to choose the least aggressive option,

forcing other manufacturers or suppliers to search for more “ecological” ways to

maintain competitiveness. The generation of economic-financial benefits represents

an extra advantage for the adoption of this project, enabling the company to recover

the investments made for its implementation. Already in 2006, Tachizawa predicted

that Brazilian consumers would start to give preference to products that were

environmentally responsible (Tachizawa 2006; Perera 2010). According to Tan

et al. (2014), voluntary carbon labeling schemes have been introduced in several

countries, with significant participation from companies that do not want to be seen

as lagging behind rivals in cornering the green market.

68 M. Carvalho et al.

There are also opportunities for carbon offsetting, where emissions can be

mitigated by investing in projects that avoid the production of emissions or remove

them from the atmosphere. According to the Ministry for the Environment of

New Zealand (2015), commitments to reduce emissions should always be accom-

panied by offsetting measures in order to be worthy of belief or confidence, as it is

more effective to avoid creating the emissions than elaborating strategies for

offsetting. Both emission reduction and offsetting can be integrated into an envi-

ronmental responsibility plan, and it is important to obtain the advice of experts. In

Brazil, during the 2014 Soccer World Cup, the Fédération Internationale de Foot-

ball Association (FIFA) announced a set of carbon offsetting projects in Brazil that

were selected to reduce the overall emissions of the tournament, which included

emissions from staff travel and accommodation, and extended to officials, teams,

volunteers and guests—four certified low-carbon development projects helped

achieve the goal (Fédération Internationale de Football Association 2014).

In recent years, the carbon market has progressively expanded and has become a

lucrative business for businesses. This market can also include stock market actions

and voluntary markets, where a business that reduces pollution generates compen-

sation credits and can sell them. In 2012, Brazil occupied the third position among

the countries that participated in the global carbon market, with approximately 5%

of the world total and 268 projects—however, initial estimates indicated that Brazil

would absorb 20% of the carbon credits (Brasil 2012). The CDM is a flexible tool

that allows the participation of developing countries (or countries with no reduction

commitments) in the carbon market, and has incentivized the creation of new

technologies for reduction of GHG gases in Brazil. There is a series of criteria for

recognizing carbon credit projects, such as alignment with the sustainable devel-

opment premises of the host country, defined by a Designated National Authority

(DNA)—in Brazil, this authority if the Interministerial Commission of Climate

Change, and only after approval of the Commission the project can be submitted to

the United Nations for evaluation and registry.

According to Perera (2010), paradoxically, the Brazilian clean energy matrix

could hinder CDM mechanisms in Brazil, but the country could become the largest

exporter of carbon credits—therefore it is important to be the first in this market to

reach leadership in the ability of recruiting international resources for sustainable

development.

Final Remarks

Encouraging consumers to make more informed choices requires access to envi-

ronmental performance information of products. The QRP project presented herein

has the ultimate goal of informing consumers about how the purchase of different

products within a substitutable range would have differing impacts on the environ-

ment. Since Brazilian consumers are starting to demand more data on how their

consumption patterns affect the environment, the adoption of the QRP proposal

6 Promotion of Sustainability by Quantifying and Reducing the Carbon Footprint. . . 69

helps businesses and institutions keep up with the competition through the provi-

sion of guidance to consumers on the impact of purchases on GHG emissions.

According to Tan et al. (2014), the implementation of carbon labeling is likely to

have positive effects on the environment.

Transfer of know-how from this project will increase the interest of Brazilian

industry and help the sector perceive the effect and importance of quantifying and

reducing the GHG emissions, with posterior transference (promotion) of results to

the general public as well as other sectors. Technology transfer can be achieved

through this proposal, and gaining commitment and buy-in from the company is

crucial. Highlighting the reductions achieved has a twofold goal: promote the

company as an environmentally-friendly organization and improve its reputation.

The QRP project explained herein brings opportunity, innovation and compet-

itive advantage to the companies and institutions that decide to be on-board. The

project will improve the image of the company, even if the initial commitment is

only to achieve reduction goals or profit.

Regional integration and articulation with other sectors can be achieved through

this project, which will provide specialized services and suggest better technologies

or processes, which can be available locally. Integration and articulation will be

promoted through the Life Cycle Thinking approach, propelling local and regional

economy, and positively influencing the region involved in the project.

The implementation of the activities contained in this project guarantees the

rational use of natural resources, decreases social and environmental impacts

deriving from their utilization and impels regional economy, resulting in the

increase of life quality standards and social standards for local communities.

Additionally, the QRP project contributes to sustainable development and improve-

ment of environmental quality.

Acknowledgments The authors wish to acknowledge the support of the Institute for the Devel- opment of Paraı́ba (IDEP-PB) and of the National Council for Scientific and Technological

Development (CNPq), through project n� 475879/2013-9.

References

Ashton, J., & Wang, X. (2003). Equity and climate: In principle and practice. In Beyond Kyoto: Advancing the international effort against climate change. Pew Center on Global Climate Change working papers series.

Baer, P., Harte, J., Haya, B., Herzog, A. V., Holdren, J., Hultman, N. E., et al. (2000). Climate

change: equity and greenhouse gas responsibility. Science, 289(5488), 2287–2291. Blaue Engel. The blue angel. Retrieved December 10, 2014, from https://www.blauer-engel.de/

sites/default/files/pages/downloads/our-label-environment/be-8-seitiger-eng-web.pdf.

BM&FBOVESPA. (2011). See how sustainability can guide investments (in Portuguese). Retrieved January 18, 2015, from http://www.bmfbovespa.com.br/pt-br/noticias/2011/Veja-

como-a-sustentabilidade-pode-nortear-os-investimentos-2011-09-22.aspx?tipoNoti-

cia¼1&idioma¼pt-br.

70 M. Carvalho et al.

https://www.blauer-engel.de/sites/default/files/pages/downloads/our-label-environment/be-8-seitiger-eng-web.pdf

Brasil—Ministry of Environment. (2012). Understand how the carbon credit market operates (in Portuguese). Retrieved January 15, 2015, from http://www.brasil.gov.br/meio-ambiente/

2012/04/entenda-como-funciona-o-mercado-de-credito-de-carbono.

Brasil—Ministry of International Affairs. Process for the preparation of the contribution of Brazil to the new agreement under UNFCCC (in Portuguese). Retrieved December 30, 2014, from http://diplomaciapublica.itamaraty.gov.br/consultaclima.

Buoro, D., Casisi, M., De Nardi, A., Pinamonti, P., & Reini, M. (2013). Multicriteria optimization

of a distributed energy supply system for an industrial area. Energy, 58, 128–137. Carvalho, M., & Freire, R. S. (2014). Quantificar, reduzir, evidenciar: uma nova prática para

empresas sustentáveis. In: ENCONTRO INTERNACIONAL SOBRE GEST ~AO EMPRESARIAL E MEIO AMBIENTE, 16, 2014, S~ao Paulo. Anais. . . S~ao Paulo: FEA-USP (in Portuguese).

Carvalho, M., Lozano, M. A., & Serra, L. M. (2012). Multicriteria synthesis of trigeneration

systems considering economic and environmental aspects. Applied Energy, 91, 245–254. Carvalho, M., Serra, L. M., & Lozano, M. A. (2011a). Geographic evaluation of trigeneration

systems in the tertiary sector. Effect of climatic and electricity supply conditions. Energy, 36 (4), 1931–1939.

Carvalho, M., Serra, L. M., & Lozano, M. A. (2011b). Optimal synthesis of trigeneration systems

subject to environmental constraints. Energy, 36(6), 3779–3790. CBIEE—Brazilian Center for Information on Energy Efficiency. The PROCEL seal

(in Portuguese). Retrieved December 17, 2014, from http://www.procelinfo.com.br/main.

asp?TeamID¼{88A19AD9-04C6-43FC-BA2E-99B27EF54632}. Csutora, M., & Zs�oka, A. (2012). Effective choice of consumer-oriented environmental policy

tools for reducing GHG emissions, greenhouse gases—Capturing, utilization and reduction. Croatia: Intech.

Curran, M. (1999). The status of LCA in the USA. International Journal of Life Cycle Analysis, 4 (3), 123–124.

Dahl, R. (2010). Green washing: Do you know what you’re buying? Environmental Health Perspectives, 118(6), A246–A252.

De Benedetto, L., & Klemeš, K. (2009). The environmental performance strategy map: An

integrated LCA approach to support the strategic decision-making process. Journal of Cleaner Production, 17, 990–996.

EIONET—European Topic Centre on Sustainable Consumption and Production. (2003). Life- cycle assessment and life-cycle thinking in resource and waste management. Retrieved January 18, 2015, from http://scp.eionet.europa.eu/themes/lca.

Fédération Internationale de Football Association—FIFA. (2014). FIFA to offset all its opera- tional carbon emissions through certified projects in Brazil. Retrieved January 15, 2015, from http://www.fifa.com/worldcup/news/y¼2014/m¼6/news¼fifa-to-offset-all-its-operational-car bon-emissions-through-certified--2379123.html.

Kosgaard, S., & Anderson, A. R. (2010). Sustainability and entrepreneurial action. In 33rd annual ISBE conference. London: ISBE.

Lima, A. M. F., Kiperstock, A., & Caldeira-Pires, A. (2006). Evaluation of life cycle in the

Brazilian academic environment. In I Simp�osio Nordestino de Saneamento Ambiental—ABES, Seç~ao Paraı́ba. Jo~ao Pessoa (in Portuguese).

Marques, F. R., Magellan, G., & Parente, V. (2010). The Brazilian carbon market and the absence of a regulatory framework (in Portuguese). Business School S~ao Paulo, July/2010. Retrieved January 16, 2015, from http://www.revistabsp.com.br/edicao-julho-2010/o-mercado-

brasileiro-de-carbono-e-a-ausencia-de-um-marco-regulatorio/.

Ministry for the Environment of New Zealand. (2015). Major event greening guide: A practical guide to reducing the environmental impact of a major event—Section two: Greening focus areas. Retrieved January 11, 2015, from http://mfe.govt.nz/publications/sus-dev/major-event- greening-guide/page2.html.

Perera, L. C. J. (2010). Investing in clean development mechanism (CDM) projects in Brazil.

Journal of Operations and Supply Chain Management, 3(1), 1–14.

6 Promotion of Sustainability by Quantifying and Reducing the Carbon Footprint. . . 71

http://mfe.govt.nz/publications/sus-dev/major-event-greening-guide/page2.html

http://www.revistabsp.com.br/edicao-julho-2010/o-mercado-brasileiro-de-carbono-e-a-ausencia-de-um-marco-regulatorio/

http://www.fifa.com/worldcup/news/y=2014/m=6/news=fifa-to-offset-all-its-operational-carbon-emissions-through-certified--2379123.html

http://www.procelinfo.com.br/main.asp?TeamID=%7B88A19AD9-04C6-43FC-BA2E-99B27EF54632%7D

http://diplomaciapublica.itamaraty.gov.br/consultaclima

http://www.brasil.gov.br/meio-ambiente/2012/04/entenda-como-funciona-o-mercado-de-credito-de-carbono

Pirrong, C. (2011). Commodity price dynamics: A structural approach. Cambridge: Cambridge University Press.

Ribeiro, M. A. J. (2011). Application of life cycle assessment to the search for eco-efficiency in the

manufacturing of sliced bread. MSc dissertation. Centro Federal de Educaç~ao Tecnol�ogica Celso Suckow da Fonseca, CEFET/RJ (in Portuguese).

Silva, J. C. A. (2010). Life cycle analysis. In: Theory and practice in sustainable construction in Brazil . Rio de Janeiro: Environment State Secretary of Rio de Janeiro (in Portuguese). Retrieved January 18, 2015, from http://download.rj.gov.br/documentos/10112/1312245/

DLFE-56323.pdf/01_SECAOI_1_INTRODUcaO_docfinal_rev.pdf.

Spain—Ministry of Agriculture, Food and Environment. What is the European ecological label? (in Spanish). Retrieved December 17, 2014, from http://www.magrama.gob.es/es/calidad-y-

evaluacion-ambiental/temas/etiqueta-ecologica-de-la-union-europea/etiqueta-ecologica-

europea/que_es.asp.

Tan, M. Q. B., Tan, R. B. H., & Khoo, H. H. (2014). Prospects of carbon labelling: A life cycle

point of view. Journal of Cleaner Production, 72, 76–88. Tachizawa, T. (2006). Gest~ao ambiental e responsabilidade social corporativa [Environmental

management and corporative social responsibility] (4th ed.). Atlas: S~ao Paulo [In Portuguese]. UNFCCC Newsroom—United Nations Framework Convention on Climate Change Newsroom.

Decision -/CP.20 Lima call for climate action. https://unfccc.int/files/meetings/lima_dec_ 2014/application/pdf/auv_cop20_lima_call_for_climate_action.pdf.

UNFCCC—United Nations Framework Convention on Climate Change. Full text of the Conven- tion. Retrieved December 5, 2014, from http://unfccc.int/essential_background/convention/ background/items/1349.php.

United Nations. (2014). The mechanisms under the Kyoto protocol: Emissions trading, the clean development mechanism and joint implementation. Retrieved January 16, 2015, from http:// unfccc.int/kyoto_protocol/mechanisms/items/1673.php.

Upham, P., Dendler, L., & Bleda, M. (2011). Carbon labelling of grocery products: Public

perceptions and potential emissions reductions. Journal of Cleaner Production, 19, 348–355. WBCSD—World Business Council for Sustainable Development. (2010). Eco-efficiency learning

module (231p). Yale—The Forum on Religion and Ecology at Yale. (2014). Ethical considerations in reducing

global greenhouse gas emissions. Retrieved December 5, 2014, from http://fore.research.yale. edu/climate-change/ethics/ethical-considerations-in-reducing-global-greenhouse-gas-

emissions.

York, J. G., & Venkataraman, S. (2010). The entrepreneur–environment nexus: Uncertainty,

innovation, and allocation. Journal of Business Venturing, 25(5), 449–463.

72 M. Carvalho et al.

http://unfccc.int/kyoto_protocol/mechanisms/items/1673.php

http://unfccc.int/essential_background/convention/background/items/1349.php

https://unfccc.int/files/meetings/lima_dec_2014/application/pdf/auv_cop20_lima_call_for_climate_action.pdf

http://www.magrama.gob.es/es/calidad-y-evaluacion-ambiental/temas/etiqueta-ecologica-de-la-union-europea/etiqueta-ecologica-europea/que_es.asp

http://download.rj.gov.br/documentos/10112/1312245/DLFE-56323.pdf/01_SECAOI_1_INTRODUcaO_docfinal_rev.pdf

Part II

Global Warming and Climate Change: General Issues and Challenges

Climate Change Mitigation Measures and Prospects

Chapter 7

Group Comparison, Trends and Cluster Analysis to Understand Historical Precipitation

Raphael Abrah~ao

Introduction

In recent years, much research has been carried out regarding climate change and its

consequences. The current concentrations of greenhouse gases are already a con-

cern and several scientists predict that the average temperature of the planet can

increase between 1.8 and 4.0 �C until the end of this century, which may cause dramatic environmental impacts (IPCC 2007; Malhi et al. 2009; Davidson

et al. 2012). According to the IPCC (2014), warming of the climate system is

unequivocal, and since the 1950s, many of the observed changes are unprecedented

over decades to millennia.

This scenario of increasing temperatures is only one facet of climate change.

Shifting in precipitation patterns (frequency and intensity) is another important

change that needs to be deeper understood. Such changes in climate may impact

ecosystems, trigger plagues and epidemics, threaten urban infrastructure, water and

energy supply, as well as agriculture, especially in regions where shortage of water

is already an issue (Knapp et al. 2002; Disch et al. 2012; Davidson et al. 2012;

Durack et al. 2012; IPCC 2014).

Understanding the nature and extent of these impacts is crucial for the determi-

nation of adaptation policies towards avoiding or diminishing the negative impacts

of climate change, as well as taking advantage of the positive impacts. However, to

understand the potential impacts and plan adequately, we first need to understand

how climate is changing.

R. Abrah~ao (*) Department of Renewable Energy Engineering (DEER), Center of Alternative and Renewable

Energy (CEAR), Federal University of Paraı́ba (UFPB), Caixa Postal 5115, Cidade

Universitária, Jo~ao Pessoa 58051-970, PB, Brazil e-mail: [email protected]

mailto:[email protected]

Climate models are useful tools to project climate change scenarios. Although

nowadays they are very comprehensive and can take into consideration several

parameters and relationships, there is still a high level of uncertainty in the studies

using these projections, especially for precipitation (Von Storch et al. 1993;

Grillakis et al. 2011; Zhang et al. 2011).

In addition, in many parts of the world, relatively long historical climate datasets

are available and little (and in many cases, none) use of this information is made

towards a better understanding of climate change impacts. The high costs associ-

ated with installation and maintenance of these monitoring stations throughout

decades could be better spent and deeper information about the dynamics of

regional and local climate change could be obtained from the datasets.

A number of studies used historical data, confirming that climate change is not

something that will happen in the future but is a current reality (Magnuson

et al. 1997; Vincent and Gullett 1999; Alexander et al. 2006; Wang and Ding

2006). These studies are good examples of how deeper information about climate

change can be obtained from real historical data. Furthermore, confidence in the

projections from climate models is higher for temperature than for other climate

elements such as precipitation; confidence is also higher at global and continental

scales than for regional and local scales (AMS 2012).

Thus, can historical data provide sufficient information about climate change in

order to understand the potential impacts and develop adaptation strategies? And,

more importantly, are the methodologies effective to provide this information? The

objective of this paper is to assess the use of cluster analysis, together with other

more traditional methodologies such as group comparison and trend analysis, to

expand knowledge about climate change on local and regional scales from histor-

ical data of precipitation.

Methodology

The methodology was based on three different approaches: (1) a general assessment

of annual totals with comparison of past and recent periods, (2) trend analysis, and

(3) the application of cluster analysis to analyse monthly and seasonal changes. The

intention was not compare these approaches, but evidence the importance of using

different approaches, instead of a single one, to assess climate changes that will

affect the water cycle and others factors regionally.

Monthly rainfall and snowfall data were obtained from the Sudbury airport

station (Canada), from January 1956 to December 2010 (55 complete years).

Data was obtained from Environment Canada (Canadian National Climate Data

and Information Archive, www.climate.weatheroffice.gc.ca) and it was subjected to

a process of quality control before becoming available. The city of Sudbury is part

of the province of Ontario and is located at 46�290N and 81�000W. The climate of the area is classified as humid continental (Dfb according to the K€oppen-Geiger classification).

78 R. Abrah~ao

http://www.climate.weatheroffice.gc.ca/

The 20 first years (1956–1975) and 20 last years of the dataset (1991–2010) were

selected for evaluation of annual changes. Since the annual data presented normal

distribution, the t-test was applied to compare both periods. The t-test performed a

comparison of means to determine whether the means of the two periods where

significantly different. A probability of less than a 5% error (p< 0.05) was considered.

The Mann-Kendall test was used for trend analysis. A non-parametric test was

selected because the monthly and seasonal data did not present normal distribution

(Mann 1945; Kendall 1975). The trend estimation was performed applying the

Sen’s slope calculation (Sen 1968) and error probabilities between 0.1% and 10% were used.

Cluster analysis was carried out to analyze changes in the distribution of rainfall

and snowfall throughout the year. The purpose was to place the objects (month-year

combinations) into groups (or clusters) suggested by the data, not defined a priori.

Thus, data was organized monthly, and each month was considered as a different

variable, thereby obtaining data from 660 month-year combinations (12 months in

55 years). Years with similar precipitation distribution were placed into the same

cluster. The cluster analysis was performed by standardizing the variables and using

the Euclidean square distance as similarity measure (Hair et al. 1998). Due to its

simplicity and computational efficiency, the Ward method was used to obtain

hierarchical clustering (Hair et al. 1998).

In hierarchical cluster techniques, the objects are progressively aggregated until

they form a single cluster. Each object begins in a cluster itself and then the closest

clusters are merged to form a new cluster that replaces the two previous clusters.

Merging of the two closest clusters is repeated until only one cluster is left (Ramos

2001; Munoz-Dı́az and Rodrigo 2004). In some studies, similar results were

obtained by applying cluster techniques and principal component analysis

(Munoz-Dı́az and Rodrigo 2004; Yin et al. 2011).

The “median year” of the objects (month-year combinations) was used as an

indicator to compare recent and past periods. All statistical procedures were carried

out with Statgraphics 15 and Makesens 1.0 softwares.

Results and Discussion

Changes in Annual Rainfall and Snowfall

The dataset suggests that annual rainfall is increasing in the Sudbury site. Even with

the expected variability of rainfall between years, an increasing trend during recent

years could be observed (Fig. 7.1). Significant statistical differences (p< 0.05) were observed when comparing the 1956–1975 period versus the 1991–2010 period,

with average values of 608 and 680 mm/year respectively, which represents a 12%

increase in rainfall.

7 Group Comparison, Trends and Cluster Analysis to Understand Historical. . . 79

Regarding snowfall, the trend was not that clear. Although a slight increase in

snowfall could be observed (Fig. 7.2), there was no statistically significant differ-

ence between the means of the two periods (p< 0.05).

Changes in Monthly and Seasonal Distribution of Rainfall and Snowfall—Trend Analysis

Trend analysis also detected the annual changes presented in the previous section.

A significant increasing trend in rainfall (p< 0.10) was quantified by the Sen’s slope through a rate of 1.74 mm/year and no significant trend was detected for

annual snowfall (Table 7.1).

Fig. 7.1 Annual rainfall

Fig. 7.2 Snowfall in the Sudbury site during the 1956–2010 period

80 R. Abrah~ao

The trend analysis could be considered more comprehensive for evaluation of

annual changes than the t-test group comparison, because all years of the dataset are

included in the analysis and not only the 20 first and 20 last years. However, the

expected variability of precipitation could hinder the detection of trends, which was

not the case for the Sudbury site during the 1956–2010 period.

Changes in the distribution of precipitation throughout the year were also noted

during the studied period. It means that the annual increasing trends observed for

rainfall volumes were not uniform over the year. March and May presented

significant (p< 0.10) positive trends with Sen’s slopes of 0.28 and 0.58 mm/year respectively. October presented a more significant (p< 0.05) positive trend and a Sen’s slope of 0.49 mm/year. The remaining months did not present significant trends.

Seasonally, significant increasing trends were observed in winter (p< 0.10) and spring (p< 0.05) through Sen’s slopes of 0.32 and 1.04 mm/year respectively. The Mann-Kendall test did not detect significant trends in rainfall during summer and

fall. Regarding snowfall, no significant trends were detected for any month or

season.

Table 7.1 Rainfall and snowfall trends detected by

the Mann-Kendall test and

quantified by the Sen’s slope for the Sudbury site during the

1956–2010 period

Period

Rainfall

(mm/year)

Snowfall

(cm/year)

January 0.05 ns 0.20 ns

February – 0.17 ns

March 0.28a �0.07 ns April 0.22 ns 0.07 ns

May 0.58a –

June �0.13 ns – July 0.13 ns –

August 0.36 ns –

September �0.18 ns – October 0.49b –

November 0.15 ns �0.10 ns December 0.07 ns 0.17 ns

Winter 0.32a 0.67 ns

Spring 1.04b 0.06 ns

Summer 0.08 ns –

Fall 0.35 ns �0.15 ns Annual 1.74a 0.60 ns

ns non significant ap< 0.10 bp< 0.05 cp< 0.01 dp< 0.001

7 Group Comparison, Trends and Cluster Analysis to Understand Historical. . . 81

Changes in Monthly and Seasonal Distribution of Rainfall and Snowfall—Cluster Analysis

For the monthly rainfall data from the Sudbury site, the cluster analysis applied

separated the 55 years into three clusters (Table 7.2). Cluster 1 consisted of years

1956, 1959, 1960, 1961, 1962, 1964, 1970, 1972, 1976, 1978, 1987, 1992, 1997 and

2010. Cluster 2 consisted of years 1957, 1958, 1963, 1965, 1966, 1967, 1968, 1969,

1971, 1973, 1974, 1975, 1977, 1979, 1981, 1982, 1984, 1985, 1986, 1989, 1990,

1991, 1994, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007 and 2009.

Finally, cluster 3 included years 1980, 1983, 1988, 1993, 1995, 1996 and 2008.

Each cluster included similar years regarding precipitation distribution over the

year. It is important to note that the median year in Table 7.2 does not necessarily

have to be included in the years within the cluster, since it is just an indicator for

comparison between clusters representative of past and recent periods.

As the interannual variability of rainfall is often high, there were past and recent

years within the three clusters. However, cluster 1 presented a greater concentration

of earlier years (median year¼ 1971), while cluster 2 (median year¼ 1985) and cluster 3 (median year¼ 1993) gradually corresponded to more recent years.

The separation into three clusters highlighted the temporal increase in annual

rainfall, with cluster 1 adding up to 611 mm/year; cluster 2 to 656 mm/year and

cluster 3, representing the most recent years, adding up to 701 mm/year. These

results of increased rainfall over time had been indicated by the methods applied

previously, however, through cluster analysis, changes in the seasonal distribution

of rainfall could also be observed, with little interference from the interannual

variability of the data. Thereby, the most interesting result from the cluster analysis

was the observation of changes in the distribution of rainfall throughout the year.

Increases were observed in most months, but at different scales (Table 7.2).

Decreases were observed during the months of June, July and September despite

the annual increases. Since these months belong to the rainy period of the site

(May–October), the shift may have consequences on local water and agricultural

management.

Observing these changes through the seasons, it is easier to verify the gradual

influence of climate changes on the annual variability of rainfall (Fig. 7.3). Changes

were very important during winter and spring, with increases of 309% and 65%

respectively, when comparing clusters 1 and 3. During the fall, increases were not

very important (6%), while in summer, which is the most important rainy season in

Sudbury, the 15% reduction represented a decrease of 41 mm in rainfall.

For snowfall, cluster analysis separated the 55 years into two clusters. Cluster

1 comprised years 1956, 1957, 1958, 1959, 1960, 1961, 1963, 1964, 1966, 1968,

1969, 1970, 1973, 1977, 1980, 1984, 1986, 1987, 1991, 1993, 1994, 1995, 1998,

2003, 2005, 2007 and 2010, and cluster 2 consisted of years 1962, 1965, 1967,

1971, 1972, 1974, 1975, 1976, 1978, 1979, 1981, 1982, 1983, 1985, 1988, 1989,

1990, 1992, 1996, 1997, 1999, 2000, 2001, 2002, 2004, 2006, 2008 and 2009. The

median years of the two clusters were close (1977 and 1987), implying in that the

82 R. Abrah~ao

T a b le

7 .2

T h re e cl u st er s d is cr im

in at ed

b y th e cl u st er

an al y si s b as ed

o n m o n th ly

ra in fa ll d at a in

S u d b u ry

si te

fr o m

1 9 5 6 to

2 0 1 0

C lu st er

M ed ia n

Y ea r

Ja n u ar y

(m m )

F eb ru ar y

(m m )

M ar ch

(m m )

A p ri l

(m m )

M ay

(m m )

Ju n e

(m m )

Ju ly

(m m )

A u g u st

(m m )

S ep te m b er

(m m )

O ct o b er

(m m )

N o v em

b er

(m m )

D ec em

b er

(m m )

S u m

(m m )

1 1 9 7 1

6 0

1 1

3 7

6 7

8 6

9 5

1 2 9

5 1

3 5

7 6 1 1

2 1 9 8 5

7 9

3 0

4 7

7 2

8 6

7 9

7 5

9 4

8 1

5 7

1 9

6 5 6

3 1 9 9 3

3 6

5 2 5

6 9

9 7

5 0

7 0

1 0 6

1 0 4

8 2

4 1

1 6

7 0 1

M ed ia n y ea r an d an n u al

su m

co rr es p o n d en t o f ea ch

cl u st er

ar e al so

p ro v id ed

7 Group Comparison, Trends and Cluster Analysis to Understand Historical. . . 83

trends of change in snowfall distribution over the year were not as clear as for

rainfall.

Nevertheless, changes in snowfall distribution could be observed for December,

January and February, the 3 months of higher snowfall values in Sudbury. Although

the annual sum of snowfall did not change significantly, more recent years

presented lower values in December (13%), and higher values in January (38%)

and especially in February (116%), when values more than doubled (Fig. 7.4).

The application of cluster and trend analysis evidenced that the increasing

annual trends for rainfall volumes in the Sudbury area were not uniform over the

year. This annual increase was mainly in winter and spring. Decreases in summer

rainfall were detected only through cluster analysis. According to cluster analysis,

although years are currently more humid, summers are becoming drier in the

location. Previous studies have detected and/or projected changes in rainfall in

Sudbury and nearby sites (Magnuson et al. 1997; OCCIAR 2010; IEESC 2012;

Charron 2014), however, the changes in seasonality were not considered in depth.

Regarding snow precipitation, while group comparison and trend analysis did

not indicate any significant trends, cluster analysis showed clear changes for the

months of greatest snowfall (December, January and February). Reductions in

December and increases in January and February were observed. This means that

the climate of the site is changing towards later winters regarding snowfall, which

may also be related to changes in other variables (e.g., temperature).

Although it was not the focus of this study, changes in extreme events should

also be investigated. According to Folland et al. (2002), in regions where annual

rainfall has increased it is very likely that there have been even more pronounced

increases in heavy and extreme rainfall events. And the converse is also true.

Fig. 7.3 Trends of changes in rainfall distribution throughout the seasons in the Sudbury site from 1956 to 2010, represented by the three clusters discriminated by cluster analysis

84 R. Abrah~ao

In some regions, heavy and extreme precipitation events have increased, despite the

fact that total precipitation has decreased or remained constant.

Conclusions

The methodologies used in this study demonstrated that the detection of annual

changes is only the initial step in a more comprehensive understanding of climate

change, which also includes complex seasonal and monthly changes. In many areas

of the world, the absence of detected changes or significant trends from annual data

may give a false idea of the absence of climate change in the location (e.g., snowfall

in the site of this study). However, the results presented herein indicate that the

inclusion of simple methods, such as cluster analysis, can contribute to a better

understanding of seasonal and monthly climate changes.

Acknowledgement This work was supported by the Ontario Centre for Climate Impacts and Adaptation Resources (OCCIAR) and Environment Canada.

Fig. 7.4 Trends of changes in snowfall distribution

throughout December,

January and February in the

Sudbury site from 1956 to

2010, represented by the

two clusters discriminated

by cluster analysis

7 Group Comparison, Trends and Cluster Analysis to Understand Historical. . . 85

References

Alexander, L. V., Zhang, X., Peterson, T. C., Caesar, J., Gleason, B., Klein, A. M. G., et al. (2006).

Global observed changes in daily climate extremes of temperature and precipitation. Journal of Geophysical Research: Atmospheres, 111, 1–22.

AMS, American Meteorological Society. (2012). Climate change: An information statement of the American Meteorological Society. Adopted by AMS Council in 20 August 2012, Boston.

Charron, I. (2014). A guidebook on climate scenarios: Using climate information to guide adaptation research and decisions. Montreal: Ouranos.

Davidson, E. A., de Araújo, A. C., Artaxo, P., Balch, J. K., Brown, I. F., Bustamante, M. C.,

et al. (2012). The Amazon basin in transition. Nature, 481(7381), 321–328. Disch, J., Kay, P., & Mortsch, L. (2012). A resiliency assessment of Ontario’s low-water response

mechanism: Implications for addressing management of low-water under potential future

climate change. Canadian Water Resources Journal, 37(2), 105–123. Durack, P. J., Wijffels, S. E., & Matear, R. J. (2012). Ocean salinities reveal strong global water

cycle intensification during 1950 to 2000. Science, 336(6080), 455–458. Folland, C. K., Karl, T. R., & Salinger, M. J. (2002). Observed climate variability and change.

Weather, 57(8), 269–278. Grillakis, M. G., Koutroulis, A. G., & Tsanis, I. K. (2011). Climate change impact on the

hydrology of Spencer Creek watershed in Southern Ontario, Canada. Journal of Hydrology, 409(1–2), 1–19.

Hair, J., Anderson, R., Tatham, R., & Black, W. (1998). Multivariate data analysis. Englewood Cliffs, NJ: Prentice-Hall.

IEESC, Institute for Energy, Environment and Sustainable Communities. (2012). Producing high- resolution (25 km� 25 km) probabilistic climate change projections over Ontario using UK PRECIS. Regina: University of Regina.

IPCC, Intergovernmental Panel on Climate Change. (2007). Climate change 2007: The physical science basis. Contribution of working group I to the fourth assessment report of the Inter- governmental Panel on Climate Change. Cambridge/New York: Cambridge University Press.

IPCC, Intergovernmental Panel on Climate Change. (2014). Summary for policymakers. In

Climate change 2014: Impacts, adaptation, and vulnerability. Cambridge/New York: Cam- bridge University Press.

Kendall, M. G. (1975). Rank correlation methods. London: Griffin. Knapp, A. K., Fay, P. A., Blair, J. M., Collins, S. L., Smith, M. D., Carlisle, J. D., et al. (2002).

Rainfall variability, carbon cycling, and plant species diversity in a mesic grassland. Science, 298(5601), 2202–2205.

Magnuson, J. J., Webster, K. E., Assel, R. A., Bowser, C. J., Dillon, P. J., Eaton, J. G., et al. (1997).

Potential effects of climate changes on aquatic systems: Laurentian Great lakes and Precam-

brian shield region. Hydrological Processes, 11(8), 825–871. Malhi, Y., Aragao, L. E., Galbraith, D., Huntingford, C., Fisher, R., Zelazowski, P., et al. (2009).

Exploring the likelihood and mechanism of a climate-change-induced dieback of the Amazon

rainforest. Proceedings of the National Academy of Sciences of the United States of America, 106(49), 20610–20615.

Mann, H. B. (1945). Nonparametric tests against trend. Econometrica, 13, 245–259. Munoz-Dı́az, D., & Rodrigo, F. S. (2004). Spatio-temporal patterns of seasonal rainfall in Spain

(1912–2000) using cluster and principal component analysis: Comparison. Annales Geophysicae, 22(5), 1435–1448.

OCCIAR, Ontario Centre for Climate Impacts and Adaptation Resources. (2010). Climate change and conservation authorities in northern Ontario. Workshop report. OCCIAR, Sudbury.

Ramos, M. C. (2001). Divisive and hierarchical clustering techniques to analyse variability of

rainfall distribution patterns in a Mediterranean region. Atmospheric Research, 57(2), 123–138.

86 R. Abrah~ao

Sen, P. K. (1968). Estimates of the regression coefficient based on Kendall’s tau. Journal of the American Statistical Association, 63, 1379–1389.

Vincent, L. A., & Gullett, D. W. (1999). Canadian historical and homogeneous temperature

datasets for climate change analyses. International Journal of Climatology, 19(1), 1375–1388. Von Storch, H., Zorita, E., & Cubasch, U. (1993). Downscaling of global climate change estimates

to regional scales: An application to Iberian rainfall in wintertime. Journal of Climate, 6, 1161–1171.

Wang, B., & Ding, Q. (2006). Changes in global monsoon precipitation over the past 56 years.

Geophysical Research Letters, 33, 1–4. Yin, H., Gao, Y., & Fan, C. (2011). Distribution, sources and ecological risk assessment of heavy

metals in surface sediments from Lake Taihu, China. Environmental Research Letters, 6(4), 1–11.

Zhang, H., Huang, G. H., Wang, D., & Zhang, X. (2011). Uncertainty assessment of climate

change impacts on the hydrology of small prairie wetlands. Journal of Hydrology, 396(1–2), 94–103.

7 Group Comparison, Trends and Cluster Analysis to Understand Historical. . . 87

Chapter 8

Ground Response to Global Warming

Mohamad Kharseh and Mohammed Al-Khawaja

Introduction

Over the period 1880–1985 the mean global temperature increased by 0.5–0.7 �C (Hansen and Lebedeff 1987), bearing in mind that the warming rate at high latitudes

of the northern hemisphere during recent past decades was greater (Lachenbruch

and Marshall 1986; Peterson et al. 2009). Certainly, the change in surface air

temperature (SAT) is more than the change of mean global temperature. A com-

parison of the averages anomalies of SAT between 1880–1890 and 2000–2010

shows that the SAT has increased 1.2 �C above the preindustrial level (NCDC and NOAA 2010). Figure 8.1 and the meteorological data presented by Hansen and

Lebedeff (1987) clearly show that the recorded meteorological data of air temper-

ature varies greatly over time, which might lead to a miscalculation of the warming

level (Lachenbruch and Marshall 1986). In other words, the warming that was

calculated above might be different if different periods were compared.

The analysis of borehole temperature depth profile (BTDP) has therefore

recently become an accepted method for inferring recent climatic changes, rather

than measuring the SAT (Deming 1995; Ferguson 2006; Goto 2010; Harris and

Chapman 1997). Although in some cases, e.g. in North America, it was shown that

warming estimated from the analysis of BTDP is consistent with warming esti-

mated from the analysis of meteorological data over the period 1880–1987 (Hansen

and Lebedeff 1987).

Measurements of BTDP evidently show that there are temperature deviations

from the linear steady-state ground temperature in the upper sections of boreholes

M. Kharseh (*) • M. Al-Khawaja Mechanical & Industrial Engineering Department, Qatar University,

Al Dafna, Jamaa Street, Doha, Qatar

e-mail: [email protected]; [email protected]

mailto:[email protected]

(Lachenbruch and Marshall 1986; Goto 2010; Harris and Chapman 1997; Guillou-

Frottier et al. 1998).

This deviation in temperature might be theoretically attributed to many different

sources (Harris and Chapman 1997):

• There is a disturbance in the energy balance at the Earth’s surface on a multi- decade scale. This disturbance might be interpreted by a continental-scale

change in the SAT, i.e. recent warming of the mean annual SAT (Deming

1995; Harris and Chapman 1997).

• Change in land use such as more buildings (Lachenbruch and Marshall 1986;

Ferguson 2006). Yoshikawa et al. attributed this temperature deviation to

increase in albedo and reduction of the leaf area involved in transpiration

following deforestation or wildfire (Yoshikawa et al. 2002). It was shown that

a recent change in vegetation cover and increased surface temperature over the

past century result in a similar shape of BTDP (Nitoiu and Beltrami 2005).

• Changes in thermal conductivity might lead to this temperature departure, that

is, “a systematic upward increase in conductivity might cause a systematic

upward decrease in gradient and simulate the transient warming” (Lachenbruch

and Marshall 1986; Deming 1995).

Thus, using the borehole temperature to analyze the warming is not always easy

(Deming 1995). However, in general, the departure of BTDP from the steady state

line is considered a direct consequence of a change in SAT (Lachenbruch and

Marshall 1986; Deming 1995). Moreover, the effects of other non-climatic sources

(e.g. change in land use, variability of thermal conductivity, groundwater move-

ment and so forth) have been shown to be negligible at the noise level of data

(Chisholm and Chapman 1992).

Fig. 8.1 Global mean surface air temperature anomalies (NCDC and NOAA 2010)

90 M. Kharseh and M. Al-Khawaja

It is important to mention that there are temperature measurements of boreholes

that show recent cooling trends at the surface which started in the 1970s

(Lachenbruch and Marshall 1986; Deming 1995).

However, measurements of borehole temperature generally show smooth

enough curves to permit us to approximate it to a mathematical formula

(Lachenbruch and Marshall 1986). The current study mainly aims to derive an

equation that expresses ground temperature deviation from the steady-state line as a

result of warming at ground surface. The derived equation was used to determine

the average change of ground temperature over a certain depth and therefore the

heat retained by a column of earth during the warming period. This average change

of ground temperature is of great importance in the borehole system.

Methodology

Dominating Equation

In order to obtain an equation that expresses the ground temperature change from its

linear steady-state profile, the heat conduction equation needs to be solved. For this

purpose the transient ground temperature θ(z,t) at depth z and time t is given as follows:

θ z; tð Þ ¼ Ts þ γ � zþ T z; tð Þ ð8:1Þ

where Ts is the air temperature at the surface level; γ is the temperature gradient due to geothermal heat flux; z is the depth below the ground surface; t is the time

elapsed since the warming started; and T(z,t) is ground temperature deviation from

the steady-state profile, i.e. the response of the ground to recent warming of the

mean annual surface temperature.

It is worth mentioning that in current study and for the sake of simplicity some

assumptions were made as follows. It is well established that urban areas can be

3–6 �C warmer than their surrounding rural areas (Kolokotroni 2009; EPA 2013- 01-15) . Certainly, such local temperature changes affect the ground temperature.

However, due to the insulating effect of the ground itself (i.e., low thermal

conductivity and big heat capacity), it was shown that the effect of change in land

use will only extend 50 m beyond the affected area at the surface (Ferguson 2006).

In the shallow subsurface, the transfer of heat can have an advection component

owing to the transfer of water between the different compartments, but this com-

ponent might be compensated by phase changes (evaporation). In addition the

thermal diffusivity of the ground is assumed to be constant and evaluated at the

average over value (Guillou-Frottier et al. 1998; Chisholm and Chapman 1992).

In nutshell, the effect of lateral heat flow and the advection component of heat

transfer are neglected and one dimensional heat flow is considered. This

8 Ground Response to Global Warming 91

simplification of the analysis provides insight into time scales of ground tempera-

ture deviation. Thus, in the case with absence of any internal heat generation, the

governing equation is:

∂θ z; tð Þ ∂t

¼ α∂ 2θ z; tð Þ ∂z2

ð8:2Þ

Substitution Eq. (8.1) in Eq. (8.2) yields

∂T z; tð Þ ∂t

¼ α∂ 2 T z; tð Þ ∂z2

ð8:3Þ

This way, any factor that might affect thermal exchanges at the air-ground interface

was removed. Thus the subsequent analysis will lead to the best estimate of ground

temperature deviation (Harris and Chapman 1997).

Another important assumption is that the ground surface temperature has line-

arly changed over time τ (i.e. it was assumed that the warming began τ years ago), see Eq. (8.5) (Lachenbruch and Marshall 1986; Winterberg 1991). Indeed, assum-

ing nonlinear form of surface warming leads to a more complex solution.

Reference Depth

Because the ground has a relatively low thermal diffusivity, changes in temperature

at the Earth’s surface propagate slowly into the ground and diminish with depth. The reference depth (hereafter referred to as H) is defined as the depth beyond

which, for practical purposes, the effect of warming at surface becomes difficult to

observe. This depth depends on both the time elapsed since the start of warming at

the surface and thermal diffusivity of the ground. In the current study, Laplace

transformation technique was used to give an acceptable approximation to the

reference depth, see Eq. (8.4):

H ¼ π � ffiffiffiffiffiffiffiffiα � tp ð8:4Þ Note that the temperature change at the depth given by above equation is less than

2.6% of the surface temperature change. The measurements made by Lachenbruch

and Marshall (1986), Goto (2010), Harris and Chapman (1997), Williams and Gold

(1976) show no change in ground temperature beyond the depth given by Eq. (8.4).

It is good to mention that, Lachenbruch and Marshall defined this depth as the depth

beneath where the changes in the ground temperature becomes <5% of the surface temperature change. Consequently, the reference depth in their study is H¼ 2.07 √α.t. However, in this study Eq. (8.4) will be used, and it can be shown that it is more accurate. For alternative approximations it is recommended to consult Chap. 9

given by Özişik (1980).

92 M. Kharseh and M. Al-Khawaja

This way, the boundary conditions for Eq. (8.3):

T 0; tð Þ ¼ δ τ � t ¼ ε � t ð8:5Þ

T H; tð Þ ¼ 0 ð8:6Þ

While the initial condition is

T z; 0ð Þ ¼ 0 ð8:7Þ

where τ is the time during which the surface temperature increased by δ �C; ε¼ δ/τ is the warming rate; and H is the reference depth (Eq. 8.4).

Results

To obtain the equation that gives the change in ground temperature due to linear

increase of surface air temperature, Eq. (8.3) that is subject to the boundary

conditions and initial condition are given by Eqs. (8.5), (8.6) and (8.7), respectively.

Using Fourier’s theory technique for solving partial deferential equation, the temperature change in ground temperature is:

if z � π ffiffiffiffiffiffiffiffiα � tp then T z; tð Þ ¼ ε

2 � z

6π ffiffiffiffiffiffiffiffi α � tp �

π ffiffiffiffiffiffiffiffi α � tp � z 3

� � þ ε � t � 1� z

π ffiffiffiffiffiffiffiffi α � tp þ

X1 n¼1

e�n 2 � sin n � zffiffiffiffiffiffiffiffi

α � tp � � n3

0 BB@

1 CCA

if z > π ffiffiffiffiffiffiffiffi α � tp then

T z; tð Þ ¼ 0 ð8:8Þ

This equation represents the ground temperature deviation at depth z and time t

elapsed since the start of linear warming at the surface.

Figure 8.2 illustrates some of the partial sums (containing only a finite number of

terms) for T(z,t¼ τ), Eq. (8.8), where terms up to n¼ 4 were considered. The same ground thermal properties assumed by (Lachenbruch and Marshall 1986) were used

in the current example, i.e. thermal conductivity λ and thermal diffusivity α are 2.1 W/m K, and 1.10–6 m2/s, respectively. The ground surface temperature was

linearly increased to δ¼ 2.5 �C over time τ¼ 130 years. For other assumptions, the curve can be easily adjusted using Eq. (8.8).

To examine the accuracy of the derived equation, Eq. (21) given by (Winterberg

1991) and Eq. (10) given by (Lachenbruch and Marshall 1986) (for n¼ 2) were also illustrated in Fig. 8.2 using the same assumptions made above. As it is shown, the

8 Ground Response to Global Warming 93

suggested equation (i.e., Eq. 8.8 in the current study) is consistent with the solutions

proposed in other studies using other techniques.

Application of Derived Equation

The total heat absorption Q as a result of increased air temperature is about the same

for all forms of warming curve at the surface (linear, step, accelerating as the square

of time and so forth) (Lachenbruch and Marshall 1986). The knowledge of this heat

is of significant importance in analyzing global warming’s sources (Nordell 2003). The heat retained by a column of earth surface due to increasing the air can now be

Fig. 8.2 Comparison between our suggested equation and equations derived by Lachenbruch and Marshall (1986) and Winterberg (1991) of the response of the ground to recent warming of the

mean annual surface temperature of 2.5 �C started in 1880. The following assumptions were made: Ground thermal conductivity λ¼ 2.1 W/m K, thermal diffusivity α¼ 1.10–6 m2/s and warming rate of ambient air ε¼ 0.0192 �C/year

94 M. Kharseh and M. Al-Khawaja

calculated by integrating the result of Eq. (8.8) and volumetric heat capacity of the

ground during the warming event (i.e., t)

Q tð Þ ¼ ðH 0

C � T z; tð Þdz ¼ K � C � ε � t � ffiffiffiffiffiffiffiffiα � tp ð8:9Þ where K is a constant (K¼ 0.74727) given by Eq. (8.10); C is volumetric heat capacity of the ground that is in the range of 2 MJ/m3 K.

K ¼ π 2 � π

24 þ 4 π

X1 n¼0

e� 2nþ1ð Þ 2

2nþ 1ð Þ4 � π

2 � π

24 þ 4 π � e ð8:10Þ

Thus, for the same warming rate and thermal properties assumed above, the total

heat absorption by 1 m2 of ground is 251 MJ/m2 (about 0.06 W/m2).

Calculating the mean change in ground temperature over a particular depth,

say L, (ΔTm(L,t)) is of great importance for ground source heat pump system design (Kharseh et al. 2011; Kharseh and Altorkmany 2012; Fontaine et al. 2011) .

This mean change ΔTm(L,t) is given by integrating Eq. (8.8) from zero to the concerned depth (L) and dividing the result by L as follows:

if L � π ffiffiffiffiffiffiffiffiα � tp ΔTm L; tð Þ ¼ ε

6α L2 � L

4π � ffiffiffiffiffiffiffiffiα � tp � π ffiffiffiffiffiffiffiffi α � tp � L

� � þ

þ ε � t � 1� L 2π � ffiffiffiffiffiffiffiffiα � tp � 4 �

ffiffiffiffiffiffiffiffi α � tp

π � L X1 n¼1

e�n 2 � sin 2 n � L

2 � ffiffiffiffiffiffiffiffiα � tp � � n4

0 BB@

1 CCA

if L > π ffiffiffiffiffiffiffiffi α � tp

ΔTm L; tð Þ ¼ ε � π � t � ffiffiffiffiffiffiffiffi α � tp

2L 1� π

12 þ 8 π2

X1 n¼0

e� 2nþ1ð Þ 2

2nþ 1ð Þ4 !

ð8:11Þ

Conclusions

The aim of this study was to find an equation relating ground temperature change

with global warming. To achieve this goal, a heat conduction equation was solved

using Fourier’s theory. The derived equation in the current study and the equations established in other studies are in excellent agreement. The suggested equation is

more user-friendly than other equations that are published in previous publications.

Because of its simplicity, the suggested equation was used to state the mean change

8 Ground Response to Global Warming 95

in ground temperature and the heat retained by a column of earth surface due to the

increasing surface air temperature. These equations are expected to be useful in

situations where the ground temperature is of importance; e.g. design of under-

ground thermal energy storage systems, ground source heat pump, studies of

microbiological systems in the ground, plant growth, frost heave, in addition to

the understanding of the effect of global warming. Although the study is based on

large uncertainties (a fact typical of this subject), the derived equation provides

insight into time scales of ground temperature anomalies.

Acknowledgements This work was made possible by an NPRP 7-725-2-270 a grant from the Qatar National Research Fund (a member of The Qatar Foundation). The statements made herein

are solely the responsibility of the authors.

Nomenclature

C Volumetric heat capacity (J/m3 k)

H Reference depth (m)

L A certain depth that is of interest to calculate the ΔTave (m) Q(t) Heat retained by a column of earth surface due to the climatic changes

(J/m2)

t Time elapsed since start-up warming (s)

T(z,t) Ground temperature anomaly (�C) Ts Air temperature at the surface level (

�C) z Depth below ground surface (m)

α¼ λ/C Thermal diffusivity (m2/s) γ Temperature gradient due to geothermal heat flux (�C/m) δ Temperature change at the ground surface (�C) ΔTm(L,t) Average change of ground temperature over a certain depth L (�C) ε Warming rate of air (assumed to be constant over time) (�C/s) θ(z,t) The transient ground temperature at depth z and time t λ Thermal conductivity (W/m K)

References

Chisholm, T. J., & Chapman, D. S. (1992). Climate change inferred from analysis of borehole

temperatures—An example from western Utah. Journal of Geophysical Research-Solid Earth, 97, 14155–14175.

Deming, D. (1995). Climatic warming in North America: Analysis of borehole temperatures.

Science, 268, 1576–1577. EPA. (2013). Retrieved January 15, 2013, from www.epa.gov/hiri/index.htm.

Ferguson, G. (2006). Transient lateral heat flow due to land-use changes. Earth and Planetary Science Letters, 242, 217–222.

Fontaine, P., Marcotte, D., Pasquier, P., & Thibodeau, D. (2011). Modeling of horizontal

geoexchange systems for building heating and permafrost stabilization. Geothermics, 40, 211–220.

96 M. Kharseh and M. Al-Khawaja

http://www.epa.gov/hiri/index.htm

Goto, S. (2010). Reconstruction of the 500-year ground surface temperature history of northern

Awaji Island, southwest Japan, using a layered thermal property model. Physics of the Earth and Planetary Interiors, 183, 435–446.

Guillou-Frottier, L., Mareschal, J., & Musset, J. (1998). Ground surface temperature history in

central Canada inferred from 10 selected borehole temperature profiles. Journal of Geophys- ical Research, 103, 7385–7397.

Hansen, J., & Lebedeff, S. (1987). Global trends of measured surface air-temperature. Journal of Geophysical Research: Atmospheres, 92, 13345–13372.

Harris, R. N., & Chapman, D. S. (1997). Borehole temperatures and a baseline for 20th-century

global warming estimates. Science, 275, 1618–1621. Kharseh, M., & Altorkmany, L. (2012). How global warming and building envelope will change

buildings energy use in central Europe. Applied Energy, 97, 999–1004. Kharseh, M., Altorkmany, L., & Nordell, B. (2011). Global warming’s impact on the performance

of GSHP. Renewable Energy, 36, 1485–1491. Kolokotroni, M. (2009). Heating and cooling degree day prediction within the London urban heat

island area. Building Services Engineering Research & Technology, 30, 183–202. Lachenbruch, A. H., & Marshall, B. V. (1986). Changing climate: Geothermal evidence from

permafrost in the Alaskan arctic. Science, 234, 689–696. NCDC and NOAA. (2010). Retrieved February 2013 from www.ncdc.noaa.gov/oa/climate/

research/anomalies/index.html.

Nitoiu, D., & Beltrami, H. (2005). Subsurface thermal effects of land use changes. Journal of Geophysical Research, 110, F01005.

Nordell, B. (2003). Thermal pollution causes global warming. Global and Planetary Change, 38, 305–312.

Özişik, M. N. (1980). Heat conduction. Wiley, New York, 0-471-05481-X.

Peterson, T. C., Baringer, M. O., Thorne, P. W., Menne, M. J., Kennedy, J. J., Christy, J.,

et al. (2009). Bulletin of the American Meteorological Society, 90, S13. Williams, G. P., & Gold, L. W. (1976). Canadian Building Digest.

Winterberg, F. (1991). Detection of global warming through spatial temperature-variations below

the earth surface. Kerntechnik, 56, 143–146. Yoshikawa, K., Bolton, W. R., Romanovsky, V. E., Fukuda, M., & Hinzman, L. D. (2002).

Impacts of wildfire on the permafrost in the boreal forests of Interior Alaska. Journal of Geophysical Research-Atmospheres, 108, FFR 4-1–FFR 4-14.

8 Ground Response to Global Warming 97

http://www.ncdc.noaa.gov/oa/climate/research/anomalies/index.html

Chapter 9

Specific Case: Regional Estimates of Global Climate Change: A Dynamical Downscaling Approach to Southeast Europe

Rafaella-Eleni P. Sotiropoulou, Efthimios Tagaris, Andreas Sotiropoulos, Ioannis Spanos, Panagiotis Milonas, and Antonios Michaelakis

Introduction

Climate change is a major environmental problem that will affect future weather

and will modify the meteorological data, locally. General Circulation Models

(GCMs) estimate that the global mean surface temperature change for the near

future (i.e., for the period 2046–2065 relative to 1986–2005) will likely be in the

range of 0.4–2.6 �C while globally-averaged precipitation increases with global mean surface temperature at about 1–3% �C-1 are projected. However, the mini- mum and the maximum estimated changes cover a wide range of values for all

geographical regions (IPCC 2013). For example, under the RCP4.5 experiments,

annual temperatures for northern, central, and southern Europe are estimated to be

modified in the range of �0.5 �C to 3.8 �C, 0.4 �C to 3.2 �C and 0.7 �C to 3.1 �C, respectively, while annual precipitation rates are estimated to be modified in the

R.-E.P. Sotiropoulou (*) Department of Mechanical Engineering, University of Western Macedonia, 50100 Kozani,

Greece

Environmental Research Laboratory, NCSR Demokritos, 15310 Athens, Greece

e-mail: [email protected]

E. Tagaris

Environmental Research Laboratory, NCSR Demokritos, 15310 Athens, Greece

e-mail: [email protected]

A. Sotiropoulos • I. Spanos

Environmental Engineering Consultancy, Terra Nova Ltd., 11527 Athens, Greece

e-mail: [email protected]; [email protected]

P. Milonas • A. Michaelakis

Department of Entomology and Agricultural Zoology, Benaki Phytopathological Institute,

14561 Kifisia, Greece

e-mail: [email protected]; [email protected]

mailto:[email protected]

range of �5% to 17%, �6% to 9%, and �14% to 3%, respectively for the period 2046–2065 relative to 1986–2005. However, the outputs from the GCM are rela-

tively coarse for applications to regional scales. To increase their spatial resolution,

the coarse resolution data of the GCM are used as initial and boundary conditions

by a regional climate model (RCM) (dynamical downscaling). The purpose of

doing this is to add-up more detail from local topography, coastline and land

use/land cover to obtain high resolution data, with the greatest possible accuracy

for the area of interest.

During the last years there is an increasing interest related to the climate change

over Mediterranean as it is one of the most vulnerable regions of the globe given

that large climate shifts have been observed in the past (Luterbacher et al. 2006). As

a result, Mediterranean has been identified as one of the most prominent “Hot-

Spots” in future climate change projections (Giorgi 2006). It is located in a

transition zone between the arid climate of northern Africa and the wet climate of

central Europe and even a minor change in large scale climatic factors might

impose large impacts on the climatic conditions of different Mediterranean areas.

The objective of this study is to estimate the changes in temperature and

precipitation over southeast Europe in the near future at a very fine resolution

since the topography and the coastlines of the region suggest a fine scale spatial

variability of the climatic conditions (Gao and Giorgi 2008).

Methods

General Circulation Model

The NASA GISS GCM ModelE (Goddard Institute for Space Studies General

Circulation Model) (Schmidt et al. 2006) is used to simulate current and future

climate. The GISS model has been chosen for simulations since it is a state-of-

the-art and widely used global climate model. The version of the NASA GISS GCM

ModelE used here has horizontal resolution 2� � 2.5� latitude by longitude and 20 vertical layers (from surface to 0.1 hPa). The model accounts for both the

seasonal and diurnal solar cycles in its temperature calculations. It simulates the

emissions, transport, chemical transformation and deposition of several chemical

tracers. Sea surface temperatures (SST) are calculated using model-derived surface

energy fluxes and specified ocean heat transports. In the present study the IPCC-

A1B emissions scenario (IPCC 2000) is used. This scenario describes alternative

directions of technological change in the energy system suggesting balance across

all sources, where balanced is defined as not relying too heavily on one particular

energy source, on the assumption that similar improvement rates apply to all energy

supply and end-use technologies. The simulations cover the period from 1880 to

2061. The beginning of the simulations is chosen prior to significant anthropogenic

forcing and climate change, but sufficiently recent to contain observations that

100 R.-E.P. Sotiropoulou et al.

allow extensive evaluation of the model. The main perturbation to climate over the

historic period (up to 2008) is the change in atmospheric composition: primarily the

increasing concentration of greenhouse gases and aerosols. Greenhouse gas con-

centrations up to 2008 are prescribed using ice-core measurements (Schmidt

et al. 2011). For the period 2009–2061 the GHG levels are supplied from the

IPCC A1B emissions scenario (IPCC 2000).

Regional Climate Downscaling

The outputs from the GCM are relatively coarse (i.e., 2� � 2.5�) for applications to regional and local scales. The need for regional climate projections in a finer grid

size is assessed, here, using the Weather Research and Forecasting (WRF version

3.4.1) model to dynamically downscale GCM simulations. WRF is a next genera-

tion limited area, non hydrostatic, terrain following model designed to serve both

research and operational applications (http://www.wrf-model.org/index.php). The

domain covers the south—southeast Europe in 273� 161 horizontal grids of 9 km� 9 km, with 28 vertical layers (Fig. 9.1).

For the set of physics options we used the following modules: the WRF Single-

Moment 3-class scheme for microphysics, the Rapid radiative transfer model

(RRTM) for long-wave radiation, the Dudhia scheme for short-wave radiation,

the Monin-Obukhov with Carslon-Boland viscous sub-layer for surface layer

options, the five-layer thermal diffusion for land surface options, the Yonsei

University scheme for the planetary boundary layer and the Kain-Fritsch scheme

for the cumulus cloud option. Due to the time needed for the downscaling procedure

meteorological conditions are simulated for five current (i.e., 2008–2012) and five

future (i.e., 2058–2062) years.

151

136

121

106

1 46 91 136 181 226

Fig. 9.1 Modeling domain

9 Specific Case: Regional Estimates of Global Climate Change: A Dynamical. . . 101

http://www.wrf-model.org/index.php

Results and Discussion

The temperature trend suggests an overall increase in the future, as a result of the

reduction of the low temperatures and the increase of the high temperatures for all

seasons (Table 9.1). A reduction in the number of days for which the daily average

temperature is below 10 �C for both winter and spring is estimated, with a consequent increase in the number of days with daily average temperature above

10 �C. These changes suggest milder winters and warmer springs in the future. During summer and autumn, a reduction is estimated in the number of days for

which the daily average temperature is below 20 �C, leading to an increase in the number of days above 20 �C. The number of days with daily average temperature above 30 �C is estimated to be ten times higher in the future summers and eight times higher in the future springs. Daily average temperatures above 30 �C start to appear in the future autumns too. What is interesting to point out here is that, the

increase in the number of days characterized by high temperatures during future

springs and autumns suggests an extension of the future summer period beyond the

traditional summer months.

Analysis of the spatial distribution plots suggests that annual average tempera-

ture is estimated to be higher in the future all over the domain (Fig. 9.2), while

increases in the range of 1.0–1.5� cover the major part of it. A maximum increase of up to 2.0� is estimated in the eastern and southeastern parts of the domain, while a minimum increase in the range of 0.5–1.0� is estimated in the western and south- western parts of the domain, as well as in the eastern Mediterranean Sea. During

winter, an increase up to 1.5� is estimated in the Tyrrhenian Sea, most of Italy, central Mediterranean Sea, Adriatic Sea, Ionian Sea and the western part of the

Balkan Peninsula; a smaller increase of up to 1.0� is estimated in north Balkan Peninsula, north Italy and the Ligurian and Balearic Seas. Central Greece, the

Aegean Sea and the eastern Mediterranean face temperature increases in the

order of 0.5�. The maximum increase is simulated in the greater Venice area (i.e., up to 2.0�). During spring, an increase of up to 1.0� is estimated in the major part of the domain. A higher increase (i.e., up to 1.5�) is found over the east land of the domain, central Mediterranean, north Italy and at the central and north Greece

while a milder increase (i.e., up to 0.5�) is found locally over Mediterranean Sea. During summer, an increase of up to 2.0� is estimated in Balkan Peninsula, most of Italy, southeastern France and central Mediterranean Sea, while temperature

increases up to 2.5� are found over the east land of the domain. For the rest of the domain an increase of up to 1.5� is found. During autumn a gradual increase from 0.5 to 3� from the west to the east, respectively, is found. An increase of up to 2.5� is estimated in a major part of Greece and Bulgaria, while the rest part of the Balkan

Peninsula is estimated to be warmer more than 2.0�. Temperature change over Italy is found to cover a range between 0.5 to 2.0�.

Precipitation trend suggests an increase of the dry days (i.e., precipitation rate

less than 1 mm/day) and a decrease of the days with precipitation rate in the range

of 1–10 mm/day for future winter, spring and autumn (Table 9.2) over the domain.

102 R.-E.P. Sotiropoulou et al.

T a b le

9 .1

N u m b er

o f d ay s p er

te m p er at u re

ra n g e o f th e d ai ly

av er ag e te m p er at u re

fo r cu rr en t an d fu tu re

se as o n s (%

)

W in te r

S p ri n g

S u m m er

A u tu m n

C u rr en t

F u tu re

C u rr en t

F u tu re

C u rr en t

F u tu re

C u rr en t

F u tu re

T em

p er at u re

ra n g es

N u m b er

o f d ay s (%

)

T < 0

� C 1 8 .4 2 7

1 5 .6 7

4 .1 6 9

2 .9 0 9

0 .0 3 8

0 .0 1 4

5 .7 2 1

1 .8 7 4

0 � C

< T < 1 0

� C 3 9 .0 1 9

3 8 .2 1 6

2 7 .0 1 1

2 4 .5 1 2

1 .8 2 0

1 .2 8 9

2 3 .8 4 7

2 3 .7 1 5

1 0

� C < T < 2 0

� C 4 2 .5 4 7

4 5 .9 8 4

6 6 .9 9 7

6 8 .5 6 7

3 6 .3 7 2

2 3 .4 4 8

4 6 .5 9 0

4 4 .9 5 8

2 0

� C < T < 3 0

� C 0 .0 0 7

0 .1 3 0

1 .8 1 7

3 .9 6 6

6 1 .7 3 2

7 4 .8 1 8

2 3 .8 4 2

2 9 .4 3 1

T > 3 0

� C 0 .0 0 0

0 .0 0 0

0 .0 0 6

0 .0 4 6

0 .0 3 9

0 .4 3 1

0 .0 0 0

0 .0 2 2

9 Specific Case: Regional Estimates of Global Climate Change: A Dynamical. . . 103

The changes are much higher during winter compared to spring and autumn. More

days with precipitation rates in the range of 10–200 mm/day are estimated for future

winters and less for future springs. Fewer days with precipitation rates in the range

of 10 mm/day up to 100 mm/day are estimated for future autumns, while a small

increase is found for precipitation rates in the range of 100–200 mm/day. Future

summer is estimated to be slightly wetter than the present; however around 90% of

the days are dry. Extreme precipitation rates (i.e., greater than 200 mm/day) are

more frequent during all future seasons; especially for future winter and spring, a

doubling in the number of days characterised by extreme rates is fund.

Analysis of the spatial distribution plots, suggests that precipitation change is

very location dependent, presenting a mixed trend. Given that, the fine resolution

151 136 121 106 91 76 61 46 31 16 1

1 46

Winter Spring

Summer Autumn

Annual

91 136 181 226 1 46 91 136 181 226

1 46 91 136 181 226

3.0

2.5

2.0

1.5K

1.0

0.5

0.0

1 46 91 136 181 226

151 136 121 106 91 76 61 46 31 16 1

Fig. 9.2 Seasonal and annual temperature change between future and current years

104 R.-E.P. Sotiropoulou et al.

T a b le

9 .2

N u m b er

o f d ay s p er

p re ci p it at io n ra n g e o f th e d ai ly

av er ag e p re ci p it at io n fo r cu rr en t an d fu tu re

se as o n s (%

)

W in te r

S p ri n g

S u m m er

A u tu m n

C u rr en t

F u tu re

C u rr en t

F u tu re

C u rr en t

F u tu re

C u rr en t

F u tu re

P re ci p it at io n ra n g es

N u m b er

o f d ay s (%

)

R < 1 m m /d ay

7 2 .2 3 9

7 4 .0 0 9

8 3 .6 3 3

8 4 .2 3 3

8 9 .6 4 3

8 9 .0 6 1

7 7 .5 8 7

7 8 .4 7 8

1 m m /d ay

< R < 1 0 m m /d ay

2 1 .9 2 4

2 0 .0 4 0

1 2 .7 5 7

1 2 .2 6 7

6 .9 0 4

7 .2 0 0

1 6 .0 6 0

1 5 .3 9 9

1 0 m m /d ay

< R < 1 0 0 m m /d ay

5 .7 7 1

5 .8 5 8

3 .5 2 1

3 .4 0 6

3 .1 5 5

3 .3 6 1

6 .0 2 9

5 .7 8 8

1 0 0 m m /d ay

< R < 2 0 0 m m /d ay

0 .0 6 1

0 .0 8 3

0 .0 7 5

0 .0 6 9

0 .2 2 9

0 .2 9 0

0 .2 6 4

0 .2 6 6

R > 2 0 0 m m /d ay

0 .0 0 5

0 .0 1 1

0 .0 1 4

0 .0 2 5

0 .0 6 9

0 .0 8 8

0 .0 6 0

0 .0 7 0

9 Specific Case: Regional Estimates of Global Climate Change: A Dynamical. . . 105

grid size used in our analysis (i.e., 9 km) provides a detailed insight of the localised

precipitation changes (e.g., over islands) happening in the future (Fig. 9.3).

Annual precipitation is estimated to be lower up to 40% in the major part of the

southeast land (i.e., Balkan Peninsula and Turkey) and the west part of the domain,

while an increase of up to 60% is found over central Mediterranean, northern Italy

and the central European countries belonging to the domain. A higher increase is

simulated at the south of the domain. Seasonally, various changes take place.

During winter a decrease of more than 20% is estimated over the land at the

southeast and the north parts of the domain. A decrease is also found over the

Balkan Peninsula, except for central Greece. Precipitation is estimated to increase

over most of Italy. High precipitation increase (i.e., more than 100%) is found over

northern Italy and Sicily. Precipitation increase is dominant over sea also (i.e.,

central Mediterranean and Aegean Sea), however, a decrease is found at the east

and the west Mediterranean regions of the domain. During spring, an increase at the

154 137 120 103

86 69 52 35 18

1 46 91 136 181 226 1 46 91 136 181 226

1 46 91 136 181 226

154

137

120

103

154

137

120

103

154 137 120 103

86 69 52 35 18

154

137

120

103

120.0 100.0

80.0 60.0 40.0%

20.0 0.0

-20.0 -40.0 -60.0

Winter Spring

Summer Autumn

Annual

Fig. 9.3 Seasonal and annual precipitation change between future and current years

106 R.-E.P. Sotiropoulou et al.

northern and a decrease at the southern parts of the land of the domain dominate.

The major parts of Italy and Greece are found to face less precipitation (up to 60%)

in the future, with some local exceptions. Reduction is also found above sea except

for parts of the central Mediterranean and the Aegean Sea. During summer, higher

precipitation rates (i.e., more than 100%) are found mainly at northern Italy,

Tyrrhenian Sea, Adriatic Sea, western Greece and at the south—southeast borders

of the domain, while lower precipitation rates up to 60% are found over sea,

locally. During autumn, a decrease is found for the west part of the Mediterranean

Sea and an increase for the southern and southeast regions of the domain. An

increase is also dominant for the central European countries of our domain.

Precipitation is projected to be lower in the future over south and north Italy in

contrast to the central part of the country. A decrease of up to 60% is found over

Greece, except for the southwest part of the country.

A direct comparison of our results with the results of other researchers (e.g.,

Christensen et al., 2012; Dubrovsky et al., 2014; Garcı́a-Ruiz et al., 2011; Gao and

Giorgi, 2008) focusing in the area of our interest is not possible due to the different

spatiotemporal scales and emissions projection used. However, the following

conclusions can be extracted: All the models point to a warmer future. Domain’s temperature is projected to increase for all seasons. All models project a homoge-

nous increase which depends on the season. There is less agreement among the

models about future precipitation change with differences in regions for increasing,

decreasing, or similar-to-current precipitation rates. The general trend is a reduction

at the south—southeast part of the domain which turns to an increase at the north

with a transition zone between them. Due to the largest grid size used in the other

studies, precipitation presents a more homogenous change compared to our results,

where seasonal trends are available in a very fine scale providing detailed infor-

mation for the continental regions and the islands.

Conclusions

Future temperature is estimated to be higher over southeast Europe. The increase

depends on both the season and the location, with higher increases during spring

and autumn at the south and southeast of the domain. More days with high

temperatures and fewer days with low temperatures are estimated in the future,

suggesting an extended future warmer period. Precipitation change is very location

dependent, presenting a mixed trend for all seasons. A large part of the land at the

southeast is estimated to have less annual precipitation in the future, however,

seasonal analysis suggests a wetter summer and an increase in the extreme precip-

itation rates during all future seasons.

Acknowledgement This work was supported by the EU co-funded LIFE-CONOPS project through grand agreement LIFE12 ENV/GR/000466.

9 Specific Case: Regional Estimates of Global Climate Change: A Dynamical. . . 107

References

Christensen, O. B., Goodess, C. M., & Ciscar, J.-C. (2012). Methodological framework of the

PESETA project on the impacts of climate change in Europe. Climatic Change, 112, 7–28. Dubrovsky, M., Hayes, M., Duce, P., Trnka, M., Svoboda, M., & Zara, P. (2014). Multi-GCM

projections of future drought and climate variability indicators for the Mediterranean region.

Regional Environmental Change, 14, 1907–1919. Gao, X., & Giorgi, F. (2008). Increased aridity in the Mediterranean region under greenhouse gas

forcing estimated from high resolution simulations with a regional climate model. Global and Planetary Change, 62, 195–209.

Garcı́a-Ruiz, J. M., L�opez-Moreno, J. I., Vicente-Serrano, S. M., Lasanta–Martı́nez, T., & Beguerı́a, S. (2011). Mediterranean water resources in a global change scenario. Earth-Science Reviews, 105, 121–139.

Giorgi, F. (2006). Climate change hot-spots. Geophysical Research Letters, 33, L08707. Intergovernmental Panel on Climate Change (IPCC). (2000). In N. Nakicenovic, & R. Swart

(Eds.), Emissions scenarios. Cambridge: Cambridge University Press. Intergovernmental Panel on Climate Change (IPCC). 2013. In T. F. Stocker, D. Qin, G.-K.

Plattner, M. Tignor, S. K. Allen, J. Boschung, et al. (Eds.), Climate change 2013: The physical science basis. Contribution of working group I to the fifth assessment report of the intergov- ernmental panel on climate change. Cambridge/New York, NY: Cambridge University Press.

Luterbacher, J., Xoplaki, E., Casty, C., Wanner, H., Pauling, A., Küttel, M., and 43 co-authors,

2006. Mediterranean climate variability over the last centuries: a review. Edited by Lionello, P., Malanotte-Rizzoli, P., Boscolo, R., The Mediterannean Climate: An overview of the main

characteristics and issues, Amsterdam, Elsevier, pp. 27–148

Schmidt, G. A., Jungclaus, J. H., Ammann, C. M., Bard, E., Braconnot, P., Crowley, T. J.,

et al. (2011). Climate forcing reconstructions for use in PMIP simulations of the last millen-

nium (v1.0). Geoscientific Model Development, 4, 33–45. Schmidt, G. A., Ruedy, R., Hansen, J. E., Aleinov, I., Bell, N., Bauer, M., et al. (2006). Present day

atmospheric simulations using GISS ModelE: Comparison to in-situ, satellite and reanalysis

data. Journal of Climate, 19, 153–192.

108 R.-E.P. Sotiropoulou et al.

Part III

Global Warming and Climate Change: General Issues and Challenges

Climate Change Observatory

Worldwide climate change observations, specific cases

Chapter 10

Drought Conditions in Turkey Between 2004 and 2013 Via Drought Indices Derived from Remotely Sensed Data

Nazila Molavizadeh, Elif Sertel, and Hande Demirel

Introduction

Drought is one of the major hazards that has a significant adverse effect on the

socio-economy, agriculture, and ecosystem. According to the United Nations

Convention to Combat Desertification, drought is defined as “the naturally occur-

ring phenomenon that exists when precipitation has been significantly below

normal recorded levels, causing serious hydrological imbalances that adversely

affect land resource production systems” (UN 2014). Evaporation (affected by

temperature and wind), soil types and their ability to store water, the depth and

presence of ground water supplies and vegetation are among the most important

parameters that influences occurrence of drought. Each drought year is unique in its

climatic characteristics and impacts, because drought is related to the timing and

the effectiveness of the precipitation. Therefore, it is impossible to make a defini-

tion of drought that can be universally accepted (Li and Xiao 1992; Wilhite 1993).

Drought can be described by three characteristics: spatial coverage, duration and

N. Molavizadeh (*) Satellite Communication & Remote Sensing Program, Department of Advanced Technology,

Informatics Institute, Istanbul Technical University, Maslak, 34469 Istanbul, Turkey

e-mail: [email protected]

E. Sertel

Geomatics Engineering Department, Istanbul Technical University, Maslak, 34469 Istanbul,

Turkey

Center for Satellite Communications and Remote Sensing, Istanbul Technical University,

Ground Receiving Station, Maslak, 34469 Istanbul, Turkey

e-mail: [email protected]

H. Demirel

Geomatics Engineering Department, Istanbul Technical University, Maslak, 34469 Istanbul,

Turkey

e-mail: [email protected]

113

mailto:[email protected]

intensity (Wilhite and Glantz 1985). Briefly, according to (Heim 2002; Keyantash

and Dracup 2002), meteorological drought is a precipitation deficit, agricultural

drought is a total soil moisture deficit, hydrological drought is a shortage of stream

flow, and socioeconomic drought is associated with the shortage of any economic

goods affected by the drought process. The relationship between meteorological,

agricultural and hydrological drought is illustrated in Fig. 10.1 (NDMC 2014).

According to climate change scenarios such adverse impacts will gain speed in

the near future especially for certain locations of the world, including Turkey and

its neighborhood. Hence, monitoring its severity has a vital importance. This

requires understanding historical droughts in the region as well as impacts of

droughts during their occurrences. However, monitoring drought presents various

challenges such as inadequate data collection networks with respect to density of

stations, high cost of data and insufficient data sharing, difficulties in forecasting,

insufficiencies of drought indices for detecting the early beginning and end of the

drought, data integration problems such as soil parameters and socioeconomic

indicators, mitigation and response programs needs to be regional, therefore

regional assessments are required and data sharing and dissemination is limited

(WMO 2006). Several of these challenges could be eased by means of spatial

information technologies. Remote sensing based drought indices are becoming

more popular, since it is possible to determine spatio-temporal distribution of

Decreasing emphasis on the natural event (precipitation deficiencies)

Increasing emphasis on water/natural resource management Increasing complexity of impacts and conflicts

Meteorological Agricultural

Time/duration of the event

Hydrological

Socio-economic and political

Fig. 10.1 Interrelationships between meteorological, agricultural, hydrological and socioeco- nomic drought (NDMC 2014)

114 N. Molavizadeh et al.

droughts. Remote sensing satellites could monitor large areas rapidly, accurately,

periodically, economically and have been widely used to examine drought impacts.

In order to analyze the possibilities of remote sensing based drought indices,

three different indices namely Temperature Condition Index (TCI), Vegetation

Condition Index (VCI) and Vegetation Health Index (VHI) were generated to

determine drought conditions in Turkey for the last decade. MODIS-derived Nor-

malized Difference Vegetation Index (NDVI) and Land Surface Temperature

(LST) values were used to derive these indexes. NDVI values could be used to

identify healthy and unhealthy vegetation, where LST values derived from thermal

bands indicates the variations in temperature. Since, LST and NDVI are negatively

correlated; drought areas and periods could be investigated for the research area.

The paper is set out as follows: Section “Introduction”, introduces the problem and

the aim of the study. Section “Data and Methodology” covers case study area, the

data and methodology used. In Section “Results and Conclusion”, the achieved

results, problems encountered, major findings and conclusions from the study is

presented.

Data and Methodology

The development of remote sensing, spatial drought monitoring and assessment has

become possible in the last decades (Kanellou et al. 2008). Remote Sensing data

presents significant advantages and is the integral part of monitoring drought,

especially for the spatial and temporal evolution. A number of satellite drought-

monitoring indices are developed based on the Advanced Very High Resolution

Radiometer (AVHRR) of National Oceanic and Atmospheric Administration

(NOAA) polar-orbiting satellite series, MODIS (Moderate Resolution Imaging

Spectroradiometer) and others. Historically, the most commonly used remote

sensing tool for large-area drought monitoring has been the daily orbiting National

Oceanic and Atmospheric Administration (NOAA) Advanced Very High Resolu-

tion Radiometer (AVHRR), partially because there is now a sufficiently long time

series to let for the identification of anomalies to compare to “normal” conditions.

MODIS is superior to AVHRR because it provides higher spatial and spectral

resolutions, improved atmospheric corrections and more precise geolocation.

When compare the MODIS and AVHRR data sets such as NDVIAVHRR with

NDVIMODIS atmospherically corrected MODIS NDVI generally displays a higher

dynamic range than atmospherically corrected AVHRR NDVI. This is attributed to

the small bandwidth of MODIS (Huete et al. 2002; IWMI 2014). Within this study,

The Moderate-resolution Imaging Spectroradiometer (MODIS) data is used.

MODIS sensor was launched into Earth orbit by NASA in 1999 on board the

Terra (EOS AM) Satellite, and in 2002 on board the Aqua (EOS PM) satellite.

The MODIS has 36 spectral bands ranging in wavelength from 0.4 μm to 14.4 μm and at varying spatial resolutions (two bands at 250 m, five bands at 500 m and

29 bands at 1 km). Together the instruments image the entire Earth every 1–2 days.

10 Drought Conditions in Turkey Between 2004 and 2013 Via Drought Indices. . . 115

They are designed to supply measurements in large-scale global dynamics, includ-

ing changes in Earth’s cloud cover, radiation budget and processes occurring in the oceans, on land, and in the lower atmosphere. More information on MODIS data

could be obtained from NASA web-page (NASA 2014). Products of one of the well

known satellite system, MODIS, have been used for numerous research applica-

tions including mapping deforestation, identifying desertification and crop yield

estimation, natural and non-natural disasters—such as floods and droughts—in

many areas due to the its high temporal resolution and coverage. Terra MODIS

monthly composite NDVI images of 1 km resolution and Terra MODIS 8-day

composite LST of 1 km resolution were used in this research for the period

2004–2013.

The three remote sensing based drought indices, Vegetation Condition Index

(VCI), Temperature Condition Index (TCI) and Vegetation Health Index (VHI)

were generated and analyzed to determine drought conditions in Turkey for the last

decade.

Vegetation Condition Index (VCI): Kogan (1987) proposed a vegetation condi-

tion index based on the relative NDVI change with respect to minimum historical

NDVI value. VCI is pixel based normalization of NDVI values. The basic assump-

tion is that drought conditions will weaken the growth of vegetation resulting in

lower NDVI values in multiyear NDVI values (Du et al. 2013; Kogan 1995). VCI is

a good indicator of drought stress and its values scaled between 0 and 1. In case of

very dry month, vegetation conditions will be weakened and the value will close to

zero whereas a VCI value of 0.5 reflects fair vegetation conditions (Du et al. 2013).

It is defined as following:

VCI ¼ NDVI � NDVImin NDVImax � NDVImin ð10:1Þ

where NDVI, NDVImax, and NDVImin the smoothed monthly NDVI, multi-year

maximum NDVI and multi-year minimum NDVI, respectively, for each grid cell.

Temperature Condition Index (TCI): is a remote sensing based thermal stress

indicator that is used to quantify temperature component of droughts. There is a

higher LST in the drought year than the same month of normal years and this index

assumes that drought event will decrease soil moisture and cause land surface

thermal stress (Du et al. 2013; Kogan 1995). TCI is used to find out thermal stressed

regions by using the maximum/minimum temperature in a given time series. Since

drought is expected to decrease soil moisture and increase LST values, higher LST

values are signal for drought conditions and lower LST values indicates favorable

conditions, opposite to the NDVI (Du et al. 2013). Thus, the TCI formula was

modified as the following expression 10.2.

TCI ¼ LSTmax � LST LSTmax � LSTmin ð10:2Þ

116 N. Molavizadeh et al.

where LST, LSTmax and LSTmin are the values of LST, maximum LST and

minimum LST of each pixel respectively in the same month during the study period

of January 2004–December 2013. The is a good indicator to determine drought and

to find out its beginning time, intensity, duration and dynamics. The VCI could be

successfully used to define both prolonged and short-term droughts either global or

localized (Kogan 1995).

Vegetation Health Index (VHI): is calculated from an empirical formula by

giving equal weights to Vegetation Condition Index (VCI) and the Temperature

Condition Index (TCI) to reflect the impacts of both temperature and vegetation

components. The equation of VHI is below:

VHI ¼ 0:5 VCI þ TCIð Þ ð10:3Þ

The TCI indicates areas that are hotter than usual and the VCI’s normalized NDVI anomalies identify areas where vegetation is more or less dense than usual.

VHI reflects both vegetation cover and temperature anomalies and also it has been

widely applied for the early drought warning, monitoring of crop yield and pro-

duction, and assessment of irrigated areas and extreme wetness (Karnieli

et al. 2006) The classification of indices for drought conditions are presented in

Table 10.1 (Kogan 2001).

Results and Conclusion

Turkey is located in Anatolia and the Balkans, bordering the Black Sea, between

Bulgaria and Georgia, and bordering the Aegean Sea and the Mediterranean Sea,

between Greece and Syria. The total land area is about 783,562 km2, of which

756,816 km2 are in West Asia (Anatolia) and 23,764 km2 are in Southeastern

Europe (Thrace). Climatic conditions of Turkey vary significantly from one region

to another, due to topography and the geo-location of the country. While the coastal

regions have milder climates, extreme hot summers with limited rain fall and cold

winters are generally experienced at the inner Anatolian plateau (Sensoy

et al. 2008). The Aegean and Mediterranean coasts have cool, rainy winters and

hot, moderately dry summers. Annual precipitation in those areas varies from

580 to 1300 mm, depending on location. The Black Sea coast receives the greatest

amount of rainfall. The eastern part of that receives 2200 mm annually and is the

only region of Turkey that receives rainfall throughout the year. Climate types of

Turkey are presented in Fig. 10.2 (Atalay and Efe 2012).

In order to automate the process of generating indices and data handling, codes

were written in Interactive Data Language programming language and all indices

Table 10.1 Classification of VCI, TCI and VHI drought conditions (Kogan 2001)

VCI, TCI, VHI values * 100 <10 10–20 20–30 30–40 40–60 >60

Drought conditions Extreme Severe Moderate Mild Normal Wet

10 Drought Conditions in Turkey Between 2004 and 2013 Via Drought Indices. . . 117

were generated automatically. In the last 10 years, Turkey observes two drought

periods, the first one start from 2006. This drought period, is observed from

November and December of 2006 until December of 2008. This long period

between 2007 and 2008 clearly can be observed by analyzing the VCI and

VHI maps.

Drought is a slow occurring process starts with precipitation deficits, then

causing soil moisture deficits resulted in higher Land Surface Temperature (LST)

values. Finally, vegetation growth is affected because of water deficits and temper-

ature increases (Du et al. 2013). In this research LST and NDVI data were used to

monitor LST and NDVI anomalies during 10 year period using TCI and VCI

indexes. In order to represent both soil moisture deficit and vegetation growth,

VHI was calculated using TCI and VCI. VHI values between 40–60% represent

normal conditions whereas VHI values lower than 0.4 represents drought higher

than 0.6 represents wet climatic conditions.

TCI is based on LST values and could be used to identify regions that are hotter

or colder than usual values. For drought affected regions, higher temperature values

resulted in lower TCI values than normal conditions. TCI values lower than 30%

might give the signal of extreme, severe and/or moderate drought conditions. In

drought conditions, land surface will have thermal stress and TCI could be used to

determine temperature-related drought conditions (Du et al. 2013; Kogan 1995).

VCI is based on NDVI anomaly values and could be used to identify areas where

vegetation is more or less than usual values. In normal/usual conditions VCI pre-

sents same seasonal pattern and presents higher values in May-September period

and lower values in October-April period. Figure 10.3 shows an example of VCI for

2004 a normal year in terms of climatic conditions. As can be seen from the figure

VCI values are comparatively higher between May and September. Vegetation

response in the May–September period is related to the very wet period from

November–April (months where most of the geographic regions receive most of

Fig. 10.2 Climate types of Turkey (Atalay and Efe 2012)

118 N. Molavizadeh et al.

Fig. 10.3 VCI maps for the year 2004

10 Drought Conditions in Turkey Between 2004 and 2013 Via Drought Indices. . . 119

the precipitation). For drought occurring years such as 2007, VCI presents lower

values in May–September period as well unlike the normal conditions mentioned.

Turkey has different climatic regions as shown in Fig. 10.2. Black Sea Region

having coastal (humid-temperate) climate has vegetation throughout the year

resulting in higher VCI values as can be seen in Fig. 10.3. This region is highly

vegetated with mostly evergreen forests causing higher NDVI values. Considering

Turkey boundaries, during the winter months, most of the country has lower NDVI

values due to the fact that there are not planted agricultural areas and deciduous

plants.

Analysis of TCI, VCI and VHI maps illustrated that 2007, 2008 and 2013 were

drought impacted years in Turkey. In order to consider for temperature and vege-

tation growth, VHI maps were extensively analyzed. Figure 10.4 illustrates the

comparison of a normal (2004) and drought (2007) years. After comparing

12 months of each year, it was found that impact of drought is more detectable

between July and September. As can be seen from Fig. 10.4, during the drought

year 2007 most of the country has VHI values lower than 0.2 indicating the excess

or very excess drought conditions.

Fig. 10.4 Comparison of VHI maps between 2004–2007 for July, August and September

120 N. Molavizadeh et al.

Droughts can lead significant environmental, social, and economic conse-

quences by impacting agriculture, ecology and socio-economy. Therefore, it is

important to monitor droughts and their impacts in local, regional and global scales.

Meteorological data and drought indices derived from these data could be used to

monitor drought conditions however their spatial and temporal availability are

limited. To this end, remotely sensed data derived indices could be an important

asset to monitor drought conditions globally and timely.

References

Atalay, I., & Efe, R. (2012). Ecology of Scots pine (Pinus sylvestris var. sylvestris) forests and their dividing into regions in terms of seed transfer. Ministry of Environment and Forestry Publ. 45, Ankara. ISBN 975-605-4610-11-2.

Du, H. Y., Shen, Y. Z., & Huang, Z. J. (2013). Function of the wheat TaSIP gene in enhancing

drought and salt tolerance in transgenic Arabidopsis and rice. Plant Molecular Biology, 81, 417–429.

Heim, R. (2002). A review of twentieth-century drought indices used in the United States. Bulletin of the American Meteorological Society, 83, 1149–1165.

Huete, A., Didan, K., Miura, T., Rodriguez, E. P., Gao, X., & Ferreira, L. G. (2002). Overview of

the radiometric and biophysical performance of the MODIS vegetation indices. Remote Sensing of Environment, 83, 195–213.

IWMI. Retrieved February, 6, 2014, from http://www.iwmi.cgiar.org/.

Kanellou, E., Domenikiotis, C., Tsiros, E., & Dalezios, N. R. (2008). Satellite-based drought

estimation in Thessaly. European Water Publications, 23(24), 111–122. Karnieli, A., Bayasgalan, M., Bayarjargal, Y., Agam, N., Khudulmur, S., & Tucker, C. J. (2006).

Comments on the use of the Vegetation Health Index over Mongolia. International Journal of Remote Sensing, 27(10), 2017–2024.

Keyantash, J., & Dracup, J. (2002). The quantification of drought: An evaluation of drought

indices. Bulletin of the American Meteorological Society, 83, 1167–1180. Kogan, F. N. (1987). Vegetation index for areal analysis of crop conditions. In Proceedings of 18th

conference on agricultural and forest meteorology, September 15–18 (pp. 103–106). W. Lafayette, Indiana: AMS.

Kogan, F. N. (1995). Droughts of the late 1980s in the United States as derived from NOAA polar-

orbiting satellite data. Bulletin of the American Meteorological Society, 76(5), 655–668. Kogan, F. N. (2001). Operational space technology for global vegetation assessment. Bulletin of

the American Meteorological Society, 82(9), 1949–1964. Li, S.-X., & Xiao, L. (1992). Distribution and management of dryland in the People’s Republic of

China. Advances in Soil Science, 18, 148–278. NASA. Retrieved February 6, 2014, from http://modis.gsfc.nasa.gov/.

NDMC. Retrieved February 6, 2014, from http://drought.unl.edu/.

Sensoy, S., Demircan, M., Ulupınar, U., & Balta, İ. (2008). Türkiye İklimi, DMİ. http://www.dmi.

gov.tr/iklim/iklim.aspx.

UN. Retrieved February 6, 2014, from http://www.unccd.int/en/Pages/default.aspx.

Wilhite, D. A. (1993). Drought assessment, management, and planning: Theory and case study. Boston: Kluwer.

Wilhite, D. A., & Glantz, M. H. (1985). Understanding the drought phenomenon: The role of

definitions. Water International, 10, 111–120. World Meteorological Organization. (2006). Drought monitoring and early warning: Concepts,

progress and future challenges. WMO-No. 1006. ISBN 92-63-11006-9.

10 Drought Conditions in Turkey Between 2004 and 2013 Via Drought Indices. . . 121

http://www.unccd.int/en/Pages/default.aspx

http://www.dmi.gov.tr/iklim/iklim.aspx

http://drought.unl.edu/

http://modis.gsfc.nasa.gov/

http://www.iwmi.cgiar.org/

Chapter 11

Carbon Foot Print of a Passanger Aircraft Engine at Landing and Take-Off Cycle

Yasin Ş€ohret and T. Hikmet Karakoç

Introduction

In last decade, rapid civilization forces us to develop more eco-friendly systems

with respect to the environmental issues. Mankind population growth on the earth

and utilization of the sources callously leads to consider sustainable development.

On the other hand, environmental impact reduction is as important as sustainability

at the present time. Especially damage and impact of the energy industry on the

environment become more of an issue for the future of the mankind. In this case,

transportation industry, which is an ever-growing and consuming energy sources

more and more, should be evaluated in terms of environmental issues (Winter 2014;

Lee et al. 2009). Under consideration of the aviation transportation growth in

Turkey, environmental impact of the aircrafts plays a key role for understanding

slice of this industry within the contribution of Turkey to the global warming and

climate change. As mentioned in a previous study (Ekici et al. 2013), number of

aircrafts in aviation fleet enormously increases day by day.

Many researcher studied on exhaust emission related issues of the aviation with

concern of environmental issues. Beck et al. (1992) presented the impact of the

aircraft emissions on atmosphere’s tropospheric layer by a two-dimensional model. Authors especially focused on ozone formation as a result of aircraft exhaust

emissions in the paper. Role of the nitrogen oxides within the global warming

was highlighted by authors. In another text, international airports in Korea was

Y. Ş€ohret (*) Aircraft Technology Program, Keciborlu Vocational School,

Suleyman Demirel University, 32700 Isparta, Turkey

e-mail: [email protected]

T.H. Karakoç

Faculty of Aeronautics and Astronautics, Anadolu University, 26470 Eskisehir, Turkey

e-mail: [email protected]

123

mailto:[email protected]

handled and dependence among the air pollution and the greenhouse gases emitted

from commercial aircrafts was investigated. Fan et al. (2012) calculated fuel

consumption and aircraft emissions from domestic flights for China in 2010. As a

result of their study, an airline emitting excessive emissions is selected in China. Hu

et al. (2009) evaluated air pollutants near an airport depending on real-time

measurements. Aircraft engine exhaust emissions, exhaust gases emitted from

other vehicles in the airport were discussed in the paper. Yilmaz and Ilbas (2012),

presented the emission parameters of various aircraft engine in service. Conse-

quently, the necessity of alternative fuel utilization in aircraft engines is empha-

sized by the authors. Aircraft engine emissions over the course of landing and take-

off cycle are investigated by Ekici et al. (2013) for the busiest airports in Turkey. In

another study, it is aimed to develop a model for nitrogen oxide emissions of a

turbofan engine for determining environmental impact of aircraft engine emissions

on the basis of the operational and meteorological conditions. In another text

(Naugle and Fox 2014), contribution of the emitted gases from aircrafts to air

pollution was discussed. Also, aircraft emissions caused health issues were

highlighted by the authors. Exhaust emissions of an aircraft engine which is fed

with both an alternative fuel and kerosene were evaluated by Santoni et al. (2011).

Especially unburned hydrocarbon and nitrogen oxide emissions were given in

details by authors. It is reported that, unburned hydrocarbon concentrations in

engine exhaust were lower than ambient concentrations at higher thrust levels.

Mazaheri et al. (2011) evaluated exhaust emissions of large aircrafts at an airport.

Authors presented emission rates depending on aircrafts operating in the airport.

Additionally, particulate matter emissions were discussed in details by researchers.

Synylo and Duchêne (2014) modelled nitrogen oxide emissions of a turbofan

engine to evaluate the impact of operational and meteorological conditions on

nitrogen oxide formation. Additionally the environmental sustainability of the

engine was discussed in the paper.

In the present paper, a turbofan engine of a commercial aircraft in service is

investigated. Carbon footprint of the examined engine is intended to present with

the aid of ICAO aircraft engine emissions inventory. The main goal and differences

of the current paper from previous studies may be listed as follows:

• Introducing the correlation between emission index and carbon footprint.

• Revealing the carbon footprint of an aircraft engine for the first time.,

• Presenting a different perspective to understand environmental impact of the

aviation.

Turbofan Engine and Evaluation Methodology

In this study, a mixed turbofan type aircraft engine is evaluated. The engine which

is named as JT8D is operated on many aircraft such as Boeing 727 and 737 series,

McDonnell Douglas DC-9 and MD-80. The JT8D serves the industry by providing

124 Y. Ş€ohret and T.H. Karakoç

power to more than 2400 aircraft. The sectional view of the engine is shown in

Fig. 11.1 (Pratt & Whitney 2014). For evaluation of the engine, data is provided

from the ICAO aircraft engine emissions inventory (EASA 2014).

The ICAO aircraft engine emissions inventory (EASA 2014) contains emission

data for the ICAO landing and take-off flight envelope. A typical flight envelope is

demonstrated in Fig. 11.2. ICAO landing and take-off flight cycle is the part of this

envelope which is under the 3000 feet altitude. In the course of emission measure-

ment, engine was operated under the relevant flight settings. That is to say, engine

was operated at 100%, 85%, 30% loads for 0.7, 2.2, 4.0 min at take-off, climb-out

and approach flight phases respectively (ICAO 1993).

Carbon footprint is the total sets of greenhouse gas emissions caused by an

organization, event, product or person and a useful parameter to understand con-

tribution to the climate change. The calculation of the carbon footprint is performed

by finding carbon dioxide equivalent for 100-year time horizon of the greenhouse

gases emitted by an organization, event, product or person. In this framework,

carbon footprint of the examined turbofan engine can be found as following

(Schimel et al. 1996; Wright et al. 2011):

C ¼ X

CO2eð Þi ¼ X

EIimfGWP 100ð Þi ð11:1Þ

Here, C notates carbon footprint whereas CO2e, EI, mf, GWP(100) and i

represents carbon dioxide equivalent, emission index, fuel mass flow rate, global

warming potential for 100-year time horizon and ith greenhouse gas emitted from

the engine. Carbon dioxide equivalent of any gas means global warming potential

of the gas for 100-year time horizon. Emission index indicates emitted gas amount

per consumed fuel amount within the combustion chamber. In Table 11.1, global

warming potentials of emitted gases for 100-year time horizon are given.

Fig. 11.1 The sectional view of the JT8D engine (Pratt & Whitney 2014)

11 Carbon Foot Print of a Passanger Aircraft Engine at Landing and Take-Off Cycle 125

Results and Discussion

In this study, carbon footprint of emitted greenhouse gases from JT8D engine which

is still operated on many commercial passenger aircraft. During a typical landing

and take-off flight cycle, exhaust gas emissions of the engine are given in

Table 11.2.

Calculations based upon data given in Table 11.2, are performed with the aid of

Eq. (11.1). Herein, unburned hydrocarbon (UHC) emission was assumed to be

Fig. 11.2 A typical flight envelope for a commercial aircraft (adopted from ICAO 1993)

Table 11.1 Global warming potential values of greenhouse gases emitted from an aircraft engine for 100-year time horizon (Altuntas 2014; Schimel et al. 1996)

Greenhouse gas GWP(100)

CO2 1

CO 1

NOx 310

CH4 21

Table 11.2 Exhaust gas emissions of the JT8D engine

at landing and take-off flight

cycle (EASA 2014)

Flight phase EICO EINOx EIUHC

Take-off 0.74 19.20 0.69

Climb-out 1.00 15.23 0.79

Approach 8.54 6.10 1.96

Idle 31.00 3.30 0.00

Total 41.28 43.83 3.44

126 Y. Ş€ohret and T.H. Karakoç

methane (CH4). As a result of the study, obtained carbon footprint equivalent of

each emission gas was summarized in Table 11.3 on the basis of flight phases.

For better comprehension of the situation, Figs. 11.3 and 11.4 are plotted. As

indicated in Fig. 11.3, unburned hydrocarbon emission index of the engine is

approximately same at take-off and climb-out phases of flight. However, emitted

unburned hydrocarbon per consumed fuel increases at approach phase and dramat-

ically decreases at idle. Additionally, reverse proportion among carbon monoxide

and nitrogen oxide emission index is clarified in the graph. So, it can be asserted

that, while amount of emitted carbon monoxide per consumed fuel raises, nitrogen

oxide emission descents over through the landing and take-off flight cycle.

Figure 11.4 reveals the carbon footprint of the engine during landing and take-

off flight cycle in simple terms. Herein, carbon footprint values of carbon monoxide

and unburned hydrocarbon are approximate to zero in comparison with nitrogen

oxide emission. However, carbon footprint of emitted nitrogen oxide decreases

from 7410.24 g to 150.381 g. So, impact of nitrogen oxides emitted from aircraft

engines on global warming is clearly proven.

Table 11.3 Carbon footprint equivalents of emitted

greenhouse gases from JT8D

engine at landing and take-off

flight cycle

Flight phase C(CO) C(NOx) C(UHC)

Take-off 0.921 7410.240 18.040

Climb-out 0.997 4707.136 16.540

Approach 3.023 669.414 14.570

Idle 4.557 150.381 0

Total 9.498 12937.170 49.150

Fig. 11.3 Emission index variation of JT8D engine greenhouse gases with flight phases

11 Carbon Foot Print of a Passanger Aircraft Engine at Landing and Take-Off Cycle 127

Conclusions

As a result of the study, following statements are concluded by authors:

• With regard to emission measurement, emitted greenhouse gases from the

engine are concern. On the other, in terms of carbon footprint calculation carbon

monoxide and unburned hydrocarbons can be disregarded in future studies. But

it is not possible to assert for nitrogen oxide emission.

• Conducting similar study for various engine types can be beneficial as a com-

parison. So that, contribution of aircraft engine exhaust emissions to global

warming and carbon cycle can be revealed in details.

• If the flights all around the world are considered, obtained results can be more

meaningful. However, from this point of view, impact of aircraft transportation

on the environment may be more comprehensible.

In a future study, it is planned to cover that issue from perspective of aviation

fleet and comparison of different aircraft engine types.

Acknowledgements Authors gladly thank to Anadolu and Suleyman Demirel Universities of Turkey.

Fig. 11.4 Carbon footprint variation of JT8D engine greenhouse gases with flight phases

128 Y. Ş€ohret and T.H. Karakoç

Nomenclature

C Carbon footprint CO2e Carbon dioxide equivalent EI Emission index (g kg�1) GWP Global warming potential m Mass flow rate (kg s�1)

Subscripts

f Fuel i ith greenhouse gas emitted from the engine

References

Altuntas, O. (2014). Calculation of domestic flight-caused global warming potential from aircraft

emissions in Turkish airports. International Journal of Global Warming, 1, 367–379. Beck, J. P., Reeves, C. E., De Leeuw, F. A., & Penkett, S. A. (1992). The effect of aircraft

emissions on tropospheric ozone in the northern hemisphere. Atmospheric Environment. Part

A. General Topics, 26(1), 17–29. EASA. (2014). ICAO Aircraft engine emissions databank. Retrieved December 15, 2014, from

http://easa.europa.eu/document-library/icao-aircraft-engine-emissions-databank#1.

Ekici, S., Yalin, G., Altuntas, O., & Karakoc, T. H. (2013). Calculation of HC, CO and NOx from

civil aviation in Turkey in 2012. International Journal of Environment and Pollution, 53, 232–244.

Fan, W., Sun, Y., Zhu, T., &Wen, Y. (2012). Emissions of HC, CO, NOx, CO2, and SO2 from civil

aviation in China in 2010. Atmospheric Environment, 56, 52–57. Hu, S., Fruin, S., Kozawa, K., Mara, S., Winer, A., & Paulson, S. (2009). Aircraft emission impacts

in a neighborhood adjacent to a general aviation airport in southern California. Environmental Science & Technology, 43, 8039–8045.

ICAO. (1993). Annex 16. In Aircraft engine emissions (2nd ed.). Lee, D. S., Fahey, D. W., Forster, P. M., Newton, P. J., Wit, R. C. N., Lim, L. L., et al. (2009).

Aviation and global climate change in 21st century. Atmospheric Environment, 43, 3520–3537. Mazaheri, M., Johnson, G. R., & Morawska, L. (2011). An inventory of particle and gaseous

emissions from large aircraft thrust engine operations at an airport. Atmospheric Environment, 45, 3500–3507.

Naugle, D., & Fox, D. (2014). Aircraft and air pollution. Environmental Science and Technology, 15, 391–395.

Pratt & Whitney, JT8D engine. Retrieved December 15, 2014, from http://www.pw.utc.com/

JT8D_Engine.

Santoni, G., Lee, B., Wood, E., Herndon, S., Miake-Lye, R., Wofsy, S., et al. (2011). Aircraft

emissions of methane and nitrous oxide during the alternative aviation fuel experiment.

Environmental Science & Technology, 45, 7075–7082. Schimel, D., Alves, D., Enting, I., Heimann, M., Joos, F., Raynaud, D., et al. (1996). Radiative

forcing of climate change. In J. T. Houghton, L. G. M. Filho, B. A. Callander, N. Harris,

A. Kattenbergan, & K. Maskell (Eds.), Climate change 1995: The science of climate change. Cambridge, England: Intergovernmental Panel on Climate Change.

11 Carbon Foot Print of a Passanger Aircraft Engine at Landing and Take-Off Cycle 129

http://www.pw.utc.com/JT8D_Engine

http://easa.europa.eu/document-library/icao-aircraft-engine-emissions-databank#1

Synylo, K., & Duchêne, N. (2014). NOx emission model of turbofan engine. International Journal of Sustainable Aviation, 1, 72–84.

Winter, R. A. (2014). Innovation and the dynamics of global warming. Journal of Environmental Economics and Management, 68, 124–140.

Wright, L. A., Kemp, S., & Williams, I. (2011). ‘Carbon footprinting’: towards a universally accepted definition. Carbon Management, 2, 61–72.

Yilmaz, I., & Ilbas, M. (2012). Investigation of pollutant emissions in aircraft gas turbine engines.

Journal of the Faculty of Engineering and Architecture of Gazi University, 27, 343–351.

130 Y. Ş€ohret and T.H. Karakoç

Chapter 12

Greenhouse Gas Emissions Trends from Waste in Greece

L. Kallinikos, I. Sebos, A. Progiou, P. Eleni, I. Katsavou, K. Mangouta,

and I. Ziomas

Introduction

United Nations Framework Convention on Climate Change (henceforth the Con-

vention) was adopted on 9May 1992 and was opened for signature in Rio de Janeiro

in June 1992 in response to the emerging evidence that climate change could have a

major global impact. Greece signed the Convention in Rio and ratified it in 1994.

The Conference of the Parties (COP) in 2007, by its decision 1/CP.13 (the Bali

Action Plan) launched a comprehensive process to enable the full, effective and

sustained implementation of the Convention through long-term cooperative action,

now, up to and beyond 2012, to be conducted under a subsidiary body of the

Convention, the Ad Hoc Working Group on Long-term Cooperative Action under

the Convention (AWG-LCA).

The Protocol entered into force on 16 February 2005, after its ratification from

141 Parties (with the exception of USA and Australia) including developed coun-

tries with a contribution of more than 55% to global CO2 emissions in 1990.

With respect to the EU target under the Kyoto Protocol (i.e. reduction of

emissions by 8% for the period 2008–2012), EU has stated that this will be

achieved jointly by EU Member-States under the provisions of Article 4 of the

Protocol. The Burden-Sharing agreement between all Member States was finalized

during the Environment Council in June 1998 and entered into force with Decision

2002/358/EC concerning the approval, on behalf of the European Community, of

the Kyoto Protocol. According to this agreement, Greece is committed to limit its

L. Kallinikos • I. Sebos (*) • A. Progiou • P. Eleni • I. Katsavou • K. Mangouta • I. Ziomas Department of Chemical Engineering, National Technical University of Athens, Zografou

Campus, 9 Heroon Polytechniou Street, 15780 Zografou, Greece

e-mail: [email protected]; [email protected]; [email protected]; peleni@central.

ntua.gr; [email protected]; [email protected]; [email protected]

131

mailto:[email protected]

GHG emissions increase for the period 2008–2012 toþ25% compared to base year emissions.

For the period 2013–2020 EU adopted the climate and energy package which is a

set of binding legislation aiming in ensuring of the European Union meets its

ambitious climate and energy targets for 2020. These targets, known as the “20-

20-20” targets, set three key objectives for 2020 (http://ec.europa.eu/clima/policies/

ets/index_en.htm):

• A 20% reduction in EU greenhouse gas emissions from 1990 levels.

• Raising the share of EU energy consumption produced from renewable

resources to 20%.

• A 20% improvement in the EU’s energy efficiency.

Finally, EU leaders agreed on 23 October 2014 the domestic 2030 greenhouse

gas reduction target of at least 40% compared to 1990 together with the other main

building blocks of the 2030 policy framework for climate and energy, as proposed

by the European Commission in January 2014. This 2030 policy framework aims to

make the European Union’s economy and energy system more competitive, secure

and sustainable and also sets a target of at least 27% for renewable energy and

energy savings by 2030.

Regarding Greek contribution in the first commitment period, 2008–2012, the

country ratified the Kyoto Protocol in 2002 (Law 3017/2002) and adopted a

National Programme for achieving its commitment by a decision of the Council

of Ministers (DCM5/2003).

Annual inventories of greenhouse and other gases emissions form an essential

element of each national environmental policy-making process. They can be used

to derive information on emissions trends, with reference to a pre-selected base

year, and can assist in monitoring the progress of existing abatement measures for

the reduction of greenhouse gases emissions and the fulfillment of the KP target

(MRPEE 2014b).

According to UNFCCC structure for the first commitment period, 2008–2012,

annual inventories regarding emissions sources could be categorized to the follow-

ing sectors (IPCC 1997, 2002):

Energy sector

Industrial processes

Solvents and other products

Agriculture

Waste

Land Use, Land Use Change and Forestry (LULUCF)

Waste sector consists one of the sectors as they are categorized by IPCC

Guidelines and it is recognized that the waste management industry plays an

increasing role in climate change mitigation (Ragossnig and Hilger 2008).

The definition of ‘waste management’ adopted here covers four basic divisions (UN 1998; Bogner et al. 2008; Braschel and Posch 2013):

132 L. Kallinikos et al.

http://ec.europa.eu/clima/policies/ets/index_en.htm

• Solid waste disposal on land

• Wastewater handling

• Waste incineration

• Other (Biological treatment)

Solid Waste Disposal on Land

Solid waste disposal on land is responsible for methane emissions. Methane is

emitted during the anaerobic decomposition of organic waste disposed in various

solid waste disposal sites (SWDS). The main characteristic of this process is that

organic waste decomposes at a diminishing rate over time and takes many years to

decompose completely. Moreover, other factors such as the type of waste disposed,

the characteristics of the disposal sites and the climate conditions, affect the

decomposition rate.

Carbon dioxide emissions occur during the flaring of biogas released from the

decomposition of waste. However, these emissions should not be included in the

total GHG emissions of the sector as they are of biogenic origin. Recovery and

flaring of biogas constitute a waste management practice in the major

managed SWDS.

Methane emissions from solid waste disposal on land consist of emissions from

municipal solid waste disposal on sites, emissions from sewage sludge (generated

during municipal wastewater handling) landfilled and emissions from industrial

solid waste and construction and demolition solid waste disposal in managed and

unmanaged sites (MRPEE 2014b; IPCC 1997, 2002).

The estimation of methane emissions from solid waste disposal on land could be

based on default emission factors or more detailed methodologies. IPCC Guidelines

provide three accounting methods; Tier 1, Tier 2 and Tier 3. Tier 1 provides IPCC

default data to countries with little data available (Braschel and Posch 2013). Tier

2 includes first-order decay (FOD) equations with some default parameters defined

by the IPCC, while Tier 3 is based on FOD equations with nationally developed

parameters, such as the degradable organic content of the waste (Gentil et al. 2009).

The method is applied separately for the managed and unmanaged waste disposal,

taking account of the different conditions in those sites and the detailed information

available regarding the opening and closure years of the operation of the managed

sites (MRPEE 2014b; IPCC 1997, 2002, 2006).

Wastewater Handling

Domestic and industrial wastewater handling under anaerobic conditions produces

CH4 while under aerobic treatment they result in sewage sludge production, the

disposal of which produces also CH4. Moreover, from both sub sectors N2O

12 Greenhouse Gas Emissions Trends from Waste in Greece 133

emissions are released (MRPEE 2014b; IPCC 1997, 2002). For the estimation of

the emissions from waste water handling default methodologies are provided by

IPCC (1997), IPCC (2002) and IPCC (2006).

Waste Incineration

Carbon dioxide, Methane and Nitrous oxide emissions produced from the inciner-

ation of waste such as clinical waste, biogenic agricultural residues produced in

slaughterhouses and from the incineration of small amounts of industrial chemical

waste are being estimated (MRPEE 2014b; IPCC 1997, 2002). For the estimation of

the emissions from this sector default methodologies are provided by IPCC (1997),

IPCC (2002) and IPCC (2006).

Emissions Trend

Total Emissions

Information regarding the methodologies utilized on the estimation of emissions

from the different sectors and the data collection are provided by the annual

emissions inventory submission of Greece (MRPEE 2014b).

According to these estimations in 2012, GHG emissions (without LULUCF)

amounted to 110.78 Mt CO2 eq showing an increase of 3.63% compared to base

year emissions and of 5.86% compared to 1990 levels.

Carbon dioxide emissions accounted for 81.67% of total GHG emissions in

2012 (without LULUCF) and increased by approximately 9.11% from 1990.

Methane emissions accounted for 8.57% of total GHG emissions in 2012 and

decreased by 8.77% from 1990, while nitrous oxide emissions accounted for

6.15% of the total GHG emissions in 2012 and decreased by 33.39% from 1990.

Finally, f-gases emissions (from production and consumption) that accounted for

3.95% of total GHG emissions in 2012, and 41.16% of the IP sector, has an average

increase of 33.19% from 1995 (base year for F-gases).

In Fig. 12.1, the evolution of the emissions for the period 1990–2012 are

provided. In the same figure the evolution of the Gross Domestic Product (GDP)

is provided. As it is observed GHG emissions follow the trend of GDP. Over the last

5 years Greek economy faced its most-severe crisis since it experienced a signif-

icant recession having recorded a cumulative decline in real terms exceeding 20%

(by the end of 2012 compared to GDP at the end of 2007).

The repercussions from the international financial crisis are unavoidable felt also

in Greece especially through the negative impact in the two significant exporting

sectors (tourism and ship transportation) but at a large extent economic downturn

134 L. Kallinikos et al.

relates also to the diminishing growth potential of the country since no significant

changes have occurred in the domestic production model towards innovative or

high value added activities.

Before this 5 years period, Greek growth performance was impressive. The

annual rate of increase of the GDP during the period 2000–2004 was approximately

4.5% due to the financial market liberalization coupled with membership in the

monetary union, which led to substantial increase in credit expansion and reduction

in borrowing costs, the stimulus given by the Olympic Games hosted in Athens in

2004 and the Community Structural Funds. Contrary to expectations of a post-

Olympics slump, the economy continued to grow briskly in 2005–2007 period.

GDP increased by an average growth rate of 3.7% and thus Greece enjoyed one of

the highest growth rates in the EU and the Eurozone.

Regarding EU-15 and E-28 related information are provided by the annual

emissions inventory submission of European Commission (European Environmen-

tal Agency 2014b). In 2012 total GHG emissions in the EU-15, without LULUCF,

were 15.1% (644 million tonnes CO2 equivalents) below 1990. Between 2011 and

2012 emissions decreased by 0.8% (31 Mt of CO2 equivalents) (http://unfccc.int/).

Total GHG emissions, without LULUCF, in the EU-28 decreased by 19.2%

between 1990 and 2012 (�1082 Mt of CO2 equivalent). Between 2011 and 2012, emissions decreased by 1.3% (59 Mt CO2 equivalent) (Fig. 12.2).

In the same figure the evolution of the GDP is provided. As it is observed GDP of

the European Union, for both EU-15 and EU-28, decreases only for 2009, while

GHG emissions decreases for the period 2005–2012 as a result of the mitigation

measures adopted by its members.

2.E+05

Greece

GDP1.E+05

1.E+05

8.E+04

6.E+04

4.E+04

2.E+04

0.E+00

19 90

19 91

19 92

19 93

19 94

19 95

19 96

19 97

19 98

19 99

20 00

20 01

20 02

20 03

20 04

20 05

20 06

20 07

20 08

20 09

20 10

20 11

20 12

300

250

200

150

100

G D

P (

co n

st an

t 20

05 U

S E

)- b

ill io

n s

U S

T o

ta l G

H G

e m

is si

o n

s, E

xc lu

d in

g L

U L

U C

F (

G g

C O

2e q

)

Fig. 12.1 Total GHG emissions of Greece and GDP

12 Greenhouse Gas Emissions Trends from Waste in Greece 135

http://unfccc.int/

Waste Sector

In general, waste sector is the fourth largest sector in Greece, contributing 4.3% of

the total greenhouse gas emissions sector in 2012 (excluding Land Use, Land-Use

Change and Forestry, LULUCF), while GHG emissions from waste decreased by

19.6% in 2012 compared to 1990 levels, based on the latest official GHG inventory

for the country. Similarly, the waste sector is the fourth largest sector in the EU-28

with approximately 3.1% contribution on the total GHG emissions for 2012, while

the total decrease over the period 1990–2012 is about 31.5% (Fig. 12.3).

Information regarding the methodologies utilized on the estimation of emissions

from the waste sector and the data collection are provided by the annual emissions

inventory submission of Greece (MRPEE 2014b).

Specifically, the major Waste category since 1999 for Greece is the solid waste

disposal on land with its contribution increasing from 37.8% in 1990 to 67.7% in

2012. On the contrary, GHG emissions from wastewater handling was the major

source up to 1999, presenting a declining trend with an average annual rate of

�2.69% for the period 1990–2012. Emissions from the incineration of waste present a negligible contribution on the total GHG from the waste sector. Similarly,

GHG emissions from waste disposal on land accounts for 72.3% of the total waste

greenhouse gas emissions in the EU-28 for the 2012.

Emissions from the Waste Sector (4.27% of the total emissions, without

LULUCF), decreased by approximately 19.58% from 1990. Living standards

improvement resulted in an increase of the generated waste and thus of emissions.

However, the increase of recycling along with the exploitation of the biogas

European Union (15)

GDP

European Union (28)

GDP 6.E+06

5.E+06

4.E+06

3.E+06

2.E+06

1.E+06

0.E+00

19 90

19 91

19 92

19 93

19 94

19 95

19 96

19 97

19 98

19 99

20 00

20 01

20 02

20 03

20 04

20 05

20 06

20 07

20 08

20 09

20 10

20 11

20 12

16000

14000

12000

8000

10000

6000

4000

2000

G D

P (

co n

st an

t 20

05 U

S D

)- b

ill io

n s

U S

T o

ta l G

H G

e m

is si

o n

s, E

xc lu

d in

g L

U L

U C

F (

G g

C O

2e q

)

Fig. 12.2 Total GHG emissions for European Union (EU15 and EU28) versus GDP

136 L. Kallinikos et al.

produced limits the increase of methane emissions. At the same time, emissions

from wastewater handling have considerably decreased, due to the continuous

increase of the population served by aerobic wastewater handling facilities.

Waste sector is the fourth largest sector in the EU-15, after energy, agriculture

and industrial processes, contributing 3% to total GHG emissions (European

Environmental Agency 2014b). Total emissions from Waste have been decreasing

by 40% from 171 Tg in 1990 to 102 Tg in 2012 (Fig. 12.4 for EU-15, Fig. 12.5 for

EU-28). In 2012, emissions decreased by 3.3% compared to 2011.

As it shown in this figure, CH4 emissions from Managed Waste Disposal on

Land had the greatest decrease of all waste-related emissions, but still account for

66% of waste-related GHG emissions in the EU-15 in 2012.

Solid Waste Disposal

Given the fact that solid waste sector is the main source for both Greece and EU, an

analysis on it is presented in this paragraph. As it is observed in the Fig. 12.2,

Greenhouse gas emissions from solid waste disposal on land present an increasing

trend, with some fluctuations due to variations on the CH4 recovered each year. This

is the result of the increasing trend observed on the municipal solid waste disposal

on land for the period 1990–2012, Fig. 12.6. While the solid waste generation

increase rate is significantly higher than this of disposal on solid waste disposal

Other

Incineration

Solid Waste

Wastewater Handling

7.E+03

6.E+03

5.E+03

3.E+03

4.E+03

2.E+03

1.E+03

0.E+00

19 90

19 91

19 92

19 93

19 94

19 95

19 96

19 97

19 98

19 99

20 00

20 01

20 02

20 03

20 04

20 05

20 06

20 07

20 08

20 09

20 10

20 11

20 12

T o

ta l G

H G

e m

is si

o n

s fr

o m

W as

te S

ec to

r (G

g C

O 2e

q )

Fig. 12.3 GHG emissions from Waste Sector for Greece

12 Greenhouse Gas Emissions Trends from Waste in Greece 137

2.E+05

1.E+05

8.E+04

6.E+04

4.E+04

2.E+04

0.E+00

T o

ta l G

H G

e m

is si

o n

s fr

o m

W as

te S

ec to

r fo

r E

U -1

5 (G

g C

O 2e

q )

19 90

19 91

19 92

19 93

19 94

19 95

19 96

19 97

19 98

19 99

20 00

20 01

20 02

20 03

20 04

20 05

20 06

20 07

20 08

20 09

20 10

20 11

20 12

Other

Incineration

Solid Waste

Wastewater Handling

Fig. 12.4 GHG emissions from Waste Sector for European Union (EU15)

3.E+05

2.E+05

1.E+04

5.E+04

0.E+00

T o

ta l G

H G

e m

is si

o n

s fr

o m

W as

te S

ec to

r fo

r E

U -2

8 (G

g C

O 2e

q )

19 90

19 91

19 92

19 93

19 94

19 95

19 96

19 97

19 98

19 99

20 00

20 01

20 02

20 03

20 04

20 05

20 06

20 07

20 08

20 09

20 10

20 11

20 12

Other

Incineration

Solid Waste

Wastewater Handling

Fig. 12.5 GHG emissions from Waste Sector for European Union (EU28)

138 L. Kallinikos et al.

sites, the increasing trend on the treatment of solid waste, recycling and

composting, is not able to decrease the amounts of solid waste disposal on sites.

For this reason, emissions of the sector are showing an increasing trend. In contrast,

both for EU-15 and EU-28 the solid waste amount treatment increases for all the

period of 1990–2012 resulting in a decreasing trend on the amounts of solid waste

disposal on sites and the emissions (Figs. 12.7 and 12.8).

Projections

For the projection of the evolution of the emissions for the period 2013–2030 the

impact of the implemented, adopted and planned policies and measures for the

mitigation of the emissions are utilized (MRPEE 2014a). This policy is fully

harmonized with the EU policy for the mitigation of GHG emissions from waste

and is mainly described by the regulation for the Municipal Waste disposal on land

(Landfill Dir. 1999/31/EC), the sewage sludge use in agricultures (Dir. 86/278/

EEC), the Paper/Cardboard recycling (Dir. on Packaging and Packaging Waste,

94/62/EC) and the Bio-wastes in the Waste Framework Dir. (art. 22, 2008/98/EC).

With Decision 50910/2727 (December 2003), the National Law 4042/2012

(OJG 24 A) and the transposition of Directive 2008/98/EC into national legislation

the measures, the terms and the processes for the rational management of waste in

national and regional level have been specified.

S o

lid W

as te

D is

p o

sa l (

G g

)

19 90

19 91

19 92

19 93

19 94

19 95

19 96

19 97

19 98

19 99

20 00

20 01

20 02

20 03

20 04

20 05

20 06

20 07

20 08

20 09

20 10

20 11

20 12

6.E+03

5.E+03

4.E+03

3.E+03

2.E+03

1.E+03

0.E+00

170.00

150.00

130.00

90.00

110.00

70.00

50.00

S o

lid w

as te

G en

er at

ed c

o m

p . t

o 1

99 0

(% )

Annual MSW at Managed SWDS (Gg)

Annual MSW at Unmanaged SWDS (Gg)

Solid waste Generated comp. to 1990 (%)

Fig. 12.6 Annual municipal solid waste disposal and solid waste generated compared to 1990 of Greece

12 Greenhouse Gas Emissions Trends from Waste in Greece 139

S o

lid W

as te

D is

p o

sa l (

G g

)

19 90

19 91

19 92

19 93

19 94

19 95

19 96

19 97

19 98

19 99

20 00

20 01

20 02

20 03

20 04

20 05

20 06

20 07

20 08

20 09

20 10

20 11

20 12

3.E+05

2.E+05

1.E+05

5.E+04

0.E+00

110.00

120.00

130.00

140.00

150.00

100.00

90.00

70.00

80.00

60.00

50.00

S o

lid w

as te

G en

er at

ed c

o m

p . t

o 1

99 0

(% )

Annual MSW at Managed SWDS (Gg)

Annual MSW at Unmanaged SWDS (Gg)

Solid waste Generated comp. to 1990 (%)

Fig. 12.7 Annual municipal solid waste disposal and solid waste generated compared to 1990 of EU-15

19 90

19 91

19 92

19 93

19 94

19 95

19 96

19 97

19 98

19 99

20 00

20 01

20 02

20 03

20 04

20 05

20 06

20 07

20 08

20 09

20 10

20 11

20 12

S o

lid W

as te

D is

p o

sa l (

G g

)

3.E+05

2.E+05

1.E+05

5.E+04

0.E+00

110.00

120.00

130.00

140.00

150.00

100.00

90.00

70.00

80.00

60.00

50.00

S o

lid w

as te

G en

er at

ed c

o m

p . t

o 1

99 0

(% )

Annual MSW at Managed SWDS (Gg)

Annual MSW at Unmanaged SWDS (Gg)

Solid waste Generated comp. to 1990 (%)

Fig. 12.8 Annual municipal solid waste disposal and solid waste generated compared to 1990 of EU-28

140 L. Kallinikos et al.

Fundamental objectives are the elimination of unmanaged solid waste disposal

sites, the coverage of all urban and rural areas of the country with modern instal-

lations for final disposal and the promotion of measures for the prevention and

reduction of produced waste, as well as the exploitation of materials with maximi-

zation of recycling and recovery of products and energy. The necessity to reduce the

quantities of biodegradable wastes landfill through the installation of treatment

facilities, Joint Ministerial Decision 29407/3508 in agreement with Directive 1999/

31/EC, is acknowledged.

The reduction of biodegradable waste landfill is enhanced by the directive for

Packaging and Packaging Waste (94/62/EC) Paper/Cardboard recycling.

Concerning bio-wastes treatment the legislative framework is based in theWaste

Framework Dir. (art. 22, 2008/98/EC). According to this, Article 41, until 2015

separately collected bio-waste shall be minimum 5% of the total produced

bio-waste and until 2020, separately collected bio-waste shall be minimum 10%

of the total produced bio-waste.

The flaring of landfill gas in all managed sites for urban centres with population

more than 100,000 is partially an integrated measure. Already, the managed

disposal sites serving the population of the largest cities of Greece are equipped

with systems for the collection or for the flaring of biogas.

As regards wastewater, a collection network with its corresponding wastewater

treatment plants has already been developed during the last 5-years, covering the

needs of 70% of the population in 2001 and the 91% in 2011, in compliance with

the Directive 91/271/EEC concerning the collection, treatment and discharge of the

urban wastewater. In the Psyttalia wastewater treatment plant that serves approx-

imately four millions of Attica population, a part the sludge produced is treated

under anaerobic conditions resulting in the production of biogas. The biogas

produced covers the energy needs of the wastewater treatment facilities, while the

surplus is flared.

The quantities of the solid waste end out at disposal sites were estimated on the

bases of historical data as well as on the implementation of adopted policies and

measures taking into consideration the deflection from the targets due to economic

recession. The composition of the solid waste landfill at disposal sites was esti-

mated taking into account the composition of MSW generated and the amounts of

waste recycling and compost.

The obtained results for Greece are presented in Fig. 12.9 and for EU in

Fig. 12.10 (European Environmental Agency 2014a).

As it is shown, in 2020 emissions from waste sector of Greece are estimated to be

decreased by 22% compared to 1990 and in 2030 28% compared to 1990. At the

same time, emissions from waste for EU are estimated to be decreased in 2020 49%

(EU-15) and 44% (EU-28) compared to 1990 and in 2030 63% (EU-15) and 50%

(EU-28) compared to 1990. Therefore, it is estimated that if the total targets for the

Greenhouse Gas emissions are equal to the targets for the waste sector (20% in

2020 compared to 1990 and 40% in 2030 compared to 1990) EU-15 and EU-28

have already achieved with the measures that already have adopted/planned, while

for Greece additional measures are needed for 2030.

12 Greenhouse Gas Emissions Trends from Waste in Greece 141

19 90

20 30

20 25

20 20

20 15

20 10

20 05

20 00

19 95

7.E+03

6.E+03

5.E+03

3.E+03

4.E+03

2.E+03

1.E+03

0.E+00

G H

G e

m is

si o

n s

fr o

m W

as te

S ec

to r

(G g

C O

2e q

) Waste incineration

Industrial wastewater

Domestic wastewater

Solid waste disposal on land

Fig. 12.9 Emissions from waste sector projections for Greece

19 90

20 30

20 20

20 10

G H

G e

m is

si o

n s

fr o

m W

as te

S ec

to r

(G g

C O

2e q

)

European Union (15) European Union (28)3.E+05

2.E+05

1.E+04

5.E+04

0.E+00

Fig. 12.10 Emissions from waste sector projections for EU-15 and EU-28

142 L. Kallinikos et al.

Conclusions

Based on the analysis presented in the current work the following conclusions

derive:

• Total GHG emissions of Greece follow the trend of GDP. They increase up to

2007 and they decrease in the period 2008–2012 during economic recession.

• Total GHG emissions of EU trend decreases for all the period 1990–2012.

• Waste sector is the fourth largest sector in Greece and it has shown a decreased

trend from 2000 mainly due to declining trend of emissions from wastewater

handling subsector while GHG emissions from waste sector for EU decrease for

all the period 1990–2012.

• If the total targets for the Greenhouse Gas emissions are equal to the targets for

the waste sector, EU-15 and EU-28 has already achieved their targets with the

measures that already have adopted/planned.

• Greece seems to need some additional measures for 2030.

• It must be mentioned that specific targets for waste sector depends on the

disaggregation of total GHG emission targets taking into consideration

EU-ETS and non EU-ETS specific targets and the ability for emission decrease

of the sectors like F-gases and Agriculture sector.

References

Bogner, J., Pipatti, R., & Hashimoto, S. (2008). Mitigation of global greenhouse gas emissions

from waste: Conclusions and strategies from the Intergovernmental Panel on Climate Change

(IPCC) Fourth Assessment Report. Working Group III (Mitigation). Waste Management & Research, 26, 11–32.

Braschel, N., & Posch, A. (2013). A review of system boundaries of GHG emission inventories in

waste management. Journal of Cleaner Production, 44, 30–38. European Environmental Agency. (2014a). Sixth National Communication and first biennial

report from the European Union under the UN framework convention on climate change (UNFCCC), technical report.

European Environmental Agency. (2014b). Annual European Union greenhouse gas inventory 1990–2012 and inventory report 2014 Submission to the UNFCCC.

Gentil, E., Christensen, T. H., & Aoustin, E. (2009). GHG accounting and waste management.

Waste Management and Research, 27, 696–706. Intergovernmental Panel on Climate Change (IPCC). (1997). Revised 1996 IPCC guidelines for

national greenhouse gas inventories—Greenhouse gas inventory reference manual (Vol. 3). Bracknell: IPCC/OECD/IEA, UK Meteorological Office.

Intergovernmental Panel on Climate Change (IPCC). (2002).Good practice guidance for land use, land use change and forestry. Japan: IPCC National Greenhouse Gas Inventories Programme, Institute for Global Environmental Strategies.

Intergovernmental Panel on Climate Change (IPCC). (2006). IPCC guidelines for national GHG inventories. Japan: IPCC National Greenhouse Gas Inventories Programme, Institute for Global Environmental Strategies.

12 Greenhouse Gas Emissions Trends from Waste in Greece 143

Ministry of Reconstruction of Production Environment & Energy (MRPEE) (former: Ministry of

Environment, Energy and Climate Change). (2014a). Sixth National Communication and 1st biennial report under the United Nations framework convention on climate change.

Ministry of Reconstruction of Production Environment & Energy (MRPEE) (former: Ministry of

Environment, Energy and Climate Change). (2014b). Emissions inventory annual inventory submission of Greece under the convention and the Kyoto protocol for greenhouse and other gases for the years 1990–2012.

Ragossnig, A., & Hilger, H. (2008). Editorial: Waste management: Stepping up to the climate

change challenge. Waste Management & Research, 26, 3–4. United Nations (UN). (1998). Kyoto-protocol to the United Nations Framework Convention on

Climate Change. http://ec.europa.eu/clima/policies/ets/index_en.htm on March 31, 2015. http://unfccc.int/, Accessed on March 31, 2015

144 L. Kallinikos et al.

http://unfccc.int/

http://ec.europa.eu/clima/policies/ets/index_en.htm

Part IV

Global Warming and Climate Change: General Issues and Challenges

Climate Prediction Tools

Development and Application of Climate Prediction Tools

Chapter 13

Development of Models for the Estimation of Global Solar Radiation Over Selected Stations in India

M. Maroof Khan, M. Jamil Ahmad, and Basharat Jamil

Introduction

Solar radiation, passing through the atmosphere, reaching the earth on a horizontal

surface can be classified into two components: beam radiation and diffuse radiation.

Beam radiation is the solar radiation propagating along the line joining the receiv-

ing surface and the center of the sun. It is also referred to as direct radiation. Diffuse

radiation on the other hand, is the solar radiation scattered by aerosols, dust and

molecules in the atmosphere, it does not have a unique direction. The total radiation

is the sum of the beam and diffuses radiation and is sometimes referred to as the

global radiation. When the amount of diffuse radiation reaching the earth’s surface is less than or equal to 25% of global radiation, the sky is termed as clear sky

(Duffie and Beckman 1991).

In many applications of solar energy, the solar irradiance incident on the surface

of the earth at the location of interest is an important input parameter. The temporal

and spatial fluctuations of such irradiance necessitate a method to predict them.

M.M. Khan

Mechanical Engineering Section, University Polytechnic, Aligarh Muslim University,

Aligarh, 202002 Uttar Pradesh, India

e-mail: [email protected]

M.J. Ahmad

Department of Mechanical Engineering, Zakir Husain College of Engineering

and Technology, Aligarh Muslim University, Aligarh, 202002 Uttar Pradesh, India

e-mail: [email protected]

B. Jamil (*) Heat Transfer and Solar Energy Laboratory, Department of Mechanical Engineering, Zakir

Husain College of Engineering and Technology, Aligarh Muslim University,

Aligarh, 202002 Uttar Pradesh, India

e-mail: [email protected]

149

mailto:[email protected]

The systematic variation of solar irradiance outside the earth’s atmosphere makes it possible to introduce many models for such prediction (Munroe 1980).

Knowledge of global solar irradiance at a site is essential for the proper design

and assessment of solar energy conversion systems. Some of the systems such as

concentrating systems require information on direct beam component whereas in

the case of tilted plain surfaces the diffuse component of solar irradiance is also

important for the computation of system performance (Khogali et al. 1983). How-

ever, at locations on the Earth’s surface, the solar radiation is also a function of variables such as the nature and extent of cloud cover, the aerosol and water vapor

content of atmosphere, etc. Good prediction of the actual value of solar irradiance

for a given location requires, in principle, long-term, average meteorological data,

which are still scarce for many developing countries like India (Leung 1980;

Ezekwe and Ezeilo 1981; Khogali 1983). It is, therefore, not always possible to

predict the actual value of solar irradiance for a location of interest.

There are several formulae available in literature on solar radiation modelling

that relate global radiation to climatological parameters such as sunshine hours,

relative humidity, maximum temperature, and average temperature. The first such

correlation proposed for estimating the monthly average daily global irradiation is

due Angstrom (1924). The original Angstrom-type regression equation relates

monthly average daily radiation to clear day radiation at the location in question

and average fraction of possible sunshine hours:

H=Hc ¼ aþ b S So

� � ð13:1Þ

A basic difficulty with Eq. (13.1) lies in the ambiguity of the terms S/So and Ho.

Page (1961) modified the method to base it on extraterrestrial radiation on a

horizontal surface rather than on clear sky day radiation.

H=H0 ¼ a0 þ b0 S So

� � ð13:2Þ

Inspite of having complication in Hc calculations, better results were obtained

using Hc instead of H0 (To�grul 1999). The major objective of this article to investigate usability of clear sky radiation to predict and express the average

measured values of solar irradiance on a horizontal surface by using various

regression analyses for selected locations in India.

Clear Sky Solar Radiation

Hottel (1976) has presented a method for estimating the beam radiation transmitted

through clear atmospheres which takes into account zenith angle and altitude for a

standard atmosphere and four climate types. The atmospheric transmittance for

beam radiation is given in the form:

150 M.M. Khan et al.

τb ¼ ao þ a1exp �k cos θzð Þ ð13:3Þ

The constant and k for the standard atmosphere with 23 km visibility are found

from ao*, a1* and K* which are given for altitudes less than 2.5 km by

a*o ¼ 0:4237� 0:00821 6� Að Þ2 ð13:4Þ a*1 ¼ 0:5055þ 0:00595 6:5� Að Þ2 ð13:5Þ K* ¼ 0:2711þ 0:01858 2:5� Að Þ2 ð13:6Þ

where, A is the altitude of the observer in kilometers.

The correction factors are applied to ao*, a1* and K* to allow for changes in climate types.

The correction factors ro¼ ao/ao*, r1¼ a1/a1* and rk¼ k/K* are given in Table 13.1.

Thus, the transmittance of this standard atmosphere for beam radiation can be

determined for any zenith angle and any altitude up to 2.5 km. The clear sky beam

radiation (Gcb, W/m 2) is than

Gcb ¼ Gonτb ð13:7Þ

where, Gon is the extraterrestrial radiation, measured on the plane normal to the

radiation on the nth day of the year and given in the following form (W/m2).

Gon ¼ Gsc 1þ 0:33 cos 360n 365

� �� ð13:8Þ

where, Gsc is the solar constant equal to 1367 W/m 2.

The clear sky horizontal beam radiation is

Gcb ¼ Gonτb cos θz ð13:9Þ

It is also necessary to estimate the clear sky diffuse radiation on a horizontal

surface to get the total radiation as suggested by Liu and Jordan (1960). They

developed an empirical relationship between the transmission coefficients for beam

and diffuse radiation for clear days.

Table 13.1 Correction factors for different climates

Climate type r0 r1 rk

Tropical 0.95 0.98 1.02

Midlatitude summer 0.97 0.99 1.02

Subarctic summer 0.99 0.99 1.01

Midlatitude winter 1.03 1.01 1.00

13 Development of Models for the Estimation of Global Solar Radiation Over. . . 151

τd ¼ 0:271� 0:294τb ð13:10Þ

where τd is the ratio of diffuse radiation to the extraterrestrial radiation on the horizontal plane. The clear sky diffuse radiation Gcd (W/m

2).

Gcd ¼ Gonτd cos θz ð13:11Þ

Thus, the clear sky global solar radiation is given by

Gc ¼ Gcb þ Gcd ð13:12Þ

Meteorological Data

In the present study, the monthly average global solar radiation, have been calcu-

lated, using sunshine hour data on horizontal surfaces. Six models have been

developed which include the effect of latitude and altitude of a location. These

six stations have been selected for different geographical locations covering most

part of India (Table 13.2).

The measured values of the monthly average global solar radiation (G) and the

S/So ratio for six locations are obtained from Chandel et al. (2005) and are provided

in Table 13.3. Gc values calculated by Hottle’s model for six cities are given in Table 13.4.

Development of Models

The following equations were obtained by investigating the relation between G/Gc and S/So by different regression analysis. The scatter of monthly mean values

between G/Gc and S/So are given in Fig. 13.1.

Table 13.2 Geographical location of six Indian cities (Chandel et al. 2005)

Station (State) Longitude (�E) Latitude (�N) Altitude (m) Palampur (Himachal Pradesh) 76.30 32.60 1270

Amritsar (Punjab) 74.87 31.63 234

Kodaikanal (Tamil Nadu) 77.47 10.23 2339

Nandi Hill (Karnatka) 77.68 13.37 1479

New Delhi (Delhi) 77.20 28.58 216

Shillong (Meghalaya) 91.88 25.57 1600

152 M.M. Khan et al.

T a b le

1 3 .3

M ea su re d v al u es

o f m o n th ly

av er ag e g lo b al

so la r ra d ia ti o n (G

) an d S /S

o fo r si x ci ti es

(C h an d el

et al . 2 0 0 5 )

P al am

p u r

A m ri ts ar

K o d ai k an al

N an d i H il ls

D el h i

S h il lo n g

M o n th

G S/ S o

Ja n u ar y

2 .8 0

0 .5 7

3 .1 0

0 .6 6

6 .2 8

0 .6 2

6 .3 7

0 .8 6

3 .9 9

0 .7 3

4 .0 1

0 .5 2

F eb ru ar y

3 .3 7

0 .5 5

3 .9 9

0 .6 9

6 .7 1

0 .6 7

6 .2 6

0 .8 1

5 .0 0

0 .8 1

5 .0 8

0 .6 5

M ar ch

4 .3 1

0 .5 8

4 .8 8

0 .6 3

6 .8 7

0 .6 3

7 .4 9

0 .8 4

6 .1 4

0 .6 9

5 .6 3

0 .6 8

A p ri l

5 .2 4

0 .6 5

6 .2 6

0 .7 3

6 .4 3

0 .5 5

7 .3 3

0 .8 0

6 .9 4

0 .6 8

5 .7 0

0 .6 2

M ay

6 .1 5

0 .6 9

6 .2 3

0 .6 5

5 .8 4

0 .4 1

7 .2 9

0 .6 2

7 .2 9

0 .6 0

5 .2 3

0 .5 3

Ju n e

5 .3 3

0 .6 0

6 .6 0

0 .7 4

5 .2 8

0 .2 7

6 .2 7

0 .3 3

6 .5 4

0 .4 3

4 .1 2

0 .3 3

Ju ly

3 .9 2

0 .2 9

6 .3 2

0 .6 3

4 .5 4

0 .2 0

4 .9 2

0 .2 9

5 .3 3

0 .4 3

4 .2 6

0 .3 9

A u g u st

4 .3 4

0 .3 3

5 .3 0

0 .6 5

4 .7 0

0 .3 2

5 .1 7

0 .3 2

5 .0 5

0 .4 3

4 .2 1

0 .3 5

S ep te m b er

3 .9 4

0 .5 3

5 .4 5

0 .7 1

4 .8 0

0 .3 3

4 .7 8

0 .3 6

5 .6 0

0 .5 7

3 .8 7

0 .4 1

O ct o b er

5 .0 8

0 .8 5

4 .4 7

0 .7 6

4 .4 4

0 .3 0

5 .6 6

0 .5 5

5 .3 6

0 .7 8

4 .0 2

0 .5 4

N o v em

b er

3 .6 1

0 .8 2

3 .7 1

0 .7 8

4 .7 4

0 .3 6

3 .4 7

0 .3 9

4 .5 2

0 .8 7

3 .9 4

0 .5 5

D ec em

b er

2 .7 6

0 .6 6

3 .0 1

0 .7 4

5 .2 2

0 .5 3

4 .3 8

0 .5 7

3 .8 4

0 .7 8

4 .1 5

0 .5 7

13 Development of Models for the Estimation of Global Solar Radiation Over. . . 153

Gc ¼ 0:7604 S

� � þ 0:3750 linearð Þ ð13:13Þ

Gc ¼ 0:0163 S

� �2 � 0:7424 S

� � þ 0:3794 quadraticð Þ ð13:14Þ

Gc ¼ �3:2664 S

� �3 þ 5:5108 S

� �2 � 2:1434 S

� � þ 0:8428 cubicð Þ

ð13:15Þ G

Gc ¼ 1:0742 S

� �0:4933 powerð Þ ð13:16Þ

Table 13.4 Calculated Gc values for each city (using Hottle’s Model) in kW/m 2/day

Months Palampur Amritsar Kodaikanal Nandi Hill Delhi Shillong

January 3.6401 3.3702 6.6410 6.0672 3.7228 4.6388

February 4.6831 4.3351 7.2561 6.7572 4.6764 5.6139

March 5.9138 5.4802 7.7983 7.4148 5.7955 6.7156

April 6.9983 6.4898 8.0260 7.7831 6.7738 7.6232

May 7.5867 7.0321 7.9153 7.7856 7.2861 8.0549

June 7.7606 7.1892 7.7717 7.6932 7.4271 8.1534

July 7.6540 7.0924 7.8044 7.7038 7.3364 8.0782

August 7.2133 6.6886 7.9330 7.7408 6.9578 7.7667

September 6.3071 5.8471 7.8448 7.5193 6.1472 7.0345

October 5.0445 4.6710 7.3853 6.9265 5.0007 5.9287

November 3.8828 3.5941 6.7671 6.2146 3.9439 4.8615

December 3.3433 3.0965 6.4305 5.8408 3.4459 4.3497

Fig. 13.1 G/Gc vs S/So for six cities in India

154 M.M. Khan et al.

Gc ¼ 0:3761ln S

� � þ 1:0401 logarithmicð Þ ð13:17Þ

Gc ¼ 0:4511exp0:989 SSoð Þ exponentialð Þ ð13:18Þ

Various statistical methods are available in solar energy literature, which deal

with the assessment and comparison of solar radiation estimation models (Stone

1993; To�grul 1999; To�grul and Onat 1999; Walpole and Mayers 1989; Şahin 2007). Presently, statistical tests, root mean square error (RMSE), mean bias error (MBE)

and t-statistics are utilized to evaluate the accuracy of the correlations developed.

Methods of Comparison

Statistical tests, root mean square error (RMSE) and mean bias error (MBE) were

used to evaluate the accuracy of the correlations developed. Also, t-statistics was

applied to the developed models to illustrate the statistically significant results.

Root Mean Square Error (RMSE)

The root mean square error is defined as

RMSE ¼ 1 N

XN i¼1

Gi,pre � Gi,meas � �2 !12 ð13:19Þ

where, Gi,pre is ith predicted value, Gi,meas is the ith measured value, andN is the total number of observations. The RMSE is always positive, a zero value is ideal. This test

provides information on short-terms performance of the correlation by arranging a

term by term comparison of the actual deviation between the calculated value and

the measured value. The smaller the value, the better the model’s performance, however, a few large errors in the sum can produce a significant increase in RMSE.

Mean Bias Error (MBE)

The mean bias error is defined as

MBE ¼ 1 N

XN i¼1

Gi,pre � Gi,meas � � ð13:20Þ

13 Development of Models for the Estimation of Global Solar Radiation Over. . . 155

This test provides information on the long term performance. A low value is

desired. Ideally a zero value of MBE should be obtained. A positive value gives the

average amount of over-estimation in the calculated value and vice versa. A

drawback of this test is that over estimation of an individual observation will cancel

under estimation in a separate observation.

It is obvious that each test by itself may not be an adequate indicator of a model’s performance. It is possible to have a large RMSE value and at the same time a small

MBE (a large scatter about the line of perfect estimation). On the other hand, it is

also possible to have a relatively small RMSE and a relatively large MBE

(a consistently small over or under estimation).

However, these statistical indicators generally provide a reasonable procedure to

compare models, they do not objectively indicate whether a model’s estimates are statistically significant, i.e. not significantly different from their measured counter-

parts. Therefore, an additional statistical indicator, the t-statistic is used. This

statistical indicator allows models to be compared and at the same time indicate

whether or not a model’s estimates are statistically significant at a particular confidence level. It was seen that the t-statistic used in addition to the RMSE and

MBE gave more reliable and explanatory results (Walpole and Mayers 1989).

t-Statistics

t ¼ N � 1ð ÞMBE 2

RMSE2 �MBE2 � �1

ð13:21Þ

The smaller the value of t, the better is the model’s performance. To determine whether a model’s estimates are statistically significant, one simply has to deter- mine a critical t-value obtainable from standard statistical tables, at a particular confidence level, i.e. tα/2 at an α-level of significance and (N-1) degrees of freedom. For the model’s estimates to be judged statistically significant at the (1-α) confi- dence level, the calculated t-value must be less than the critical t-value.

Results and Discussion

As observed from Table 13.5, good results were not seen in the short term (RMSE)

but relatively good results were observed in the long term performance (MBE).

Equation (13.17) has the best result among the equations developed.

When investigations were compared among all the equations the best MBE

value was seen in Eq. (13.17). The best RMSE value was obtained with

Eq. (13.15) which is a cubic equation.

156 M.M. Khan et al.

Also, it is observed that considering country as a whole and each city individ-

ually, the performance of developed equations is different. Therefore, the MBE and

RMSE values of the developed equations separately for each city were calculated.

The results of this statistical comparison are given in Table 13.6.

At the first view, it is seen that the MBE values of Table 13.4 are higher than

tabulated in Table 13.5 RMSE and MBE for the whole country (India). Each

equation developed for the city was compared with the equations in its group and

the results obtained were setup in order below (Table 13.7).

Although the models give overall good results for the whole country (Table 13.5)

but the errors were higher for individual cities (Table 13.6). These tables did not

include adequate information about on usability of the developed equation. In view

of this, t-statistics is applied to the developed models to investigate the usability of

each model. The critical t-values are shown in Table 13.8, t-values higher than the critical t-values show that the equation has no statistical significance.

Equations which have t-values lower than the critical t-value exhibited good and logical results. In case of Palampur, Eqs. (13.16) and (13.17) are significant. In case

of Amritsar and Kodaikan almost all of the equations showed good and logical

results. In case of Nandi Hills and Delhi Eqs. (13.13), (13.14) and (13.18) are

significant. In case of Shillong, Eqs. (13.15) and (13.18) are significant.

Conclusions

It was observed that the clear sky solar radiation and sunshine hour can be used to

estimate the global radiation in India. It was further observed that the cubic

equation gave the lowest RMSE error, and the lowest MBE error was obtained by

the logarithmic equation developed for the whole year (Table 13.5). It is also

observed that the performance of the equations is different for all the stations taking

together and for the cities individually. Cubic and logarithmic models gave the best

results among all the developed equations for the country as a whole. While for

individual cities cubic, logarithmic and exponentials yield better results.

Finally these results clearly indicate that reliance on the RMSE and MBE used

separately can lead to a wrong decision in selecting the best model suited from the

candidate models and that the use of the RMSE and MBE in isolation is not an

adequate indicator of model performance. Therefore, the t-statistics should be used

in conjunction with these two indicators to evaluate a model’s performance in a better way.

Table 13.5 RMSE and MBE for the whole country (India)

Equation number RMSE MBE

13.13 0.5726 �0.0222 13.14 0.5723 �0.0227 13.15 0.5662 �0.0233 13.16 0.5869 �0.0496 13.17 0.6096 �0.0192 13.18 0.5711 �0.0511

13 Development of Models for the Estimation of Global Solar Radiation Over. . . 157

T a b le

1 3 .6

T h e R M S E an d M B E v al u es

o f th e eq u at io n d ev el o p ed

fo r ea ch

ci ty

P al am

p u r

A m ri ts ar

K o d ai k an al

N an d i H il ls

D el h i

S h il lo n g

E q u at io n

R M S E

M B E

R M S E

M B E

R M S E

M B E

R M S E

M B E

R M S E

M B E

R M S E

M B E

1 3 .1 3

0 .5 9 9 2

0 .4 9 4 5

0 .2 1 6 2

�0 .0 6 9 9

0 .3 7 9 6

�0 .2 5 5 2

0 .5 6 4 5

�0 .1 0 2 8

0 .7 3 7 3

�0 .6 4 2 4

0 .7 4 4 8

0 .4 4 2 8

1 3 .1 4

0 .5 9 7 7

0 .4 9 3 8

0 .2 1 6 4

�0 .0 7 1 1

0 .3 7 9

�0 .2 5 4 7

0 .5 6 4 3

�0 .1 0 1 6

0 .7 3 8 5

�0 .6 4 3 1

0 .7 4 4

0 .4 4 0 8

1 3 .1 5

0 .6 2 1 3

0 .1 1 7 3

0 .2 1 3 7

�0 .0 0 6 7

0 .3 5 3 7

�0 .2 0 7 5

0 .5 6 3 4

�0 .1 5 4 8

0 .7 5 4 3

�0 .6 7 0 9

0 .6 9 3 1

0 .4 0 3 1

1 3 .1 6

0 .5 9 8 8

0 .1 1 1 5

0 .2 3 0 1

�0 .1 0 2 3

0 .4 3 3

�0 .2 9 4 1

0 .5 7 5 7

�0 .1 6 7 3

0 .7 5 2 7

�0 .6 6 6

0 .7 5 4 9

0 .4 5 9 4

1 3 .1 7

0 .6 4 9 5

0 .1 1 9 4

0 .2 2 7 5

�0 .0 7 2 9

0 .4 9 8 4

�0 .2 9 0 6

0 .5 8 6 4

�0 .1 6 0 8

0 .7 1 7 1

�0 .6 2 7 7

0 .8 0 6

0 .5 3 0 7

1 3 .1 8

0 .5 5 1 5

0 .1 0 9 1

0 .2 2 7 3

�0 .1 0 1 1

0 .3 9 9 8

�0 .2 8 2 6

0 .5 8 2 3

�0 .0 8 9 7

0 .7 7 6 5

�0 .6 6 8 6

0 .7 0 6 4

0 .3 7 2 9

158 M.M. Khan et al.

Nomenclature

A Altitude (km)

a, b, a’, b’ Empirical constants Gc Clear sky global solar radiation (W/m

Gcb Clear sky beam radiation (W/m 2)

Gcd Clear sky diffuse radiation (W/m 2)

Gon Extraterrestrial radiation (W/m 2)

Gsc Solar constant (¼1367 (W/m2)) H Monthly mean daily global radiation on a horizontal surface (MJ/m2) Hc Clear sky monthly mean daily global radiation on a horizontal surface

(MJ/m2)

Ho Monthly mean daily extraterrestrial radiation (MJ/m 2)

n Day of the year N Number of observations S Monthly average daily hours of bright sunshine So Monthly average of maximum possible daily hours of bright sunshine

(i.e. day length of average day of the month)

Greek Symbols

α Level of significance θz Zenith angle (�) τb Atmospheric transmittance for beam radiation

Table 13.7 Equations with significant results for selected

stations

Station Equation number

Palampur 13.18

Amritsar 13.15

Kodaikanal 13.15

Nandi Hills 13.15 and 13.18

Delhi 13.17

Shillong 13.15 and 13.18

Table 13.8 Critical t-values and the results of t-statistics analyses for each city

Equation Palampur Amritsar Kodaikanal Nandi Hills Delhi Shillong

13.13 4.8466 1.1332 3.012 0.6143 5.8881 2.4523

13.14 4.8633 1.1538 3.0099 0.6071 5.875 2.4392

13.15 4.4236 0.104 2.4026 0.9478 5.4541 2.3712

13.16 4.2603 1.6462 3.0693 1.0073 6.2982 2.5436

13.17 4.1172 1.1219 2.3803 0.9457 6.0041 2.9015

13.18 5.1024 1.6471 3.3142 0.5171 5.6157 2.0614

Critical t 4.2658 1.2702 3.1036 0.7687 5.979 2.4175

13 Development of Models for the Estimation of Global Solar Radiation Over. . . 159

τd Atmospheric transmittance for diffuse radiation ω The sunset hour angle (�) ϕ Latitude (�) δ Declination angle (�)

References

Angstrom, A. (1924). Solar and terrestrial radiation. Report to the international commission for

solar research on actinometric investigations of solar and atmospheric radiation. Quarterly Journal of the Royal Meteorological Society, 50(210), 121–126.

Chandel, S. S., Aggarwal, R. K., & Pandey, A. N. (2005). New correlation to estimate global solar

radiation on horizontal surfaces using sunshine hour and temperature data for indian sites.

Journal of Solar Energy Engineering, 127, 417–420. Duffie, J. A., & Beckman, W. A. (1991). Solar engineering of thermal processes. New York:

Wiley.

Ezekwe, G. I., & Ezeilo, C. C. O. (1981). Measured solar radiation in a Nigerian environment

compared with predicted data. Solar Energy, 26(2), 181–186. Hottel, H. C. (1976). A simple model for estimating the transmittance of direct solar radiation

through clear atmosphere. Solar Energy, 18, 129–134. Khogali, A. (1983). Solar radiation over Sudan-Comparison measured and predicted data. Solar

Energy, 31(1), 45–53. Khogali, A., Ramadan, M. R. I., Ali, Z. E. H., & Fattah, Y. A. (1983). Global and diffuse solar

irradiation in Yemen (Y.A.R.). Solar Energy, 31(1), 55–62. Leung, C. T. (1980). The fluctuation of solar irradiation in Hong Kong. Solar Energy, 25(6),

485–494.

Liu, B. Y. H., & Jordan, R. C. (1960). The interrelationship and characteristics distribution of

direct, diffuse and total solar radiation. Solar Energy, 4(3), 1–19. Munroe, M. M. (1980). Estimation of totals of irradiance on a horizontal surface from UK average

meteorological data. Solar Energy, 24, 235–238. Page, J. K. (1961). The estimate of monthly mean values of daily total short wave radiation on

vertical and inclined surfaces from sunshine records for latitudes 40�N–40�S. In Proceedings of U.N. conference on new sources of energy, Rome.

Şahin, A. D. (2007). A new formulation for solar radiation and sunshine duration estimation.

International Journal of Energy Research, 31(2), 109–118. Stone, R. J. (1993). Improved statistical procedure for the evaluation of solar radiation estimation

models. Solar Energy, 51, 289–291. To�grul, I. T. (1999). Estimation of clear sky radiation in Elazig. Chimica Acta Turcici, 27(1),

25–30.

To�grul, I. T., & Onat, E. (1999). A study for estimating solar radiation in Elazı�g using geographical and meteorological data. Energy Conversion and Management, 40, 1577–1584.

Walpole, R. E., & Mayers, R. H. (1989). Probability and statistics for engineers and scientists (4th ed.). New York: Macmillan.

160 M.M. Khan et al.

Chapter 14

Effect of Gap Between Absorber Plate and Condenser Cover on the Performance of a Solar Still

Basharat Jamil and Naiem Akhtar

Introduction

Availability of fresh water for domestic and industrial use is an important issue

facing the human world today. Lack of potable sources of water in developing

countries is even severe. Rise is pollution levels of the local surface water resources

have worsened the conditions leading to fatal water borne diseases and conse-

quently an increase in human mortality rate.

Although several methods to purify water are available in industry, but most of

them involve high energy requirements and are technologically complicated, thus,

require sophisticated personnel for operation. Therefore, it is required that simple

yet effective methods of water purification/desalination must be developed to

reduce dependence on conventional energy resources.

Solar energy is a capable prospect for utilization in solar-energy conversion

systems. This can be exploited to heat and evaporate brackish or polluted water

which can later be condensed to form purified water suitable for drinking. Distil-

lation is one of the important methods of making clean and potable water from

brackish or polluted water using the abundant energy supply from the sun. Forma-

tion of clouds and rains in the atmosphere of earth is an example of desalination

cycle using solar energy to produce huge amounts of pure water from the sea.

B. Jamil (*) • N. Akhtar Heat Transfer & Solar Energy Laboratory, Department of Mechanical Engineering,

Zakir Husain College of Engineering and Technology, Aligarh Muslim University,

Aligarh, 202002 Uttar Pradesh, India

e-mail: [email protected]; [email protected]

161

mailto:[email protected]

Conventional Solar Still

A solar still is a promising device for the desalination of brackish water into potable

form. The schematic diagram of conventional single slope solar still is shown in

Fig. 14.1. A solar still imitates the process of desalination through which the earth’s atmosphere forms rain. Water is heated through incoming solar radiation in a closed

chamber with an inclined transparent glass cover to form vapours. The vapours

travel through the chamber height to reach the inclined condensing cover and lose

heat to form liquid water. The condensed liquid water trickles on the condensing

cover and falls in the collection trough. The condensed liquid produced is usually

highly purified and free of microorganisms and other harmful bacteria. This is

because only heated water evaporates leaving behind the salts and other dissolved

impurities. Also, temperatures within the solar still reaches sufficiently high values

to kill the microorganisms and bacteria present in polluted water.

Although the construction, operation, and maintenance of a solar still is quite

simple but the main limitation of a simple solar still is its low output (yield) and

efficiency of the order of 2 lt/m2/day and 20–30% respectively (Tiwari and Tiwari

2006). A large number of research activities around the world address the perfor-

mance improvement and evaluation of solar stills.

Heat Transfer in a Solar Still

Heat transfer in a conventional solar still can be categorized in two parts: internal

heat transfer and external heat transfer (Tiwari and Tiwari 2007). Internal heat

transfer in a solar still consists of three modes viz; convection, radiation and

evaporation heat transfers.

Fig. 14.1 Schematic diagram of conventional single slope solar still

162 B. Jamil and N. Akhtar

The incoming solar radiation heats the blackened absorber of the solar still. Heat

is transferred from the heated absorber plate to the water in basin and from vapors to

inner surface of glass cover by convection. Radiative heat exchange occurs between

water interface and glass surface. Evaporative heat transfer occurs due to mass

transfer of vapors from the basin to inner surface of glass cover. While the external

heat transfer refers to heat exchange between the solar still and the surrounding

atmosphere. This consists of convection and radiation heat transfers. Heat is

transferred through convection between the glass cover and the ambient; and

bottom and side insulations and ambient. Radiative heat exchange occurs between

glass cover and sky. Heat transfer interactions of a solar still and the relationships to

model these mathematically are presented below.

Factors Affecting Performance of Solar Still

Meteorological parameters (such as solar intensity, ambient temperature and wind

velocity etc.), design features (such as slope of condensing cover, different cover

materials, various absorber material and their thickness and aspect ratio of absorber,

thickness of insulation etc.) and operational parameters (such as input water

temperature, effect of water depth, orientation of still etc.) have been extensively

studied and presented in literature for different designs under local operating

conditions of environment for various locations (Refalo et al. 2014). However,

meteorological parameters cannot be controlled. On the other hand design features

and operational parameters can be optimized for better yield from the solar still.

Some important studies related to factors that affect the performance of a solar still

are discussed below.

Manokar et al. (2014) presented an extensive review of factors affecting the

rate of evaporation and condensation on passive solar still. They reported that the

rate of evaporation is dependent on basin construction materials, depth of water in

basin, absorption rate of basin water, absorption rate of still basin, volumetric heat

capacity of the basin, inlet temperature of water and temperature of top surface

water. They also reported that the condensation rate is affected by glass cover

temperature and wind speed. As the wind velocity increases the cover temperature

decreases and hence an increase in the overall yield is observed (Dimri

et al. 2008). In other word, convective heat transfer increases with increase in

wind velocity.

A cover inclination equal to the latitude angle of the site help receive sun rays

close to normal throughout the year was reported by Murugavel et al. (2008).

Studies conducted on the effect of water depth in stills have shown that the highest

outputs and efficiencies occur at lower depths (Nafey et al. 2000).

14 Effect of Gap Between Absorber Plate and Condenser Cover on the Performance. . . 163

Performance Gap

It was observed from thorough literature review that although several solar still

designs are analysed in literature but the effect of distance (or gap) between the

absorber plate and the condensing cover has never been properly addressed. Only a

single study concerned with 2-D simulation study performed by Rahbar and

Esfahani (2013) reported that when the specific height of the solar still decreases,

the distance between the glass-cover and water-surface also decreases. This

enhances the convective heat transfer and, therefore, the condensation rate of

water-vapor increases. This is an important parameter since the distance between

the absorber plate and the condensing cover directly affect the amount of solar

radiation incident on the absorber plate. Also, the formation of water vapours in the

cavity is greatly affected. The distance vapours travels from the heated water

surface in absorber basin to condensing cover determines the yield of the solar

still. Hence, this distance (or gap) has to be experimentally analysed for optimum

solar still design.

Experimental Setup and Procedure

Fabrication of Solar Still

In this work, a conventional single slope solar still is designed and analysed for

desalination of brackish water. Solar still was fabricated using locally available

materials. Solar still is made out of Galvanised Iron (GI) sheet of 22 gauge. The

area of the absorber plate is 1 m2, with an aspect ratio of 2:1. Glass wool insulation

of 1 in. is provided around all the sides and bottom of the solar still to avoid heat

losses. The basin was painted black to maximize the absorption of solar radiation

in the solar still. Ordinary glass of 5 mm thickness forms the condensing cover

with the inclination of 28� (approximately equal to latitude of Aligarh City, 27.88�). Aluminium frame is used to support the glass cover over the solar still cavity and silicon sealant is used to fix the glass to the aluminium frame. An

aluminium trough is fixed along the lower edge of the condenser cover to collect

the condensate trickling from the inclined glass cover. Finally, a flexible rubber

tube transfers the condensate (distillate) to the collection bottle. Every possible

effort is made to make the solar still leak proof. The experimental setup was

aligned in a way so that the glass cover faces the exact south direction to receive

maximum solar radiation. Figure 14.2 shows the clear view of the experimental

setup (conventional solar still) and Fig. 14.3 gives the dimensional details of the

absorber/water basin.

164 B. Jamil and N. Akhtar

Instrumentation

• Temperatures were measured using T-type (copper-constantan) thermocouples.

Thermocouples were used to measure temperatures of absorber, water,

air-vapour mixture, glass inner and outer surface and ambient air. The output

of the thermocouples was read on a digital multimeter.

• Global solar radiation was measured using Kipp and Zonen Pyranometer

(CMP-11) and diffused solar radiation was measured using CMP-11 with

CM-121B shading ring. Difference of the two provides the beam radiation.

Global and diffused solar radiation values were stored in LOGBOX SD

datalogger.

Fig. 14.2 Actual view of experimental setup (conventional solar still)

Fig. 14.3 Details of absorber basin

14 Effect of Gap Between Absorber Plate and Condenser Cover on the Performance. . . 165

• Wind speed was observed using Precision AM804 CPM/CMM vane-type digital

anemometer.

• A borosil measuring flask with a least count of 1 ml was used to measure the

yield of distilled water from the solar still.

Observations

Experiments were conducted at Department of Mechanical Engineering, Aligarh

Muslim University, Aligarh (27.88�N, 78.08�E), Uttar Pradesh, India. The exper- iments have been conducted during the month of March 2015 on clear days under

similar conditions of environment.

Experiments were firstly conducted to investigate the depth of water. Solar

radiation, wind velocity and atmospheric temperatures were measured. The tem-

peratures, solar radiation intensity, wind speed and the distillate yield were

observed from morning 8 a.m. to evening 5 p.m.

A separate absorber plate was also fabricated for the solar still so that it can be

adjusted to effectively change the distance between the absorber and condenser

cover. The separate absorber can be raised from the bottom to change the height of

vapour chamber while the condensing cover remains fixed at top of the solar still.

Effect of varying the gap between absorber and condensing cover of the solar still is

presently analysed. The yield was analysed in terms of productivity of fresh water

per unit area of the absorber plate. Regular cleaning of deposits in the basin and

cleaning of dust on glass cover was taken care to maintain radiation absorption in

the absorber and transparency properties of glass respectively.

Results and Discussion

The first set of experiments was performed to verify the depth of water for

maximum water distillation in solar still. Figure 14.4 shows the measured temper-

ature of basin or absorber, water, air-vapours mixture and average glass tempera-

tures for different depths of water.

It is observed that the water temperature rises rapidly in case of lower depths and

gradually at higher depths. Also the highest temperature attained shows a phase

shift in case of higher depths.

Figure 14.5 shows the hourly and cumulative yield for different depths of water.

The variation of metrological parameters viz., solar radiation (global, diffused and

direct), ambient temperature and wind speed on the day of experiments are also

depicted.

It can be observed that the meteorological parameters were similar on the days of

experiment. The effect of increasing the depth of water in the basin has been

166 B. Jamil and N. Akhtar

analysed. It can be observed that increasing the depth of water in the basin reduces

the productivity (or yield) of the solar still.

Figure 14.6a shows the comparison of cumulative distillate yield for three

different depths of water Hw ¼ 1 cm, 2cm and 3cmð Þ. The observed cumula- tive yield during the day is 1260 ml, 1045 ml and 635 ml respectively. In other

words, twice the depth of water reduces the yield by 17.06% and thrice the depth of

water reduces the yield by 49.60%. This can be attributed to the higher amount of

energy required for heating and further evaporating a larger mass of water in the

basin. In other words, total specific energy requirement of the basin water increases.

Thus, it is verified that lower level of water should be kept in basin for better yield.

The distillation process continue even after the experiments were stopped

(at 5 p.m.) due to available thermal energy within the solar still. The distilled

Fig. 14.4 Comparison of temperature variation during the day for different depths of water (a) absorber or basin (b) water (c) vapour and (d) glass

14 Effect of Gap Between Absorber Plate and Condenser Cover on the Performance. . . 167

water collected between evening 5 p.m. to 7 a.m. the next morning (known as

“overnight productivity”) was also observed. It was found that increasing the

depth of water in the basin increases the overnight productivity (Fig. 14.6b).

But the amount of overnight distillate is small in comparison to daytime distillate.

Therefore, the total yield is still greater at lower depth of water. The observed

values of overnight distilled water were 30 ml, 55 ml, 96 ml for

Hw ¼ 1cm,ð 2cm and 3 cmÞ respectively. The second set of experiments was performed to investigate the effect of

distance between absorber plate and condenser cover on the performance of the

solar still. For this purpose a separate absorber was fabricated in the form of water

tray of approximately the same dimensions as the original absorber of the solar still.

This secondary absorber or water tray was then raised from the bottom with the help

of 1 in. thick polystyrene sheets as shown in Fig. 14.7. This effectively changes the

Fig. 14.5 Yield (hourly and cumulative) of distilled water for different depths of water in the basin along with observed solar radiation, ambient temperature and wind speed

168 B. Jamil and N. Akhtar

average distance between the absorber and condensing glass cover (H), thereby

reducing the height of vapour chamber.

Experiments were performed with different gaps as shown in figure above with

each time raising the absorber (or water tray) from the base by 1 in. Thus, H1

(¼15 in.) forms the first experiment with the largest distance between absorber and condenser cover and H4 (¼12 in.) forms the last experiment of the set with smallest distance between the absorber and condenser. For each experiment 1 cm depth of

water was maintained in the water tray throughout the experiment. Figure 14.8

shows the measured absorber, water, air-vapour mixture and glass temperatures for

different gaps between the absorber and condenser.

It can be observed that at the largest gap (H1), the observed temperatures are the

lowest while at the smallest gap (H4) the observed temperatures are the highest.

Fig. 14.5 (continued)

14 Effect of Gap Between Absorber Plate and Condenser Cover on the Performance. . . 169

Also, all the temperature curves show a similar trend with peak temperatures

between 12 p.m. to 1 p.m.

Figure 14.9a shows the observed hourly distillate yield for various gaps and

Fig. 14.9b compares the cumulative productivity of the solar still with different

gaps. It can clearly be observed that reducing the gap improves the distillate yield

significantly. This can be attributed to higher rate of convective heat transfer. As the

heated water surface and comparatively cooler glass surface comes closer the rate

of distillation increases. Therefore an increase in productivity is observed on

reducing the gap.

Observed yield at H1, H2, H3 and H4 are 1260 ml, 1964 ml, 2312 ml and

2695 ml respectively. Therefore, an increase of 55.87% (for H2), 83.49% (for H3)

and 113.88% (for H4) is observed in comparison to the base case (H1).

Fig. 14.5 (continued)

170 B. Jamil and N. Akhtar

Conclusions

A conventional single slope solar still was designed, fabricated and analysed for

desalination of brackish water. Initially, the effect of water depth was investigated.

It was found that increasing the depth of water in the basin of solar still decreases

the daytime productivity or yield. Also it was observed that the overnight produc-

tivity of the solar still increases with increase in water depth. These results verified

the investigations of previous researchers. Next, the effect of reducing the gap

Fig. 14.6 Comparison of (a) hourly cumulative yields (b) overall daytime, overnight and total yields at different depths of water

Fig. 14.7 Gap between absorber and condenser

14 Effect of Gap Between Absorber Plate and Condenser Cover on the Performance. . . 171

between absorber and condenser cover was experimentally evaluated. It was found

that reducing the gap increases the daily productivity. Reducing the gap increases

the convective heat transfer between the water surface and condenser cover.

This distance or gap is important because it directly affects the overall yield of

the solar still. It is believed that the results obtained under this study are valuable for

future solar still designs and optimization of heat and mass transfer processes

involved.

Fig. 14.8 Temperatures of (a) absorber or basin (b) water mass (c) air-vapour mixture (d) glass at different gaps between absorber and condenser

172 B. Jamil and N. Akhtar

References

Dimri, V., Sarkar, B., Singh, U., & Tiwari, G. (2008). Effect of condensing cover material on yield

of an active solar still: An experimental validation. Desalination, 227, 178–189. Manokar, A. M., Murugavel, K. K., & Esakkimuthu, G. (2014). Different parameters affecting the

rate of evaporation and condensation on passive solar still-A review. Renewable and Sustain- able Energy Reviews, 38, 309–322.

Murugavel, K., Chockalingam, K. K. S., & Srithar, K. (2008). Progresses in improving the

effectiveness of the single basin passive solar still. Desalination, 220, 677–686. Nafey, A. S., Abdelkader, M., Abdelmotalip, A., & Mabrouk, A. (2000). Parameters affecting

solar still productivity. Energy Conversion and Management, 41, 1797–1809. Rahbar, N., & Esfahani, V. (2013). Productivity estimation of a single-slope solar still: Theoretical

and numerical analysis. Energy, 49, 289–297. Refalo, P., Ghirlando, R., & Abela, S. (2014). The effect of climatic parameters on the heat transfer

mechanisms in a solar distillation still. Heat Transfer Engineering, 35(16-17), 1473–1481. Tiwari, A., & Tiwari, G. (2006). Effect of water depths on heat and mass transfer in a passive solar

still: In summer climatic condition. Desalination, 195, 78–94. Tiwari, A., & Tiwari, G. (2007). Thermal modeling based on solar fraction and experimental study

of the annual and seasonal performance of a single slope passive solar still: The effect of water

depths. Desalination, 207, 184–204.

Fig. 14.9 (a) Hourly yields for different gaps (H) between absorber and condenser cover. (b) Corresponding cumulative productivity

14 Effect of Gap Between Absorber Plate and Condenser Cover on the Performance. . . 173

Chapter 15

Solar Assisted Organic Rankine Cycle for Power Generation: A Comparative Analysis for Natural Working Fluids

€Onder Kizilkan, Sandro Nižetić, and Gamze Yildirim

Introduction

The steam Rankine cycle is one of the most important ways to transform on large

scale thermal energy into power. Because of its good properties, water is the most

suitable working fluid for high temperature applications and large centralized

systems. Seeking for small and medium scale power plants, the problems encoun-

tered with water can be partially mitigated by selecting an appropriate fluid.

Organic compounds characterized by higher molecular mass and lower critical

temperature than water have been proposed in so called Organic Rankine Cycles

(ORC) (Tchanche et al. 2011). ORC, as a method of low grade heat utilization can

rise the energy utilization by conversion of heat into electric energy

(He et al. 2012). There are lots of low temperature practices in which the ORC

can be used such as solar thermal, biomass geothermal oceanic, waste heat from

power plants, combined heat and power, waste heat from industrial processes, etc.

(Peris et al. 2015).

The development of solar assisted power plants is becoming more crucial

because of effects of fossil fuels. For this reason, there is a need to improve existing

technologies integrated with solar energy. These systems offer better advantages

Ö. Kizilkan • G. Yildirim (*) Department of Energy Systems Engineering, Faculty of Technology,

Süleyman Demirel University, 32200 Isparta, Turkey

e-mail: [email protected]; [email protected]

S. Nižetić Department of Thermodynamics and Heat Engines, Faculty of Electrical

and Mechanical Engineering and Naval Architecture,

University of Split, R. Boskovica 32, 21000 Split, Croatia

e-mail: [email protected]

175

mailto:[email protected]

when compared traditional energy sources. Parabolic trough solar collector

(PTSC) technology is considered the most established solar thermal technology

for power generation. Therefore, this technology has been chosen for this study

(Al-Sulaiman 2013).

Organic Rankine Cycle (ORC) as a promising energy transformation technology

has been the focus of many investigators (Kerme and Orfi 2014). Over the last

decades, significant researches have been carried out in the field of ORC systems.

Dai et al. (2009) studied ORC for low grade waste heat recovery using various

fluids. They examined thermodynamic parameters of the ORC for every working

fluid. They concluded that the cycle with R236EA had the highest exergy perfor-

mance. He et al. (2012) recommend a theoretical model to check out optimal

evaporation temperature of subcritical ORC. In a different study, organic Rankine

cycle and supercritical Rankine cycle for the transformation of low-grade heat into

electrical power investigated by Chen et al. (2010). They analysed 35 different

fluids for two cycles and analysed the effects of the selected fluid characteristics on

the cycle performance. Wang et al. (2013) conducted a regenerative ORC to make

use of the solar energy over a low temperature series. They used flat-plate solar

collectors to collect the solar radiation for their low costs. Lee et al. (2012) inves-

tigated the impact of changing the proportion of the cooling water to the condenser

on the performance of the ORC. They used R245fa in their analysis. Shengjun

et al. (2011) studied performance comparison of the fluids in subcritical and

transcritical ORC power cycle in 80–100 �C binary geothermal power system. They conducted the analyses with a program in MATLAB for thermal efficiency,

exergy efficiency, recovery efficiency, heat exchanger area and levelized energy

cost. Thermodynamic optimization of ORCs for power generation combined

heating and power from different average heat source profiles researched by

Maraver et al. (2014). Vélez et al. (2011) investigated the use of a low temperature

heat source for power generation a carbondioxide transcritical power cycle theo-

retically. They reported that the efficiency have been increased by the use of an

additional internal heat exchanger. Franchini et al. (2013) carried out simulations to

estimate the performance of a solar Rankine Cycle and an integrated solar com-

bined cycle. They combined the system with two different solar field configurations

based on parabolic trough and power tower systems.

In this study, solar energy driven ORC is investigated thermodynamically for

different natural refrigerants. For collecting the solar energy, PTSCs are used

because of their good advantages. For the analyses of ORC, eight natural working

fluids and a HFC type fluid are considered including, R170 (ethane), R1270

(propylene), R600 (butane), R600a (isobutene), R717 (ammonia), R744

(carbondioxide), R161 (fluoroethane), R218 (octofluoropropane), and a HFC type

fluid, R134a. Analyses are made to examine the system performances energetically

and exergeticaly. An attempt is also made to evaluate the exergy destruction rates in

order to determine how to improve the process. Furthermore, a comprehensive

performance assessment of the integrated system is conducted through parametric

analysis to investigate the effects of changing operating conditions on the system

efficiencies.

176 Ö. Kizilkan et al.

Natural Refrigerants and System Description

Natural refrigerants provide alternatives to a number of HCFC, CFC and HFC type

refrigerants in addition to their zero ozone depletion potential (ODP) and low or no

global warming potential (GWP) (Bolaji and Huan 2013). They are naturally

occurring substances, such as hydrocarbons, ammonia, carbon dioxide, water and

air. These substances can be used as cooling agents (heat transfer medium) in

refrigerators and air conditioners (Refrigerants naturally 2015).

The general properties of the previously mentioned working fluids are given in

Table 15.1 (ASHRAE 2004; Restrepo et al. 2008; Calm and Hourahan 2011).

In the table, critical properties of the fluids are obtained using EES software

(F-Chart 2015). As seen from the table, the selected natural refrigerants have zero

ODP and relatively very small GWP values excluding R218 and R134a. Addi-

tionally, their atmospheric life times are relatively short. In spite of this, it must

be noted that some natural refrigerants such as R170, R1270, R600, R600a and

R161 are in A3 safety group which means they are highly flammable. Besides,

R744, R218, R134a are belonged to A1 group that means they are

non-flammable. The last fluid, R717, is in the lower flammability group with

higher toxicity.

The ORC consists of four compounds: a turbine, an evaporator, a condenser and

a pump. Required heat energy for the evaporator of the ORC is supplied by means

of PTSCs. Therminol-VP1 is for the PTSC system as the heat transfer fluid (HTF),

for its good heat transfer properties and good temperature control (Therminol

2014). Because of its good properties, it is used in many high temperature applica-

tions driven by PTSC such as power plants (Kumar and Reddy 2009; Vogel

et al. 2014; Cheng et al. 2012; Al-Sulaiman 2014). The system operates as follows:

The liquid organic working fluid from condenser is compressed by the pump and

fed back to the evaporator, where it is heated by the useful heat delivered by the

solar PTSCs, and becomes superheated vapor. The superheated vapor then enters to

the turbine and expands to a low pressure. Subsequently, the turbine exhaust is

intensified to liquid in the condenser by extracting heat to the environment and the

cycle completes when the fluid is compressed by the pump. The schematic repre-

sentation of the system and the T–s diagrams of the case study are given in

Figs. 15.1 and 15.2 respectively.

In Fig. 15.2, there are two T–s diagrams, where the first one is for subcritical

and the second one is transcritical cycle. In subcritical cycle, the system properties

are under the critical values and in transcritical cycle, the heat absorption process

takes place above the critical values where heat rejection process takes place

below the critical values. For the second case, the gas heater placed instead of

evaporator.

15 Solar Assisted Organic Rankine Cycle for Power Generation: A Comparative. . . 177

T a b le

1 5 .1

P ro p er ti es

o f th e se le ct ed

w o rk in g fl u id s

A S H R A E n u m b er

M o le cu la r fo rm

u la

C ri ti ca l

p re ss u re

(k P a)

C ri ti ca l

te m p er at u re

(� C )

S af et y

g ro u p

O D P (r el at iv e

to R 1 1 )

G W P (r el at iv e

to C O 2 )

A tm

o sp h er ic

li fe

ti m e (y ea r)

R 1 7 0

C H 3 C H 3

4 8 7 2 .2

3 2 .1 7 2

A 3

0 2 0

0 .2 1

R 1 2 7 0

C H 3 C H ¼C

H 2

4 6 6 4 .6

9 2 .4 2 0

A 3

0 3

0 .0 0 1

R 6 0 0

C H 3 C H 2 C H 2 C H 3

3 7 9 6 .0

1 5 1 .9 7 5

A 3

0 2 0

0 .0 1 8

R 6 0 0 a

C H (C H 3 ) 3

3 6 4 0 .0

1 3 4 .6 6 7

A 3

0 2 0

0 .0 1 9

R 7 1 7

N H 3

1 1 ,3 3 3

1 3 2 .2 5

B 2

0 0

0 .2 5

R 7 4 4

C O 2

7 3 7 7 .3

3 0 .9 8

A 1

0 1

1 2 0

R 1 6 1

C H 3 C H 2 F

5 .0 9

1 0 2 .2 0

A 3

0 1 2

0 .1 8

R 2 1 8

C F 3 C F 2 C F 3

2 .6

7 1 .9 5

A 1

0 8 8 3 0

2 6 0 0

R 1 3 4 a

C H 2 F C F 3

4 0 5 9 .0

1 0 1 .0 3 0

A 1

0 .0 0 0 0 1 5

1 4 1 0

1 4

178 Ö. Kizilkan et al.

Thermodynamic Analysis

The performance of the solar driven ORC is mathematically modelled using mass,

energy and exergy balance equations. Some assumptions are made in order to find

the work and heat interactions, the rate of exergy destructions, and the energy and

exergy efficiencies. These are as follows:

• All the processes in the system are steady state and steady flow.

• The changes in potential and kinetic energies are neglected.

• The turbine and pumps are adiabatic.

• The heat transfer to/from ambient and pressure drops in the pipes are neglected.

Fig. 15.1 Schematic representation of solar assisted ORC system (modified from Volker 2015)

T T

a b

Fig. 15.2 T–s diagrams for ORC (a) subcritical (b) transcritical

15 Solar Assisted Organic Rankine Cycle for Power Generation: A Comparative. . . 179

• The natural fluid at pump inlet is saturated liquid.

• The dead state pressure and temperature are taken to be P0¼ 101.325 kPa and T0¼ 25 �C.

• The pinch point temperature of the evaporator and condenser/gas heater are

taken as 10 �C (Al-Sulaiman 2014).

The general mass balance equation can be written as (Cengel and Boles 2006):X _m in ¼ X

_m out

ð15:1Þ

where m is the mass flow rate, subscripts in and out are entering and exiting streams

to and from the system, respectively.

The general energy balance X _E in ¼ X

_Eout ð15:2Þ

For steady-flow processes the general energy balance can be written in more

detail as:

_Q þ X

_m in hin ¼ _W þ

X _m out hout ð15:3Þ

In above equations, Ein is the ratio of net energy transfer to the system, Eout is

the ratio of net energy transfer from the system, Q is the ratio of net heat, W is the

ratio of net work, and h is the specific enthalpy.

The rate of useful energy delivered by solar collector is (Tiwari 2003;

Kalogirou 2009)

_Qu ¼ FR SAa � ArUL Ti � T0ð Þ½ � ð15:4Þ

_Qu ¼ _mcp T0 � Tið Þ ð15:5Þ

where FR is the heat removal factor, S is the solar irradiation, Aa is the aperture area,

Ar is the receiver area, UL is the overall heat loss coefficient of solar collector,

subscripts i, o and 0 are inlet, outlet and dead state, respectively.

The heat removal factor, FR can be calculated from (Kalogirou 2009)

FR ¼ _mCp ArUL

1� exp �ArULF 0

_mCp

� �� ð15:6Þ

where F’ is the collector efficiency factor and given by

F0 ¼ U0 UL

ð15:7Þ

180 Ö. Kizilkan et al.

In Eq. (15.7), U0 is the overall heat transfer coefficient. Based on PTSC

properties, U0 and UL can be determined from (Kalogirou 2009):

U0 ¼ 1 UL

þ Do hfDi

þ Doln

Do Di

0 @

1 A

2 4

3 5 �1

ð15:8Þ

UL ¼ Ar hc,c�a þ hr,c�að ÞAg þ

hr, r�c

� ��1 ð15:9Þ

In above equations, hc,c-a is the convection heat loss coefficient between ambient

and the cover, hr,c-a is the radiation heat transfer coefficient for the glass cover to the

ambient, hr,r-c is the radiation heat transfer coefficient between the receiver tube and

the glass cover and hf is the heat transfer coefficient of fluid inside the tube.

Additionally, D is the tube diameter and Ag is the glass cover area. The definitions

of heat transfer coefficients mentioned above can be found in reference Kalogirou

(2009) in more detail.

The general exergy balance equation can be defined as (Dincer and Rosen 2007):X _Exin ¼

X _Ex

out þ X

_Ex dest

ð15:10Þ

The exergy balance equation can be expressed more explicitly as:

_ExQ � _ExW � X

_m in ein �

X _m out eout þ T0 _Sgen ð15:11Þ

where, ExQ and ExW terms are the exergies of heat and work, e is the specific

exergy, T0 is the dead state temperature and Sgen is the rate of entropy generation.

The exergy terms in Eq. (15.11) are described below (Dincer and Rosen 2007):

_Exdest ¼ T0 _Sgen ð15:12Þ

_ExQ ¼ _Q T � T0 T

� � ð15:13Þ

_ExW ¼ _W ð15:14Þ

The specific exergy can be expressed as (Cengel and Boles 2006; Bejan 1997):

e ¼ h� h0ð Þ � T0 s� s0ð Þ ð15:15Þ where, s is entropy, and subscript 0 stands for dead state properties.

The exergy of the solar radiation in terms of reference and sun’s temperature is given by Petela (2005):

15 Solar Assisted Organic Rankine Cycle for Power Generation: A Comparative. . . 181

_Exsolar ¼ SAa 1þ 1 3

T0 Tsun

� �4 � 4 3

T0 Tsun

� � ! ð15:16Þ

where Tsun is the temperature of sun’s surface and assumed as 5739 K (Tiwari 2003).

The energy and exergy efficiencies are described below (Dincer and

Rosen 2007):

η ¼ _WORC _QE

ð15:17Þ

ηex ¼ _Exout _Exin

¼ 1� _Exdest _Exin

ð15:18Þ

Results and Discussion

For the thermodynamic analyses of the solar driven ORC, the system parameters for

baseline conditions are given in Table 15.2. System characteristics of solar assisted

ORC Table 15.2.

Using the general balance equations given in previous section, the analyses were

made for the base line conditions first. According to data given in Table 15.2,

the turbine power generations for different working fluids are given in Fig. 15.3.

Table 15.2 System characteristics of solar assisted ORC

PTSC system (Al-Sulaiman 2014;

Kalogirou 2009)

Pipe receiver inner diameter 0.04 m

Pipe receiver outer diameter 0.05 m

Glass cover diameter 0.09 m

Total length of PTSC 50 m

Mass flow rate of HTF 0.32 kg/s

Receiver emissivity 0.92

Glass cover emissivity 0.87

Temperature of the sun 5739 K

Absorbed solar radiation 500 W/m2

Wind velocity 5 m/s

ORC Turbine isentropic efficiency 0.85

Pump isentropic efficiency 0.90

Evaporator temperaturea 50 �C Condenser temperature 27 �C Turbine inlet temperature 150 �C

aTurbine inlet pressure of ORC is determined from saturation pressure corresponding to evaporator

temperature excluding R170 and R744, since the critical properties of these fluids are below from

the specified values

182 Ö. Kizilkan et al.

As seen from the figure, ORC working with R744 has the highest power generation

capacity and followed by R170, R717 and R161.

Figures 15.4 and 15.5 show the energy and exergy efficiencies of ORC for

different working fluids according to the energy and exergy analysis. As seen

from Fig. 15.4, the best energy performance is obtained using R744 with an energy

efficiency of 8%, whereas the lowest energy efficiency belongs to R218 with an

efficiency rate of 4.3%. The exergy efficiency results show that the highest

efficiency is found to be 7.1% with R744 and followed by R170 and R717.

A comparison of the calculated exergy destruction rates of the solar assisted

ORC is given in Fig. 15.6. As seen from the figure, R218 has the highest exergy

destruction rate and followed by R600a, R600 and R134a. The lowest exergy

destruction rate is found to be 75.33 kW using R717.

Fig. 15.3 Comparison of net power generation for different natural refrigerants

Fig. 15.4 Comparison of energy efficiencies of ORC for different natural refrigerants

15 Solar Assisted Organic Rankine Cycle for Power Generation: A Comparative. . . 183

In Fig. 15.7, exergy destruction in the heat transfer process between the HTF and

the working fluid in the evaporator is given. As mentioned earlier, Therminol-VP1

was used as HTF and its properties were kept constant during the calculations.

Therefore, the differences between exergy destruction of evaporator is mainly

depends on the working fluid properties. From the figure, it can be seen that the

lowest exergy destruction rate in the evaporator is found to be 16.55 for R170,

followed by R218 and R744 where evaporator of R717 has the highest exergy

destruction with 19.41 kW.

Through parametric analyses, a comprehensive performance assessment of the

integrated system was conducted to investigate the effects of varying operating

conditions on the system efficiencies. For the parametric analyses, the variable

parameters were selected to be solar radiation intensity, turbine inlet temperature,

Fig. 15.5 Comparison of exergy efficiencies of ORC for different natural refrigerants

Fig. 15.6 Comparison of exergy destruction rates of ORC for different natural refrigerants

184 Ö. Kizilkan et al.

and normalized pressure at the turbine inlet and condenser temperature. Figure 15.8

shows the variation of solar radiation intensity with turbine power generation. As

seen from the figure, turbine power generation increases with increase of solar

radiation from 350 to 800 W/m2.

Turbine inlet temperature also affects the cycle performance characteristics. To

determine the variation of turbine inlet temperature on energy and exergy efficien-

cies, it was varied between 70–150 �C (Figs. 15.9 and 15.10). As seen from the figures, with the increase of turbine inlet temperature, energy and exergy efficien-

cies increase for R717. For the working fluids R744, R170, R134a, R600, R600a

and R218, the efficiencies decrease whereas they are not affected so much for R161

and R1210 with the temperature.

Figure 15.11 shows the variation of turbine inlet temperature with the total

exergy destruction rate of the system. As seen from the figure, the trend is contrary

Fig. 15.7 Comparison of exergy destruction rates of evaporator for different natural refrigerants

Fig. 15.8 Variation of net power generation with solar radiation

15 Solar Assisted Organic Rankine Cycle for Power Generation: A Comparative. . . 185

Fig. 15.9 Variation of turbine inlet temperature with energy efficiency

Fig. 15.10 Variation of turbine inlet temperature with exergy efficiency

Fig. 15.11 Variation of turbine inlet temperature with exergy destruction rate

186 Ö. Kizilkan et al.

to energy and exergy efficiency variation. The total exergy destruction rate

decreases with increasing the turbine inlet temperature for R1270, R717, R744,

R170, it increases for R600a, R134a, R600, R218 and R161.

The condensation temperature is also one of the important parameter for assess-

ment of the system performance. To determine its effect on system performance, it

was changed from 25 �C to 30 �C and energy, exergy efficiencies and exergy destruction rates were calculated (Figs. 15.12, 15.13 and 15.14). The results are

showed that, the energy and exergetic efficiencies decrease with the increase of the

condenser temperature for all working fluids except for R744 and R170. This result

is interesting since these two fluids are transcritical fluids. On contrary to this, the

total exergy destruction rate increase with the temperature, while for R744 and

R170 it decreases.

As declared in Table 15.2 at the beginning of this section, working pressures of

solar assisted ORC were determined according to the corresponding saturation

Fig. 15.12 Variation of condensation temperature with energy efficiency

Fig. 15.13 Variation of condensation temperature with exergy efficiency

15 Solar Assisted Organic Rankine Cycle for Power Generation: A Comparative. . . 187

temperatures of evaporator for subcritical working fluids. For transcritical fluids,

the pressures were determined from the literature. Since the pressure values

of each working fluid differs from each other, they were normalized and the

figures were plotted using normalized pressure ranges for better understanding

of the results.

Figures 15.15 and 15.16 show the variation of energy and exergy efficiencies

with normalized turbine inlet pressure. It is very clear from the figures that with the

increase of turbine inlet pressure, efficiencies increase, too.

The effect of normalized turbine inlet pressure on the exergy destruction is given

in Fig. 15.17. From the figure, exergy destruction rates decrease with the turbine

inlet pressure since the exergy destruction rate is inversely proportional to the

energy and exergy efficiencies.

Fig. 15.14 Variation of condensation temperature with exergy destruction rate

Fig. 15.15 Variation of normalized turbine inlet pressure with energy efficiency

188 Ö. Kizilkan et al.

Conclusions

A comparative analysis of solar assisted Organic Rankine Cycle for power gener-

ation using natural working fluids was investigated. The analyses were carried out

for environmentally friendly subcritical and transcritical natural working fluids.

The heat energy demand of the ORC was supplied using PTSCs working with

Therminol-VP1 as the heat transfer fluid. From the results it was observed that the

best cycle performance was obtained using R744 with a power generation rate of

4.87 kW and followed by R170, R717 and R161. Energy analysis results showed

that the best cycle had an energy efficiency of 8% using R744 as working fluid. The

exergy efficiency of the same cycle was found to be 7.1%. The highest total exergy

destruction rate was found to be 76.98 kW for R218. Additionally, the effects of

turbine inlet temperature, turbine inlet pressure and condensation temperature on

Fig. 15.17 Variation of normalized turbine inlet pressure with exergy destruction rate

Fig. 15.16 Variation of normalized turbine inlet pressure with exergy efficiency

15 Solar Assisted Organic Rankine Cycle for Power Generation: A Comparative. . . 189

system performance were analysed for different working fluids. This study points

out that natural refrigerants are compatible with ORC power generation systems

and more detailed experimental studies should be carried out for green energy

production assisted by solar energy.

Nomenclature

Aa Aperture area, m 2

Ag Glass cover area, m 2

Ar Receiver area, m 2

Cp Specific heat, kJ/kg K

D Tube diameter, m

e Specific exergy, kJ/kg _E: Energy, kW

_E x Exergy, kW

F’ Collector efficiency factor

FR Heat removal factor

h Specific enthalpy, kJ/kg

hc,c-a Convection heat loss coefficient between ambient and the cover, kW/m 2K

hr,c-a Radiation heat transfer coefficient for the glass cover

to the ambient, kW/m2K

hf Heat transfer coefficient of fluid inside the tube, kW/m 2K

hr,r-c Radiation heat transfer coefficient between the receiver tube

and the glass cover, kW/m2K

ṁ Mass flow rate, kg/s _Q: Heat, kW

s Specific entropy, kJ/kg K _S: Entropy, kW/K

S Solar irradiation, kW/m2

T Temperature, �C or K UL Overall heat loss coefficient, kW/m

2 K _W: Work, kW

U0 Overall heat transfer coefficient, kW/m 2 K

Greek Letters

η Efficiency

Subscripts

dest Destruction

gen Generation

190 Ö. Kizilkan et al.

i Inlet

o Outlet

u Useful

0 Dead state

References

Al-Sulaiman, F. A. (2013). Energy and sizing analyses of parabolic trough solar collector

integrated with steam and binary vapor cycles. Energy, 58, 561–570. Al-Sulaiman, F. A. (2014). Exergy analysis of parabolic trough solar collectors integrated with

combined steam and organic Rankine cycles. Energy Conversion and Management, 77, 441–449.

ASHRAE. (2004). Designation and safety classification of refrigerants. Atlanta, GA: ANSI/ ASHRAE Standard 34-2001.

Bejan, A. (1997). Advanced engineering thermodynamics. New York: John Wiley and Sons. Bolaji, B. O., & Huan, Z. (2013). Ozone depletion and global warming: Case for the use of natural

refrigerant. Renewable and Sustainable Energy Reviews, 18, 49–54. Calm, J. M., & Hourahan, G. C. (2011). Physical, safety, and environmental data summary for

current and alternative refrigerants. In Proceedings of the 23rd international congress of refrigeration, Prague, Czech Republic, August 21–26, 2011.

Cengel, Y. A., & Boles, M. A. (2006). Thermodynamics: An engineering approach (5th ed.). New York, USA: McGraw-Hill.

Chen, H., Goswami, D. Y., & Stefanakos, E. K. (2010). A review of thermodynamic cycles and

working fluids for the conversion of low-grade heat. Renewable and Sustainable Energy Reviews, 14, 3059–3067.

Cheng, Z. D., He, Y. L., Cui, F. Q., Xu, R. J., & Tao, Y. B. (2012). Numerical simulation of a

parabolic trough solar collector with nonuniform solar flux conditions by coupling FVM and

MCRT method. Solar Energy, 86, 1770–1784. Dai, Y., Wang, J., & Gao, L. (2009). Parametric optimization and comparative study of organic

Rankine cycle (ORC) for low grade waste heat recovery. Energy Conversion and Management, 50, 576–582.

Dincer, I., & Rosen, M. A. (2007). Exergy: Energy, environment and sustainable development (1st ed.). Amsterdam: Elsevier Science.

F-Chart, F-Chart Software. Retrieved February 1, 2015, from http://www.fchart.com/.

Franchini, G., Perdichizzi, A., Ravelli, S., & Barigozzi, G. (2013). A comparative study between

parabolic trough and solar tower technologies in Solar Rankine Cycle and Integrated Solar

Combined Cycle plants. Solar Energy, 98, 302–314. He, C., Liu, C., Gao, H., Xie, H., Li, Y., Wu, S., et al. (2012). The optimal evaporation temperature

and working fluids for subcritical organic Rankine cycle. Energy, 38, 136–143. Kalogirou, S. A. (2009). Solar energy engineering: processes and systems (1st ed.). Oxford:

Academic Press.

Kerme, E. D., & Orfi, J. (2014). Exergy- based thermodynamic analysis of solar driven organic

Rankine cycle. Journal of Thermal Engineering, 33, 192–202. Kumar, K. R., & Reddy, K. S. (2009). Thermal analysis of solar parabolic trough with porous disc

receiver. Applied Energy, 86, 1804–1812. Lee, Y. R., Kuo, C. R., & Wang, C. C. (2012). Transient response of a 50 kW organic Rankine

cycle system. Energy, 48, 532–538.

15 Solar Assisted Organic Rankine Cycle for Power Generation: A Comparative. . . 191

http://www.fchart.com/

Maraver, D., Royo, J., Lemort, V., & Quoilin, S. (2014). Systematic optimization of subcritical

and transcritical organic Rankine cycles (ORCs) constrained by technical parameters in

multiple applications. Applied Energy, 117, 11–29. Peris, B., Navarro-Esbri, J., Moles, F., Collado, R., & Mota-Babiloni, A. (2015). Performance

evaluation of an organic Rankine cycle for power applications from low grade heat sources.

Applied Thermal Engineering, 75, 763–769. Petela, R. (2005). Exergy analysis of the solar cylindrical-parabolic cooker. Solar Energy, 79,

221–233.

Refrigerants naturally, C/O Heat International. Retrieved February 2, 2015, from http://www.

refrigerantsnaturally.com/.

Restrepo, G., Weckert, M., Brüggemann, R., Gerstmann, S., & Frank, H. (2008). Ranking of

refrigerants. Environmental Science & Technology, 42, 2925–2930. Shengjun, Z., Huaixin, W., & Tao, G. (2011). Performance comparison and optimization of

subcritical ORC and transcritical power cycle system for low-temperature geothermal power

generation. Applied Energy, 88, 2740–2754. Tchanche, B. F., Lambrinos, G., Frangoudakis, A., & Papadakis, G. (2011). Low-grade heat

conversion into power using organic Rankine cycles—A review of various applications.

Renewable and Sustainable Energy Reviews, 15, 3963–3979. Therminol, Heat transfer fluids by Eastman. Therminol VP-1. Retrieved December 10, 2014, from

http://www.therminol.com/products/Therminol-VP1.

Tiwari, G. N. (2003). Solar energy: Fundamentals, design, modelling and applications. Pangbourne: Alpha Science International Ltd.. 525 p.

Vélez, F., Segovia, J., Chejne, F., Antolin, G., Quijano, A., & Martı́n, M. C. (2011). Low

temperature heat source for power generation: Exhaustive analysis of a carbondioxide

transcritical power cycle. Energy, 36, 5497–5507. Vogel, T., Oeljeklaus, G., G€orner, K., Dersch, J., & Polklas, T. (2014). Hybridization of parabolic

trough power plants with natural gas. Energy Procedia, 49, 1238–1247. Volker. Retrieved January 14, 2015, from http://www.volker-quaschning.de/articles/fundamen

tals2/index_e.php.

Wang, M., Wang, J., Zhao, Y., Zhao, P., & Dai, Y. (2013). Thermodynamic analysis and

optimization of solar-driven regenerative ORC based on flat-plate solar collectors. Applied Thermal Engineering, 50, 816–825.

192 Ö. Kizilkan et al.

http://www.volker-quaschning.de/articles/fundamentals2/index_e.php

http://www.therminol.com/products/Therminol-VP1

http://www.refrigerantsnaturally.com/

Chapter 16

Rainfall Trend Analysis in the Region of Curitiba Using Regional Climate Model Scenarios

Robinson Ploszai and Miriam Rita Moro Mine

Introduction

The climate change studies in hydrological time series have a great scientific and

practical importance in water management. In general, the water resources systems

are designed assuming that the hydrological data series (streamflow or precipita-

tion) are statistically stationary (Alexandre et al. 2010).

The operational management of water resources is predicted assuming the

hydrologic stationarity. According to Matalas (1997), the designers are uncertain

about how the global warming can be converted in a hydrologic non-stationarity

and how this non-stationarity could be incorporated into water resources

management.

In the context of climatic changes in hydrological time series, it is not possible to

assume whether these changes are related to anthropogenic causes (e.g., land uses

changes or greenhouse gas emissions) or to natural climate variability, which is a

consequence from multi annual or secular cycles in the Earth’s climate (Tucci 2002).

Applying a probabilistic method in a large hydrological time series (e.g.,

100 years or more with the minimum gaps or incorrect data), it is possible to

identify changes in the time series, even if these changes are cyclical or related to

trends. These changes do not distinguish the natural effects from anthropogenic

effects.

To detect trends in time series, several studies have been performed worldwide

(Coscarelli and Caloiero 2012; Li et al. 2011; Sayemuzzaman and Jha 2014;

Oguntunde et al. 2011; Wang et al. 2008; Liang et al. 2011; Stipp et al. 2013;

Fisch and Folhes 2006; Romano et al. 2011; Meschiatti et al. 2012; among others).

R. Ploszai (*) • M.R.M. Mine Federal University of Parana, PO Box 19011, 81531-990 Curitiba, PR, Brazil

e-mail: [email protected]; [email protected]

193

mailto:[email protected]

According to these authors, the most efficient methods in trends detection are the

Mann Kendall and Seasonal Mann Kendall tests and linear regression.

Statistical methods in both time series: the measured monthly precipitation and

the rainfalls generated by Regional Climate Models (RCM) were applied. This

paper verifies whether the RCM simulations can reproduce the historical period

data and analyses precipitation trends through 2100 in the region of Curitiba to

develop tools that will allow safety measure criteria to be taken for water resources

management.

Methods

According to Kundzewicz and Robson (2000), before performing any statistical

analysis, such as the application of a test or a method, it is necessary to do the

Exploratory Data Analysis (EDA) on the preliminary data. These authors state that

an analysis trend study is incomplete if the EDA is not used.

The EDA consists in using graphics and other heuristic methods to explore,

understand and represent the information. Several methods are used to evaluate

trends in time series, such as histograms and your relation with the normal proba-

bility distribution, temporal and autocorrelation graphs, normality tests, and serial

independence tests and analysis of the smoothing curves (Kundzewicz and Robson

2000). Linear regression is a powerful tool to evaluate the existence of a secular

trend in hydrological variables. The linear regression method in this case is

represented by Eq. (16.1)

yt ¼ b1 � tþ b0 þ Et ð16:1Þ

where t is a time counter ðt ¼ 1, 2, . . . , nÞ; yt is the hydrological variable (precip- itation) on time t; b1 is the angular coefficient of the regression’s line; b0 is the linear coefficient of the regression’s line; and E assumes the errors of the regression. After assuming some hypothesis and that the error E is normally distributed, the param- eters b1 and b0 are estimated by Ordinary Least Squares, solving the Gauss’s normal equations (Johnson 1984).

Adopting the residuals of the linear regression as normally distributed, this

hypothesis can be tested using the t-test, well described in Sharma et al. (2000).

According to Alemaw and Chaoka (2002), another important tool to detect possible

trends in hydrological time series is the Rescaled Adjusted Partial Sums (RAPS)

method. According to these authors, the sum of a RAPS represented in a function Y

(t) is defined by Eq. (16.2).

Xk ¼ Xk t¼1

YðtÞ � Y SY

ð16:2Þ

194 R. Ploszai and M.R.M. Mine

where the value of k ¼ 1, 2, . . . , n. The variable Xk is the RAPS at limit k; Y(t) is the value of the variable at time t; Y is the mean of the sample values; SY is the

sample’s standard deviation; and k is the counter limit of the actual sum. The significance of RAPS analysis and EDA can be tested through the application of

statistical tests, such as a t-test and a Fisher-Snedecor test for annual analysis and

the Mann Whitney test and rho’s Spearman coefficient test for seasonal analysis. These tests are fully described in Tozzi (2014).

Other tools were used (statistical indexes), such as the Nash-Sutcliffe

(NS) coefficient, the index Root-Mean-square-Error (RMSE), and the determina-

tion coefficient (R2). All methods are well described by Moriasi et al. (2007),

Hyndman and Koehler (2006), and Naghettini and Pinto (2007), respectively. To

evaluate the significance of the time series, the mean, median, variance, standard

deviation, kurtosis excess, and asymmetry of the series under a confidence interval

of 95% were all estimated.

A common and practical issue in analysing hydrological time series consists in

finding statistical techniques to verify the occurrence of some variation along the

period (Buishand 1984). In order to do that, some statistical methods, such as the

Mann Kendall test and Seasonal Mann Kendall test, were applied to analyse trends

in hydrological time series.

The Mann Kendall and Seasonal Mann Kendall tests are largely used to verify

homogeneity in hydrological time series. According to Back (2001), Barros

et al. (2011), Buchir (2013), and Müller et al. (1998), the Mann Kendall test

application is the most powerful in analysing climatic changes from climatological

time series because it allows the beginning of the trend can be detected.

The Mann Kendall test consists in comparing each value in a chronological time

series with the residuals, always ordered on the time. Hence, the number of times

that the result terms are lower than the analysed terms is counted. The statistics of

the MK test (SMK) are given by Eq. (16.3).

SMK ¼ Xn j¼1

Xn i¼jþ1

signal Rj � Ri � � ð16:3Þ

where n is the number of observations; Ri is the previous observation; Rj is the latest

observation; i is the position of Ri at the previous time; j is the position of Rj at the

latest time. The signal is defined through conditions, as represented by Eq. (16.4)

signal Rj � Ri � � ¼ 1, if Rj � Ri > 00, if Rj � Ri ¼ 0

�1, if Rj � Ri < 0

8< : ð16:4Þ

It is possible to apply the Mann Kendall test to investigate trends on time series,

only if the series has shown serial independence. Therefore, the series observations

are tested to see if they are independent and identically distributed, in other words,

to check the hypothesis:

16 Rainfall Trend Analysis in the Region of Curitiba Using Regional Climate. . . 195

H0: The series observations are independent and identically distributed; H1: The

series observations have some trends along the period.

It is possible to show under a null hypothesis that S_MK is normally distributed

with null mean, according to Eq. (16.5). The statistic is calculated by Eq. (16.6)

EðSMKÞ ¼ 0 and VARðSMKÞ ¼ n� ðn� 1Þ � ð2nþ 5Þ 18

ð16:5Þ

MK ¼

SMK � 1ffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi VAR SMKð Þ

p , if SMK > 0 0, if SMK ¼ 0

SMK þ 1ffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi VAR SMKð Þ

p , if SMK < 0

8>>>>< >>>>:

ð16:6Þ

Even for values lower than 30, it is possible to use the statistics MK ¼ Z to do the test. In a bilateral test, the null hypothesis, H0, is rejected given a 95% significance

interval α, in the case of the quartile values Zα/2, pursuing a normal standard distribution, or MK � Zα=2.

The Seasonal Mann Kendall was proposed by Hirsch et al. (1982) and later was

improved by Hirsch and Slack (1984). It has been created due to the difficulties in

facing seasonality’s climate events. This test is an adaptation of the Mann Kendall’s test. It is an alternative to control the difficulties imposed by the high observational

seasonal variabilities (Buchir 2013). According to Fisch and Folhes (2006), this test

is largely recommended by the World Meteorological Organization (WMO) in

detecting trends or abrupt changes in climate time series.

According to Lettenmaier et al. (1994) and Blain (2011), in the case of the

monthly series, the MKS can be calculated, organizing the data into a matrix. The

columns are filled with the series values, and the factor Tj is initially estimated for

each month. Then, the statistics are calculated using the same assumptions: the null

hypothesis H0, is rejected for a significance interval α equal to 95%. This method is fully described in Stipp et al. (2013).

Study Area and Data

The region of this work is the Curitiba city, Parana State, Brazil. The pluviometric

station is located at Centro Politécnico, in the High Iguassu River basin. This station

was chosen because of its location and because it is considered as a key station in

south Brazil. The station has a good length of the observational time series, in other

words, up to 100 years of extension (1889–2013).

Curitiba is the capital and the main city of the Parana state. It is considered the

eighth largest city of Brazil with more than 1.75 million people living in the city

(IBGE 2013). According to INMET (2013) and Fill et al. (1999), Curitiba has a

subtropical wet climate, with average temperatures between 11 �C and 23 �C, in the

196 R. Ploszai and M.R.M. Mine

winter and summer, respectively. These temperatures can oscillate according to

each epoch of the year. The annual average precipitation is around 1400 mm in

Curitiba; and the average of rainy days is 164 days per year. The relative moisture

of the capital is around 80.7%.

The pluviometric station Curitiba is situated in the Guabirotuba neighbourhood

of Curitiba. The station’s coordinates are 25�270S and 49�140E, and the average altitude is around 924 m. This station is shown in Fig. 16.1.

The rainfall records and the RCM’s outputs are used in this work. The historical records of the Curitiba station are used to compare and verify if the RCM’s outputs can represent the rainfall records in Curitiba, in the period from 1961 to 2008. The

observational data were collected at the Hydrological Information System

(Hidroweb), held by ANA (National Waters Agency, in Portuguese).

The observed data and the precipitation scenarios were split into two groups:

(1) Historical period is the rainfall observed at the Curitiba hydrological station and

the precipitation scenarios generated by three RCM (ETA, PROMES and RCA1);

(2) Future period is only the precipitation generated by the RCM. Based on the

project, CLARIS LPB was identified as the most representative models for the

region, the ETA, PROMES and RCA1 (Mine et al. 2009).

For the preliminary analysis, the total of annual and monthly precipitation and

the maximum and minimum values of the monthly rainfalls of RCM’s outputs and observed records were used. After the most representative model for the Curitiba

region was identified, the annual and seasonal total rainfall in each period were

analysed.

Fig. 16.1 Location of the main rivers, capital and the pluviometric station Curitiba

16 Rainfall Trend Analysis in the Region of Curitiba Using Regional Climate. . . 197

Preliminary Analysis

Both the historical time series, as the series generated by the RCM, were analysed in

order to identify the most representative scenario for the region of Curitiba. First of

all, the frequency bias correction method was applied as presented in Saurral

(2010). After the bias correction was performed, the gaps were set up both in

historical time series, as in RCM’s outputs. There were found 75 months and 24 months of gaps in the historical time series and ETA series, respectively. The

years with gaps were disregarded because the historical time series were

1491 months long.

Using the frequency polygons it was observed that the ETA model generates

better-simulated series, after the bias correction. The series generated by the RCA1

model were not as satisfactory as the PROMES series, both shown in Fig. 16.2a.

The rainfall permanence curves are presented in Fig. 16.2b. The periods to con-

struct the curves were the same for the observed and each simulated series (histor-

ical period).

Figure 16.2b shows the permanence curves for all precipitations (simulated and

observed). From the curves’ analysis, it is possible to conclude that the PROMES model does not represent the historical observed series. The analysis of the scenario

generated by the RCA1 model has shown a satisfactory adjustment (observed and

simulated data curves), but the ETA model is the most representative.

To finalize the analysis of the precipitation scenarios obtained by RCM simula-

tions, the descriptive statistics of monthly precipitation series were computed.

Table 16.1 indicates the ETA scenario as the most representative for the region,

when comparing to observed rainfall (OBS).

Regarding the scenario generated by the ETA model, both the mean and median

between the two samples were so close. The other indicators such as standard

deviation, kurtosis excess, and the asymmetry coefficient resulted in close values

Fig. 16.2 (a, b) Frequency polygons and permanence curves for all scenarios and models

198 R. Ploszai and M.R.M. Mine

between the observed rainfall (OBS) and the ETA outputs. The ETA simulations

were not efficient in representing the minimum rainfall records but were efficient in

representing the maximum records of each month (Table 16.1).

From all the previous analysis, the ETA model has shown the best results,

resulting in its being adopted as the most representative for the region for the

next analysis.

Annual Analysis

The precipitation scenario generated by the ETA model in this section was split into

two precipitation scenarios: ETA01, representing the historical period, and ETA02,

representing the future period. The observed rainfalls at the pluviometric station

called Curitiba were represented by OBS.

The common period in the scenarios ETA01 and OBS is limited to December

2008. The initial point for both series is centred in January 1961. There are gaps in

the OBS and ETA series. Therefore, the series were limited in 2008. The ETA’s gaps correspond to a period of about 24 months: January 2009 to December 2010.

The future period represented by ETA02 corresponds to the interval: January 2012

to November 2099. The last month obtained by ETA simulations is

November 2099.

In order to precede an initial analysis of the annual precipitations, the descriptive

statistics of the three precipitation scenarios: OBS, ETA01 and ETA02, were

calculated, as follow the results in Table 16.2. Table 16.2 shows that the ETA01

and OBS series have almost the same mean values as well as almost the same

medians and the standard-deviation indexes.

Comparing the statistics between these two scenarios, OBS and ETA01, it is

clearly showed that both minimum and maximum values of ETA01 have higher

Table 16.1 Statistical indexes of monthly precipitation during the historical period from 1961 to 2008

Statistics OBS ETA PROMES RCA1

N (months of precipitation) 564 576 576 576

Mean 122.48 123.36 114.07 121.18

Median 114.35 114.09 103.36 107.56

Standard-deviation 76.29 76.62 87.28 82.52

Kurtosis excess 1.48 1.24 11.83 8.29

Asymmetry 1.00 0.91 2.51 2.02

Minimum 2.00 0.25 1.09 5.71

Maximum 473.80 498.71 833.36 685.61

Nash-Sutcliffe coefficient – �0.51 �0.77 �0.67 RMSE – 93.78 103.78 98.41

R2 – 0.06 0.05 0.06

16 Rainfall Trend Analysis in the Region of Curitiba Using Regional Climate. . . 199

values than those represented by scenario OBS, according to Table 16.2. The

ETA02 scenario showed an increase of three statistical indexes: mean, median,

and standard deviation. It is possible to conclude that there is an increasing trend in

precipitation in the region.

Below are presented the temporal graphs of mean and median, with a variation

of about 10 years. Following that are the graphs using the linear regressions for all

scenarios (Fig. 16.3). As shown in Fig. 16.3a, the historical series has shown an

increasing trend throughout its length, according to the linear regression line, which

is slightly positive from the series beginning (1889) to the end (2008). This trend

can be visualized through the angular coefficient of the equation generated by the

linear regression’s line (positive signal). The smoothing curves (mean and median variation around 10 years) have shown

a slightly increasing trend in the end of the hydrological series. Figure 16.3b shows

that, in the ETA01 scenario, the trend at the period decreases for the techniques

mentioned in the legend. The angular coefficient of the linear regression line has

shown a decreasing trend (negative signal).

Figure 16.3c depicts an increasing trend on scenario ETA02. Analysing the

smoothing functions and linear regression technique shows an increasing trend in

rainfall. The smoothing functions, such as mean and median variation, have shown

a slightly positive trend.

The test of the linear regression coefficient for the precipitation series of the

three scenarios (OBS, ETA01, and ETA02) was applied in order to identify the

trend significance. As described in Sharma et al. (2000), this test was applied and

compared to the critical values obtained from t-test tables for the pre-specified

freedom degrees.

The null hypothesis to a given significance level at α ¼ 5% is H0 : b ¼ 0, and b is the angular coefficient of the linear regression line. The test results (Table 16.3)

showed a trend both in ETA01 and in ETA02 scenarios. From the initial analysis of

the angular coefficient and the test applied to this coefficient, it was shown that

there is an increasing trend (positive) in ETA02, when in ETA01 there is a

decreasing trend (negative).

The results of the coefficient test (Table 16.3) have not shown significant trends

at observational series (OBS). As follows, the graphs using the RAPS method were

Table 16.2 Descriptive statistics of the annual

precipitation

Statistics OBS ETA01 ETA02

N (months of precipitation) 43 48 88

Mean 1467.19 1480.30 1789.49

Median 1473.70 1434.95 1780.11

Standard-deviation 294.24 287.97 370.52

Kurtosis excess �0.17 1.93 �0.38 Asymmetry �0.10 1.05 0.22 Minimum 765.50 994.99 950.49

Maximum 2071.20 2497.80 2603.94

200 R. Ploszai and M.R.M. Mine

elaborated. The RAPS was applied in order to identify possible trends in all

scenarios, represented in Fig. 16.4.

From the RAPS graphs, an abrupt change in the OBS scenario was observed

(Fig. 16.4a). This point shows a possible change in the mean (possible trend) in the

year 1952, represented in Fig. 16.4a by year 54. The same behaviour was perceived

in Fig. 16.4b and c as a result of abrupt changes observed in the years 1982 (year 22)

and 1995 (year 35), represented in Fig. 16.4b and c, respectively.

In analysing Fig. 16.4c, an abrupt change is perceived in 2056 (47). These

changes do not prove the existence of a trend in the series (abrupt changes), but

show that these characteristics must be proven through the statistical tests

Fig. 16.3 (a–c) Total annual precipitated for all scenarios

16 Rainfall Trend Analysis in the Region of Curitiba Using Regional Climate. . . 201

application. These tests can help us visualize and analyse the significance of the

abrupt changes.

In order to consolidate the results obtained by the RAPS method application, a

graph with the total annual precipitation throughout each series was elaborated. The

function cumulative curve is represented by Fig. 16.5 for all scenarios (Fill

et al. 2008).

In analysing Fig. 16.5, there were no significant trends perceived in the OBS

series. However, at the end of the period, a slight increase in precipitation was

observed in the region. The same does not occur in the ETA01 scenario, in which

Table 16.3 Hypothesis test results of the angular coefficient of the linear regression line

Scenario Regression line equations R2 coefficient t t (tab.) H0 Trend

OBS y¼ 1.17xþ 1362.00 0.02 1.37 1.99 Accept H0 No ETA01 y¼ -6.15xþ 1630.90 0.09 2.12 2.02 Reject H0 Yes ETA02 y¼ 3.93xþ 1613.60 0.07 2.63 1.99 Reject H0 Yes

0.02

0.01

−0.01

−0.02

−0.03

−0.04

0.025

0.02

0.01

0.005

−0.005

0.015

0 0 10 20 30 40 50

0 10 20 30 40 50 60 70 80 90

OBS Null Line Null LineETA01

Null LineETA02

40 60

Year Year

Year

R A

P S

0.01

−0.01

−0.02

−0.03

−0.04

R A

P S

R A

P S

80 100

Fig. 16.4 (a–c) RAPS of annual amount precipitated for all scenarios

202 R. Ploszai and M.R.M. Mine

were found several fluctuations through the line. It is possible to visualize in

Fig. 16.5 that an increasing trend occurs in the year 2056, year 35 in Fig. 16.5.

In order to verify the significance of these alterations, the series were submitted

for statistical tests. To apply the statistical tests, the series were split at the exact

point of the abrupt changes identification, detected in RAPS, Cumulative Curves,

and Mid-division analysis. The results of the test applications are shown in

Table 16.4.

The mid-division method was applied according to studies of Tozzi (2014). The

following statistical tests were applied: t-test, Fisher-Snedecor (F), Mann-Whitney

or Wilcoxon (U), and Spearman’s rho coefficient. The t-test and F test were applied to annual analysis, whereas the U and rho coefficient to seasonal analysis.

Table 16.4 shows the results of the statistical test applications, such as the t-test

and F-Snedecor test. The results in Table 16.4 show the total number of rejections

per accepts on tests application in the same year as the abrupt changes were

observed. For example, on the RAPS method in the 1952 and OBS scenario,

Fig. 16.5 Cumulative curves for all precipitation scenarios

Table 16.4 Statistical test results t and F for the annual analysis

Rejections per Accepts quantity

Method RAPS

Scenario OBS ETA01 ETA02

Year 1952 1992 1982 1995 2023 2028 2058

Result 1_1 0_2 0_2 0_2 2_0 0_2 1_1

Method Cumulative curves

Scenario OBS ETA01 ETA02

Year 1905 1925 1975 1980 2025 2030 2035

Result 0_2 0_2 1_1 0_2 1_1 0_2 1_1

Method Mid-division

Scenario OBS ETA01 ETA02

Year 1950 – 1985 – 2055 – –

Result 1_1 – 1_1 – 1_1 – –

H0 Accept Accept Reject

16 Rainfall Trend Analysis in the Region of Curitiba Using Regional Climate. . . 203

one rejection per one accept (1_1), was observed and on the RAPS method in the

2023 and ETA02 scenario, two rejections per null accept (2_0) were detected. In the

same way, the results of the Cumulative Curves and Mid-division analysis for all

years showed in Table 16.4 can be interpreted.

The results in Table 16.4 show the presence of no significant trends in the

historical series (OBS) and in scenario ETA01 due to the number of rejections

being lower than the number of accepts in both scenarios throughout the years.

In the ETA02 scenario, rejections were higher than accepts, showing a presence

of trends. In order to consolidate the obtained results at the previous analysis, the

powerful Mann Kendall (MK) test was applied for the total annual precipitation, as

shown in Table 16.5. The average, maximum, and minimum precipitations of each

year were analysed for a better understanding of the annual precipitation patterns,

as can be seen in Table 16.5.

The null hypothesis was accepted for a given significance level of 5% in all

cases studies for the OBS scenario. Therefore, no trend was detected in the

historical period, according to the results of the MK test. Both scenarios generated

by the ETA model have shown significant trends, showing a higher rejects rate due

to lower accepts rate, according to the results shown in Table 16.5. This indicates a

trend presence in the series generated by the ETA model (scenarios ETA01 and

ETA02).

From the annual analysis, it can be concluded that the rainfall has presented

trends in some tests and analysis applied to scenarios OBS and ETA01. In the

historical series, increasing trends were identified after the analysis of the smooth-

ing curves, regressions, coefficients, and the application of statistical tests. The MK

test application has shown the presence of significant trends.

Seasonal Analysis

After the annual analysis, the precipitation scenarios were submitted to a seasonal

analysis. This analysis has occurred observing the monthly amount precipitated, by

splitting these amounts in two and four seasons. Splitting the series in two seasons,

as performed by Tozzi (2014) and Fill et al. (2008), the summer series were

considered in the period between November and April. Consequently, the spring

series were considered in the period between May and October.

Table 16.5 Annual precipitation analysis—Mann

Kendall test (α¼ 5%) Accept H0: Z (tab.)¼ 1.96

Annual period

OBS ETA01 ETA02

Situation Situation Situation

Total Accept H0 Reject H0 Reject H0

Maximum Accept H0 Accept H0 Reject H0

Minimum Accept H0 Reject H0 Accept H0

Average Accept H0 Reject H0 Reject H0

Trend No Yes Yes

204 R. Ploszai and M.R.M. Mine

Trimestral rainfalls were analysed by splitting the series by seasons of the year:

summer (December to February), autumn (March to May), winter (June to August),

and spring (September to November). In both the semi-annual and trimestral series,

the total precipitation in the period was analysed. The same methods were applied

in annual analysis. The results of all analyses are summarized in Table 16.6

(next section).

Results and Discussions

From the previous analysis, significant trends for the application of some tests were

present in graphical analysis of some statistical indexes for all scenarios

(Table 16.6).

No increasing trend was detected in the observational series for the annual and

trimestral analysis for the winter and spring seasons. Just two analyses have shown

the presence of trends in the OBS scenario. The OBS scenario shows an increasing

trend on the warmest months because more analyses have shown increasing trends

(positive) in this scenario. All tests and methods showed that in the ETA01 scenario

there are some decreasing (negative) trends on seasons corresponding to the coldest

months of the year. For the hottest months, the ETA01 scenario shows that the

precipitation is increasing at most of the applied tests. Some exceptions were

detected in the ETA01 scenario analysis as described in the last half of Table 16.6.

Table 16.6 Summarized results of all analysis

Station Period OBS ETA01 ETA02

Annual – " (2) (3) # All " All SEM—Summer NOV–APR " (2) (3) (6) " All " All SEM—Winter MAY–OCT " (2) (3) (6) # All " (1) (2) (3) (6) TRIM—Summer DEC–FEB " (2) (3) (6) " All " (1) (2) (3) (5) (6) TRIM—Autumn MAR–MAY " (2) (3) (5) (6) " (2) (3) (6) " (1) (2) (3) (4) (6) TRIM—Winter JUN–AUG " (2) (3) # All " (1) (2) (3) TRIM—Spring SEP–NOV " (2) (3) # All " (1) (2) (3) Monthly – " (2) (3) (5) (6) # All " All (1) Descriptive statistics analysis

(2) Functions and regressions analysis

(3) Line’s angular coefficient analysis

(4) Line’s angular coefficient test

(5) t-test and Fisher-Snedecor test or Mann-Whitney and Spearman’s rho tests

(6) Mann Kendall and Seasonal Mann Kendall tests

Exceptions Except by maximum statistics higher than (due to OBS)

Except by maximum statistics lower than (due to OBS)

Descriptive statistics (all lowers due to OBS)

16 Rainfall Trend Analysis in the Region of Curitiba Using Regional Climate. . . 205

The studied methods were efficient in identifying trends in historical and sim-

ulated data series; however, the application of Mann Kendall and Seasonal Mann

Kendall tests have shown to be better suited for trends identification than linear

regression analysis and EDA. This fact can be seen in Table 16.6 results, which

shows trends in almost all annual and seasonal analyses performed by the MK and

SMK tests. It is not proved the significance of trends in some scenarios through the

analysis of the linear regression line, because of the significance tests results

(presented by number 4 in Table 16.6), have not appeared in many analyses,

showing no significant trends in these cases.

In Table 16.6, increasing trends (positive) are shown to occur in almost all tests

and analyses applied to the ETA02 scenario. The inflexion of the Cumulative Curve

occurs in the year 2056. The curve’s inflexion depicts an increasing trend in rainfall in the region of Curitiba in 2056 year (according to the ETA02 scenario and

considering the RCM’s uncertainties).

Conclusions

The performed analyses in both the historical period and future period have allowed

the conclusion that the scenarios generated by the ETA model have presented the

best results for the region of Curitiba. The initial analysis has presented this model

as a better representative than the others (PROMES and RCA1 scenarios). For trend

analysis, the ETA model was adopted to study the rainfalls in Curitiba until

November 2099. Based on these studies, the future projections studies were

performed.

From the annual analysis, it is shown that, in some tests applied, an increasing

trend in rainfall was identified. This increasing trend is observed as positive through

the diagram Cumulative Curves, statistical indexes, and the regression analysis. To

proceed the semi-annual analysis, the series were split in two seasons (summer and

winter), as did Tozzi (2014). It has verified the presence of positive trends in the

summer precipitation series, whereas the winter season results were not conclusive.

At trimestral analysis (splitting in the annual seasons), the presence of significant

trends in the summer season were observed. In other seasons (applying the statis-

tical tests), significant trends in the series were not detected. For a better under-

standing of the precipitation patterns, a monthly analysis was performed that has

shown trends both in historical series and in the series generated by the ETA model.

Summarizing the results, the ETA model has shown the best results for the

analysis of precipitation in the region of Curitiba. The rainfalls generated by this

model have shown an increase in monthly precipitation around 18%, since 2012.

Meanwhile, when comparing the increase of 18% of monthly rainfall with the

RCM’s uncertainties, it is possible to conclude that this is just an indicative about the increasing trends of rainfall in the region of Curitiba until 2100.

According to the last IPCC (2013) report, it is shown that rainfall trends for the

future scenario (presented as ETA02 in this paper) are increasing. Based on data

206 R. Ploszai and M.R.M. Mine

generated by this RCM, it is possible to predict that rainfall in the region will

increase, and that it is possible to take some preventive measures toward planning

and managing water resources.

Acknowledgements We acknowledge the Superior Teaching People Improving Coordination (CAPES, in Portuguese) for the support developed in this work. We also acknowledge the National

Waters Agency (ANA, in Portuguese) and the CLARIS LPB Project for the data available for

using.

References

Alemaw, B. F., & Chaoka, T. R. (2002). Trends in the flow regime of the Southern African rivers

as visualized from Rescaled Adjusted Partial Sums (RAPS). African Journal of Science and Technology, 3(1), 69–78.

Alexandre, G. R., Baptista, M. B., & Naghettini, M. (2010). Estudo para Identificaç~ao de Tendências do Regime Pluvial na Regi~ao Metropolitana de Belo Horizonte a Partir de Métodos Estatı́sticos. Revista Brasileira de Recursos Hı́dricos, 15, 115–126.

Back, A. J. (2001). Aplicaç~ao de análise estatı́stica para identificaç~ao de tendências climáticas. Pesquisa Agropecu�aria Brasileira, 36(5), 717–726.

Barros, V., Clarke, R., & Dias, P. S. (2011). Climate change in the La Plata Basin (p. 221). Inter American Institute on Global Change.

Blain, G. C. (2011). Considerações estatı́sticas relativas a seis séries mensais de temperatura do ar

da secretaria de agricultura e abastecimento do Estado de S~ao Paulo. Revista Brasileira de Meteorologia, 26(2), 279–296.

Buchir, L. M. S. T. (2013). Análise da influência de mudanças climáticas nas precipitações.

Dissertaç~ao de Mestrado, Universidade Federal do Paraná. Buishand, T. A. (1984). Tests for detecting a shift in the mean of hydrological time series. Journal

of Hydrology, 73, 51–69. Coscarelli, R., & Caloiero, T. (2012). Analysis of daily and monthly rainfall concentration in

Southern Italy (Calabria region). Journal of Hydrology, 416–417, 145–156. Fill, H. D., Oliveira, F. B., & Santos, P. (2008). Avaliaç~ao de Cheias Considerando Distribuições

Sazonais. Revista Brasileira de Recursos Hı́dricos, 13, 5–13. Fill, H. D. O. A., Sugai, M., & Hilu, A. (1999). Caracterizaç~ao Climatol�ogica da Regi~ao

Metropolitana de Curitiba. Engenharia e Construç~ao, 2, 17–28. Fisch, G., & Folhes, M. T. (2006). Caracterizaç~ao climática e estudo de tendências nas séries

temporais de temperatura do ar e precipitaç~ao emTaubaté (SP).Revista Ambiente e �Agua, 1(1), 11. Hirsch, R. M., & Slack, J. R. A. (1984). Nonparametric trend test for seasonal data with serial

dependence. Water Resources Research, 20(6), 727–732. Hirsch, R. M., Slack, J. R., & Smith, R. A. (1982). Techniques of trend analysis for monthly water

quality data. Water Resources Research, 18(1), 107–121. Hyndman, R. J., & Koehler, A. B. (2006). Another look at measures of forecast accuracy.

International Journal of Forecasting, 22(4), 679–688. IBGE. (2013). IBGE—Instituto Brasileiro de Geografia e Estatı́stica. Rio de Janeiro: IBGE. INMET. (2013). INMET—Instituto Nacional de Meteorologia Inmet.

IPCC. (2013). IPCC—Intergovernmental Panel on Climate Change. Cambridge: Cambridge University Press.

Johnson, J. (1984). Econometric methods (3rd ed., pp. 1–565). New York: McGraw-Hill. Kundzewicz, Z. W., & Robson, A. (2000). Detecting trend and other changes in hydrological data

(p. 168). Geneva: World Meteorological Association.

16 Rainfall Trend Analysis in the Region of Curitiba Using Regional Climate. . . 207

Lettenmaier, D. P., Wood, E. F., & Wallis, J. R. (1994). Hydro-climatological trends in the

continental United States, 1948–88. Journal of Climate, 7, 586–607. Li, Z., He, Y., Wang, C., Wang, X., Xin, H., Zhang, W., et al. (2011). Spatial and temporal trends

of temperature and precipitation during 1960–2008 at the Hengduan Mountains, China.

Quaternary International, 236(1–2), 127–142. Liang, L., Li, L., & Liu, Q. (2011). Precipitation variability in Northeast China from 1961 to 2008.

Journal of Hydrology, 404(1–2), 67–76. Matalas, N. C. (1997). Stochastic hydrology in the context of climate change. Climatic Change,

37, 89–101. Meschiatti, M. C., Fontolan, M. R., Helena, D., & Ferreira, L. (2012). Caracterizaç~ao estatı́stica de

tendências em séries anuais de dados hidro-climáticos no Estado de S~ao Paulo. Revista Geogr�afica Brasileira, 6(1), 52–64.

Mine, M. R. M., Fill, H. D. O. A., Kaviski, E., Bessa, M. R., Fernandes, C. V. S., Santos, I.,

et al. (2009).Water resources in La Plata Basin in the context of climate change—Impact of the climate changes in hydropower. Partial report, Curitiba.

Moriasi, D. N., Arnold, J. G., VAN Liew, M. W., Bingner, R. L., Harmel, R. D., & Veith, T. L.

(2007). Model evaluation guidelines for systematic quantification of accuracy in watershed

simulations. Transactions of the ASABE, 50(3), 885–900. Müller, I. I., Kruger, C. M., & Kaviski, E. (1998). Análise de estacionariedade de séries

hidrol�ogicas na bacia incremental de Itaipu. Revista Brasileira de Recursos Hı́dricos, 3(4), 51–71.

Naghettini, M., & Pinto, E. J. D. A. (2007). Hidrologia Estatı́stica (1st ed., p. 600). Belo Horizonte: CPRM Serviço Geol�ogico do Brasil.

Oguntunde, P. G., Abiodun, B. J., & Lischeid, G. (2011). Rainfall trends in Nigeria, 1901–2000.

Journal of Hydrology, 411(3–4), 207–218. Romano, E., Petrangeli, A. B., & Preziosi, E. (2011). Spatial and time analysis of rainfall in the

Tiber River Basin (central Italy) in relation to discharge measurements (1920–2010). Procedia Environmental Sciences, 7, 258–263.

Saurral, R. I. (2010). The hydrologic cycle of the La Plata Basin in the WCRP-CMIP3 Multimodel

Dataset. Journal of Hydrometeorology, 11(5), 1083–1102. Sayemuzzaman, M., & JHA, M. K. (2014). Seasonal and annual precipitation time series trend

analysis in North Carolina, United States. Atmospheric Research, 137, 183–194. Sharma, K. P., Moore, B., & Vorosmarty, C. J. (2000). Anthropogenic, climatic, and hydrologic

trends in the Kosi basin, Himalaya. Climatic Change, 47, 141–165. Stipp, R. D., Buchir, L. M. S. T., & Mine, M. R. M. (2013). Tendência sazonal da precipitaç~ao na

bacia do Iguaçu. In XX Simp�osio Brasileiro de Recursos Hı́dricos (p. 8). Tozzi, B. K. M. (2014). Verificaç~ao da Estacionariedade de Séries Hidrol�ogicas de Vazões na

Bacia do Rio Iguaçu. Dissertaç~ao de Mestrado, Universidade Federal do Paraná. Tucci, C. E. M. (2002). Impactos da variabilidade climática e do uso do solo nos recursos hı́dricos

(p. 150). Brası́lia.

Wang, W., Chen, X., Shi, P., & Gelder, P. H. A. J. M. V. (2008). Detecting changes in extreme

precipitation and extreme streamflow in the Dongjiang River Basin in southern China. Hydrol- ogy and Earth System Sciences, 12, 207–221.

208 R. Ploszai and M.R.M. Mine

Chapter 17

Modelling of Wind Speed Using Artificial Neural Networks for University Campus of Burdur (Turkey)

Alper Kerem, €Onder Kizilkan, and Serdar Salman

Introduction

Energy plays a significant role in the socio-economic development of a country.

The level of prosperity can be evaluated by the amount of energy which is

consumed by a nation (Pishgar-Komleh et al. 2015). In parallel to the worldwide

growing population and emerging technologies, the demand for electricity has been

increasing every year. While the growing demand of energy causes rapid consump-

tion of energy the sources, mankind has been focused on alternative energy

resources. The growing energy demand, rapidly decreasing country’s fossil fuel reserves, day by day increasing oil import cost and environment degradation have

required to utilize renewable sources of energy like wind energy to generate

electricity (Khahro et al. 2014).

According to some researchers, the rest of oil reserves are 225.4 billion tons,

natural gas reserves are 208.4 trillion m3 and coal reserves are 860.94 billion tons in

the world. The lifetimes are estimated as 54 years for oil, 64 years for natural gas

and 112 years for coal (Koc and Senel 2013). In 2013, Turkey’s electricity installed capacity was 64,000.4 MW. This value has increased progressively and reached to

A. Kerem (*) Department of Electricity and Energy, K. Vocational High School,

Osmaniye Korkut Ata University, Osmaniye, Turkey

e-mail: [email protected]

Ö. Kizilkan

Department of Energy Systems Engineering, Faculty of Technology,

Süleyman Demirel University, Isparta, Turkey

e-mail: [email protected]

S. Salman

Department of Metallurgical and Materials Engineering, Faculty of Technology,

Marmara University, İstanbul, Turkey

e-mail: [email protected]

209

mailto:[email protected]

68,719.1 MW in 2014 as seen from Fig. 17.1 (EMO 2014). In 2013, Turkey’s electricity consumption increased by 1.3% compared to the previous year, and

attained 24,484 GWh (Energy Institute 2014). Therefore, Turkey is strictly depen-

dent on imported energy at an exceeding rate of 70%. In order to provide the

supply-demand balance, it is obvious that Turkey’s current energy resources must be assessed and should be increased in number and capacity of the native power

plants.

It is known that the solar energy transferred to the earth corresponds to energy

generated from 200 billion tons of coal per year. The amount of this energy equals

to 20 thousand times of the total energy consumption of the world (Hayli 2001). For

this reason, it is clear that the sun is a powerful source of energy. Wind energy is an

indirect form of solar energy which occurs from temperature and pressure differ-

ence. Due to increasing energy demand and resulting environmental problems

during electricity generation, wind energy can be considered as an attractive and

alternative renewable energy resource (Shamshirband et al. 2014). Wind is a clean

energy source which is natural and inexhaustible (Mohandes et al. 2011). It is

environmentally friendly alternative energy source without releasing CO2 gas to the

environment like fossil fuels (Monfared et al. 2009). Actually, this situation is a

chance for geographic regions which have favorable winds. So, in recent years it

has been drawn attention for energy production from wind energy in all over the

world. According to the research for Turkey, the total potential of wind energy was

determined to be 48 GW, using the wind speed data of above 7 m/s (ETKB 2014).

However, the total power of the wind farms established in Turkey is 3512 MW

(EMO 2014). This power value constitutes about 7–8% of Turkey’s total wind energy potential. Thereby, it is seen that a great deal of wind energy potential is

waiting to be evaluated.

Fig. 17.1 Electric power installed capacity in Turkey (EMO 2014)

210 A. Kerem et al.

In order to determine the wind power potentials, it is very important to measure

long term wind speed characteristics. Instead of this, modelling of wind speeds

using small data sets can be a good alternative for long term data. However the

modeling of wind speed is not easy because of its nonlinear nature and multiple

input and outputs. The long-term estimation problem predicts long-term wind

speeds at a target site in order to estimate the wind energy potential of wind

turbines. In general, long term wind data over several years is not available at the

target site (Jung and Kwon 2013). For forecasting the long term statistics of wind

speed, some new models were used such as Artificial Neural Networks (ANNs).

During the past years there has been a substantial increase in the interest on the

ANNs. Researches have been applying the ANN method successfully in various

fields of mathematics, engineering, medicine, economics, meteorology, psychol-

ogy, neurology, in the prediction of mineral exploration sites, in electrical and

thermal load predictions and in adaptive and robotic control and many other sub-

jects (Bilgili et al. 2007).

Several researchers investigated design and modeling of wind speed, wind

direction, wind turbine analyses using Artificial Neural Networks. Ekonomou

et al. (2012) developed an artificial neural network (ANN) model which has the

ability to estimate the optimal number of wind turbines and the total produced

power in a wind farm. Jiang and Lu (2014) developed an improved elastic back-

propagation neural network method to forecast system frequency. The effectiveness

of the proposed method was verified using field data from a real wind farm in

Guangdong, China. Tagliaferri et al. (2015) proposed two methods for short term

forecasting of wind direction with the aim to provide input for tactic decisions

during yacht races. They used two methods which were based on artificial neural

networks (ANN) and support vector machines (SVM), respectively. Fadare (2010)

modelled the profile of wind speed in Nigeria using artificial neural network

(ANN). The used ANN model consisted of three-layered, feed-forward, back-

propagation network with different configurations, designed using the Neural

Toolbox for MATLAB. Jung and Kwon (2013) applied the artificial neural network

(ANN) to predict long-term wind speeds of a particular site, and to estimate the

annual energy production of wind turbines using the predicted wind speeds.

Oztopal (2006) presented weighting factors of surrounding stations necessary for

the prediction of a pivot station by an artificial neural network (ANN) technique. He

also compared the wind speed prediction results with measured values at a pivot

station. Pourmousavi Kani and Ardehali (2011) used artificial neural network

(ANN) and Markov chain (MC) methods to develop a new ANN–MC model for

forecasting wind speed in very short-term time scale. They predicted very short-

term wind speed in a few seconds using the data patterns for short-term (about an

hour) and very short-term (about minutes or seconds).

In this study, wind speed potential of a university campus located in Burdur,

Turkey is modelled using Artificial Neural Networks. For this aim, a wind energy

measurement station is assembled in Mehmet Akif Ersoy University İstiklal Cam-

pus and data measuring-monitoring was made for 12 months. The measured data

were modelled with artificial neural networks to predict the long term wind

17 Modelling of Wind Speed Using Artificial Neural Networks for University. . . 211

parameters. Feed-forward backpropagation learning algorithm is used for the anal-

ysis with different hidden neuron numbers.

Artificial Neural Networks (ANNs)

The modeling of nonlinear systems is difficult and success has been restricted to

restrictive classes of nonlinear systems. The major application of artificial neural

network (ANN) is that they tender the potential of a generic approach to the

modeling of nonlinear systems (Yıldız and Uzun 2015). ANNs learn from exam-

ples, called patterns. In other words, to train and test a neural network, input data

and corresponding output values are necessary. A neural network usually consists

of an input layer, a number of hidden layers and an output layer. ANNs have been

used in a broad range of applications including; pattern classification, function

approximation, optimization, and prediction (Cam et al. 2005). ANNs can be

trained to overcome the limitations of the conventional approaches to solve com-

plex problems that are difficult to model analytically (Bilgili et al. 2007).

Commonly neural networks are adjusted, or trained, so that a particular input

leads to a specific target output. Such a situation is shown in Fig. 17.2. There, the

network is adjusted, based on a comparison of the output and the target, until the

network output matches the target. Typically many such input/target pairs are used,

in this supervised learning, to train a network (Sencan 2007; Kizilkan 2011).

Different learning algorithms can be applied in order to train a network. How-

ever, it is not easy to guess the fastest one for a given problem, and the best one is

usually determined by trial and error. The most popular of them is the

backpropagation algorithm, which has different variants. Standard backpropagation

is a gradient descent algorithm, in which the network weights are moved along the

negative of the gradient of the performance function. The term backpropagation

refers to the manner in which the gradient is computed for nonlinear multilayer

networks (Sencan and Kalogirou 2005).

In Fig. 17.3, the general architecture of a neural network unit is shown. Each

artificial neural unit consists of inputs (xn), weights (Wn), summation function (R),

activation function (a) and outputs (y). The figure illustrates how the information is

processed through a single node. The node receives weighted activations of other

nodes through its incoming connections. First, these are added up (summation). The

result is then passed through an activation function, the outcome being the activa-

tion of the node. For each of the outgoing connections, this activation value is

multiplied by the specific weight and transferred to the next node (Kalogirou 2000).

212 A. Kerem et al.

Study Field and Data Collection

Before establishing wind turbines for electricity generation, some data should be

determined such as wind speed, wind frequency (the frequency of wind blowing),

wind direction, the average temperature, pressure, etc. (Hayli 2001; Pishgar-

Komleh et al. 2015). In order to achieve these data, it is important to do a feasibility

study at first. Then, wind measurement stations should be established by determin-

ing the most convenient points and the measurements should be made for at least

12 months. Afterwards, data should be recorded, stored and analyzed (Akova 2008;

Ozerdem and Turkeli 2005; Genc et al. 2005; Sahin 2004). The measurements must

be carried out with a great attention and evaluation since an error of 10% in the

measured wind speed causes an error of 30% in generated power (Akova 2008).

Furthermore, investments which excess of measured wind power capacity return to

idle capacity and lead to increase energy production costs (Akova 2008; Demirci

and Senlik 2009).

Taking into consideration of the above mentioned concerns, first the coordinates

of study field was determined carefully in order to determine the wind energy

potential of Mehmet Akif Ersoy University İstiklal Campus. Wind speeds were

monitored at different points on the land for every minute. In accordance with the

Fig. 17.2 Representation of neural networks

Fig. 17.3 General architecture of neural

network unit

17 Modelling of Wind Speed Using Artificial Neural Networks for University. . . 213

criteria included in the literature, the most efficient land-coordinate considered was

determined by GPS system. So, measuring station and stretching ropes’ foundation were established on 1313 m altitude and coordinates of UTM E 263254 and N

4173479 (Figs. 17.4 and 17.5).

After the determining of the best suitable study field, the tower was built. The

height of the tower was 63 m in total with 21 modules which were 3 m in height.

Then, the relevant sensors were installed on the tower (Fig. 17.6).

Measurement tower was fed by 20 W solar panel and 12 V batteries in order to

make the measurements without a connecting of public electricity grid. Measured

data were recorded by a data logger at every 10 min and transferred to the project

Fig. 17.4 Measuring station and stretching ropes’ groundbreaking shape (Kerem et al. 2014)

Fig. 17.5 3D image of the field work (to scale)

214 A. Kerem et al.

team via GSM modem. Tower and sensors were protected against lightning by

grounding line. Furthermore, an aircraft warning light was mounted on the top of

the tower for protecting the system from undesirable situations. Measurements were

made for heights of 61 m and 31 m for every 10 min. The measured data were wind

speed at 61 m and 31 m, wind direction, temperature, pressure and humidity. The

data used in this study were wind speed at different elevations (Figs. 17.7 and 17.8).

Application of ANNs

The ANN parameters such as, the number of neurons in the input, hidden and output

layers, network architecture, transfer function, learning algorithm, momentum

factor and learning rate are to be selected for developing an ANN model. Proper

data selection also plays a major role in the success of ANN architecture used. The

number of neurons in the input layer is usually equal to the number of parameters

that affect the system performance (Mohanraj et al. 2015). For modelling the wind

speed potential of the university campus, one input and one output with different

number of neurons were tested. The input parameter is the months and the output

parameters are monthly average wind speed data for 61 m and 31 m. The number of

neurons in hidden layer is selected to be in the range of 6–16 for determining the

best approach. Feed-forward backpropagation learning algorithm is used for

Fig. 17.6 Wind measuring station installation procedure

17 Modelling of Wind Speed Using Artificial Neural Networks for University. . . 215

learning algorithm with one hidden layer. Inputs and outputs are normalized

between the ranges of 0 and 1 by the equation below (Sozen et al. 2010).

dN ¼ 0:8� dact þ dmin dmax þ dmin

� � þ 0:1 ð17:1Þ

In above equation, d represents data, act represents actual, min and max repre-

sents minimum and maximum.

Levenberg–Marquardt (LM) algorithm is selected for the training function.

Gradient descent with momentum weight and bias learning function

(LEARNGDM) is selected to be the adaption learning function. Neurons in input

layer have no transfer function. Computer program is performed under MATLAB

environment using neural network toolbox. The training of the network is accom-

plished by adjusting the weights and is carried out through training sets and training

cycles (epochs). The goal of the learning procedure is to find the optimal set of

weights. The output of the network is compared with a desired response to produce

an error (Kizilkan 2011). The performance of the network is measured in terms of

the absolute fraction of variance (R2) and the root mean square error (RMSE). The

equations for these functions are given below (Akdag et al. 2009).

Aircraft Warning Light

Temperature and Humidity Sensor

Pressure Sensor and

Data Logger

Anemometer

63 m

61 m

30 m

3. 5

28 m

59 m

4 m

Direction Sensor

Fig. 17.7 Schematic illustration of the wind measuring station

216 A. Kerem et al.

R2 ¼ 1� X

i ti þ oið Þ2X i oið Þ2

ð17:2Þ

RMSE ¼ 1 i

X i ti þ oij j2

� �1=2 ð17:3Þ

In above equations, t is the target value, o is the output value and i is the number

of patterns.

Results and Discussion

For the long term forecasting of wind speed data for the university campus, ANNs is

successfully applied using different number of layers. For each wind speed data,

80% of data are used for training and 20% of data are used for testing the neural

network. Log-sig activation function is used and for this reason all data were

normalized between 0 and 1. In order to determine the output parameters, logistic

sigmoid (log-sig) transfer function used here is given by;

Fig. 17.8 Wind measuring station final form

17 Modelling of Wind Speed Using Artificial Neural Networks for University. . . 217

Fi ¼ 1 1þ e�Ei ð17:4Þ

where;

Et ¼ Xt n¼1

InWn1 þ bn ð17:5Þ

In the above equations for Ei, the first two values are the multiplication of the

input parameters (In) with their weights at location, and the last constant value (bn)

represents the bias term. The subscript i represents the number of hidden neuron

(Karatas et al. 2009). The training parameters of ANNs are given in Fig. 17.9.

The results of the training in terms of statistical error values such as R2 and

RMSE for different number of hidden layers are given in Table 17.1. As seen from

the table, the best approach which has minimum error is obtained using seven

neurons for predicting the monthly average wind speed at 61 m and 11 neurons for

predicting the monthly average wind speed at 31 m. The performance of training

and test sets of the established ANNmodel for the two cases are given in Figs. 17.10

and 17.11 for two cases. It must be noted that the results given in Figs. 17.10 and

17.11 are for the best approaches obtained from ANNs.

Figures 17.12 and 17.13 show comparisons of the actual data obtained from the

measurements and predicted data from the modelling of ANNs for the two cases. As

seen from the figures the actual and predicted data are very similar to each other and

the established ANNs models give very accurate modeling of the measured data

instead of setting up several measurements.

As a result, it is very obvious that with this methodology, prediction of wind

speed instead of making several measurements can be carried out in a very short

time periods with high accuracy. The major advantages of ANNs are the calculation

speed, learning capability and simplicity. Consequently, for the forecasting of long

term wind speeds, ANNs approach shows almost precise estimations.

Fig. 17.9 Training parameters of ANNs

218 A. Kerem et al.

Table 17.1 Statistical error values of the models

Wind speed at 61 m Wind speed at 31 m

R2 RMSE R2 RMSE

LM6 0.4843 0.146275 0.4265 0.150973

LM7 0.8908 0.057074 0.8687 0.052959

LM8 0.7297 0.077489 0.4086 0.163676

LM9 0.2617 0.224754 0.3126 0.212168

LM10 0.126 0.244656 0.0834 0.246077

LM11 0.8835 0.053905 0.9026 0.050677

LM12 0.4196 0.156515 0.4906 0.173811

LM13 0.1426 0.217326 0.2481 0.196354

LM14 0.4182 0.215233 0.2017 0.179746

LM15 0.3968 0.19915 0.3667 0.197422

LM16 0.804 0.092906 0.0409 0.259957

100

0.8

0.6

0.4

0.2

10−2

10−4

10−6

0 0 0.2

R2=0.8908

0.4 0.6 0.8 1 1 2 3 4 5 6

11 Epochs Predicted values

A ct

u al

v al

u es

Best Validation Performance is 0.0091834 at epoch 5

M ea

n S

q u

ar ed

E rr

o r

(m se

)

7 8 9 10

Train Validation Test Best

Fig. 17.10 Performance of training and test sets for modelling of average wind speed at 61 m (LM7)

100

10−2

10−4

10−6

10−8

M ea

n S

q u

ar ed

E rr

o r

(m se

)

0 1 2 3 4 5 6 10 Epochs

7 8 9 10

0.8

0.6

0.4

0.2

0 0 0.2

R2=0.9026

0.4 0.6 0.8 1

Predicted values

A ct

u al

v al

u es

Train Validation Test Best

Best Validation Performance is 0.010091 at epoch 4

Fig. 17.11 Performance of training and test sets for modelling of average wind speed at 31 m (LM11)

17 Modelling of Wind Speed Using Artificial Neural Networks for University. . . 219

Conclusions

Wind energy potential of Mehmet Akif Ersoy University campus was analyzed

using ANNs. In order to determine the wind energy potential, a measurement tower

which was 63 m in height was built up. Measurements were made for 12 months.

The ANNs were used for long term forecasting of wind speed data. For this aim,

80% of data were used for training while 20% of data were used for testing. The

results showed that the deviation between the actual values and predicted values

were within acceptable uncertainties. The best approaches were found using seven

neurons for predicting the wind speed at 61 m and 11 neurons for predicting wind

speed at 31 m while the R2 values for the models were found to be 89.08% and

90.26%, respectively. As a result, the established ANNs models exhibited almost

Fig. 17.12 Comparison of actual and predicted values for average wind speeds at 61 m

Fig. 17.13 Comparison of actual and predicted values for average wind speeds at 31 m

220 A. Kerem et al.

precise long-term wind speed estimations instead of setting up several

measurements.

Acknowledgement The authors gratefully acknowledge support of this research by West Med- iterranean Development Agency (BAKA, Project Number: TR61/13/DFD/036) and Mehmet Akif

Ersoy University Scientific Research Projects Commission (Project Number: 0212-Güdümlü-13).

References

Akdag, U., Komur, M. A., & Ozguc, A. F. (2009). Estimation of heat transfer in oscillating annular

flow using artificial neural networks. Advances in Engineering Software, 40, 864–870. Akova, İ. (2008). Renewable energy resources. Ankara: Nobel (in Turkish). Bilgili, M., Sahin, B., & Yasar, A. (2007). Application of artificial neural networks for the wind

speed prediction of target station using reference stations data. Renewable Energy, 32, 2350–2360.

Cam, E., Arcaklıoglu, E., Cavusoglu, A., & Akbıyık, B. (2005). A classification mechanism for

determining average wind speed and power in several regions of Turkey using artificial neural

networks. Renewable Energy, 30, 227–239. Demirci, E., & Senlik, İ. (2009). Seasonal evaluation of wind energy potential of Ondokuz Mayıs

University. In Second wind energy symposium, 4–5 June 2009, Samsun, Turkey (in Turkish). Ekonomou, L., Lazarou, S., Chatzarakis, G. E., & Vita, V. (2012). Estimation of wind turbines

optimal number and produced power in a wind farm using an artificial neural network model.

Simulation Modelling Practice and Theory, 21, 21–25. EMO, Chamber of Electric Engineers (in Turkish). Retrieved November 26, 2014, from http://

www.emo.org.tr/.

Energy Institute. Retrieved November 25, 2014, from http://enerjienstitusu.com.

ETKB, Ministry of Energy and Natural Resources (in Turkish). Retrieved November 26, 2014,

from http://www.enerji.gov.tr/.

Fadare, D. A. (2010). The application of artificial neural networks to mapping of wind speed

profile for energy application in Nigeria. Applied Energy, 87, 934–942. Genc, A., Murat, E., Pekgor, A., Oturanc, G., Hepbaslı, A., & Ulgen, K. (2005). Estimation of

wind power potential using Weibull distribution. Energy Sources, 27, 809–822. Hayli, S. (2001). The importance of wind energy and its current status in the world and in Turkey.

Fırat University Journal of Social Science, 11, 1–26 (in Turkish). Jiang, W., & Lu, J. (2014). Frequency estimation in wind farm integrated systems using artificial

neural network. Electrical Power and Energy Systems, 62, 72–79. Jung, S., & Kwon, S. D. (2013). Weighted error functions in artificial neural networks for

improved wind energy potential estimation. Applied Energy, 111, 778–790. Kalogirou, S. A. (2000). Applications of artificial neural-networks for energy systems. Applied

Energy, 67, 17–35. Karatas, C., Sozen, A., & Dulek, E. (2009). Modelling of residual stresses in the shot peened

material C-1020 by artificial neural network. Expert Systems with Applications, 36, 3514–3521.

Kerem, A., Atayeter, Y., G€orgülü, S., & Salman, S. (2014). Preparation and implementation of wind energy feasibility infrastructure of Mehmet Akif Ersoy University, İstiklal Campus,

Mehmet Akif Ersoy University. Journal of Institute of Natural and Applied Science, 5, 18–24 (in Turkish).

Khahro, S. F., Tabbassum, K., Soomro, A. M., Dong, L., & Liao, X. (2014). Evaluation of wind

power production prospective and Weibull parameter estimation methods for Babaurband,

Sindh Pakistan. Energy Conversion and Management, 78, 956–967.

17 Modelling of Wind Speed Using Artificial Neural Networks for University. . . 221

http://www.enerji.gov.tr/

http://enerjienstitusu.com/

http://www.emo.org.tr/

Kizilkan, O. (2011). Thermodynamic analysis of variable speed refrigeration system using artifi-

cial neural networks. Expert Systems with Applications, 38, 11686–11692. Koc, E., & Senel, M. C. (2013). The state of energy in world and Turkey—General evaluation.

Engineer and Machinery, 54, 32–44 (in Turkish). Mohandes, M., Rehman, S., & Rahman, S. M. (2011). Estimation of wind speed profile using

adaptive neuro-fuzzy inference system (ANFIS). Applied Energy, 88, 4024–4032. Mohanraj, M., Jayaraj, S., & Muraleedharan, C. (2015). Applications of artificial neural networks

for thermal analysis of heat exchangers—A review. International Journal of Thermal Sciences, 90, 150–172.

Monfared, M., Rastegar, H., & Kojabadi, H. M. (2009). A new strategy for wind speed forecasting

using artificial intelligent methods. Renewable Energy, 34, 845–848. Ozerdem, B., & Turkeli, H. M. (2005). Wind energy potential estimation and micrositting in Izmir

Institute of Technology Campus, Turkey. Renewable Energy, 30, 1623–1633. Oztopal, A. (2006). Artificial neural network approach to spatial estimation of wind velocity data.

Energy Conversion and Management, 47, 395–406. Pishgar-Komleh, S. H., Keyhani, A., & Sefeedpari, P. (2015). Wind speed and power density

analysis based on Weibull and Rayleigh distributions (a case study: Firouzkooh county of

Iran). Renewable and Sustainable Energy Reviews, 42, 313–322. Pourmousavi Kani, S. A., & Ardehali, M. M. (2011). Very short-term wind speed prediction: A

new artificial neural network–Markov chain model. Energy Conversion and Management, 52, 738–745.

Sahin, A. D. (2004). Progress and recent trends in wind energy. Progress in Energy and Combus- tion Science, 30, 501–543.

Sencan, A. (2007). Performance of ammonia–water refrigeration systems using artificial neural

networks. Renewable Energy, 32, 314–328. Sencan, A., & Kalogirou, S. A. (2005). A new approach using artificial neural networks for

determination of the thermodynamic properties of fluid couples. Energy Conversion and Management, 46, 2405–2418.

Shamshirband, S., Petkovic, D., Anuar, N. B., Kiah, M. L. M., Akib, S., Gani, A., et al. (2014).

Sensorless estimation of wind speed by adaptive neuro-fuzzym ethodology. Electrical Power and Energy Systems, 62, 490–495.

Sozen, A., Arcaklioglu, E., & Menlik, T. (2010). Derivation of empirical equations for thermo-

dynamic properties of a ozone safe refrigerant (R404a) using artificial neural network. Expert Systems with Applications, 37, 1158–1168.

Tagliaferri, F., Viola, I. M., & Flay, R. G. J. (2015). Wind direction forecasting with artificial

neural networks and support vector machines. Ocean Engineering, 97, 65–73. Yıldız, Z., & Uzun, H. (2015). Prediction of gas storage capacities in metal organic frameworks

using artificial neural network. Microporous and Mesoporous Materials, 208, 50–54.

222 A. Kerem et al.

Chapter 18

Cultural Landscapes as a Means of Energy Reduction at Global Warming

Afroditi Venetsanou, Alexandros-Theodoros Venetsanos,

and Lena Mantziou

Introduction

Reflection Framework

During the twentieth century, unconditional development led to dramatic alteration

of climate and environmental balance on the planet. Similar is the fate of cultural

heritage, where the memory and the ecological balance have been also sacrificed to

the rapid and massive development. The need for rescue measures for the natural

and historic environment became a universal appeal.

International mobilizations, declarations and treaties such as UNESCO,

RAMSAR and UNEP recognize values in sensitive natural and anthropogenic

landscapes and identify institutional frameworks to protect them.

The above already reflects the change in mentality, the diametric shift in

ecological conception and interpretation: The dominance of humans on the nature,

expressed by the over exploitation of the environment is now gradually succeeded

from a symbiotic logic of human labour with the environment.

The expansionist perception to absorb new virgin landscapes, to cover and

expand the living needs is gradually succeeded from recovery and reuse of existing

A. Venetsanou (*) Chemical Engineering NTUA, Tatoiou 89, Athens 14564, Greece

e-mail: [email protected]

A.-T. Venetsanos

Mechanical Engineering NTUA, Tatoiou 89, Athens 14564, Greece

e-mail: [email protected]

L. Mantziou

Dr. Architect Eng. NTUA, Assistant professor, School of Architecture NTUA, Adamon 2,

Athens 14564, Greece

e-mail: [email protected]

223

mailto:[email protected]

bio-landscapes and facilities. The strategic use of natural inventory, acts protective

on the existing ecosystem, contributes indirectly (in this way) to reduce global

warming in the spirit of the contemporary international positions on sustainability

and viability.

At the dawn of the new millennium the balance between climate change, culture

and economy are the main issues of international concern. More and more we

concord that these matters are interrelated and influence each other.

The need for reasonable development under environmental equilibrium is get-

ting clear. Also awareness, that the way to protect the natural and cultural heritage

is neither the exclusion nor a museum, but creating worth-living growth conditions.

The recovery and reuse of historic living spaces, with a view to environmental

sustainability generates the local prerequisites for a reversal of global warming.

This work is based on the position that the ecological development of cultural

landscapes will act as a significant leverage for environmental improvements and

contribute locally to address global warming. In particular it considers that a new

strategic utilization of the ecosystem must activate regeneration of the environment

and at the same time ensure cultural continuity, social service, human recreation.

Starting at the micro scale of a landscape, this reflection may be extended to the

global range, to redefine the actual energy and environmental needs of future

mankind.

Project Terminology, Clarifications and Limitations

The term “Cultural landscapes” applies to areas obtained from the combined work

of man and nature over the time. They are bearer of tangible and intangible values,

precious to the broader community and significant to the environmental balance.

We recognize that cultural landscapes:

1. May bloom due to the long-time toil of man,

2. May then decline due to neglect inattention or abandonment,

3. Are threatened mainly by uncontrolled or incompatible ecosystem development.

Cultural landscapes are systemic areas with particular characteristics and qual-

ities, distinct from the surrounding environment. Such cultural and ecological

clusters can be perceived as living organisms, which offer particular experiences.

They are spatially distributed around the globe. We recognize heterogeneous

contents in cultural landscapes, covering the whole range of human interventions

in the nature. They also vary widely in their size, ranging from small blocks to

extensive manmade interventions in the natural landscape (Fig. 18.1–18.4).

This paper argues that cultural landscapes are best protected and revived when

people live act and learn through them. A main question is: which modern inter-

vention in a cultural landscape could retrieve memories, bring wealth to future

generations and at the same time upgrade the environment and climate of the

region?

224 A. Venetsanou et al.

The issue of reducing the global warming is of particular importance in densely

built urban environment. Areas out of the densely populated urban tissue may also

indirectly affect the balance of the environment to the extent that they either

develop a polluting activity or belong to a global network of travellers’ destinations accessible over intensive commuting and transport.

Fig. 18.1 Oil platform, North Sea

Fig. 18.2 Wetlands, Amvrakikos Gulf

18 Cultural Landscapes as a Means of Energy Reduction at Global Warming 225

Fig. 18.3 Historical City Centre, Athens

Fig. 18.4 “Forte Portuense”, Rome

226 A. Venetsanou et al.

Methodology

The study emphasizes to the analysis of individual components of cultural land-

scapes. The purpose is to enable a systemic study of ecological dependencies.

Examination of the contribution of cultural landscapes to the reduction of global

warming will take place for some representative landscapes organized for this

purpose in two sections:

1. Cultural landscapes outside the urban tissue [Oil platforms (Fig. 18.1), Wetlands

(Fig. 18.2)].

2. Cultural landscapes in densely built urban tissue (Historical City—Centre

(Fig. 18.3), Citadel (Fig. 18.4)].

Selection criteria for the proposed landscape sample have been so far: Spatial

planning, scale characteristics, function, historical context, accessibility, commu-

nication, inclusion into the surrounding ecosystem.

Theoretical basis of the investigation may consist of multiple approaches—

“readings” of cultural landscapes. The uniqueness of each landscape will be

gradually further recognized by means of the above framework.

Project work for each of the selected landscapes will comprise:

1. The claim of reuse or revival

2. Identification of the current situation

3. Intervention strategy

4. Contribution to reduction of global warming.

Valuation

Many environmental and culture values remain intangible for valuation methods

like the LCC. Therefore a more sophisticated valuation method based on the

“common good” balance Matrix of the GCE may be more applicable for the

purpose of this study.

This work’s “added value” is on a “change of the way to think of the Environ- ment” through anthropocentric proposals (reuse, awareness, and sustainability).

Such a contribution cannot be evaluated by quantitative measurements, or a solely

technical feasibility assessment today. The main Goal is rather to start a process of

"change of mentality" which may then "cultivate" further individual quantitative

targets and technical solutions.

Sample pictures below highlight different structural models of Cultural

Landscapes

18 Cultural Landscapes as a Means of Energy Reduction at Global Warming 227

1. Cultural Landscapes Outside the Urban Tissue

1.1 Alternative use of oil platforms at the end of their service life for energy retain.

Opening Question

Could the alternative use of oil platforms at the end of their service life contribute to

retain energy?

Identification of the Cultural Landscape

In the UK continental shelf—an area of the North Sea with large resources of

hydrocarbons—there are over 600 offshore oil rigs and subsea installations, while

approximately half of them are over 15 years old and approaching the end of their

service life. According to the Oil & Gas UK Economic Report 2013, about

475 installations, 10,000 km of pipelines, 15 onshore terminals and 5000 wells

will eventually need to be decommissioned. Over the next 25 years,

decommissioning costs are estimated to be in the region of £31.5bn.

This issue is not limited to the UK but concerns every country having offshore

activity, because it triggers many environmental concerns relative to the required

energy, CO2 emissions and the ocean water contamination. At present, the common

decommissioning practice in case of fixed oil rigs is either to remove the hazardous

waste and topple them creating in this way artificial reefs, or to remove the topsides

by reverse installation of modules using heavy lift vessels and recycle them onshore

(Scottish Enterprise Energy Team 2008). As for the jackets they are cut into pieces

using diamond wire techniques before being transported onshore for recycling.

Regarding to the floating platforms, they are towed to the shore for scraping or

they sink.

According to the Institute of Petroleum both direct and indirect energy require-

ments for different decommissioning solutions are compared in Table 18.1. As

reference point has been set the required energy for toppling a platform, while the

rest alternatives are compared to this value.

However, there are also several alternatives for sustainable reusing the existing

facilities for non production purposes. More specifically, Wan Abdullah Zawawi

et al. (2014) have proposed viable possibilities including (a) offshore maintenance

and logistics bases, (b) sites for wind turbines, wave energy generating equipment

and(or) photovoltaic panels, (c) LNG terminals, (d) sites for aquaculture facilities,

(e) tourism attractions, (f) offshore research and training centres, and (g) bases for

search-and rescue operations.

228 A. Venetsanou et al.

Figure 18.5 shows a proposal designed byMorris Architects which won the 2008

Radical Innovation in Hospitality Awards for a self-sustaining and eco-friendly

hotel offshore. Figures 18.6 and 18.7 illustrate a conceptual design by Ku Yee Kee

and Hor Sue-Wern of a transformed abandoned oil rig into a modern city. This

proposal was one of the finalists of the Evolo’s 2011 Skyscraper Competition. The main idea is that a former oil rig could be inspected reinforced and converted into an

offshore accommodation building. Residents would live above the water level,

while underwater laboratories could be used for subsea observations. As for the

energy requirements of the building, they could be covered by wind turbines and

solar panels on the top of the structure and tidal turbines at the bottom.

At this point must be mentioned that the jackets of fixed platforms could be

transported to the shore and be used as frames for buildings after being properly

reinforced.

Table 18.1 Comparison of energy requirements for various decommissioning alternatives

Scenario

% of total energy (compared to

toppling as baseline)

A—Toppling (Baseline) 100

B—Partial ashore and partial in-situ 101

C—Partial removal with partial in-situ and creation of

reef in other location

106

D—Complete removal ashore 114

E—Complete removal to deep water 154

Source: ERT 1997, Page 11, Table 4

Fig. 18.5 Proposal by Morris Architects 2008 Radical Innovation in Hospitality

18 Cultural Landscapes as a Means of Energy Reduction at Global Warming 229

Fig. 18.6 Design by Ku Yee Kee and Hor Sue-Wern—transformed abandoned oil rig into a modern city

Fig. 18.7 Cross-section model of Fig. 18.6

230 A. Venetsanou et al.

Summary

To sum up, reuse takes place when a component or a whole structure can be

reclaimed after the expiry of its lifespan for similar or different purpose compared

to the initial one instead of recycling or disposal. In this way, the embodied energy

is retained, and the environmental impacts are eliminated. Reusing existing facil-

ities potentially removes thousands of tons of steel from the waste stream and

reduces the input energy required for reprocessing or recycling. Reuse is an

important aspect of sustainability as the energy used for retrofit or refurbishment

is relatively small compared to the energy consumed by the recycling process.

1.2 A Gateway to the Amvrakikos Gulf

Opening Question

How would the invisible natural wealth of Amvrakikos Gulf reverse declining

economic progress of the region and help its residents to undertake ecological

actions for the sake of the ecosystem’s balance?

Identification of the Cultural Landscape

The Amvrakikos Gulf covers a wetland area of 400qm2, between Central Greece

and Epirus forming the “largest wetland system” of Greece, surrounded by moun-

tains with a narrow mouth to the open sea.

Wealthy cities grew since the ancient time in this region, such as Kassiopi,

Amvrakia (Arta), and Nikopolis. Testimonies of wealth are important archaeolog-

ical sites with outstanding monuments, like the Roman aqueduct of Nicopolis.

Ecosystem

The wealth of Amvrakikos is due to the double delta of the rivers Louros and

Arachthos, who, flowing into in the northern part of the bay, creates a true mosaic of

wetlands, the largest one in Mediterranean Europe. The biotope has been an

inexhaustible source of life for centuries nourishing both wild animals and birds

that find shelter here, as also humans who has learned to use and exploit it.

Riparian strip islands form the boundary between the bay waters and the lagoon

(Fig. 18.8). This linear “shell beach” is naturally formed by sediment concentra-

tions, and get interrupted by natural water mouths, communication channels that

continuously enrich the lagoons with saltwater. With the rivers causing aggrada-

tions and occasional flooding a network of freshwater is maintained in the lagoons,

18 Cultural Landscapes as a Means of Energy Reduction at Global Warming 231

reaching the fish populations, revitalising them with spawn transferred from the

Ionian Sea’s saltwater.

Human Presence and Intervention

By the ancient times local residents have been taking advantage of the biotope.

Fishing methods in the lagoons have been based on the observation of the behaviour

of fish populations in various weather conditions (winds, moon phases), oceano-

graphic conditions (tides, currents), environmental conditions (water temperature,

salinity) and good knowledge of the biological dispersal of the species to and from

the lagoon. Based on this experience, the residents designed and implemented fish

traps and constructions such as fish pens, etc. Applying simple interventions they

transformed the brackish basins in natural fish farms. In passageways within the

islets special dams are installed, which allow water to pass through, but entrap fish

and crustaceans (Petrou and Mantziou 2014) (Fig. 18.9).

The life of the fishermen has its own distinctive features, since the management

of lagoons requires continuous human presence in site, serving for the several daily

tasks and fisheries, and also as custody of facilities, catch and fishing gear.

Today fishing in the lagoons has been streamlined. With the introduction of

modern fish pen facilities, empirical knowledge is now coupled with scientific one

for optimal results. With very few exceptions, these new permanent fish pen are

Fig. 18.8 Amvrakikos Gulf—Riparian strip islands form the boundary between the bay waters and the lagoon. [©Processing M. Petrou]

232 A. Venetsanou et al.

placed in the same locations and arranged in almost the same way as the former,

traditional ones.

Around the perimeter of the bay scattered villages and small towns (Vonitsa,

Amfilochia, Arta, Preveza) have been developed.

Today’s Picture—Ecosystem and Environmental Problems

Anthropogenic interventions like changes in river bed patterns, hydropower plant

dams and intensification of agriculture and farming have caused pollution of the bay

and the lagoons. Interventions in the morphology of the mouth of Amvrakikos as

the port of Preveza and a private marina in Aktion generated silting negatively

affecting the fluid dynamic equilibrium of the bay (Fig. 18.10).

The commercial port of Preveza, built in 1968 is nowadays a complex environ-

mental pollutant. The oversized scale of the port in combination with its location

reduces the cross section and the opening of the mouth of Ambrakikos to 46% of its

original size (from 740 m to 393 m). This increases the speed of Input—Output

currents in the bay which in turn increases risks of erosion of the coastal zone. The

port construction directly in the city’s traditional tissue in front of the castle has

altered the form of the city. Operations in the commercial harbour pollute with dust

and noise due to heavy vehicle movements, degrading the quality of life in the

historic city centre and the seafront (Kanioris et al. 2009).

Fig. 18.9 Amvrakikos Gulf—linear “shell beach”—In passageways within the islets special dams are installed [©Processing M. Petrou]

18 Cultural Landscapes as a Means of Energy Reduction at Global Warming 233

Contamination led to lower fish populations and lower yields from fisheries.

Reduction of fishermen’ income brought a gradual disinterest for the profession, finally the new generation is rather willing to abandon the territory and find better

paying jobs elsewhere.

Ecological Reconstruction Proposal

The area has significant potential for environmental friendly activities. Efforts for

fishery and marine conservation are crucial, as they bring harmony and balance to

the ecosystem:

1. The proposal for a fishing tourism includes developing of fishing activities by

professional fishermen, aimed both for recreation tourism and for spreading the

alternative fishing culture in the country, as well for directly support the fisher-

men financially and stimulate the social web of the local communities.

2. The bipolar system of benefits resulting via the fishing tourism, with final

consumers (tourists) and service providers (fishermen) follows the requirements

of sustainable development.

3. The harmonic coexistence of fishermen and their natural environment through

the promotion and protection of natural, historical, cultural and traditional values

of the region complements the quality of life of residents who already enhanced

their incomes.

4. This new touristic segment is a unique model in the Greek territory.

Fig. 18.10 The port of Preveza and a marina in

Aktion reduce the cross

section and the opening of

the mouth of Ambrakikos

234 A. Venetsanou et al.

5. The non-existent road exits make the wetland ecosystem of Amvrakikos invis-

ible and difficult to reach. Therefore, it is proposed to set up a network of fishing

tourism activities, and mark up this action in waterfronts of cities on the

periphery and near the Gulf.

6. As a pilot project is proposed to create a gateway to the Amvrakikos at Preveza.

The choice of Preveza is due to the comparative advantage this city possesses,

given the multiple elements of natural and cultural heritage, and it’s European, national and local importance (Amvrakikos, Ancient Nicopolis, further ancient

and medieval castles and monuments).

Urban Planning Intervention a Gateway to the Amvrakikos Gulf on the Waterfront of Preveza

The seaside promenade will be extended over the entire long side of the historic city

centre, along which the port for sailing ships and yachts resides. On the southern

edge of the pedestrian esplanade a distinctive enlargement is formed, which meets

the sea front. During the early morning hours eve of fishing vessels may be

observed at this point, where fishermen conduct an informal catch market.

1. The Gateway to the Amvrakikos will be located in the plateau that penetrates the

sea, on the border of land and water.

2. The structure of the fish pens inspires the architecture proposal. The narrow

passage between two constructions, identifies the communication channel of two

different worlds and symbolizes the initiation of residents or visitors to the

invisible world of the fishermen.

3. The first construction constitutes a “floating” sloping square, orientated to the

historic city centre and the seafront promenade. The square offers viewings in

the town and the people’s motion at the seafront as well. At the same time it accommodates exhibitions and activities about the invisible wealth of

Amvrakikos (Fig. 18.11).

4. The second construction houses the fish market, auction, production and also

storage of Amvrakikos products like fish roe under showroom conditions.

5. At the end of the passageway the boat station for transfers to the lagoons will be

located.

Both residents of the city and visitors have the opportunity to tour the site and

learn through the implemented actions about flora and fauna in the heart of

Amvrakikos. By embarking on boats and touring the broader region, travellers

may discover the wealth of Amvrakikos and traditional ways of fishing that remain

alive over centuries.

18 Cultural Landscapes as a Means of Energy Reduction at Global Warming 235

Effects on the Ecosystem

1. Restoring sustainable job prospects for the new generation prevents depopula-

tion of the country and the overconcentration of population in major urban

centres.

2. Fishing as labour dependent on the environmental balance generates the need for

conservation and a preservation consciousness, as respect to the ecological

balance.

3. The architectural configuration of Amvrakikos Gate makes the cultural area well

known publicly and contribute to a rise of visitors. It is so propagating the idea of

fishing and cultural tourism as a coexistence principle with nature also to be

applied in other similar natural habitats.

4. The ideal size and equilibrium of Amvrakikos which do not allow large indus-

trial scale interventions inspires a return to a small-scale balance.

5. The area proportions express the geological and physical properties of the

broader seaside region of the Greek landscape, this of southern Balkans, and

most coastal countries of the Mediterranean. In this region, where the climate

charges are less of industrial origin and more a result of urbanization, climate

preservation is primarily an issue of decentralization. By this reasoning, the

above proposal is a most possible direct interference against global warming in

the given broader area.

Fig. 18.11 “Floating” sloping square, orientated to the historic city centre and the seafront promenade [©Processing M. Petrou]

236 A. Venetsanou et al.

2. Cultural Landscapes Within the Dense Urban Tissue

2.1 Museum Clusters

Opening Question

How modern intervention in densely built historic centre may retrieve memories,

highlight wealth to future generations and at the same time upgrade the environ-

ment and climate of the region?

Identification of the Cultural Landscape

By the End off the twentieth century, modern metropolis became aware of their

potential to add value to their community by attempting the combined effort of

cultural, environmental and economic regeneration. Favourable field of experimen-

tation became the programmatic establishment of museums areas. The combined

investment in culture and the environment becomes eloquently in the planning of

museum clusters. The concentration of museums in a wide green area near the city

centre may be found in many large cities of today, like the National Mall in

Washington (Fig. 18.12), the Museumplein in Amsterdam, the Kunstareal in

Munich (Fig. 18.13), the Museumsufer in Frankfurt.

In the city of Athens, the project of unification of archaeological sites dilutes the

frontiers between the ancient, the neoclassical and modern city and creates the

Fig. 18.12 National Mall in Washington, DC. [©Processing L. Mantziou]

18 Cultural Landscapes as a Means of Energy Reduction at Global Warming 237

Open Museum. The pedestrian network around the Acropolis was a corrective

move, which brought the archaeological sites close to the residents. The removal

of automotive from the shadow of the Holy Rock has beneficial effects on the

microclimate of the area and restored biodiversity in the city centre. The pedestria-

nization of D. Areopagitou—Ap. Pavlou, acts as a ‘patchwork’, which brings the archaeological sites close to the residents, upgrading public space of the city and the

quality of life for citizens and visitors.

Summary

These areas serve as oases in the urban tissue, away from the disturbance of the

automobile. The embellishing nature of the planted areas privileges cultural and

social activities who take place in these gardens, attracting citizens and visitors to

use their free time participating in cultural and naturalistic events.

Fig. 18.13 Kunstareal in Munich [©L. Mantziou]

238 A. Venetsanou et al.

2.2 Rome Community Ring—Forte Portuense

Opening Question

How can we transform an object of military architecture at a local Centre for

recreation and culture, capable to supply urban regeneration, to act beneficial to

the environment and the surrounding area also attracting both residents and

tourists?

Identification of the Cultural Landscape

The municipality of Rome in cooperation with the University La Sapienza and the

agency Progetto Forti initiated a dialogue about one of its precious treasures, the

fortress “Forte Portuense” in Rome. The issue emerged in winter 2014, with an

international architectural competition for the purpose of transformation of “Forte

Portuense” to a recreation area, supporting education and sport.

The fort was part of a larger defence system of fortresses and the artillery placed

in a ring of 4 km outside the ancient walls of the city of Rome. Located at the

entrance to the city, between the River Tiber and street Via Portuense. The Field is

defined by four concentric zones:

1. The nucleus the fort,

2. The dry trench,

3. The external peripheral free space, where are scattered building facilities, while

part is formed on inclined slopes with dense vegetation

4. The urban tissue.

Proposal

The first prize, (won from the Greek team pyrphoros), proposed the creation of an

urban oasis, through the restoration and enhancement of the landscape on the hill.

The overall design attempts to create a lung in densely built urban tissue and to

reunite the various levels of the fort with each other and the city (Fig. 18.14).

In particular, the study includes:

• The use of existing areas in the nucleus of the fort, for hosting mild recreational

activities and exhibitions.

• Hosting sporting activities in the ditch, with the provision of reversible

installations.

• The design of a network of paths on the hill, which combines existing landmarks

of the city and the new reference and orientation points.

• Placement of kindergarten facilities, centre for the elderly and community

services in the outer zone in close proximity to the city.

18 Cultural Landscapes as a Means of Energy Reduction at Global Warming 239

Fig. 18.14 Forte Portuense Conceptual view, Topography, Section. First prize: team Pyrphoros: E. Ziova, C. Lazou, E. Karaoli, A. Rachioti, L.Mantziou (consultant)

240 A. Venetsanou et al.

• Taking advantage of the sloping ground to locate main building blocks under-

ground, thus highlight the landscape and the fort.

• Applying the principles of bioclimatic design with integration of passive heating

and cooling, opens space to the south and makes use of natural ventilation.

• Supports creation of local outbursts for external signalling and natural ventila-

tion of underground space.

• The redesign of the boundary between the study area and the “Via Portuense”,

with the creation of an extensive arcade, following the curve road line and filter

nuisance caused by automotive.

• The coverage of the arcade with photovoltaic panels to assemble energy

autonomy.

• The shaping of input square and reception to the fort with a gesture signifying

the contemporary image of the fort in the twenty-first century.

Conclusion and Suggestion

The examples introduced are representative for different types of cultural land-

scapes and all have as common reflection the reversing of the declining quality of

life. The various causes of decadence can be found in the exhaustion of life

expectancy (oil rigs), changes in living conditions over time (Roman castles), the

impulsive and hasty adoption of each contemporary siren.

The misplaced interventions in fragile ecosystems (Amvrakikos), the dissolution

of the urban fabric by the freedom of the motorisation, the oversized transportation

infrastructure, all require intensive actions in order to undo or correct wrong

decisions implemented so far.

The different proposals presented above shows a new consensus on the relation-

ship between human and their environment. They argue that the achievement of

(future) ecological balance presupposes changing mentalities that will result from a

combined cultural, aesthetic, economic and ecological intervention.

Already in the late twentieth century, the largest metropolises of the Western

world became aware that culture is a lever to pull the economy and try to add value

to their communities by attracting cultural tourism. In this context, the core of the

old city (inner city) is considered a “cultural object” and the heritage recognized as

urban resource. The preservation of the historic centre of the city goes along with a

new momentum for the internal urban regeneration and recovery of the material

stock. The development of the historic centre of the city, in terms of environmental

sensitivity assist the so-called urban growth without landscape consumption.

This paper proposes the conversion of deserted cultural landscapes in energy

oases. The term “urban oasis”, describes the improvement of environmental con-

ditions in the former busy urban environment. Deserted castles, museums areas

(museum clusters), automotive roads can potentially become urban oases and

contribute to the cultural, environmental and social regeneration of the city.

18 Cultural Landscapes as a Means of Energy Reduction at Global Warming 241

It is a fact that human activities within the city in conjunction with the thermal

characteristics of urban areas and urban geometry, affect the quality of the air and

emit heat, increasing the local temperature, smog levels and humidity, with nega-

tive effects on the carbon footprint of urban buildings and the thermal comfort of

the residents. Energy upgrading of building stock, due to a marked reduction of

energy that can offer, is a requirement in modern societies. Till now, the energy

upgrade focused on interventions on individual buildings. The possibility to

develop green areas in densely built urban tissue is limited. Considering that free

spaces are expensive, another type of strategies are being sought to address the

urban heat island.

The new concept redefines the scope of energy upgrade, expands the study limits

beyond the enclosed space and captures the building unity—surroundings. The

building is not considered in isolation but as a whole with its surroundings. The new

approach seeks thermal discharge of the microenvironment. The strategy of urban

oases utilizes the stock material, serves the perception of preservation of the city

centre as a “cultural object”, goes along with a new momentum for the internal

urban regeneration and enhances biodiversity in the city.

Both within cities as also outside urban tissue, a defensive strategy is often

followed, which intervenes to reduce the symptom and is exhausted in quantitative

measurements. But there are significant hidden factors which are not currently

quantifiable—traceable and they affect global warming.

One of them is considered the material stock of abandoned structures, which

multiply in an uncontrolled rate and strongly raises the question of their mainte-

nance. Dismantling and removal is often not feasible due to the excessive cost and

energy consumption. Intangible values, like cultural memories or embodied energy,

suggest the strategy of reuse as a source of hope—a most efficient environmental

option. The energy upgrading of existing cultural landscapes will be founded on the

interdisciplinarity and will demonstrate synergy—in involvement of different fac-

tors and viewpoints—in a collective global climate regeneration effort.

References

Ambrakikos Gulf. Retrieved March 21, 2016, from https://www.wettbewerbe-aktuell.de/

de/contents/5125/Rome+Community+Ring+RCR.html and https://www.pinterest.com/

yacpinterest/rome-community-ring-awarded-proposals/

“Common Good Matrix”, Economy for the Common Good and the CG Matrix. Retrieved March

21, 2016, from http://balance.ecogood.org/matrix-4-1-en/ecg-matrix-en.pdf

Consolidation of archaeological sites in Athens (in Greek language). Retrieved March 31, 2015,

from http://www.astynet.gr/static.php?c¼5 Davey, A. (2005). Oil & Gas UK Economic Report, 2013. Retrieved March 21, 2016, from http://

oilandgasuk.co.uk/wp-content/uploads/2015/07/Adam-Davey-Oil-Gas-UK.pdf

European Landscape Convention. Retrieved April 24, 2015, from http://conventions.coe.int/

Treaty/en/Treaties/Html/176.htm.

Galani, D. Pedestrianization D. Areopagitou—Ap. Pavlou (in Greek language). Retrieved March

31, 2015 from http://www.archaiologia.gr/wp-content/uploads/2011/07/70-15.pdf.

242 A. Venetsanou et al.

http://www.archaiologia.gr/wp-content/uploads/2011/07/70-15.pdf

http://conventions.coe.int/Treaty/en/Treaties/Html/176.htm

http://oilandgasuk.co.uk/wp-content/uploads/2015/07/Adam-Davey-Oil-Gas-UK.pdf

http://www.astynet.gr/static.php?c=5

http://balance.ecogood.org/matrix-4-1-en/ecg-matrix-en.pdf

https://www.pinterest.com/yacpinterest/rome-community-ring-awarded-proposals/

https://www.wettbewerbe-aktuell.de/de/contents/5125/Rome+Community+Ring+RCR.html

GCE. Retrieved March 21, 2016, from https://www.ecogood.org/en/ecg-balance-sheet/what-

common-good-balance-sheet

Kanioris, S., Lahana, E., & Logothetis, G. (2009 December). Port of Preveza. Prospects for development in connection with the operation of the traditional city center—implementation proposals (in Greek language). Preveza: TEE/Department Epirus. Retrieved April 23, 2015, from http://issuu.com/pamepreveza/docs/.

Kunstareal. Retrieved March 31, 2015, from http://projekt.kunstareal.de/projekt/images/

Publikationen/KAM%20Workshop%20Intro.pdf.

LCC. Economical valuation for sustainable construction using the Life Cycle Costing (EU). http://

ec.europa.eu/enterprise/sectors/construction/files/compet/life_cycle_costing/common_method

ology_en.pdf

Museumplein 1891–2020. Retrieved March 31, 2015, from http://www.

tentoonstellingmuseumplein.nl.

National Mall. Retrieved March 31, 2015, from https://web.archive.org/web/20140304025556,

http://www.savethemall.org/mall/resource.

Petrou, M., & Mantziou, L. (2014). The Invisible Amvrakikos (in Greek language). Dissertation. School of Architecture NTUA, Athens.

RAMSAR. Retrieved April 24, 2015, from http://www.ramsar.org/, http://www.ramsar.org/wet

land/greece.

Rome Community Ring—Forte Portuense. Retrieved March 21, 2016, from https://www.

wettbewerbe-aktuell.de/de/contents/5125/Rome+Community+Ring+RCR.html and https://

www.pinterest.com/yacpinterest/rome-community-ring-awarded-proposals/

Scottish Enterprise Energy Team. (2008). The decommissioning market report.

The Institute of Petroleum. (2002, February). Guidelines for the calculation of estimates of energy use and gaseous emissions in the decommissioning of offshore structures.

UNEP (Environment Protection Global Issues and Greece Protected Areas).

UNESCO. Retrieved March 21, 2016, from http://whc.unesco.org/en/culturallandscape/

Wan Abdullah Zawawi, N. A., Liew, M. S., & Na K. L. (2014). Decommissioning of offshore platform: A sustainable framework. 2014 MSSA Malaysian Structural Steel Association.

WWF on Wetlands. Retrieved March 21, 2016, from http://wwf.panda.org/about_our_earth/

about_freshwater/intro/value/, Amvrakikos Rodia Wetlands Center. Retrieved March 21,

2016, from http://www.rodiawetlands.gr/

18 Cultural Landscapes as a Means of Energy Reduction at Global Warming 243

http://www.rodiawetlands.gr/

http://wwf.panda.org/about_our_earth/about_freshwater/intro/value/

http://www.mssa.org.my/site/index.php

http://whc.unesco.org/en/culturallandscape/

https://www.pinterest.com/yacpinterest/rome-community-ring-awarded-proposals/

https://www.wettbewerbe-aktuell.de/de/contents/5125/Rome+Community+Ring+RCR.html

http://www.ramsar.org/wetland/greece

http://www.ramsar.org/

http://www.savethemall.org/mall/resource

https://web.archive.org/web/20140304025556

http://www.tentoonstellingmuseumplein.nl/

http://ec.europa.eu/enterprise/sectors/construction/files/compet/life_cycle_costing/common_methodology_en.pdf

http://projekt.kunstareal.de/projekt/images/Publikationen/KAM%20Workshop%20Intro.pdf

http://issuu.com/pamepreveza/docs/

https://www.ecogood.org/en/ecg-balance-sheet/what-common-good-balance-sheet

Part V

Energy Technologies and Their Effect on Global Warming

Solar Energy

Investigation of solar still performance and novel combination of solar energy with

methane reforming reactors and organic Rankine cycle for power generation.

Chapter 19

Solar-Driven Continuous Methane Reforming Reactor

M. Lange, J. Lapp, R. Rieping, L. de Oliveira, M. Roeb, and C. Sattler

Introduction

The world energy demand is covered mainly by the use of fossil fuels. Apart from

the direct use of fossil fuels, however, the use of synthetic (mainly liquid) fuels has

been attracting a lot of interest lately. Currently, synthetic fuels are produced at a

commercial scale from carbonaceous sources with low energy content, which are

upgraded at the expense of additional energy. This additional energy is also

obtained from the combustion of fossil fuels. In order to make the latter procedure

more attractive and environmentally friendlier, these processes could be combined

with a renewable energy source, such as solar energy.

Although there is an increase in the use of alternative energy vectors,

e.g. renewable electricity, the reliance on fossil fuels is still extensive. The main

advantage of liquid fuels when compared for example to electricity is their prompt

availability upon demand regardless of temporal or location-related restrictions.

The preservation of economic stability and growth creates the most significant

motive for industries to start pursuing environmentally friendlier energy vectors.

Existing technologies are further investigated and improved in order to minimize

CO2 production and renewable energy installations have started to appear with

higher frequency. An important step forward would be to employ solar energy, an

inexhaustible energy source, in order to produce synthetic fuels.

As a consequence, in the last decade an increased research activity could be

noted regarding the exploitation of the solar potential to produce Hydrogen or

synthesis gas (hydrogenþ carbon monoxide) through the dissociation of water and carbon dioxide (Ermanoski et al. 2014; Roeb et al. 2008, 2012; Muhich

M. Lange (*) • J. Lapp • R. Rieping • L. de Oliveira • M. Roeb • C. Sattler German Aerospace Center (DLR), Institute of Solar Research, Linder H€ohe, 51147 K€oln, Germany e-mail: [email protected]

249

mailto:[email protected]

et al. 2013). On one hand solar water-splitting is a totally renewable process with

zero greenhouse gas emissions, while on the other hand solar carbon dioxide

splitting utilizes CO2—amaterial which is currently characterized as an undesirable

waste—as a reactant to finally produce valuable solar fuels. However, these pro-

cesses have not yet reached the essential maturity for large-scale industrial

implementation.

A process that is considered to have one of the highest short term potential in

terms of technology and economics is solar reforming of methane (Agrafiotis

et al. 2014). With such an approach longer term carbon-neutral or carbon-free

energy solutions, such as water and carbon dioxide splitting with the aid of solar

energy for the production of solar fuels, can be given the required time to be

developed. Further, the feedstock natural gas may be replaced in the future by

biogas sources (Bereketidou and Goula 2012).

In this paper we propose a new reactor concept which acts as a solar receiver-

reactor and heat exchanger at the same time. This multi-use approach enables

continuous methane reforming and even night time operation is possible.

Concept

Several solar reactors for methane reforming have been developed and studied

previously (W€orner and Tamme 1998; Agrafiotis et al. 2014). The novelty of the proposed concept is its flexibility regarding the solar radiation. The key to this

flexibility lies in the receiver geometry. The core of the receiver consists of a

monolithic honeycomb structure with two different and separated sets of channels,

see Fig. 19.1.

For daytime operation, concentrated solar radiation is focused on the front face

of the monolith, heating it up to 900 �C. In one set of channels, the solar heat is used to run the endothermic reforming reaction. Steam reforming (19.1) and dry

reforming (19.2) or a mixture of both is possible (Rostrup-Nielsen 2002):

CH4 þ H2O ! 3H2 þ CO ΔH� 298K ¼ þ206 kj=mol ð19:1Þ CH4 þ CO2 ! 2H2 þ 2CO ΔH� 298K ¼ þ 247 kj=mol ð19:2Þ

In the other set of channels, heat is taken up by a heat transfer medium, which we

propose to be air. This heat transfer medium transfers the solar heat to a thermal

storage close to the reactor.

During nighttime operation, the air flow is reversed in order to transfer the heat

from the storage to the receiver. With this heat, the reforming reaction in the first set

of channels can be powered even without direct solar input.

A process flow diagram of the concept is shown in Fig. 19.2.

This new concept brings along the potential to reduce costs, because by contin-

uous operation all the downstream components can be reduced in size and thus

250 M. Lange et al.

Fig. 19.1 Concept drawing of novel receiver reactor monolithic structure

New Receiver- Reactor

Educts

Syngas

Heat Storage

Hot Air Concentrated Solar

Irradiation

Cold Air

New Receiver- Reactor

Educts

Syngas

Heat Storage

Hot Air

Cold Air

(H2 + CO)

(CH4 + H2O)

(H2 + CO)

Fig. 19.2 Process scheme (top: on-sun operation mode; bottom: off-sun operation mode)

19 Solar-Driven Continuous Methane Reforming Reactor 251

costs. Additionally, less start-up and shut-down cycles will be necessary which is

beneficial from an operational as well as from a durability point of view.

Production of Monolith

As the monolith concept is novel, no standard production method is readily

available to create such a geometry. Therefore, a custom-made honeycomb was

produced. The production method, which is illustrated in Fig. 19.3, is explained in

the following.

First, a common honeycomb made from recrystallized silicon carbide (RSiC)

was acquired. Such pieces are extruded mainly for the automotive industry (cata-

lytic converters, diesel particulate filters). As the channel walls of the monolith

need to be very gas tight in order to avoid crossover flow between the two channel

types, the porous RSiC needs to be infiltrated with further silicon. Only then, the

channel walls are gas tight. However, the Si-infiltrated silicon carbide (SiSiC) is

extremely hard to machine. Therefore, before infiltration, the slots which are

necessary for the side inlet channels were cut into the RSiC piece. Then, infiltration

was carried out. After that, the monolith walls were coated with a Rhodium and

Al2O3 catalyst which is necessary for the reforming reaction. In a final step, the

slots which had been cut into the front and back of the monolith were closed with

ceramic glue and SiC-sticks.

Some pictures showing the real production steps are shown in Fig. 19.4.

Fig. 19.3 Production method of custom honeycomb (only upper half shown here, lower half is symmetric). (1) Extruded RSiC monolith, (2) cutting of slots, (3) infiltration to SiSiC, (4) catalyst coating and preparation for closing of slots, (5) closing of slots, (6) burning and removal of stick for closing of slots

252 M. Lange et al.

Experimental Set-up

The concept is currently being experimentally evaluated at the high flux solar

simulator of DLR, Cologne. The reactor during assembly is displayed in Fig. 19.5.

The solar simulator has a maximum power input of 20 kW. The simulator

consists of 10 xenon lamps which have a spectrum similar to the solar spectrum.

This solar-like concentrated radiation will be used to simulate the daytime opera-

tion. Half of the input energy will be used for the reforming reaction and the other

half will be taken up by the air stream.

A scheme of the experimental set-up is shown in Fig. 19.6.

This first test campaign focuses on only thermal characterization of the concept.

This way, a more sound characterization of the thermal behaviour of the system is

possible, because no heat of reaction distorts the thermal result. Further, valuable

information can be collected to decide how the reactor should be operated.

In the experimental setup, two gas heaters are included. The first one, which is

located upstream of the reactor in the reactants stream, is employed in order to

simulate heat recovery from the product gas stream. In a future plant, such heat

recovery would most likely be implemented. As real heat recovery with a heat

exchanger would reduce the flexibility of the set-up and thus also the scientific

output of the experiments, we decided to replace a real physical heat recovery by

Fig. 19.4 Steps of producing the monolith. (1) Slots in RSiC block, (2) SiSiC block, (3) closing of slots, (4) final geometry

19 Solar-Driven Continuous Methane Reforming Reactor 253

this first gas heater. The second gas heater is placed in the air stream before entering

the reactor. This heater enables to simulate nighttime operation. Again, we apply

this electrical heater instead of a heat storage in order to stay as flexible as possible,

in order to increase the scientific output and also to save expenses.

For the experimental campaign, the methodology called Design of Experiments

is applied. This method is based on statistical evaluation of the results. During the

experiments, not one factor at a time (OFAT) will be changed, but several

Fig. 19.5 Left: assembly of monolith in reactor shell, right: final design of reactor with glass window for solar input

Fig. 19.6 Experimental set-up for continuous methane reforming

254 M. Lange et al.

parameters (like mass flows, inlet temperatures and radiation) will be changed at

once. By statistical analysis, the results have a more general character than results

obtained with the OFAT method, because interactions between parameters can be

assessed.

Conclusion

A novel receiver reactor concept for continuous operation of solar thermochemical

processes has been proposed. The core of the concept is a honeycomb monolith

with two different sets of channels. One set of channels is used for a solar-powered

reaction, the other set of channels acts as a heat exchanger to take up heat during the

day and bring it back into the reactor at night.

As the monolith is not a standard part, it was custom made. The production

process was described. Further, the monolith is integrated into a reactor, which in

turn is integrated into an experimental set-up in a high flux solar simulator. In this

experimental set-up, it is possible to simulate daytime as well as night time

operation.

Acknowledgement The authors thank the German Ministry of Education and Research for funding this work within the project ContiSol (Contract Number 03SF0468). We also greatly

acknowledge the work of our colleagues and project partners Dr. Souzana Lorentzou and

Christodoulos Lekkos from Aerosol & Particle Technology Laboratory, CERTH-CPERI.

References

Agrafiotis, C., von Storch, H., Roeb, M., Sattler, C. (2014). Solar thermal reforming of methane

feedstocks for hydrogen and syngas production—A review. Renewable and Sustainable Energy Reviews, 29, 656–682.

Bereketidou, O. A., & Goula, M. A. (2012). Biogas reforming for syngas production over nickel

supported on ceria–alumina catalysts. Catalysis Today, 195(1), 93–100. Ermanoski, I., McDaniel, A. H. (2014). Solar hydrogen production with a metal oxide based

thermochemical cycle. DOE Annual Merit Review: 25. Muhich, C. L., Evanko, B. W., Weston, K. C., Lichty, P., Liang, X., Martinek, J. (2013). Efficient

generation of H2 by splitting water with an isothermal redox cycle. Science, 341(6145), 540–542.

Roeb, M., Neises, M., Monnerie, N., Call, F., Simon, H., Sattler, C. (2012). Materials-related

aspects of thermochemical water and carbon dioxide splitting: A review. Materials, 5(11), 2015–2054.

Roeb, M., Neises, M., Säck, J.-P., Rietbrock, P., Monnerie, N., Dersch, J. (2008). Operational

strategy of a two-step thermochemical process for solar hydrogen production. International Journal of Hydrogen Energy, 34(10), 4537–4545.

Rostrup-Nielsen, J. R. (2002). Syngas in perspective. Catalysis Today, 71(3–4), 243–247. W€orner, A., & Tamme, R. (1998). CO2 reforming of methane in a solar driven volumetric receiver-

reactor. Catalysis Today, 46, 165–174.

19 Solar-Driven Continuous Methane Reforming Reactor 255

Chapter 20

Specific Applications/Examples: Use of Solar Energy in Fishing: Community Initiatives

J. Vincent Jain and Satish Babu

Research Background

Any developmental project or research project without considering the climate

change factor will be incomplete. Indeed, ‘climate change has become the defining generational challenge for the international community.’ It is considered one of the biggest threats to our world today. The aftermath of today’s global condition, if not given due attention locally and globally, would harshly affect the young generation

and the generations to come and they won’t find the earth a better place to live. The significant rise in global temperature and human activities has worsened the

situation. Energy saving, conservation of water and minimization of emission of

CO2 help to balance the Global Warming.

Introduction

Fishery is an area where an alternative energy technology, products and its services

are needed to minimize the fossil fuel dependency which could save large amount

of energy, water and reduce carbon emission. Fishing is considered as the most

energy-intensive food production method in the world. In India, thousands of large-

and medium-size fishing boats—from trawlers and seiners to liners and

J.V. Jain (*) Association of Deep Sea Going Artisanal Fishermen, Shark Street, Thoothoor P.O.,

Kanyakumari District, Tamil Nadu, India

e-mail: [email protected]

S. Babu

ICFOSS, Technopark, Trivandrum, Kerala, India

e-mail: [email protected]

257

mailto:[email protected]

gillnetters—depend primarily on one fossil fuel, diesel or kerosene. Large volumes

of energy and water are used to produce inputs for pre harvest and post harvest

activities. If we are able to use an alternate energy technology, products and its

services properly we could save large amount energy, water and avoid unnecessary

emission of CO2. There is scope to reduce CO2. by setting emission norms and

improving fuel efficiency of marine fishing boats.

Problem

An artisanal deep sea fisherman takes 15–20 days for a fishing voyage. A few

others take 25–30 days and more. During the voyage they have to keep the engine

running the engine for charging of the batteries. The engine keeps running

even they are not fishing. Some fishermen keep running the engine to prevent

restarting trouble. About 20–25% of fuel is used for the continuous operation of

the engine. The signal lights, navigational and safety equipments are operating with

the support of batteries in the boat. Many times fishermen have met with accidents

and have been unable to use the navigational and safety equipments because of

engine failure.

Community Initiatives

Though tapping solar energy for land-based applications is very popular, its use in

fisheries sector is uncommon. In India, the idea of using solar energy in fishing

boats was first initiated in the year 2010 by the Association of Deep Sea Going

Artisanal fishermen (ADSGAF), a fishermen organization based in Thoothoor,

Kanniyakumari District, Tamil Nadu, India.

The ADSGAF was established in 1992. It has 340 full-time members who are

engaged in long lining and gill-netting using small mechanized boats (15–21 m in

length) within the Indian Exclusive Economic Zone (EEZ). There are around 3400

fish workers and their dependents associated with the organization. There are

600 deep sea going fishing vessels in Thoothoor area that they fish all over the

Indian EEZ, which covers an area of 2.02 million sq. km. During 2009, the

members of ADSGAF raised the issue of increasing searching time for fish coupled

with rising fuel cost leading to decline in their income. The members also expressed

concerns about increasing cost of running the engine during idle time for lighting

and signalling requirements. It was found that fuel cost is accounting for about 70%

of the total operational costs.

Faced with this challenge and also considering the carbon footprints generated

by this fishery, the ADSGAF decided to experiment with the use of solar energy in

fishing vessels in 2010. Initially, the ADSGAF made a prototype boat (3 feet on

scale) equipped with solar panels and associated batteries etc and demonstrated its

258 J.V. Jain and S. Babu

operation and technical feasibility under laboratory conditions. In August 2012, the

ADSGAF further demonstrated the pilot-scale initiative in Chennai with the

involvement of the Bay of Bengal Programme, an Inter-Governmental Organisation

(BOBP-IGO) working in Bangladesh, India, Maldives and Sri Lanka.

Why Solar Energy

Solar energy is the cleanest, most abundant and renewable energy source available.

Today’s technology allows us to capture this power in several ways giving the

public and commercial entities flexible ways to employ both the heat and light of

the sun. Solar energy can be produced on a distributed basis, called distributed

generation, with equipment located on rooftops or on ground-mounted fixtures

close to where the energy is used. Large-scale concentrating solar power systems

can also produce energy at a central power plant.

Techno-Economic Assessments and Pilot Trials

The ADSGAF since then carried out a couple of techno-economic assessments

and pilot trials to measure the efficacy and viability of their venture in different

categories of fishing boats. It is found that while at sea the engine is run for several

hours at partial load to provide power for auxiliary activities such as lighting,

communication, navigation, signalling and on-board entertainment. Therefore,

if these services can be run by using alternative power sources there could be a

significant saving of fuel and this will improve the viability of the operation as well

as reduce the carbon footprints. From the pilot- scale trials, it is seen that switching

off the engine for 3 h can save 30 l of fuel a day and 7500 l per year. The potential

reduction of carbon dioxide emissions per year if the entire fleet switches off the

engine for three hours a day is estimated to be 117,000,00 kg (11,700 tonnes)

(refer Table 20.1). Therefore, solar power seems to be a viable alternative to reduce

fuel cost in fishing operations.

The size of the boat (Fig. 20.1) is 15.5 m length and 4.5 m width which undertake

a voyage of about 15 days. It operates long lines and gill nets. Four solar panels of

1 kW (250 W each) are fitted at the top of the wheel house of the boat. Presently

there are six such boats are in operation. The solar energy accumulated during the

day is able to light the bulbs/tube lights/focus lights and also charge/operate the

GPS, fish finder and the two VHF sets. Additionally, when required during night

time, the transistor batteries can also be charged.

Mr. Sunil who is the skipper of the vessel for the past 10 years told that he

is satisfied with the light while fishing and he never find trouble in starting

and re-starting the engine during the fishing voyage. Mr. Jose, a crew member

said, “Usually light in the boat will not be bright and need utmost care for removing

20 Specific Applications/Examples: Use of Solar Energy in Fishing. . . 259

the fish from the hooks and line. But solar energy fitted lights are bright

which enabled us to handle the fish and hooks and line without much stress. It

also saved considerable amount of time.” Mr. Salin, another crew said that they had

full lighting in their boat. The other fishing boats and ships passed over by them

gave a strange look because of the unusual brightness in their boat. He added that

usually they are stingy or miser in using lights during night because of the

recharging problem. But with the solar energy, they are encouraged to use the

lights for the whole nights. Mr. Sunil said that they could save approximately 320 l

of diesel in this voyage. Cost wise, they could save an amount of INR. 19,200

(320 l� INR. 60).

Table 20.1 The economics of using solar energy in fishing boats calculated from the Thoothoor experience

Sl.

No. Parameter Units Conversion

1. Number of fishing boats in Thoothoor 600

2. Fuel required to run engine for one hour 10 l

3. Extra running of engine ( mainly during night time) 03 h

4. Number of fishing days in one year 250

5. Cost of fuel- diesel per litre INR. 60 USD. 1

By switching off the engine for 3 h and running it on solar power:

6. Saving of fuel per year for 1 boat� 30 l� 250 fishing days 7500 l 7. Saving of fuel per year for 600 boats� 30 l� 250 fishing

days 45,00,000 l

8. Potential cash savings per year per boat (7500� INR. 60) INR. 4,50,000 USD. 7500 9. Potential cash savings per year for

600 boats� INR.4,50,000 INR. 27,00,000,00

USD. 45,000,00

10. Approximate cost for 1kw solar power plant including

modification of wheel house and other fitting charges

INR. 2,50,000 USD. 4167

11. Approximate cost for installing 1kw solar power plant each in 600 boats including modification of wheel house and other fitting charges INR. 2,50,000� 600

INR. 15,00,000,00

USD. 25,000,00

12. Net saving to a boat per year INR. 2,00,000 USD. 3333

13. Net saving to 600 boats INR. 12,00,000,00

USD. 19,998,00

Environmental benefits by reducing Carbon Emission:

14. Emission of CO2 per litre of diesel consumption 2.60 kg

15. Potential reduction in emission of CO2 (1 boat� 7500 l� 2.60 kg)

19,500 kg 19.5 ton

16. Potential reduction in emission of CO2 (600 boats� 7500 l� 2.60 kg)

117,000,00 kg 11,700 ton

260 J.V. Jain and S. Babu

Solar Power for Multi-Day Fishing Boats

This initiative was based on the successful trial and subsequent operation of solar

energy system in the deep sea fishing boats. Generally, fishermen carry charged

battery in boats for lights and for the operation of navigational and safety equip-

ments. Recharging will be a major problem for smaller boats. They need to run the

engine exclusively for recharging because while fishing, they do not run the engine.

Running the engine for recharging is highly expensive and affects the income. The

major expenditure in each fishing voyage is fuel. The department of fisheries,

Government of Tamil Nadu is supplying 250 l of kerosene for one month at the

cost of INR. 25 per litres. But, it is sufficient for only one voyage. The duration per

voyage is 5–6 days. They buy from the black market for their requirements and the

cost per litre varies from INR. 40 to INR. 45. It is expected that the solar energy

system will help them to save fuel cost and will be a boon to the community

(Fig. 20.2).

Fig. 20.1 Solar power equipped boat (funded by National Bank for Agriculture and Rural Development (NABARD))

20 Specific Applications/Examples: Use of Solar Energy in Fishing. . . 261

Solar Lanterns for Catamaran Fishermen and Fish Vending Women

The solar lantern uses solar energy and helps to reduce carbon emission and free

from the risk of fire. The emission of carbon in 1 litter kerosene is 3 kg. Solar

Lanterns are environmental friendly and can be used even in remote villages where

there is no electricity. Even in the urban areas people prefer a solar lantern as an

alternative during power cuts because of its simple mechanism. Photovoltaic cells

are solid-state semiconductor devices that convert Solar Energy into Electricity

(direct current). These Solar cells are connected in series or in parallel to obtain

desired output and are called solar modules. Solar lantern is a simple application of

solar photovoltaic technology, which has found good operations in rural regions

where the power supply is irregular. ADSGAF initiated to encourage the fish

vending women and Catamaran fishermen to use solar lanterns for their occupa-

tional operations.

Fish Vending Women use Candles

Generally fish vending women use candles or kerosene lamps at the fish markets.

These lights are not safe and not bright enough to use in the market. Poor quality

Fig. 20.2 Solar power equipped multi-day fishing boat

262 J.V. Jain and S. Babu

and irregular lighting blights lives. The light and the smoke from kerosene lamps

not only strains eyes but also release harmful carbon and also there is risk of fire

(Figs. 20.3 and 20.4).

Catamaran Fishermen Use Solar Lantern

Catamarans,1 those engage in fishing either at day or at night which operate

generally one man manually. During night they use kerosene lamps or gas lights

for handling fishing gears, overseeing the fishing accessories etc. The kerosene

lights don’t have brightness unlike the gas lights. The kerosene lights are not water proof (Fig. 20.5; Table 20.2).

Cost Benefit Analysis

No of working days in a year are 250 (Tables 20.3, 20.4, and 20.5).

Many types and designs of solar lanterns are available with a price range. They

are ideal for not only fish vendors or fishers but also good for farmers and other

vendors, and children to read and write. Solar lights can also be used at home as

light after the sunset. They are highly durable and having longer life than other

lanterns. Solar lanterns would be cheaper than kerosene in the long run but the short

Fig. 20.3 Fish vending women use candles

1 Catamaran is a fishing craft, made of logs of Albizzia falcataria timber lashed together with rope.

20 Specific Applications/Examples: Use of Solar Energy in Fishing. . . 263

Fig. 20.4 Fish vending women use solar lantern

Fig. 20.5 Solar lantern fitted catamaran

264 J.V. Jain and S. Babu

run cost is higher. There are no authorized gas filling stations and it is always a

problem to the fishermen for filling gas for every fishing voyage. The fishermen

may not be in hurry or may not be in worry in gas filling of every fishing voyage, if

they have solar lanterns. Solar lanterns are safe and easy to handle and no need to

pay recharging fee. We could eliminate unauthorized gas filing stations run by some

people in the villages.

Table 20.2 Gas lights, kerosene lamp and candle VS solar lanterns

Sl.

Problems identified in using of Gas lights, Kerosene

lamp and candle Merits of the use of solar lanterns

1 Harmful effects—breathing of smoke There is no harmful effect to

health

2 The brightness of candle/kerosene lamp is not

sufficient

The solar lanterns are brighter than

candle/kerosene lights

3 Can’t keep the candle/kerosene lamp when it is windy

Can keep the solar lanterns when it

is windy

4 Need utmost care in using Easy to handle

5 Risk of fire No risk

6 Non availability of gas/kerosene on time Can charge at all sunny days

7 Need to pay for candle, kerosene, and gas filling

charge every day

One time investment

8 Gas lights are water proof but corrosion No corrosion

Table 20.3 In the case of a fish vending woman who use

candle

Particulars INR USD

1 Candle expenditure per day 20 00.33

2 The total cost is (20� 250 days) 5000 83.00 3 The cost of 1 solar lantern is 1800 30.00

4 Total saving in an year 3200 53.00

Table 20.4 In the case of a Catamaran fisherman who use

Kerosene

Particulars INR USD

1 Kerosene expenditure per day 60 01.00

2 Total cost in an year (60� 250) 15,000 250.00 3 The cost of a solar lantern is 2800 46.70

4 Total savings in an year 12,200 203.30

Table 20.5 In the case of a Catamaran fisherman who

use gas

Particulars INR USD

1 Gas filling expenditure per day 70 01.17

2 Total cost in an year (70� 250) 17,500 291.70 3 The cost of a solar lantern is 2800 46.70

4 Total savings in an year 14,700 245.00

20 Specific Applications/Examples: Use of Solar Energy in Fishing. . . 265

Solar Powered Refrigerated Trucks for the Transportation of Fresh Fish

The dispersed and distant living population requires proper means for food preser-

vation and distribution without its spoilage. The existing food preservation and

transportation technology has developed sufficiently to preserve the wide variety of

foods for a considerable long time without losing the freshness. In the case of fish, a

highly perishable commodity needs best preservation and transportation to avoid

spoilage and to maintain freshness. This is significantly enhancing the costs—both

capital and operational. The ADSGAF has initiated a means of reducing the

operational expenses of refrigerated transport using solar power (Fig. 20.6).

Features

• Fuel not required for operation of the system

• Alternate system is arranged, if solar system fails

• Better reliability, simple and versatile

• Easy to operate

• Money and fuel saving

• Back up for night operation (Table 20.6).

Fig. 20.6 Solar powered refrigerated truck (funded by National Fisheries Development Board, Government of India)

266 J.V. Jain and S. Babu

The Larger Picture

India has a fleet size of 1,94,490 crafts comprising 72,559 (37.3%), mechanized

crafts, 71,313 (36.7%) motorized crafts and 50,618 (26%) non-mechanized crafts.2

It indicates that 1,43,872 (74%) of the fishing crafts depends on fossil fuel either on

diesel or kerosene. If 1 l of fuel is saved per day, the daily fuel saving will amount to

1,43,872 l (0.15 million) and reduction of carbon emission will amount to a total of

(1,43,872� 2.6) 3,74,067 kg (374 ton) day. Assuming that the Indian fishing fleet fishes for 250 days in a year, the total fuel saving will amount to 35.97 million litres

and the carbon reduction will amount to 9,35,167,50 kg (93,516 ton)

(3,74,067� 250 fishing days). The cash saving in a day will be INR. 8,63,232,0 (USD. 14,387,2) and in a year will be INR. 2,15,808,00,00 (USD. 35,968,00).

Ongoing Programme

Based on the immediate and future needs in the fisheries, the community

established a SIGHT3 under IEEE4 called Artisanal Deep Sea Fishers SIGHT.

The main objective of the SIGHT is to develop ideas, concepts, projects and

products with the help of existing scientific know-how, managerial efficacy and

engineering expertise and along with the traditional knowledge of fishermen.

Presently the ADSGAF is on the process of introducing solar powered OBM5 fitted

boats, solar powered small ice-making units and tricycles for fish vending women

and also establishing solar power charging stations.

Table 20.6 Description of solar powered refrigerated truck

Sl.No Particulars INR USD

1 Cost of Vehicle

Mahindra Mxi Truck Plus

5,23,000 8717

2 Cost of body building with PUF insulation 2,10,000 3500

3 Cost of refrigeration

Refrigerant-R134a

2,70,000 4500

4 Cost of solar system (1.5 KW)

Solar panels 250 W� 6 1,50,000 2500

5 Total 11,53,000 19,217

2As per the 2010 National Marine Fisheries Census conducted by the CMFRI, Kochi. 3 Special Interest Group on Humanitarian Technology. 4 Institute of Electrical and Electronic Engineers. 5 Out Board Motor.

20 Specific Applications/Examples: Use of Solar Energy in Fishing. . . 267

Suggestions

The initial investment cost of the solar power projects is high. People do not realize

the long term benefits. Hence it is necessary to organize intensive awareness

programmes to motivate the public to undertake investments in such projects.

Further the people have to be familiarised with the handling of solar power

equipments. There is need for conducting regular training sessions for handling

solar equipments. It is necessary to establish after sale services and also make

available solar power parts locally which are lacking today and which is one of the

major reasons for lack of interest using solar power systems. It is necessary to

increase the number of quality technicians in this field. It is also necessary to do

more study, experimentation and need sufficient funding to bring out right combi-

nation of goods and services in the fisheries.

Conclusion

From the energy consumption, sustainability and cost perspectives, there is an

urgent need for initiatives that reduce fuel consumption, substituting carbon-

based fuels with renewable alternatives. The initiatives taken by the community

that promote reducing the operating costs minimize dependency of fossil fuel and

minimize the carbon emission. Thus use and application of solar energy will not

only be saving fuel, money, time but also help to minimize the carbon emission

which is one of the major problems for global warming. This will lead to green

revolution in the fisheries sector.

Acknowledgment The authors acknowledge the contributions of Dr. Y.S. Yadava, Director and Mr. Prajdeep Mukherjee, Policy Analyst BOBP-IGO, Chennai, India, Mr. V. Vivekanandan, Direc-

tor, FishMARC, Trivandrum, India, Mr. Sebastian Mathew, Executive Secretary, International

Collective in Support of Fishworkers, Chennai, India, Dr. E. Vivekanandan, Emeritus Scientist,

CMFRI, Chennai, India, Mr. Sadhish Kumar, Project Head, Jagath Jothi Solar Energy Pvt Ltd,

Chennai, India, Mr. Vivek Dwivedi, Managing Director, BRIJ EXIM, Pune, India, Dr. Chinnappan

Gasper, Professor, Centre for Development Studies, Trivandrum, India and Dr. Teresa Shobana,

Professor, St. Jude’s College, Thoothoor, Tamil Nadu, India in the preparation of this paper. Special thanks to BOBP-IGO for providing advice and support to the initiatives taken by ADSGAF.

References

Department of Economic and Social Affairs, World Economic and Social Survey 2008: Over-

coming Economic Insecurity, E/2008/50/Rev.1, United Nations, New York, 2008.

Wilson, J. D. K. (1999). Fuel and financial savings for operators of small fishing vessels. FAO Fisheries Technical Papers, 383, 46.

Vivekanandan, E., Singh, V. V., & Kizhakudan, J. K. (2013). Carbon footprint by marine fishing

boats of India. CMFRI, India. Current Science, 105(3), 10 August 2013.

268 J.V. Jain and S. Babu

Chapter 21

Diagnostic of Sensors for Induction Machine Powered by Photovoltaic Generator Based on Fuzzy Logic Techniques

A. Amrane, A. Larabi, and A. Hamzaoui

Introduction

Many industrial applications require fault tolerance and continuity of service

(Benbouzid et al. 2007). This is due to the growing need to improve the availability

of systems. Therefore, strategies are defined in the early stages of design, to

facilitate fault detection, localization and reconfiguration of the order. For this,

several recent works (Green et al. 2003; Abolhassani and Toliyat 2009) deal with

fault tolerant control of electric drives.

In this article, we focus our study on the induction machine (IM), conventionally

designed for constant speed applications, has become, due to its simple, robustness

structure and the evolution of electronics power and control of the control vector

machine most commonly used for variable speed drives. This machine has the

advantage of being more robust and less expensive, with equal power, as other

machines. However, it has drawn backs. This allowed the opening of various lines

A. Amrane (*) Laboratory of Systems Electric and Industrial (LSEI), Faculty of Electronics and Informatics

(FEI), University of Science and Technology (USTHB), BP 32, EIAlia, Bab-Ezzouar, 16111

Algiers, Algeria

National School of Technology, National Road N 5 Z.I., Rouiba, 16013 Algiers, Algeria

e-mail: [email protected]

A. Larabi

Laboratory of Systems Electric and Industrial (LSEI), Faculty of Electronics and Informatics

(FEI), University of Science and Technology (USTHB), BP 32, EIAlia, Bab-Ezzouar, 16111

Algiers, Algeria

e-mail: [email protected]

A. Hamzaoui

CReSTIC of Troyes University of Reims Champagne Ardennes Troyes, Reims, France

e-mail: [email protected]

269

mailto:[email protected]

of research on its control and power (Shoudao et al. 2004; Montanari et al. 2000;

Ouhrouche 2002).

We introduced in this work, an approach widely used for the detection and

isolation of faults based on the method of estimator (Chen and Patton 1999; Holtz

1996), the main components of a tolerant control strategy to defects (CTD) sensor.

It is divided into three stages: detection, isolation and reconfiguration.

A novel estimator schemes based on fuzzy logic algorithm for the speed estimation

where derived using Lyapunov’s stability theorem (Ouhrouche 2002; Amrane and Larabi 2012; Amrane et al. 2014). Several strategies have been proposed for the

estimation in the vectorial inductionmotor drives (Ouhrouche2002;Amrane andLarabi

2012; Amrane et al. 2013). Among these techniques, model reference adaptive systems

(MRAS) schemes are the most common strategies employed due to their relative

simplicity and low computational effort (Amrane andLarabi 2012;Amrane et al. 2013).

Can be seen, the majority of estimation schemes described in the literature for

MRAS observer employ a PI controller to generate the desired value. However, due

to the continuous variation in the machine parameters and the operating conditions,

in addition to the nonlinearities present in the inverter, the PI controllers may not be

able to provide the required performance. Not much attention has been devoted to

study other types of estimation scheme (Amrane and Larabi 2012; Amrane

et al. 2013; Larabi et al. 2013).

In this article, the performances of the diagnostic of sensors, the detection of

faults and the fuzzy estimation of speed for the induction machine are analyzed by

digital simulation. To achieve our objective, this paper is organized as follows.

Section “Introduction” presents the control of the asynchronous machine; the rest of

the paper is organized as follows. Sections “Control of Asynchronous Machines” and

“Sensorless Control of the Induction Machine” present the control of the IM and the

MRAS algorithm using to estimate the speed. Section “The Fuzzy Logic Adaptation”

depicts fuzzy logic algorithm for the estimation. Section “Modelisation and Control

of Generator Photovoltaique” provides and discusses the simulation results and

Section “Simulation Results” sketches some conclusions.

Control of Asynchronous Machines

Control Scheme of an Asynchronous Machine

Figure 21.1 shows a simplified block diagram illustrating the essential of our

control system. This system consists of a dc power source, a dc link filter, a voltage

source inverter, an induction motor, and same circuit of control system. The dc

power source converts the constant-frequency ac power to dc power by a three-

phase, full wave diode bridge rectifier; the dc voltage is smothered by a smoothing

capacitor dc link filter and then applied to a three-phase bridge inverter witch

converts dc power to variable voltage variable frequency ac power supply to the

motor. The two control parameters required are frequency and voltage, the fre-

quency command also generates the voltage command through a volts/hertz ratio.

270 A. Amrane et al.

Induction Machine Model

The considered system is an induction machine with a squirrel cage of three phases.

The state representation of the mathematical model of this machine can be

represented according to usual d-q axes, as follows (Ouhrouche 2002; Amrane

and Larabi 2012; Amrane et al. 2013, 2014; Ho and Yeh 2010)

d ids

dt ¼ 1= σ*Lsð Þ -Rsm* idsþ ωs*σ*Ls* iqsþ Lm

Lr*Trð Þ *φdr � �

d iqs

dt ¼ 1= σ*Lsð Þ -Rsm* iqs-ωs*σ*Ls* ids- Lm

Lr*Trð Þ *φqr � �

d φdr

dt ¼ Lm

Tr *ids-

Tr *φdrþ ωs� ωrð Þ*φqr

d φqr

dt ¼ Lm

Tr *iqs-

Tr *φqr� ωs� ωrð Þ*φdr

Cem ¼ P*Lm Tr

iqs*φdr-φqr*idsð Þ d Ωr

dt ¼ 1

Tr Cem-Cr-Kf*Ωrð Þ

ð21:1Þ

Indirect Field-Oriented Control of an Induction Machine

This technique consists in assimilating the behaviour of asynchronous machine to

the DC machine; this is for applications requiring raised dynamic performances

(Montanari et al. 2000; Amrane et al. 2013; Larabi et al. 2013; Louri et al. 2013).

The aim of such a control technique of the torque and a choice of the (d,q)

reference, in order to obtain a decoupling between the torque and the field. From

Machine powered by

photovoltaic generator

Sensor speed

+ - DC

Power source

DC/AC Convert

Control system

Fig. 21.1 Block diagram of control system

21 Diagnostic of Sensors for Induction Machine Powered by Photovoltaic. . . 271

equation system (21.1); the torque control is made on the components of current iq

and is. The electromagnetic torque depends only on component iq. It is a maximum

for a given current if we impose is¼ 0. Consequently the obtained torque is then proportional to the current of machine power supply as in case of separately excited

DC machine. The model given by Eqs. (21.1) is expressed as follows:

Vds ¼ σ*Ls* d ids dt

-1= σ*Lsð Þ -Rsm* idsþ ωs*σ*Ls* iqsþ Lm Lr*Trð Þ *ϕdr

� �

Vqs ¼ σ*Ls* d iqs dt

-1= σ*Lsð Þ -Rsm* iqs-ωs*σ*Ls* ids- Lm Lr*Trð Þ *ϕqr-ωr*

Lsr

Lr *ϕdr

� � d ϕdr

dt ¼ Lm

Tr *ids-

Tr *ϕdr

ωs ¼ Lm Tr

* iqs

ϕdr þ ωr

Cem ¼ P*Lm Tr

iqs*ϕdrð Þ d Ωr

dt ¼ 1

Tr Cem-Cr-Kf*Ωrð Þ

ð21:2Þ

It is noted that rotor flux depends only on the satatoric current is and iq, that the

electromagnetic couple depends only on the quadratic current iq.

Sensorless Control of the Induction Machine

The Structure of Model Reference Adaptive System MRAS

The aim of this technique of control is to replace the speed sensor by a speed

estimator. Into our study, we introduced a speed estimator of type MRAS (Model

Reference Adaptive System). The latest replace the mechanical sensor without

changing the dynamics of our machine.

The principle of the method MRAS speed estimation rests on the comparison of

the sizes obtained in two different ways. One model of such a method is the voltage

one (or stator equation) and the other is current model (or rotor equation); because

the voltage method doesn’t include rotor speed then it does not depend explicitly of speed (model of reference) and the other includes rotor speed (adjustable adaptive

model). Figure 21.2 illustrates the derived MRAS scheme for speed adaptation.

Reference Model

One uses the equations of the currents (21.2) of the IM, the current expressed in the

reference fixed to the stator. The two equations of the model of reference become:

272 A. Amrane et al.

d φαr

dt ¼ Lr

Lsr Vαs-σ*Ls*

diαs

dt -Rs *iαs

� � dφβr

dt ¼ Lr

Lsr Vβs-σ*Ls*

diβs

dt -Rs *iβs

� � ð21:3Þ

Adjustable Model

To establish the adaptive model, we expressed the current in the reference fixed to

the stator, the fluxes expressed with the rotor sizes in a reference αβ are:

d φαad

dt ¼ - 1

Tr φαadþ Lsr

Tr *iαs -P *Ωest*φβad

d φβad

dt ¼ - 1

Tr φαadþ Lsr

Tr *iβs -P *Ωest*φαad

ð21:4Þ

Adaptation Mechanism

The entry of an adaptive mechanism is activated by the error between the reference

field and adaptive field. By carrying out the difference between the reference model

and the adjustable model, we obtain the following system of equations which

govern the adaptive mechanism.

deα

dt deβ

2 64

3 75 ¼ �

Lr �ω

ω � 1 Lr

2 64

3 75þ ω� ωadð Þ φαad

φβad

� � ð21:5Þ

The adaptation law chosen to ensure the convergence of ωad towards ω is:

Fig. 21.2 Structure of MRAS estimation of speed

21 Diagnostic of Sensors for Induction Machine Powered by Photovoltaic. . . 273

ωad ¼ Tp*δeþ Ti ðt 0

δe*dx ð21:6Þ

The adaptive mechanism has an integral proportional form:

ωest ¼ 1� P * Tp*eþ Ti

ð e*dt

� � ð21:7Þ

where Tp and Ti are positive gain.*

The Fuzzy Logic Adaptation

Control by Fuzzy Logic

Fuzzy logic technique makes it possible to control nonlinear systems and compli-

cated models (Amrane et al. 2013, 2014; Larabi et al. 2013). In fact, the calculation

of the parameters of the system is not necessary to carry out this control (Amrane

et al. 2013, 2014; Larabi et al. 2013).

On opposite of the adaptation of the traditional techniques; the fuzzy logic does

not treat a mathematical relations well defined, but uses inferences with a several

rules, being based on variables linguistic.

These inferences are treated by operators suitable for fuzzy logic (Amrane

et al. 2013, 2014; Larabi et al. 2013). Figure 21.3 shows the structure of a fuzzy

regulator with two input (X1 and X2) and one output (Xr).

So, we can note that the calculation of the control is carried out starting from

three fundamental stages: an interface of fuzzification; a mechanism of inference

(rules); and an interface of defuzzification.

The Fuzzification

The entries and exits are defined of the fuzzy are defined by membership functions

with 7, 5 or 3 sets. The various sets are characterized by standard designations

(Amrane and Larabi 2012; Amrane et al. 2013; Larabi et al. 2013):

X1 X2

FUZZY CONTROL

RULES DEFUZZIFICATIONFUZZIFICATION

Fig. 21.3 Functional diagram of the fuzzy control

274 A. Amrane et al.

Negative Big NB, Negative Medium NM, and Negative Small NS, Zero Z,

Positive Small PS, Positive Medium PM, Positive Big PB.

Inference Mechanism

It is well known that the realizations of the matrix of the rules are deduced by

experiment, the experiment of the human operators and rests on the analysis of the

system.

This analysis must take into an account the trajectory which one wants to give to

the system (Amrane and Larabi 2012; Amrane et al. 2013; Larabi et al. 2013).

The Defuzzification

By this stage; the return to the sets of real exit will be made. It is a question of

calculating, from the degrees of membership of all the sets variable of output, the

coordinate which corresponds with the value of this exit. Various methods are used

(Amrane and Larabi 2012; Amrane et al. 2013; Larabi et al. 2013).

The Fuzzy Logic Adaptation Mechanism Principle

The structure of the proposed PI controller used in the adaptation mechanism will

be replaced by a fuzzy logic controller as shown in Fig. 21.4.

In our work, we adopted seven sets for the two variables of input (En and dEn),

and a same number of sets for the variable of output dUn. The rules of the controller

can be presented in a matrix with seven sets known as matrix of inference shown in

Table 21.1.

In this article, the memberships function are chosen as the triangular type and

trapezoidal, and the method of reasoning is considered as the max-min method, the

UK3

Fuzzy contr oller

Z-1

Fig. 21.4 Synoptic diagram of a fuzzy adaptation

21 Diagnostic of Sensors for Induction Machine Powered by Photovoltaic. . . 275

defuzzification stage is done based on the gravity centre method, as it is frequently

quoted in the literature and because they requiring less time computing will be also

adopted in our work (Amrane et al. 2013, 2014; Larabi et al. 2013).

The Basic Rules of the Fuzzy Controller

The first step in the design of fuzzy controller is to generate fuzzy rules based on the

knowledge of the expert. According to the expert, three situations can be distin-

guished for the constant time estimation, above, around and below the reference

desired.

In our control, in order to determine the rules table that generates a command

that will be presented later Based on Fig. 21.5.

Modelisation and Control of Generator Photovoltaique

To profit from solar energy and to use it to power the IM, it is necessary to

understand the operation of this energy and optimize its use. In this way, we are

interested here, to describe the basic concepts of solar energy and the production of

electricity by the photovoltaic effect.

The connection of a generator PV to a load requires the adaptation of the

generator so that it functions with its maximum power, and then to provide the

maximum of energy delivered by the generator to the load, it is permanently

necessary to track the corresponding that called Maximum Power Point (MPP).

So, to provide this we try here to adapt the photovoltaic generator (PVG) to the

asynchronous machine. This adaptation between the source and the load is carried

out by the insertion of a converter DC-DC (chopper) controlled by a tracking

mechanism of Maximum Power Point. This method is known as MPPT (Ho and

Yeh 2010; Agrebi et al. 2006).

Table 21.1 The fuzzy rules (a regulator with five sets)

dUn

NG NP EZ PP PG

dEn NG NG NG NP NP EZ

NP NG NP NP EZ PP

EZ NP NP EZ PP PP

PP NP EZ PP PP PG

PG EZ PP PP PG PG

276 A. Amrane et al.

Model of a Generator Photovoltaic

The mathematical model of the physical process in (Ho and Yeh 2010; Agrebi

et al. 2006; Peng and Fukao 1994) a PV cell are given in figure (Fig. 21.6), known

under the name “two-diode model”, it is largely used in the literature. It is most

widespread because it gives the results closest to those obtained by a real GPV.

So, to obtain the wished values of the tensions and currents, the modules are

connected in series, parallel or parallel-series. The later association “parallel-

series” enables us to obtain the values of the tension and the desired current. The

characteristic equation of the system is given by the following relation:

I ¼ NP � IPh � NP � Is1 exp q NPV þ Ns � I � Rseð Þ½ � NsNPA1KT

� � � 1

� �

� NP � Is2 exp q NPV þ Ns � I � Rseð Þ½ � NsNPA2KT

� � � 1

� � � NPV þ Ns � I � Rseð Þ½ �

NsNPRPe

ð21:8Þ

With:

I and V: the current and the voltage of the photovoltaic cell.

q: the constant elementary charge.

Iph: the photocurrent produced.

K: the Boltzmann constant.

IS1 and IS2: the saturation currents of the diodes.

A1 and A2 factors of purity of diode (A1¼ 1 and A2¼ 2).

Reference

P2 P3

time

Polarities of E et dER e s p o n

Fig. 21.5 Temporal analysis of the rules of the regulator

21 Diagnostic of Sensors for Induction Machine Powered by Photovoltaic. . . 277

IPh ¼ IPh �� T¼298ð Þ � 1þ T� 298ð Þ � 5� 10�4

� with IPh

�� T¼298ð Þ ¼ 3:25 A

RS and RP: respectively resistance series and parallel resistance.

T: the absolute temperature �K.

IS1 ¼ K1T3e � Eg KT and IS2 ¼ K2T 52 e

� Eg KT

Eg: The energy band of the semi-conductor

K1¼ 1.2 A/Cm2 K3 and K2¼ 2.9 105/2 A/Cm2 K5/2

GPV Control

To convert solar energy with the best manner possible, it is essential to work in the

zone of maximum power of generator. In other words, they need to track the MPP in

order to maximize the power delivered to load by ordering converter DC/DC. There

are different control methods of tracking of the point of maximum power, based rest

on the generator power-tension characteristic (Ho and Yeh 2010; Agrebi

et al. 2006; Peng and Fukao 1994).

The approach of artificial fuzzy logic intelligence is implemented to improve the

performances of control and to track the point of maximum power, by the modelling

and the simulation of a controller containing fuzzy logic (FLC) (Fig. 21.7).

The fuzzy controller proposed has two variables of entries, the error E and the

variation of error CE, are expressed at a rate of sampling K. They are defined as

follows:

E kð Þ ¼ P kð Þ � P k� 1ð Þ V kð Þ � V k� 1ð Þ ð21:9Þ

CE kð Þ ¼ P kð Þ � P k� 1ð Þ

With: P (k) ET V (k): are respectively the power and the tension of PVG.

Once the two sizes of entry is calculated and converted into fuzzy linguistics

variable, the exit which is the variation of the cyclic report dα, as mentioned in table (Table 21.2), intended to control a chopper back-booster. The control rules must be

indicated so that the entry variable E must be always zero.

IID ID2 IRP

IPh D1 D2 RP V

Fig. 21.6 Model of solar cell

278 A. Amrane et al.

The synoptic diagram of the chain PV: Photovoltaic generator—Converters—

Induction Machine—Battery is given by Fig. 21.8.

Simulation Results

To diagnose the speed sensor, a MRAS estimator is used as an observer. Then, an

algorithm for selecting is used to enable the detection of defects and perform the

selection between the measured signals and the estimated signals.

So, to validate the performances of the MRAS, the proposed simulation of the

dynamic behaviour of the machine has been done using the MATLAB/SIMULINK

and that for the following conditions.

With, the value of the torque is fixed to zero and the field is fixed to 1 Wb. To

highlight the influence of speed variations and uncertainties, particularly those of

the control process, we gave reference speed of 100 rad/s (Fig. 21.9).

Afterwards, constant field and a reference speed Ωref¼ 100 rad/s, the field rotor field is fixed to 1 Wb, the initial values of the torque assumed by the machine is

zero, and between 1 s and 2.5 s, one will apply a nominal torque load (10 N.m)

(Fig. 21.10).

Finally, we will use our estimator to diagnose faults sensor for speed exceeds the

rated speed to a value of the torque is fixed to zero, the field is fixed to 1 Wb and the

initial values of the speed assumed by the machine is zero, and between 1 s and

2.5 s, we will apply variations (Fig. 21.11).

According to the simulation results we can say that the MRAS technique of

detection provides an effective solution to the problem of diagnostic. We can say

that our objective here has been successfully achieved.

Fig. 21.7 Structure of the fuzzy controller for the tracking of the PPM

Table 21.2 The fuzzy rules for algorithm MPPT

(a regulator with five sets) dα

NL NS Z PS PL

dEn NL Z Z PS NS NL

NS Z Z Z NS NL

Z PL PS Z NS NL

PS PL PS Z Z Z

PL PL PS NS Z Z

21 Diagnostic of Sensors for Induction Machine Powered by Photovoltaic. . . 279

The results presented on the previous figures, show that the dynamics of the flux

magnitude are presented can highlight the decoupling role of the flux controller

where the flux tracks its nominal value of 1.1 Wb for all speed ranges.

The MRAS observer has an advantage of avoiding integration of stator voltages,

which is of particular interest for hardware implementation. The proposed MRAS

strategy has been incorporated within the classical IM control system. Numerical

simulations are performed and shown good results for tricking the reference.

Implementation of the proposed algorithm can be used for the diagnostic issues

suitable for IM applications requiring high-performance.

Fig. 21.8 Total structure of the photovoltaic chain

0 0.5 1 1.5 2 2.5 3 -20

100

120

time(S)

s pe

ed (r

ad /s

Wsen

West

Fig. 21.9 Estimation of speed in the case of an indirect field oriented of the induction machine, speed reference (Wref), estimated speed (West) and speed with sensor (Wavec). With the torque is

fixed to zero and the field is fixed to 1 Wb and the speed fixed to 100 rad/s

280 A. Amrane et al.

s pe

ed (r

ad /s

0 0.5 1 1.5 2 2.5 3 -20

100

120

time(S)

Wsen West

Fig. 21.10 Estimation of speed in the case of an indirect field oriented of the induction machine, speed reference (Wref), estimated speed (West) and speed with sensor (Wavec). With the torque is

fixed to 10 N.m and the field is fixed to 1 Wb and the speed fixed to 100 rad/s

0 0.5 1 1.5 2 2.5 3 -50

100

150

200

time(S)

sp ee

d( ra

d/ s

Wsen West

Fig. 21.11 Estimation of speed in the case of an indirect field oriented of the induction machine, speed reference (Wref), estimated speed (West) and speed with sensor (Wavec). With the torque is

fixed to zero and the field is fixed to 1 Wb and between 1 s and 2.5 s, we will apply variations of

speed

21 Diagnostic of Sensors for Induction Machine Powered by Photovoltaic. . . 281

Conclusion

The work that we presented contributes to the analysis and the synthesis of a robust

diagnostic applied to the induction machine. The MRAS is employed for the

detection of the faults of sensor speed. The use of the fuzzy logic is a powerful

tool in realization of the robust and reliable diagnostic.

We have proposed a method for detection faults of sensor speed using the MRAS

and the fuzzy logic algorithm, to ensure a good diagnostic of induction machines.

The method proposed in this paper is applicable to a large category of induction

motor drives with a gradually varying load torque. The tests of robustness show

clearly that the performances of the diagnostic in the presence of estimator, type

MRAS, for the tracking the references is always fast. The validity of this method is

checked by several tests.

The results obtained show that the model suggested for the MRAS adapts

perfectly to all the diagnostic of the IM.

The next step of this work is the integration of a real induction motor and

estimator MRAS for testing the diagnostic is required for the practical case.

Annexes

The parameters of the induction machine cage used are shown below:

Rated power: 1.5 kw

Nominal voltage: 220/380 V

Rated power factor: 0.8.Rated

Speed: 1420 rev/min

Nominal frequency: 50 Hz

Stator resistance: 4.85Ω

Rotor resistance: 3.805Ω

Stator cyclic inductance: 0.274 H

Cyclic inductance of Rotor: 0.274 H

Cyclic mutual inductance: 0.258 H

Number of pole pairs: 2

Moment of Inertia: 0.031 Nm-s2/rad

Friction: 0.008 Nms/r

Nomenclature

Ls Stator inductance [H]

Lr Rotor inductance [H]

Lm Mutual magnetizing inductance

282 A. Amrane et al.

Lsr Mutual Inductance between the stator and rotor [H]

Kf Friction coefficient [N.s/rad]

J Total inertia [kg.m2]

P Number of pole pairs

ωs Synchronous Pulsation [rad/s] ωr Electrical angular Pulsation [rad/s] Cem Electromagnetic torque [N.m]

Cr Resistive torque [N.m]

Tr Rotor time constant [s]

References

Abolhassani, M. T., & Toliyat, H. A. (2009, May). Fault tolerant permanent magnet motor drives

for electric vehicles. In IEEE international on electric machines and drives conference, 2009. IEMDC ’09 (pp. 1146–1152, 3–6).

Agrebi, Y., Triki, M., Koubaa, Y., & Boussak, M. (2006). Commande avec et sans capteur

mécanique d’une machine asynchrone. In 7ème conférence internationale des sciences et techniques de l’automatique STA’2006, 17–19 décembre, Hammamet Tunisie (pp. 573–584).

Amrane, A., & Larabi, A. (2012). Speed control sensorless of an induction machine powered by

photovoltaic generator. In 10th global conference on sustainable manufacturing (GCSM’12), 31 October–02 November 2012, Istanbul, Turkey.

Amrane, A., Larabi, A., & Hamzaoui, A. (2014). Robust sensorless control of an induction

machine based on a fuzzy MRAS. In International conference on electrical and electronics engineering (ICEEE 2014), du 21–23 April, Antalya, Turquie.

Amrane, A., Louri, M., Larabi, A., & Hamzaoui, A. (2013). A fuzzy model reference adaptive

system control for induction. In 3rd international conference on systems and control, October 29–31, Algiers, Algeria.

Benbouzid, M. E. H., Diallo, D., & Zeraoulia, M. (2007, March). Advanced fault-tolerant control

of induction-motor drives for EV/HEV traction applications: from conventional to modern and

intelligent control techniques. IEEE Transactions on Vehicular Technology, 56(2), 519–528. Chen, J., & Patton, R. (1999). Robust model-based fault diagnosis for dynamic systems. Boston:

Kluwer.

Green, S., Atkinson, D. J., Jack, A. G., Mecrow, B. C., & King, A. (2003). Sensorless operation of

a fault tolerant PM drive. IEEE Proceedings Electric Power Applications, 150(2), 117–125. Ho, T.-J., & Yeh, L.-Y. (2010). Design of a hybrid PID plus fuzzy controller for speed control of

induction motors. In 5th IEEE conference on industrial electronics and applications (pp. 1352–1357), October 27–30. Gyeonggi-do, Korea: KINTEX.

Holtz, J. (1996). Methods for speed sensorless control of AC drives. In Sensorless control of AC motor drives. Piscataway, NJ: IEEE Press.

Larabi, A., Amrane, A. & Boucherit, M. S. (2013). Robust speed sensorless fuzzy control of the

induction machine drive with adaptation of the rotor time constant supplied by photovoltaic

solar energy. In International conference on power engineering, energy and electrical drives, POWERENG-2013, 13–17 May, Istanbul, Turkey.

Louri, M., Amrane, A., & Barazane, L. (2013). Comparison between the performances of variables

structures control and the theory of synergetic on applied to the squirrel motor drives. In 3rd international conference on systems and control, October 29–31, Algiers, Algeria.

Montanari, M., Peresada, S., Tilli, A., & Tonielli, A. (2000). Speed sensorless control of induction

motor based on indirect field-orientation. In 35th annual meeting, IEEE industrial application society, Rome (pp. 1858–1865).

21 Diagnostic of Sensors for Induction Machine Powered by Photovoltaic. . . 283

Ouhrouche, M. (2002). Estimation of speed, rotor flux and rotor resistance in cage induction motor

using the EKF algorithm. International Journal of Power and Energy Systems, 22, 103–109. Peng, F., & Fukao, T. (1994). Robust speed identification for speed-sensorless vector control of

induction motors. IEEE Transactions on Industry Applications, 30(Sept./Oct.), 1234–1240. Shoudao, H., Yaonan, W., Jian, G., Jiantao, L., & Sihai, Q. (2004). The vector control based on

MRAS speed sensorless induction machine drive, intelligent control and automation. In

WCICA, 5th world congress (pp. 4550–4553).

284 A. Amrane et al.

Chapter 22

Air Conditioning Based on Hydroxides with Solar Driving for Low GHG Emissions

R.J. Romero, S. Silva-Sotelo, Y.R. Galindo-Luna, C.V. Valdéz-Morales,

J. Ibarra-Bahena, A. Hdz-Jasso, and A. Rodrı́guez-Martı́nez

Introduction

There is a large amount of energy transformed in several ways. Ranging from the

clean use for the environment such as solar energy is the energy that is taken

directly from the sun, which with various processes is transformed into mechanical

energy and then transformed to power. Other clean energy to the environment is

nuclear energy, which is generated by reactions usually radioactive chemical

elements, this type of energy promises much but may be dangerous at the same

time; if that is not under controlled handled conditions. Some people do not

consider it as clean source of energy production due to highly toxic waste than

generates it.

Another clean energy is hydropower, which involves harnessing the potential

energy accumulated in the water to generate electricity, is a classic form of energy.

About 20% of the electricity used in the world comes from this source.

In the world today most of the energy used (60–70%) is generated by burning

fossil fuels, which have been generated over the years many waste from the

combustion of these have caused a negative impact to the environment to be the

main pollutants of this, the problem with the use of fossil fuels to generate energy is

not renewable, is that fewer and fewer of these fuels, and to use excessive release of

GHG and another contaminants.

According to International Energy Agency Moreover we have the domestic air

conditioners which take a very important role in the big cities and they generate

about 20–30% of the total to the urban emissions atmosphere.

R.J. Romero (*) • S. Silva-Sotelo • Y.R. Galindo-Luna • C.V. Valdéz-Morales J. Ibarra-Bahena • A. Hdz-Jasso • A. Rodrı́guez-Martı́nez

Centro de Investigaci�on en Ingenierı́a y Ciencias Aplicadas, Universidad Aut�onoma del Estado de Morelos, Av. Universidad 1001, Chamilpa 62209, Morelos, Mexico

e-mail: [email protected]

285

mailto:[email protected]

OECD countries supplies almost 40% of primary energy in the world, but

consumption in the OECD are large as the population number. The OECD con-

sumption for 2012 was 3582 Mtoe from 8980 World’s total consumption. That is practically the 40% of the total. OECD renewable energies for 2012 were geother-

mal 32 Mtoe, hydropower 119 Mtoe and Solar + Tide +Wind energies 48 Mtoe.

These renewable balances are 5.5% of the OECD consumption. Biggest energy

consumption is based on oil. See Figs. 22.1, 22.2, and 22.3 taken from “2014 Key

World energy statistics” by International Energy Agency.

Solar Air Conditioning Proposal

Solar air conditioning is an old dream for technician from worldwide. A proposal

for solar absorption air conditioning for building space cooling is due to the

coincidence between the availability of maximum solar irradiance and the

Fig. 22.1 Regional total primary energy supplies at

2012 (© iea.org)

Fig. 22.2 World Final consumption at 2012 (© iea. org)

286 R.J. Romero et al.

maximum load for cooling, particularly in office buildings. According to average

solar irradiance, the solar potential is available to provide the energy for the

air conditioning. An earlier patent for this concept was realized by on 1977

(Kumm 1979).

Figure 22.4 shows the global potential for installation of solar systems. Solar air

conditioning systems were studied from 1957 as a recent review reports (Siddiqui

and Said 2015). However there are some limitations for the implementation of the

thermodynamic cycle.

Fig. 22.3 OECD Final consumption at 2012

Fig. 22.4 Global solar irradiance map (© 3tier.com)

22 Air Conditioning Based on Hydroxides with Solar Driving for Low GHG Emissions 287

Description of the Hydroxide Based Solar System

Conventional air conditioning requires mechanical vapor compression by fossil fuel

driven. Electrical power energy into the compressor unit causes a pressure increase

in a gaseous refrigerant (typically an HCFC) and then condenses this at higher

temperature level to deliver the exchanged energy al lower temperature level in the

evaporator; as Fig. 22.5 shows.

Space cooling absorption technology from 14 to 22 �C requires heat supply from 100 to 150 �C while hydroxide blend is used as working pair (Romero et al. 2000). Solar collectors to drive an air conditioning system must be concentrators, cylin-

drical parabolic concentrator and evacuated tube collectors to heat at generator

temperature requirements. Additionally, photovoltaic cells must be installed to

drive the centrifugal pumps.

A HBAC system basically consists of an evaporator, a condenser, a generator, an absorber and an economizer as shown in Fig. 22.6. A quantity of waste heat QGE is

added at a relatively high temperature TGE to the generator to vaporize the working fluid from the solution. The vaporized working fluid goes to the condenser, where it

is condensed delivering an amount of heat QCO at an intermediate temperature TCO. The liquid leaving the condenser passes through a valve to the evaporator where it is

evaporated by means of a quantity of heat QEV at a low temperature TEV producing the cooling effect. After this, the vaporized working fluid goes to the absorber

where it is absorbed by the solution coming from the generator, delivering an

amount of heat QAB at an intermediate temperature TAB. Finally, the solution leaving the absorber is pre-heated in the economizer and returns to the generator

starting the cycle again.

QEV

QCO

Fossil Fuel Energy

Compressor device

Fig. 22.5 Conventional air conditioning system

288 R.J. Romero et al.

Heat Transfer Effectiveness

Heat transfer effectiveness is a function of three thermal parameters (George and

Srinivasa Murthy 1989):

η ¼ XAB � XGE XAB EQ � XGE ð22:1Þ

Economizer effectiveness has been analyzed into refined thermodynamic cycle

for some authors (Romero et al. 2000; Balghouthi et al. 2005; Fabrizio et al. 2014;

Siddiqui and Said 2015). The effect for the economizer causes an internal energy

recover from absorber to the generator.

Results

From mass and energy balances, the power into the heat transfer components is

calculated as follow:

QEV ¼ MEV HGE,V � HCO,Sð Þ ð22:2Þ QGE ¼ MGE,V HGE,V þMGE,S HGE ,S �MAB,S HVA,S ð22:3Þ

Fig. 22.6 Proposal hydroxide based thermodynamic cycle for solar air conditioning system

22 Air Conditioning Based on Hydroxides with Solar Driving for Low GHG Emissions 289

QCO ¼ MCO � HCO,S � HGE,V

� ð22:4Þ QAB ¼ MCOHEV ,V þMGE,SHGE,S �MAB ,SHAB,S ð22:5Þ

COP ¼ QEV Qsolar

ð22:6Þ

COP is a dimensionless parameter that indicates the ratio between useful energy

and inlet energy. This parameter allows the comparison between air conditioning

devices. For this case, the effectiveness of the components were calculated and the

values for each are ηEV¼ 0.9, ηGE¼ 0.8, ηAB¼ 0.75, ηCO¼ 0.7 and ηHX¼ 0.7. This mass and energy balance was computed with the following algorithm

(Fig. 22.7).

The energy for drive the centrifugal pump into the cycle is assumed that comes

from photovoltaic panels to avoid fossil fuel derived energy. That power was

calculated as 2% of the air conditioning power. That value is 350 W at 12 VCD.

Figure 22.8 show the HBAC’s COP as function of solar energy temperature for constant temperature in absorber and condenser component. The air conditioning

keeps an insulated space at 20 �C. An optimal ideal condition for the hydroxide based air conditioning system is noted in this figure. This optimal condition requires

solar energy at 125 �C for ambient temperature at 40 �C and the COP is 0.7 than indicates the CPC energy is 25 kW for a 17.5 kW of air cooling load.

Figure 22.9 show the modified HBAC’s COP as function of solar energy temperature as in previous figure. The modified COP was computed with the

shown component effectiveness. The behavior for both lines in Figs. 22.8 and

22.9 are the same. But there is a variation in the value for the optimal thermody-

namic conditions. Solar energy is required at 120 �C for ambient temperature at 40 �C but the calculated COP is 0.5 that means the CPC energy is 31 kW for 15.5 kW of air cooling at same room.

The CPC area for this solar energy panel is 20% larger than the ideal cycle, and

the air conditioning load is diminished 11% anyway. The non-ideal calculation

leads to solar engineers to precise areas to fossil fuel free air conditioning systems.

Unfortunately at 2010 the air conditionings powers were higher than 25 GW as

shown Fig. 22.10, and the associated CO2 emission are higher as well. Solar air

conditioning systems as the proposal and others may reduce the CO2 impact to 2050

(iea.org 2011). OECD countries dominate the market for space and water heating,

but not for cooling. China leads the world for annual installed capacity of solar

thermal systems and air conditioners devices.

Conclusion

Hydroxide based solar air conditioning may be a proposal for CO2 reduction at

2050. The entire system drives with solar energy from CPC and photovoltaic

panels. The effectiveness addition for calculation of air conditioning leads to

290 R.J. Romero et al.

User data

Inlet

TSurroundings TAir conditioning

TSolarAir

conditioning

load QEV

Start

Pressure calculation

P= P (T)

Concentration computing

X = X (T, P)

Enthalpies calculation

H = H (T, X)

Mass balance

M = F (H, Q)

Power balance

M = F (H, Q)

COP evaluation with and without h COP = f (hEV, hCO, hAB, hGE, hHX, QSolar, QEV)

End

hEV, hCO, hGE,

hAB, hHX

Fig. 22.7 Algorithm for calculation of powers and COP for proposal system

22 Air Conditioning Based on Hydroxides with Solar Driving for Low GHG Emissions 291

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0 20 40 60 80 100 120 140 160

CO P

(d im

en si

on le

ss )

Solar Energy Temperature (°C)

TCO = 50 °C TAB = 50 °C TEV = 10 °C Tamb = 40 °C T Air Conditioning = 20 °C

Fig. 22.8 HBAC’s COP as function of solar energy temperature for ideal cycle

0.1

0.2

0.3

0.4

0.5

0.6

0 20 40 60 80 100 120 140 160

Solar Energy Temperature (°C)

hEV = 0.9, hGE = 0.8, hAB = 0.75, hCO = 0.7 and hHX = 0.7

TCO = 50 °C TAB = 50 °C TEV = 10 °C Tamb = 40 °C T Air Conditioning = 20 °C

CO P

(d im

en si

on le

ss )

Fig. 22.9 Modified HBAC’s COP as function of solar energy temperature

292 R.J. Romero et al.

lower COP values. For two selected scenarios the air conditioning load for 17 kW

requires solar energy of 25 kW in an ideal thermodynamic cycle. For a non-ideal

scenario the hydroxides-based air conditioning load with same flow is just 15.5 kW

and solar energy of 31 kW. Due all energy in the HBAC is solar, there is not GHG

compared with conventional compression air conditioning.

Acknowledgement To CEMIE-Sol P09 and CB-167434 by CONACYT—Mexico.

Nomenclature

H Enthalpy, kJ/kg

M Flow, kg/s

P Pressure, Pa

Q Power, W

T Temperature, �C W Mechanical power, W

X Hidroxide concentration, kg/kg

Greek Letters

η Effectiveness, dimensionless

Subscripts

AB Absorber

CO Condenser

Fig. 22.10 Sales and solar thermal installations for air conditioning at 2010

22 Air Conditioning Based on Hydroxides with Solar Driving for Low GHG Emissions 293

EV Evaporator

GE Generator

HX Economizer

S Liquid solution

Solar Solar

V Vapour

References

Balghouthi, M., Hachemi Chahbani, M., & Guizani, A. (2005). Solar powered air conditioning as a

solution to reduce environmental pollution in Tunisia. Desalination, 185, 105–110. Fabrizio, E., Seguro, F., & Filippi, M. (2014). Integrated HVAC and DHW production systems for

zero energy buildings. Renewable and Sustainable Energy Reviews, 40, 515–541. George, J. M., & Srinivasa Murthy, S. (1989). Influence of absorber effectiveness on performance

of vapour absorption heat transformers. International Journal of Energy Research, 13, 629–638.

International Energy Agency. (2011). Technology roadmap energy-efficient buildings: Heating

and cooling equipment. https://www.iea.org/publications/freepublications/publication/build

ings_roadmap.pdf.

Kumm, E. L. (1979). U.S. Patent No. 4,151,721. Washington, DC: U.S. Patent and Trademark

Office.

Retrieved March 26, 2015 from http://www.3tier.com/en/support/resource-maps/.

Retrieved March 26, 2015, from http://www.iea.org.

Romero, R. J., Rivera, W., & Best, R. (2000). Comparison of the theoretical performance of a solar

air conditioning system operating with water/lithium bromide and an aqueous ternary hydrox-

ide. Solar Energy Materials and Solar Cells, 63, 387–399. Siddiqui, M. U., & Said, S. A. M. (2015). A review of solar powered absorption systems.

Renewable and Sustainable Energy Reviews, 42, 93–115.

294 R.J. Romero et al.

http://www.iea.org/

http://www.3tier.com/en/support/resource-maps/

https://www.iea.org/publications/freepublications/publication/buildings_roadmap.pdf

Chapter 23

Life Cycle Analysis as a Decision Criterion for the Implementation of Solar Photovoltaic Panels in as Northeast Brazil Hospital

Monica Carvalho, Danielle Bandeira de Mello Delgado, and Ricardo Chacartegui

Introduction

The environmental performance of products, services and processes has become

one of the key issues in today’s world, and it is important to examine ways in which negative effects on the environment are assessed. One of the reasons for undertak-

ing a Life Cycle Assessment (LCA) study is that there are growing concerns about a

variety of environmental issues expressed by public opinion, political bodies and

industry. Environmental concern may be related to the long-term resource base of

human societies or may be more health related or it may be a concern for the natural

environment as such (Baumann and Tillmann 2004). LCA is one of the tools that

can be used for such a purpose.

LCA can be defined as the “compilation and evaluation of the inputs, outputs and

potential environmental impacts of a product system throughout its life cycle”

(Guinee et al. 2001). The objective of LCA is to describe and evaluate the overall

environmental impacts of a certain action by analyzing all stages of the entire

process from raw materials supply, production, transport and energy generation to

recycling and disposal stages—following actual use, in other words, “from the

cradle to the grave” (WEC 2004). The environmental burden covers all types of

impacts upon the environment, including extraction of different types of resources,

emission of hazardous substances and different types of land use. The term

M. Carvalho (*) • D.B. de Mello Delgado Department of Renewable Energy Engineering, Center of Alternative and Renewable Energy,

Federal University of Paraı́ba, Caixa Postal 5115, Cidade Universitária, Jo~ao Pessoa 58051- 900, Paraı́ba, Brazil

e-mail: [email protected]; [email protected]

R. Chacartegui

Energy Engineering Department, University of Seville, Camino de los descubrimientos, s/n,

Seville 41092, Spain

e-mail: [email protected]

295

mailto:[email protected]

‘product’ is taken in its broadest sense—including physical goods as well as services; it includes goods and services at both operational and strategic levels

(Guinee et al. 2001).

Energy use and its associated primary energy consumption and emissions are

important contributors to the life cycle impacts of many products and processes, as

well as to greenhouse gas inventories of entities, products, and countries. LCA can

be used to calculate the environmental loads (e.g., emissions of greenhouse gases)

associated with the consumption of units of energy (electricity, heat, coolth, for

instance). In this way, alternative systems may be ranked according to their

respective emissions of greenhouse gases. The advantage of analyzing full life

cycles as opposed to using only emission factors is that renewable and nuclear

systems with no direct (stack) emissions can be compared with systems based on

fossil fuel combustion (WEC 2004).

There are actually two innovations presented herein: (1) utilization of environ-

mental data in the objective function of a mathematical model for the optimization

of an energy supply system, and (2) application of the methodology to a hospital

located in Northeast Brazil. Regarding the state of LCA in Brazil, most of the

studies have been undertaken in the South and Southeast regions—therefore the

application to the Northeast region could help disseminate good practice. The

energy supply system is optimized through the solution of an optimization model

based on Mixed Integer Linear Programming (MILP). The optimization encom-

passes the configuration of the system simultaneously with the operational strategy,

providing an energy supply system with minimum environmental impacts. These

environmental impacts are associated with the production of each piece of equip-

ment installed plus the consumption of energy resources (natural gas, diesel,

biomass, etc.) to satisfy the energy demands of the consumer center.

Polygeneration System

The study case is a university hospital, with 420 beds, located in the city of Jo~ao Pessoa (Northeast Brazil). The energy demands considered were electricity (light-

ing and equipment), hot water (internal consumption of the hospital), steam (laun-

dry and sterilization) and coolth (a/c for comfort). Hospitals are good study cases

for optimization because they present regular, stable energy demands. The study

considered an entire operational year, subdivided into two representative days per

month (weekday and holiday/weekend), with 24 hourly periods each.

Real electricity data was provided by the hospital. Coolth, hot water and steam

demands were disaggregated through the utilization of climate data, degree-days

method, occupation and energy audit data (Erbs et al. 1983; Climaticus 4.2, 2005;

Nepote et al. 2009; Araújo 2004). The hospital presents the following annual energy

demands: 2791 MWh of electricity, 1947 MWh of hot water, 138 MWh of steam,

and 2309 MWh of coolth. Table 23.1 shows the energy demands for the hospital,

throughout the year.

296 M. Carvalho et al.

One of the major steps in Mixed Integer Programming is the definition of a

superstructure that represents all options available for equipment and energy

resources. Figure 23.1 depicts the superstructure of the energy supply system for

the hospital located in Jo~ao Pessoa, following the scheme of Carvalho and Millar (2012).

The available utilities were electricity (EE), diesel (DI), biomass (BM), Natural

gas (NG), steam (VA, 180 �C), hot water (HW, 90 �C), cooling water (CW, t0þ 5 �C), ambient air (t0�C), and chilled water (CO, 5 �C). A positive node denotes supply/production of energy and a negative node denotes consumption. The hori-

zontal lines represent the energy forms considered at the site, into which the

equipment (vertical lines) are connected to consume or produce energy.

Table 23.1 Energy demands of the hospital

Month representative day

nd (days/year)

Electricity Hot Water Steam Coolth

Total

MWh/day

Total

MWh/day

Total

MWh/day

Total

MWh/day

Jan wa 20 8538 3543 0.465 5961

Jan hb 11 6315 3543 0.233 4360

Feb w 19 9696 6436 0.465 6472

Feb h 9 6247 6436 0.233 4290

Mar w 20 9861 6436 0.465 8013

Mar h 11 7474 6436 0.233 5443

Apr w 20 9949 6436 0.465 7071

Apr h 10 7348 6436 0.233 4737

May w 20 8901 6436 0.465 7895

May h 11 6383 6436 0.233 5534

Jun w 19 7489 5032 0.465 7768

Jun h 11 6832 5032 0.233 5259

Jul w 20 6568 3881 0.465 5186

Jul h 11 6045 3881 0.233 3760

Aug w 20 5954 3881 0.465 7343

Aug h 11 4681 3881 0.233 4941

Sep w 21 6686 3881 0.465 7483

Sep h 9 4755 3881 0.233 5046

Oct w 20 8041 5284 0.465 8834

Oct h 11 5969 5284 0.233 6057

Nov w 20 9309 6436 0.465 8260

Nov h 10 6022 6436 0.233 5627

Dec w 20 1036 6436 0.465 5912

Dec h 11 7389 6436 0.233 3879

Σ MWh/year MWh/year MWh/year MWh/year Year 365 2791 1947 138 2309 aw¼weekday bh¼ holiday/weekend

23 Life Cycle Analysis as a Decision Criterion for the Implementation of Solar. . . 297

Table 23.2 shows the technical and economic characteristics of the equipment

that belong to the superstructure (Fig. 23.1). The rows indicate the technologies

available, and the columns indicate the energy resources. The coefficient in bold

indicates the flow that defines the productive capacity of the equipment, and

positive and negative coefficients, indicate, respectively, that an energy flow is

either produced or consumed. At the time of writing, 1 US$¼ 2.50 R$. The PV system is constituted by PV panels and inverters (electricity storage will

not be considered). Information was obtained from consultation to PV panel

(Kyocera 2014) and inverter (Santermo 2014) manufacturers. The cost of the

system was US$ 880/panel (including the cost for the panel, inverter, installation

materials, transportation and assembly). The area of each panel is 1.64 m2. The

maintenance costs are US$ 10/m2 per year. As the geographic latitude of the

municipality of Jo~ao Pessoa is 07�S, the inclination angle of the panels to be installed in the hospital must be 10�. Historic hourly radiation data (W/m2) were available from the CLIMATICUS database (2005).

Electricity was charged with an hour-seasonal tariff, presenting differentiated

tariffs for peak and off-peak periods: US$51.60/MWh for off-peak periods, and

between 18 h and 21 h the peak value was US$79.60/MWh. Steam demand was

considered constant during the period in which the sterilization central was open,

during 6 h and 20 h, in addition to the steam demand of a hot counter in the

restaurant, during lunch and supper times. The hot water demand presents two

contributions: laundry (operating between 8 h and 18 h), and the internal use of the

hospital (no interruptions). The tariff for natural gas (US$48/MWh—PBGAS 2013)

does not include hourly or seasonal differentiation, as is the case of diesel (US

$59.60/MWh). Due to the location of Jo~ao Pessoa, the biomass considered herein originates from sugar cane bagasse, and the final price was U$ 13.20/MWh (con-

sidering 15.40 MJ/kg dry matter and 0.787 dry matter/kg).

A lifetime of 15 years was considered for the system, with an interest rate of

10% y�1, obtaining a capital recovery factor of 0.13 yy�1. The system was

Electricity

Diesel

Biomass

Steam

Hot water, 90°C Cooling water, ambient + 5°C

Chilled water, 5°C

Ambient air

El ec

tri c g

rid im

po rt

Di es

el im

po rt

Bi om

as s i

m po

Ga s

en gin

DI e

ng ine

VA b

oil er

HW b

oil er

BM b

oil er

EE b

oil er

DI b

oil er

1X A

bs C

hil ler

M ec

h Ch

ille r

Co oli

ng to

we r

VA /H

W H

HW /C

W H

Hospital demand

BM b

oil er

- Natural gas

Na tu

ra l g

as im

po rt

2X A

bs C

hil ler

- -

PV p

an els

El ec

tri c g

rid e

xp or

Fig. 23.1 Superstructure illustrating all potential conversion pathways considered

298 M. Carvalho et al.

T a b le

2 3 .2

M at ri x o f te ch n ic al

p ro d u ct io n co ef fi ci en ts an d te ch n o lo g y d at a (C ar v al h o et

al . 2 0 1 4 )

T ec h n ic al

p ro d u ct io n co ef fi ci en ts

E q u ip m en t

N G

B M

D I

V A

H W

C W

A A

C O

E E

C o st

C IN

(1 0 3 U S $ )

C o st

O & M

(U S $ /M

W h )

N o m .

P o w er

P N O M

(M W )

G as

en g in e

�2 .6 3

1 .1 0

0 .4 5

1 1 8 5 .0 0

6 .0 0

0 .4 1

D ie se l en g in e

�2 .6 6

0 .8 0

0 .5 0

1 9 0 .8 0

6 .0 0

0 .3 6

S te am

b o il (B M )

�1 .4 0

1 2 0 .4 0

3 .2 0

0 .2 5

S te am

b o il (N

G )

�1 .1 8

1 2 1 .2 9

0 .8 9

0 .3 0

S te am

b o il (E E )

1 �1

.1 5

0 .4 0

0 .8 9

0 .1 5

H X

(V A -H

W )

�1 .1 0

1 3 .5 6

0 .8 9

0 .4 0

H o t w at er

b o il (B M )

�1 .2 5

1 2 5 .0 0

3 .2 0

0 .1 7

H o t w at er

b o il (N

G )

�1 .2 2

1 1 9 .7 2

0 .8 9

0 .3 0

H o t w at er

b o il (E E )

1 �1

.1 1

1 1 .2 8

0 .8 9

0 .1 5

H X

(H W -C W )

�1 .1 0

1 2 .9 6

0 .8 9

0 .4 0

A b s ch il (2 x )

�0 .7 7

1 .7 7

1 �0

.0 1

1 8 6 .0 8

4 .0 0

0 .4 6

A b s ch il (1 x )

�1 .3 2

2 .3 2

1 �0

.0 1

2 1 5 .8 8

4 .0 0

0 .4 9

M ec h an ic al

ch il le r

1 .2 1

1 �0

.2 1

5 8 .0 0

1 .7 7

0 .2 8

C o o li n g T o w er

�1 .0 0

1 �0

.0 2

1 1 .2 8

4 .0 0

1 .0 0

23 Life Cycle Analysis as a Decision Criterion for the Implementation of Solar. . . 299

designed to interact with the electric grid also through the export of autogenerated

electricity, considering the credit compensation scheme set out by BRASIL (2012).

In this energy compensation system, surplus generated electricity can be fed into

the distribution grid and registered as energy credits, which can be consumed in up

to 36 months. This special regime for electricity exports applies to photovoltaic-

and natural gas-produced electricity. Finally, the problem to be solved consists of

two simultaneous tasks: selection of the combination of technologies (type and

power installed) that are capable of meeting the energy demands of the hospital, and

establishment of the operation mode for all equipment installed, for each time

interval defined.

Life Cycle Analysis

It takes considerable effort to conduct an LCA study, exploring large industrial

systems, collecting and analyzing a great amount of environmental information

(Baumann and Tillmann 2004). A brief overview of the basic LCA process is

provided for context when interpreting the findings. A framework for LCA has

been standardized by the International Organization for Standardization (ISO) in

the ISO 14040 series (ISO 14040 2006; ISO 14044 2006). This LCA framework

consists of the following elements (Carvalho et al. 2011): (1) Goal and Scope

definition, which specifies the goal and intended use of the LCA and delineates

the assessment (system boundaries, function and flow, required data quality, tech-

nology and assessment parameters); (2) Life Cycle Inventory analysis (LCI), which

includes the collection of data on inputs and outputs for all processes in the product

system; (3) Life Cycle Impact Assessment (LCIA), which translates inventory data

on inputs and outputs into indicators about the product system’s potential impacts on the environment, human health, and availability of natural resources; and

(4) Interpretation, the phase where the results of the LCI and LCIA are interpreted

according to the goal of the study and where sensitivity and uncertainty analysis are

performed to qualify the results and conclusions.

Because of the potential impacts of global warming and its associated climate

change, greenhouse gases (GHG) were chosen to represent the environmental loads.

The more general category name climate change replaced the formerly used

greenhouse effect and global warming (Udo de Haes 2002). Because the average

tropospheric lifetime of all greenhouse gases, even of the relatively short-lived ones

(CH4, about 10 years), exceeds the tropospheric mixing time (about 1 year), it is not

important where the emissions occur. Climate change is therefore a truly global

impact category (Udo de Haes 2002).

Although the geographic scale of GHG emissions is global, special care must be

taken at the time of defining the LCA processes and data utilized, as the results will

vary greatly if, for example, different production methods and transportation are

used. This will result in a great difference in environmental loads if natural gas is

consumed in Spain (originating from Algeria, liquefied, transported in Liquefied

300 M. Carvalho et al.

Natural Gas carriers, and regasified before being distributed via pipelines) or

Canada (originating from the province of Alberta, transported and distributed in

pipelines).

The impact evaluation method chosen to represent the environmental loads was

the 2013 version of IPCC, which expresses environmental impacts in kg CO2-eq

after atmospheric emissions are quantified and multiplied by a conversion factor

(IPCC 2014). The reader is directed to IPCC (2014) for a more complete description

of the method. Software SimaPro v. 8.0.4 (PréConsultants 2015) was utilized for

the quantification of environmental impacts, and the database utilized was

EcoInvent version 3 (EcoInvent 2014).

Equipment

For each item present in the superstructure (Fig. 23.1), the environmental emissions

were calculated as the sum of the partial emissions for each stage (construction,

operation and maintenance, and dismantlement and disposal). Data on the material

composition of each piece of equipment were obtained after exhaustive and exten-

sive consultation of catalogues and manufacturers. Table 23.3 shows the main

material composition and CO2-eq emissions associated (COE).

The best available disposal scenario was considered for each material

(recycling), and all waste flows (lubricating oil, wastewater, Li-Br, etc.) received

adequate treatment before disposal. The exception was the gas engine, which in its

specific case considered reuse of materials by the manufacturer, resulting in the

impressive low emissions shown in Table 23.3. All recycling options also consid-

ered transportation to the recycling site, which significantly contributed to the final

emissions, as a distance of 2200 km was considered (the recycling site is located in

S~ao Paulo, Southeast Brazil).

Energy Utilities

Special care was taken to correctly adapt each existing process that would be

applicable to the optimization study herein presented. For the electricity mix, a

2014 average was considered (ONS 2014) for the state of Paraı́ba: hydro 48.04%,

thermoelectrical (oil) 44.58%, and eolic 7.38%. Considering these percentages, the

final emissions associated with the consumption of 1 kWh from the electric grid

were 0.580 kg CO2-eq. This figure is very different from the overall Brazilian

electricity mix, which presents a much lower carbon content.

For the sugar cane bagasse, the emissions were 0.147 kg CO2-eq/kWh. These

emissions already take into account the drying of the bagasse. For natural gas, the

emissions were 0.256 kg CO2-eq/kWh consumed, and for diesel, 0.319 kg CO2-eq/

kWh consumed. Please note that these emissions refer to the consumption of one

23 Life Cycle Analysis as a Decision Criterion for the Implementation of Solar. . . 301

energy unit of the utility; however, the optimization model will consider adequate

conversion (Table 23.2) to different energy forms. For example, the diesel gener-

ator will produce electricity at 0.848 kg CO2-eq/kWh, considering its electrical

efficiency (1/2.66¼ 37.6%). The system boundaries were defined as in Fig. 23.2, where the selfgenerated

electricity exported to the electric grid is evaluated at the same “environmental

impact” as the electricity imported from the grid, introducing the concept of

avoided emissions as the emissions avoided elsewhere by the production of elec-

tricity by the PV panels (avoiding the purchase of electricity from the grid).

Table 23.3 Main material composition of technologies and corresponding environmental emissions

Main material composition

COE

CO2-eq

Gas engine Cast iron 1300 kg, Oil 540 kg, Low-alloyed steel 225 kg, PVC 5 kg,

Steel sheet 2 m2 3.53 102

Diesel engine Cast iron 3500 kg, Oil 1292 kg, Low-alloyed steel 300 kg, Rubber

50 kg, Copper 105 kg

6.98 106

Steam boil

(BM)

Chromium steel 1980 kg, Copper 50 kg, PVC 10 kg 2.73 103

Steam boil

(NG)

Rock wool 115 kg, Al sheet 14 m2, Stainless steel 980 kg,

low-alloyed steel 490 kg

2.23 106

Steam boil

(EE)

Rock wool 115 kg, Al sheet 14 m2, Stainless steel 980 kg,

low-alloyed steel 490 kg

2.23 106

HX (VA-HW) Fe-Ni-Cr alloy 94 kg, Epoxy resin 0.5 kg, Titanium dioxide 3 kg 1.50 103

Hot water boil

(BM)

Chromium steel 1980 kg, Copper 50 kg, PVC 10 kg 2.73 103

Hot water boil

(NG)

Rock wool 115 kg, Al sheet 14 m2, Stainless steel 980 kg,

low-alloyed steel 490 kg

2.23 106

Hot water boil

(EE)

Rock wool 115 kg, Al sheet 14 m2, Stainless steel 980 kg,

low-alloyed steel 490 kg

2.23 106

HX (HW-CW) Titanium dioxide 2 kg, Fe-Ni-Cr alloy 75 kg, Epoxy resin 0.5 kg 1.47 103

Absorption chil

(2x)

Li-Br 1600 kg, Stainless steel 7338 kg, Copper 30 kg, PVC 10 kg 2.47 105

Absorption chil

(1x)

Li-Br 2200 kg, Stainless steel 7418 kg, Copper 30 kg, PVC 10 kg 3.25 105

Mechanical

chiller

Polyurethane 30 kg, Stainless steel 2000 kg, Copper 30 kg, PVC

10 kg

1.39 104

Cooling Tower Glass fiber 2622 kg, Cast iron 200 kg, Copper 10 kg, PVC 10 kg,

Steel sheet 1 m2 9.71 103

PV panel PV panel 1.64 m2, Inverter 1, Copper 1.5 kg, PVC 0.125 kg, Steel

sheet 0.005 m2 7.80 103

302 M. Carvalho et al.

Optimization Model

A combinatorial optimization method, based on mathematical programming

(MILP), determines the optimal design and operation for the energy supply system.

The optimization model was implemented in LINGO 14.0 (2015), an optimization

tool that utilizes the combination of branch and bound and simplex methods in its

solution algorithm. The environmental objective function was the minimization of

the total annual impact (COtot):

Min COtot ¼ COfix þ COope ð23:1Þ

Where COfix referred to the impact associated with the installation of equipment,

and COope referred to the consumption of energy utilities to satisfy the energy

demands of the hospital. Then:

COfix ¼ fame Σi NEI ið Þ COE ið Þ þ PV½ � ð23:2Þ

where NEI(i) and COE(i) are, respectively, number of pieces of equipment installed

for technology i and the CO2 emissions for the production of each piece of

equipment. PV refers to the PV panels. The environmental amortization factor

fame allocates the global emissions throughout the lifetime of the system, and

was 0.10 y�1. Considering that the year was divided into d representative days, which were in

turn subdivided into h hours, (d,h) represented the hth hour of the dth representative day. The annual operation impact (COope), associated with the operation of the

system was expressed by:

Market

Electricity imports

Electricity exports

Diesel, biomass, natural gas

Polygeneration System

Energy demands

Electricity

Heat

Cooth

System boundaries

Steam

Fig. 23.2 Boundaries of the polygeneration system

23 Life Cycle Analysis as a Decision Criterion for the Implementation of Solar. . . 303

COope ¼ ΣdΣh COng Fng d; hð Þ þ COee Ep d; hð Þ � COee Es d; hð Þþ CObm Fbm d; hð Þ þ COdi Fdi d; hð Þ � �

ð23:3Þ

where CO refers to the emissions associated with the consumption of the different

utilities: ng (natural gas), ee (electricity), bm (biomass), and di (diesel). F refers to

the amount imported for each fuel, Ep refers to electricity imported from the grid

and Es refers to electricity exported to the grid (and therefore counted as avoided

emissions). Equations (23.1)–(23.3) can be changed to consider economic costs.

Capacity limits, production restrictions, and balance equations were enforced in the

optimization model.

Capacity limits: For each period (d,h) and for each technology i

POEði, d, hÞ � NEIðiÞ ∙PnomðiÞ ð23:4Þ

where POE(i,d,h) is the energy production of technology i in the period (d,h), and

Pnom is the nominal power of the equipment.

Production restrictions: For each period (d,h) and for cogeneration modules, the

production of energy was restricted to:

POE i; d; hð Þ ¼ NES i; d; hð Þ Pnom ið Þ withNOP i; d; hð Þ 2 0, 1, . . . , NEI ið Þf g ð23:5Þ

where NES(i,d,h) is the number of operational equipment of technology i in the

period (d,h). For each technology i, For each utility j,

UI i; j; d; hð Þ ¼ PC i; jð Þ POE i; d; hð Þ ð23:6Þ

where UI(i,j,d,h) is the energy flow of utility j interchanged with technology i in the

period (d,h) and PC(i,j) is the absolute value of the production coefficient

(Table 23.2).

Balance equations: For each period (d,h) and for each utility j:

Prod j; d; hð Þ � Cons j; d; hð Þ þ Imp j; d; hð Þ � Exp j; d; hð Þ� Waste j; d; hð Þ � Demand j; d; hð Þ ¼ 0 ð23:7Þ

Prodðj, d, hÞ ¼ ΣiXði, j, d, hÞ ∙YTUPði, jÞ withYTUPði, jÞ2f0, 1g ð23:8Þ Cons j; d; hð Þ ¼ ΣiX i; j; d; hð Þ YTUC i; jð Þ withYTUC i; jð Þ2 0; 1f g ð23:9Þ

Imp j; d; hð Þ � YUP jð Þ Cons j; d; hð Þ þ D j; d; hð Þð Þ withYUI jð Þ2 0; 1f g ð23:10Þ Exp j; d; hð Þ � YUS jð Þ Prod j; d; hð Þ with YUE jð Þ2 0; 1f g ð23:11Þ

Waste j; d; hð Þ � YUW jð Þ Prod j; d; hð Þ with YUW jð Þ2 0; 1f g ð23:12Þ

304 M. Carvalho et al.

Demand j; d; hð Þ � YUD jð Þ Prod j; d; hð Þ þ P j; d; hð Þð ÞwithYUD jð Þ 2 0; 1f g ð23:13Þ

YTUP(i,j) was 1 when technology i produced utility j. YTUC(i,j) was 1 when

technology i consumed utility j. Production (Prod), and Consumption (Cons)

corresponded to internal utility flows. Imports(Imp), Exports (Exp), Waste and

Demand correspond to the utility flows interchanged between the energy system

and the market environment. Binary variables YUI(j), YUE(j), YUW(j) and YUD

(j) indicated, respectively, the possibility of such interchanges.

Results and Discussion

The main criterion chosen to carry out the optimization of the energy supply system

was the total annual emissions (kg CO2-eq/year). Table 23.4 presents the results for

the optimizations carried out, considering that there are 200 PV panels available for

installation.

Table 23.4 presents three optimal solutions: economic and environmental opti-

mals, and a reference solution. The reference solution reflects the conventional way

of installing energy supply systems: restrictions were introduced within the opti-

mization model to prevent PV panels and biomass-driven equipment to be installed,

while also excluding the possibility of installing cogeneration modules and absorp-

tion chillers.

The reference solution installed hot water and steam boilers that operated on

natural gas, as well as one electrical boiler. All the electricity necessary to supply

the hospital was purchased directly from the grid. The cooling demand was met by

mechanical chillers. This solution presented the worst environmental emissions,

almost 40% higher than those of the environmental optimal.

When optimizing the system applying the economic criteria, the system took

advantage of the lower purchase cost of biomass and imported 2663 MWh/year for

this energy source to operate boilers. For the economic optimal, steam-hot water

heat exchangers, and exclusively mechanical chillers were installed. Electricity was

used to drive the mechanical chillers and auxiliary machinery in this system.

A very different configuration was obtained for the environmental optimal

(Fig. 23.3): a natural gas engine with heat recovery was installed for the production

of electricity. In Fig. 23.3, the installed equipment is shown in bold, while available

but not installed equipment are shown in gray. Only biomass boilers were installed

along with both types of heat exchangers (steam-hot water and hot water-

refrigeration water). Electricity was supplied to users by operating the gas engine

cogeneration module, by the production of the PV panels, and by purchasing a

small quantity from an outside electric power company. The environmental optimal

suggested that environmental benefits are realized through electricity exports.

Trigeneration was installed in this case, as the cold water for space cooling was

23 Life Cycle Analysis as a Decision Criterion for the Implementation of Solar. . . 305

Table 23.4 Minimum annual cost for the polygeneration system with 200 PV panels installed

Economic Optimal Reference systema CO2-eq optimal

Composition of system

Number (Installed

Power)

Number (Installed

Power)

Number (Installed

Power)

Gas engine 0 (0 MW) – (0 MW) 1 (0.41 MW)

Diesel engine 0 (0 MW) – (0 MW) 0 (0 MW)

Steam boiler (NG) 0 (0 MW) 1 (0.300 MW) 0 (0 MW)

Steam boiler (BM) 1 (0.250 MW) 0 (0 MW) 1 (0.25 MW)

Steam boiler (EE) 0 (0 MW) 0 (0 MW) 0 (0 MW)

Heat exchanger

(VA-HW)

1 (0.400 MW) 1 (0.400 MW) 1 (0.40 MW)

Hot water boiler (NG) 0 (0 MW) 1 (0.300 MW) 0 (0 MW)

Hot water boiler (BM) 2 (0.340 MW) 0 (0 MW) 1 (0.17 MW)

Hot water boiler (EE) 1 (0.150 MW) 1 (0.150 MW) 0 (0 MW)

Heat exchanger

(HW-CW)

0 (0 MW) 0 (0 MW) 1 (0.40 MW)

Double-effect absorp-

tion chiller

0 (0 MW) 0 (0 MW) 0 (0 MW)

Single-effect absorp-

tion chiller

0 (0 MW) 0 (0 MW) 1 (0.49 MW)

Mechanical chiller 3 (0.810 MW) 3 (0.810 MW) 3 (0.81 MW)

Cooling tower 1 (1.000 MW) 1 (1.000 MW) 2 (2.00 MW)

Photovoltaic panels 200 units – 200 units

Electricity imports 3244 MWh/year 4281 MWh/year 297 MWh/year

Electricity produced by

PV panels

129 MWh/year – 129 MWh/year

Electricity credits – – 760 MWh/year

Natural gas imports – 1528 MWh/year 9554 MWh/year

Diesel imports – – –

Biomass imports 2663 MWh/year – 281 MWh/year

Initial investment in

equipment

US$ 587,089 US$ 374,670 US$ 1,022,892

Annual cost of elec-

tricity imports

US$/

year

180,489 US$/

year

233,979 US$/

year

15,342

Annual credit with

electricity exports

US$/

year

– US$/

year

– US$/

year

43,488

Annual cost of natural

gas imports

US$/

year

– US$/

year

73,335 US$/

year

458,576

Annual cost of diesel

imports

US$/

year

– US$/

year

– US$/

year

–

Annual cost of biomass

imports

US$/

year

35,150 US$/

year

– US$/

year

3708

Operation and Mainte-

nance costs

US$/

year

21,813 US$/

year

16,716 US$/

year

53,519

Annual cost of

equipmentb US$/

year

76,322 US$/

year

48,707 US$/

year

132,976

TOTAL annual cost US$/

year

331,774 US$/

year

372,758 US$/

year

620,633

(continued)

306 M. Carvalho et al.

supplied by the single effect absorption chiller and mechanical chillers. Surplus

not-consumed cogenerated heat was disposed of through heat exchangers. This

result was not totally unexpected as trigeneration systems have long been seen as

good alternatives to reduce emissions; however, the potential to reduce emissions

depends also on the electricity mix supplied to the system.

Distributed energy resource systems have been recognized as an

environmentally-friendly in comparison with conventional energy systems, as

mentioned by Ren et al. (2010); these systems can employ combined heat and

power systems, PV systems, etc. and help address global environmental problems.

Saner et al. (2014) optimized the energy supply for a Swiss building considering

greenhouse gas emissions and particulate matter formation, with a drastic shift from

fossil fuel-dominated system to a biomass-dominated system. You (2012) and

Carvalho et al. (2011) have obtained divergent solutions when optimizing from

economic and environmental perspectives, corroborating the results obtained

herein.

Table 23.4 (continued)

Economic Optimal Reference systema CO2-eq optimal

Composition of system

Number (Installed

Power)

Number (Installed

Power)

Number (Installed

Power)

CO2 emissions for

equipment only

kg CO2-

eq/year

3,851,100 kg CO2-

eq/year

2,291,100 kg CO2-

eq/year

1,954,903

CO2-eq emissions for

electricity imports

kg CO2-

eq/year

1,881,711 kg CO2-

eq/year

2,482,917 kg CO2-

eq/year

172,222

CO2-eq emissions for

electricity exports

kg CO2-

eq/year

– kg CO2-

eq/year

– kg CO2-

eq/year

441,039

CO2-eq emissions for

natural gas imports

kg CO2-

eq/year

– kg CO2-

eq/year

391,230 kg CO2-

eq/year

2,445,736

CO2-eq emissions for

diesel imports

kg CO2-

eq/year

– kg CO2-

eq/year

– kg CO2-

eq/year

–

CO2-eq emissions for

biomass imports

kg CO2-

eq/year

391,448 kg CO2-

eq/year

– kg CO2-

eq/year

41,296

CO2-eq emissions for

equipmentb kg CO2-

eq/year

385,110 kg CO2-

eq/year

674,291 kg CO2-

eq/year

195,490

TOTAL annual CO2-eq

emissions

kg CO2-

eq/year

2,658,269 kg CO2-

eq/year

3,548,438 kg CO2-

eq/year

2,557,232

aCarvalho et al. (2014) bLifetime of system 15 years, interest rate 10%/year

23 Life Cycle Analysis as a Decision Criterion for the Implementation of Solar. . . 307

Conclusions

A progressive change has been observed in recent years: consumers, and society in

general, are starting to evolve towards a more environmentally-friendly conscience.

This conscience, along with restrictions on the emissions of environmental impacts,

have in turn changed how optimal solutions are obtained. Initially optimal solutions

were based exclusively on economic aspects. Nowadays, environmental aspects are

beginning to be introduced in optimizations, either as a main objective or as part of

the objective (which could include energy efficiency or economic terms).

This manuscript explained the incorporation of environmental information in an

optimization model for the energy supply of a hospital located in Northeast Brazil.

The Life Cycle Assessment methodology was applied for the quantification of

environmental loads, expressed by the emissions of CO2-eq (IPCC methodology).

Environmental data was introduced into the linear programming model, which

determined the equipment to be installed and how to operate each technology, in

order to satisfy the energy demands of the hospital. The optimal solution also

provided all energy, economic, and environmental flows.

The environmental optimal solution suggested that trigeneration is the best

option to minimize the environmental loads produced by the energy supply system.

Natural gas was imported from the grid to drive the gas engine, which produced hot

water and electricity to meet the energy requirements of the hospital. PV panels

produced electricity, and biomass was imported for hot water and steam boilers. A

single-effect absorption chiller utilized part of the cogenerated heat to produce

coolth. Mechanical chillers helped with the production of coolth also. This optimal

solution took advantage of the electricity exports to achieve higher rates of avoided

emissions, and realize environmental benefits to lower the overall emissions of the

system.

+ +

- -+ 297 129 3592 2791

138

1947

2309

281

9554 9554

3951

1616

195

139

8 333 125

1047

1841

793

1849

1516

1 1027

6239 933

6239

+ 760

- Electricity

Diesel

Biomass

Steam

Hot water, 90°C Cooling water, ambient + 5°C

Ambient air

Natural gas

El ec

tri c g

rid im

po rt

Di es

el im

po rt

Bi om

as s i

m po

Ga s

en gin

DI e

ng ine

VA b

oil er

HW b

oil er

BM b

oil er

EE b

oil er

DI b

oil er

1X A

bs C

hil ler

M ec

h Ch

ille r

Co oli

ng to

we r

VA /H

W H

HW /C

W H

BM b

oil er

Na tu

ra l g

as im

po rt

2X A

bs C

hil ler

PV p

an els

El ec

tri c g

rid e

xp or

Hospital demand

Fig. 23.3 Optimal environmental system annual flows (MWh/year)

308 M. Carvalho et al.

The optimization carried out herein was based on the emission on greenhouse

gases (IPCC 2014). Future works could include the consideration of a different,

perhaps more global, impact assessment method for the calculation of environmen-

tal impacts. This would likely provide a different result and help verify the effect of

utilizing a more wider perspective in the optimization. Also, sensitivity analyses

could verify whether the configuration varies when different electricity mixes are

applied (different regions present different mixes). The high emissions associated

with the purchase of electricity could have a considerable effect on the configura-

tion of the system, as the municipality of Jo~ao Pessoa counts with the largest thermal plant in the world (oil-based engines).

Acknowledgments The authors wish to acknowledge the support of the National Council for Scientific and Technological Development (CNPq), through project n� 475879/2013-9.

References

Araújo, M. M. D. (2004). Methodological contribution for the exergetic diagnosis of thermal and

electric systems—Study case at the Lauro Wanderley University Hospital. M.Sc. dissertation,

Department of Mechanical Engineering, Federal University of Paraı́ba, Jo~ao Pessoa, Brazil (in Portuguese).

Baumann, H., & Tillmann, A. M. (2004). The hitch hiker’s guide to LCA. An orientation in life cycle assessment methodology and application. Gazelle Book Services.

Brasil, A. (2012). Resolution N� 482, of April, 17, 2012. Establishes the general conditions for the access of distributed micro- and mini-generation to the electricity distribution system, elec-

tricity compensation system, and other matters. Retrieved August 04, 2014, from http://www.

aneel.gov.br/cedoc/ren2012482.pdf (in Portuguese).

Carvalho, M., & Millar, D. L. (2012). Concept development of optimal mine site energy supply.

Energies, 5, 4726–4745. Carvalho, M., Romero, A., & Millar, D. L. (2014). Biomass and thermal solar energy in the

synthesis and optimization of a polygeneration system. IN Proceedings of the V Brazilian solar energy conference, Recife.

Carvalho, M., Serra, L. M., & Lozano, M. A. (2011). Optimal synthesis of trigeneration systems

subject to environmental constraints. Energy, 36, 3779–3790. CLIMATICUS 4.2. Climatic database. Project strategies for 58 Brazilian cities. INMET1961-1990

database. Beta version. Faculty of Architecture and Urbanization, University of S~ao Paulo, Technology department, Laboratory of environmental comfort and energy efficiency, 2005.

Retrieved November 29, 2013, from www.usp.br/fau/pesquisa/laboratorios/labaut/conforto/

Climaticus_4_2.xls (in Portuguese).

EcoInvent database. (2015). Retrieved March 25, 2015, from http://www.ecoinvent.ch.

Erbs, D. G., Klein, S. A., & Beckman, W. A. (1983). Estimation of degree-days and ambient

temperature bin data from monthly-average temperatures. ASHARE Journal, 25, 60–65. Guinee, J. B. (Ed.). (2001). Life cycle assessment—An operational guide to the ISO standards.

http://media.leidenuniv.nl/legacy/new-dutch-lca-guide-part-1.pdf.

IPCC. (2014). 2013 revised supplementary methods and good practice guidance arising from the

Kyoto protocol. Retrieved March 25, 2015, from http://www.ipcc-nggip.iges.or.jp/public/

kpsg/.

ISO 14040. (2006). Environmental management—Life cycle assessment—Principles and frame- work. Geneva: International Organization for Standardization (ISO).

23 Life Cycle Analysis as a Decision Criterion for the Implementation of Solar. . . 309

http://www.ipcc-nggip.iges.or.jp/public/kpsg/

http://media.leidenuniv.nl/legacy/new-dutch-lca-guide-part-1.pdf

http://www.ecoinvent.ch/

http://www.usp.br/fau/pesquisa/laboratorios/labaut/conforto/Climaticus_4_2.xls

http://www.aneel.gov.br/cedoc/ren2012482.pdf

ISO 14044. (2006). Environmental management—Life cycle assessment—Requirements and guidelines. Geneva: International Organization for Standardization (ISO).

Kyocera. Kyocera Brasil. Retrieved July 30, 2014, from http://www.kyocera.com.br/.

Lingo 14.0. Lindo systems. Retrieved March 27, 2015, from http://www.lindo.com.

Nepote, M. H. A., Monteiro, I. U., & Hardy, E. (2009). Association between operational indices

and occupation rates of a general surgery center. Latino-Am. Enfermagem [online] Journal

17 (in Portuguese).

ONS—Brazilian National Electric System Operator. (2014). Daily operation bulletin. Retrieved March 27, 2015, from http://www.ons.org.br/resultados_operacao/ipdo_new.aspx.

PBGÁS—Companhia Paraibana de Gás. Tariffs. Retrieved December 24, 2013, from http://www.

pbgas.com.br/?page_id¼1477 (in Portuguese). PréConsultants. (2013). SimaPro software. Retrieved March 27, 2013, from http://www.simapro.nl.

Ren, H., Zhou, W., Nakagami, K., Gao, W., & Wu, W. (2010). Multi-objective optimization for

the operation of distributed energy systems considering economic and environmental aspects.

Applied Energy, 87, 3642–3651. Saner, D., Vadenbo, C., Steubing, B., & Hellweg, S. (2014). Regionalized LCA-based optimiza-

tion of building energy supply: Method and case study for a Swiss municipality. Environmental Science & Technology, 48, 7651–7659.

Santerno. Carraro group webpage. Monophasic solar inverters. 2014. Available at: <http://www. santerno.com/br/produtos/energia-solar/inversores-solares-monofasicos.html>. Accessed on 10 mar 2016 [In portuguese]

Udo de Haes, H. A. (Ed.). (2002). Life-cycle impact assessment: Striving towards best practice. Published by the Society of Environmental Toxicology and Chemistry (SETAC). Pensacola,

USA.

WEC—World Energy Council. (2004). Comparison of energy systems using life cycle assessment. http://www.worldenergy.org/documents/lca2.pdf.

You, F. (2012). Multiobjective optimization of energy-environmental systems. In 2012 CAPD annual meeting, Carnegie Mellon University, Pittsburgh, PA.

310 M. Carvalho et al.

http://www.worldenergy.org/documents/lca2.pdf

http://www.santerno.com/br/produtos/energia-solar/inversores-solares-monofasicos.html

http://www.simapro.nl/

http://www.pbgas.com.br/?page_id=1477

http://www.ons.org.br/resultados_operacao/ipdo_new.aspx

http://www.lindo.com/

http://www.kyocera.com.br/

Part VI

Energy Technologies and Their Effect on Global Warming

Green Buildings Technology

Available technologies and numerical investigation tools for buildings performance

optimization

Chapter 24

Energy Conservation Through Sunrays Reflecting Coating on Buildings

Imre Benk€o

Introduction

Sun reflecting coating materials are used in ambient temperature applications

(under 80 �C) such as walls, roofs, heat shields, etc. where thermal radiation is a dominant mechanism of heat transfer. Thus there is a real need for data concerning

the radiative properties of such materials.

The determination of the emissivity of coating materials is not straightforward

mater. Severe practical difficulties arise in connection with the measurement of test

specimen surface temperature using thermocouples embedded just below the sur-

face. It is extremely difficult to achieve uniformity of temperature over the surface

of a coated specimen operating at sunshine and it is probably for this reason that the

calorimetric method of emissivity measurement has not found favor in the case of

such materials and attention has instead been concentrated on radiometric tech-

niques as IR-imagery, too. But in the case of practical approach, the use of

IR-imagery gives a direct temperature difference between the coated and uncoated

surfaces resulting a lower emissivity of the coating.

Method of Examination

The measuring method consists of two successive steps. In the first step IR-imaging

equipment, which viewed the speciment at right angle to the surface of the sample,

received both the radiation emitted by the speciment and the sun radiation reflected

I. Benk€o (*) Faculty of Mechanical Engineering, Budapest University of Technology and Economics,

H-1112 Budapest, Cirmos u.1., Hungary

e-mail: [email protected]

315

mailto:[email protected]

from it. In the second step, after getting to the thermal steady state, shielded the

sample from the sunshine, the IR-imaging equipment received only the radiation

emitted by the nonuniform heated coated and uncoated sides of the specimen (that

is the ‘own radiation’). The special feature of the arrangement used in this case was a heat shield

mounted on rotating arm. The shield consisted of a plate backed by insulating

material. The shield was designed to fit over the surface of the specimen without

touching it, held in position by a spring.

The arrangement was designed so that when the specimen reached thermal

equilibrium on the sunshine, the shield could then be quickly swung on the rotating

arm, thus shielding the specimen from the sunshine and allowing only the own

radiant an convective heat transfer to take place. Measurement was terminated after

about 4–6 s (Figs. 24.1 and 24.2).

In the case of each measurements it was possible to vary the angle of view of the

measuring equipment with respect to the normal to the surface of the speciment (see

Fig. 24.3). A well defined distribution of emissivity as a function of the quality of

Radio waves

Infrared raysSunlight

X-rays

Gamma rays

Ultra- violet waves

1 m

750 nm

380 nm

750

chloro. A absorbs 450-670 (A) chloro. B absorbs 450-650 (B)

400-550 carotenoids absorbs

chlorophyl reflects: 500

Chlorophyl

chlorophyl B (P680)

A (P700)

400

700

650

600

550

500

450

400 380

1 nm

Wavelength

Fig. 24.1 Visible light and electromagnetic spectrum of pigments and absorption spectra

316 I. Benk€o

the specimen has been also presented for the coated and uncoated surfaces (see

Figs. 24.5 and 24.6). The average value of the emissivity for these surfaces can be

calculated by histographical method.

Theoretical Basis of the Direct Comparative Method

The IR-radiation of different samples was examined under practical conditions, in

direct sunshine. The half of the each sample was coated by selective coating and the

other half was uncoated (Fig. 24.4). Infrared radiation emitted by the surfaces was

measured by AGEMA thermal imaging equipment with a special method.

As indicated before, the arrangement for the ‘direct’ method of emissivity measurement consists of a relatively small heated specimen having a surface

temperature Tw within a large environment which is at uniform temperature Te .

The specimen is assumed to be opaque to thermal radiation.

The sunshine radiation views a given target area on the specimen surface in the

normal direction or at some angle θ to the normal. In the second step of the examination, the solar radiation absorbed by the specimen is transferred to the

environment by emission and convective heat transfer.

Thus

q s θð Þ :ε θ;Tð Þ ¼ ε θ;Tð Þ:σ: Tw4 � Tc4 � �þ 2:α Tð Þ: Tw � Tcð Þ ð24:1Þ

Fig. 24.2 Spectral values of the reflectivity of AL-CHR coating

24 Energy Conservation Through Sunrays Reflecting Coating on Buildings 317

Here σ is the Stefan-Boltzmann constant, α is the coefficient of heat transfer in the heated specimen surface and q•s(θ) intensity of direct sunshine radiation in direction θ.

From Eq. (24.1) it follows that

Fig. 24.3 Experimental arrangement for steady state and shielded measurements of emissivity

Fig. 24.4 A sample (Pace_04) of a slate roof

318 I. Benk€o

ε θ;Tð Þ: ¼ 2:α Tð Þ: Tw � Tcð Þ= q s θð Þ þ σ: Tc4 � Tw4 � � � ð24:2Þ

Noting that according to Kirchhoff’s Low applied to total values of absorbtivity a (θ,T) and emissivity

a θ;Tð Þ ¼ ε θ;Tð Þ ð24:3Þ

Comparison of Surfaces with Different Emissivities

The surface emissivity of the coating was compared with that of specimen material.

In Figs. 24.5 and 24.6 on the thermogram are two quadrangles marked for which

temperature distribution was computed. The temperature difference between the

area coated with SRC-coating and the uncoated surface shows that the SRC-coating

directly decreases the IR-emissivity of the material. Numerical values for the

temperature represent the so called’ effective black body temperature (at thermal imaging equipment’s ε¼ 1).

Equation between temperature and emissivity ratios comes from the next

equality

σ:T14:ε1 ¼ σ: T24:ε2 ð24:4Þ

Fig. 24.5 IV-thermogram of a sample of Fig. 24.4 on direct sunshine

24 Energy Conservation Through Sunrays Reflecting Coating on Buildings 319

So from Eq. (24.4), it follows that

ε1=ε2 ¼ T2=T1ð Þ4: ð24:5Þ

Presentation of Results

The results are presented in the form of:

(a) A plot of spectral reflectivity of SRC-coating as a function of wavelength of

the radiation (Fig. 24.2).

(b) IR-thermograms (Figs. 24.5 and 24.6) and table (Tables 24.1 and 24.2) of

sample for presenting the thermal effects of different material/coating couples.

(c) Four plots of equilibrium temperature and intensity of ‘heat gain’ of different wall structures versus emissivity of surfaces, intensity of direct sunshine,

coefficient of heat transfer and environmental temperature (Figs. 24.7, 24.8,

24.9, and 24.10).

Fig. 24.6 IV-thermogram of a sample of Fig. 24.4 shielded from sunshine

320 I. Benk€o

Table 24.1 Technical data of AL-CHR (ALUMA-

CHRON) elastomeric roof/

wall coating

Wet material

Metallic aluminium: 6%

Pigments: 2%

Nonvolatile liquid elastomer: 23%

Dry to complete: 3 days

Solids by volume: 48%

Flashpoint of solvent: 40 �C Application temperature: 5–49 �C Wet film thickness: 1 L/sq m, 1 mm

Cured coating

Elongation at 25 �C: 400% Elongation at 0 �C:200% Return after elongation: >95%

U.V. reflection, white: 90%

Light gray: 70%

Colors: <40%

U.V. resistance: excellent

I.R. emissivity:

At low temperature, 2 6 μm: 0.5 0.7 I.R. reflectance:

At sunshine: 0.4 2.4 μm: 0.45 0.48 Dry film thickness: 1 L/sq m: 388 μm Dry film weight: 1 L/sq m: 372 g/sq m

Re-coat interval: normally 10 years or more

Table 24.2 Collection of histographical data of IR-thermograms (Figs. 24.5 and 24.6) for comparison of a specimen (Fig. 24.4) on direct (s) sunshine and shielded (t) conditions: slate

roof/SRC_04

On the right: slate roof Temperature, �C On the left (Pace_04) temperature values, �C On sunshine (s) Shielded (t) Spot on the other side 36.2 31.8

Dir x/y 95/31 95/31

max 41.9 30.3

min 37.9 27.0

avg 39.4 29.2

med 39.2 29.2

sdev 0.7 0.6

skew 0.8 0.7

Ncal, pixel 1794 2420

Fmax, pixels 248 521

24 Energy Conservation Through Sunrays Reflecting Coating on Buildings 321

Applications in the Thermotechnique of Buildings

The factors affecting the infrared radiation of building surfaces and low tempera-

ture industrial equipment have not been widely enough studied. As far as building

construction is concerned, the infrared radiation emissivity of walls has been

Fig. 24.7 Equilibrium temperatures of a wall

structure (rt denotes the

thermal resistance of wall

structure) against

coefficient of heat transfer

Fig. 24.8 Equilibrium temperatures of a wall

structure (rt¼ 0.7 K m2/W) versus intensity of direct

sunshine radiation

322 I. Benk€o

regarded as an unchangeable factor basically dependent upon the temperature and

quality of their material.

The research was based on different elastometric roof coatings

(e.g. SRC-coatings), commercialized on name ‘ALUMA-CHRON’ (Data Specs of PACE Products International, Inc.), which are available also in Hungary

(MULTITREND Ltd.). The special coating is liquid-applied and cures the surface.

It is applied to forming single, tough, seem-free rubberized roof/wall membrane.

From thermal point of view the coating is a double function membrane: it saves

energy years-round, as it lowers interior temperatures in summer and its low

emissivity slows heat loss in winter.

Fig. 24.9 Values and differential ratios of

equilibrium temperatures of

wall structure vs emissivity

Fig. 24.10 Intensity of ‘heat gain’ of wall structure vs emissivity

24 Energy Conservation Through Sunrays Reflecting Coating on Buildings 323

ALUMA-CHRON’s Properties

Materials of buildings have generally good heat radiation properties, but from

energy management and building physics point of view this fact is not always

convenient. Some coating materials, e.g. ALUMA-CRON (further on: AL-CHR)

have good properties: their emissivity is considerably lower that of the material

onto which they are applied. This paper gives an account only for the infrared

emissivity decreasing effect of SRC-coating.

Performance Characteristics

AL-CHR is an elastomeric roof/wall coating available in different colours. It is

liquid-applied and it perfectly conforms to shapes. It is an economical, practical

alternative to total roof replacement. This rubberized coating provides excellent

resistance to both chemical and weather deterioration. Extensive elongation and

nearly 100% recovery allows the coating to stretch to meet changing weather

requirements as the roof expands and contracts.

AL-CHR remains flexible. It will not become rigid, crack or peel even at

temperatures of �40 �C and it keeps in heat stability under +82 �C.

Basic Uses of AL-CHR Coating

One-coat AL-CHR waterproofs, rustproofs, seal leaks, saves energy, deadens sound

of metal roofs and stretches to accommodate all sudden temperature changes

without breaking.

It restores and protects aged metal, asphalt shingles, sealed and unglazed tile and

felt (with stabilized asphalt) roofs.

It can recoat vinyl, chlorinated rubber, and epoxy coatings.

It was originally designed to fill the need for a coloured roof and tank membrane

that could handle unusual contours and steep slopes. It proved so effective that it

now is used to coat all types of roofs, tanks, silos, and stucco or masonry sidewall

where appearance, whether resistance and corrosion control are essential.

324 I. Benk€o

Role of Pigment in Sun’s Rays Utilization

Coloured pigments in living cells trap light. Light and pigments are vital to

important biological processes. There is an essential difference between chloro-

phyll molecules and the other pigments (e.g. in coat of animals): chlorophyll

participates in photosynthesis as well as giving a green leaf its colour.

Visible light and the electromagnetic spectrum. We are constantly bathed by

electromagnetic energy, from radio waves to infrared rays (heat), X-rays, and

gamma rays. Each category has a range of energies measured in oscillating waves

of specific lengths. Only the small portion of the entire electromagnetic spectrum

with wavelengths in the range 380–750 nm is visible to us as white light that can be

broken into coloured light, each colour with different wavelengths. The shorter the

wavelength, the more energetic the wave, the longer the wavelength, the less

energetic

Pigments and Absorption Spectra

The colours we see in a given object depend on which wavelengths of light the

pigments in that object absorb and which are reflected back to our because all

wavelengths are reflected. Black pigment in a coat absorbs light throughout the

whole colour spectrum and reflect nothing. Thus, it looks black to us. A leaf

contains chlorophyll-‘a’, which absorbs most strongly around 450 and 670 nm, and chlorophyll-‘b’, which absorbs most strongly around 490 and 650 nm; green light in the 500 nm range is reflected, and thus the leaf looks green. The peelings of

fruit often contain carotenoids, which absorb, wavelengths from 400 to about

550 nm and reflect back red, yellow and orange light. Because a leaf often contains

both kinds of chlorophyll plus carotenoid, its pigments can absorb and use for

photosynthesis most of the wavelengths of visible light that strike it. However

plants, algae and other autrophs use less than one percent of the energy of sunlight

in photosynthesis.

In the techniques, the spectral reflectivity of a special (Al-CHR) coating in

function of wavelength of the radiation (between 200–600 nm) is approx.

r¼ 0.5–0.7. The content of this coating is 22% pigments, 6% metallic aluminium and 23%

non-volatile liquid elastomer and lowers exterior temperature of walls of dwelling

in summer by about 5–10 K, so decreasing incoming heat of structures by some

33–38%. It slows infrared radiation heat loss by some 35–40% in winter (Data

Specs of PACE Products International, Inc.).

24 Energy Conservation Through Sunrays Reflecting Coating on Buildings 325

Results

The sunshine radiation of different samples was examined under practical condi-

tions, in direct sunshine (Benko and Kiss 1977; Benko 1981; Benko 2008). Infrared

radiation was measured by AGEMA thermal imaging equipment with a special

method. The temperature field of specimen’s surface was measured by thermocou- ples, too, in some control points (Benko 1992). The thermal imaging equipment

shows the non-uniformity of the temperature field of the specimen surface.

Conclusions

SRC coating lowers exterior temperature of wall in summer by about 5–10 �C, so decreasing incoming heat of structure by some 33–38%. It slows infrared radiated

heat loss by some 35–40% in winter (Benko 1992).

References

Benko, I., & Kiss, L. I. (1977). The struggle of mankind to ensure a comfortable thermal

environment. In The River Valley as a focus of interdisciplinary research; proceedings of the international conference to Commemorate Maupertuis’ expedition to the River Tornio, Northern Finland, 1736–1737, Oulu, Finland, 1977, p. 8.

Benko, I., Kiss, L. I. (1981). Effects of isolation and integration on the development of systems. In

Proceedings of the international conference: The Archipelago as a focus for interdisciplinary research, Turku, Finland, 1978 (pp. 49–68). Karachi: Hamdan Foundation Pakistan.

Benko, I. (1981). Possibilities of utilising renewable energy sources (Vol. 25, No. 1). Periodica

Polytechnica, Mech. Eng., Budapest, Hungary, pp. 67–86.

Benko, I. (1992). Examination of low emissivity coatings by infrared .imagery Advanced Infrared

Technology and Applications. Firenze: Grafiche Troya Publ., 1992, pp. 185–197 and 1993,

pp. 255–270.

Benko, I. (2003). The role of exergy and entropy in thermal engineering applications. In The 1st international exergy, energy and environment symposium (IEEES-1) (p. 81), Izmir, Turkey.

Benko, I. (2008). Thermal behaviour and entropy of living organisms through examples. In

Proceedings of the 2nd WSEAS/IASME international conference on energy planning, energy saving, environmental education (EPESE’08) (pp. 19–24), Corfu, Greece, October 26–28, 2008.

COEC. (1981). The solar handbook. Denver, CO: COEC. Data Specs of PACE Products International, Inc.

MULTITREND Ltd., H-1031 Budapest, Zahony u. 13., Hungary.

Postlethwait, J. H., & Hopson, J. L. (1989). The Nature of Life. New York: McGraw-Hill. Rostvik, H. N. (1992). The sunshine revolution. Stavanger, Norway: SUNLAB Publ.

326 I. Benk€o

Chapter 25

Comparison of Heating and Cooling Loads of a Typical Building with TRNSYS and eQUEST

E. Bellos, C. Tzivanidis, A. Kouvari, and K.A. Antonopoulos

Introduction

Building energy consumption is a very important parameter in the design especially

in our days with the increasing rate in the electricity cost. More specifically, the

energy consumption has increased about 50% the last years (Development Ministry

2009) in residential houses. In Europe a typical house with an average household

occupation of 2.5 persons consumes 14.2 kWh daily (http://www.mpoweruk.com/

electricity_demand.htm) and the yearly electricity consumptions is about 60 TWh

in Greece (http://en.wikipedia.org/wiki/List_of_countries_by_electricity_con-

sumption). It is obvious that energy consumption is a very important issue which

influences on our society and the new life-style. Building energy consumption for

heating and cooling is a great proportion of the total energy used. So, the knowledge

of this energy is able to create more efficient houses and systems in order to

optimize them. More specifically, by calculating with accuracy the heating and

cooling loads of a house, an optimum HVAC is able to be selected which leads to

lower electricity and fuel consumption.

It is important to find ways to lower the energy consumption of a building. For

this reason a wide variety of building energy simulation programs have been

developed, enhanced and are in use. So building designers today can use those

programs to optimize the design to reduce the heating, cooling loads and electrical

loads of the building. Some of the programs that are used worldwide on the market

either purchase or as free software are:

E. Bellos (*) • C. Tzivanidis • A. Kouvari • K.A. Antonopoulos Department of Thermal Engineering, National Technical University of Athens, Zografou,

Heroon Polytechniou 9, 15780 Athens, Greece

e-mail: [email protected]

327

mailto:[email protected]

DOE-2, Equest, EnergyPlus, ESP-r, ECOTECT, DeST, TRNSYS, BLAST,

TRACE, HEED, Hap, Energy Express, BSim, Ener-Win, DOE-2.1E (Han

et al. 2014; Crwley et al. 2008).

Some studies of the building performance with simulation tools are presented

below. Xing et al. (2014) used eQuest to simulate the energy performance of an

existing four-star hotel in Tianjin, China. Terziotti et al. modelled a seasonal solar

thermal energy building with TRNSYS 16 (Terziotti et al. 2011). The combination

of ESP-r and TRNSYS is applied on a case study of a low-energy building serviced

by a solar-thermal and PV/t system (Beausoleil-Morrison et al. 2012).

Also many comparisons between these programs have been made by many

researchers. TRNSYS and Energy Plus were compared for a single module with

100 m2 of floor area for two Italian climatic conditions and the results had a

difference of approximately 10% (Gasparella and Pernigotto 2012). A comparison

between the energy analysis model established for building by eQuest and the

actual energy consumption (IPMVP method D), for an actual office building in

Taiwan was made and the final results had errors from 0.5% to 27% (Kea

et al. 2013). Zhu et al. (2013) made a comparison for loads with EnergyPlus,

DeST and DOE-2.1E. Finally, Brahme et al. (2009) compared the three more

known programs which are Equest, Energy Plus TRNSYS. According this com-

parison, eQuest is the easiest tool to use but it has a limited number of choices in

simulated systems, EnergyPlus is able to model many net zero energy technologies

with an easy way but the lack of a friendly interface is an important drawback and

TRNSYS has the greater variety in simulations but learning this program has larger

difficulties.

In our study, a comparison between eQuest and TRNSYS is made in order to

predict how close the results of these programs are. A typical building is analyzed

and parametric analyses made by changing the main parameters that influences on

heating and cooling loads.

Simulation Data

In order to make a realistic comparison the same building was developed in the two

programs and the yearly loads was calculated for the same case studies. Typical

building parameters have been selected in order to make general results. The

analysis is made for a building in Athens and the meteorological data was taken

from data bases.

Examined Building

The characteristics of the analyzed building are given in following tables

(Tables 25.1–25.3).

328 E. Bellos et al.

After these parameters it is important to refer the structural components and their

properties. Table 25.2 gives the u-value of the external walls, of the roof and of the

ground.

The values are close to each other but there are differences because every

simulation tool uses different materials. Table 25.3 gives the analytical structure

of all the components in eQuest.

In TRNSYS similar structures was selected in order to have similar u-values and

thermal masses. Now it is important to state other differences between theses

simulation tools. Another difference is in lighting strategy. TRNSYS lighting

system is depended from outside the solar irradiation level but the eQuest has an

indoor system. There are two photo sensors per zone which each one controls 50%

of lights. Each photo sensor is located 0.76 m height above the floor and 33% of

zone depth, which is 3.3 m from East and West wall. Also, it is important to state

that the exact location of every window in the respect wall is influences the results

in the eQuest and for the reason the windows are located in the center of the wall in

every case.

Finally it is important to say that TRNSYS calculated the theoretical loads of the

building when eQuest calculates the electrical consumption of the heat pumps that

Table 25.1 Building parameters

Parameter Value Parameter Value

Area 100 m2 Specific gains 14 W/m2 K

Height 3 m Occupants density 0.1 person/m2

East glass double-2 m2 Specific light 10 W/m2

West glass double-2 m2 Infiltration rate 1.12 changes per hour

South glass double-4 m2 Rotation 0� (walls in four directions) Shading coefficient 70% Insulation conductivity 0.035 W/m K

Table 25.2 U for structural components

Program External walls U (W m2 K)

Roof

U (W m2 K)

Ground

U (W m2 K)

eQuest 0.39 0.37 0.30

TRNSYS 0.38 0.39 0.29

Table 25.3 Layers of structural components

Wall

construction

Thickness

(cm)

Roof

construction

Thickness

(cm)

Ground

construction

Thickness

(cm)

ComBrick 10.15 Conc LW

30 lb

5.09 LightSoil, Damp 0.31

Polystyrene 7.62 Blt-UpRoof 0.95 Conc HW 140 lb 3.05

ComBrick 10.15 Polystyrene 7.62 Polystyrene 12.19

– Conc HW

140 lb

15.24 –

25 Comparison of Heating and Cooling Loads of a Typical Building with TRNSYS. . . 329

operates in the house. By setting the coefficient of performance equal to 1, the

electrical consumption is the same as the heating and the cooling load respectively.

So, TRNSYS calculates the loads with a direct way and the loads can be calculated

from eQuest by an indirect way. This is may lead to differences in the final results.

A last main difference of the programs is that TRNSYS uses the S.I. system but

the eQuest uses English Units.

Results

In this section the results of the simulations are presented and the comparison of the

energy tools is made. First of all the results of the main case are given and after

parametric analyses are presented.

Main Case Comparison

The yearly cooling and heating loads for the analyzed building were calculated

analytically and are presented in Fig. 25.1.

It is shown that the heating loads are close to each other for all months, except

January where TRNSYS gives greater loads. It is also important to say that eQuest

does not give heating loads for October and May. This can be explained because the

accuracy of eQuest is lower than TRNSYS, and the very low loads are taken as zero

(Fig. 25.2).

It is obvious that the results of the programs are similar with low differences. The

months April to July, TRNSYS gives greater loads but on the August and on the

September eQuest calculated greater cooling loads (Table 25.4).

The above table presents the yearly cooling and heating loads which calculated

from the two programs. It is shown that TRNSYS gives greater loads of about 5%.

This difference is acceptable and can be explained by the small differences between

the programs. These differences are related to the way that the two programs

calculate the loads and in the used materials. TRNSYS calculates the exact load

in every case in order to keep the temperature in the desire level while Equest uses

standard equipment which covers the loads. Moreover, eQuest uses a library for the

building materials but TRNSYS gives the choice of selecting the material proper-

ties in every case.

Parametric Study

In this section parametric diagrams are given in order to compare the two programs

for different cases. The parameters that changes are the following:

330 E. Bellos et al.

• Infiltration rate

• Building orientation

• Insulation thickness

• Windows area

Fig. 25.1 Monthly heating loads of the building

Fig. 25.2 Monthly cooling loads of the building

Table 25.4 Comparison of loads

Programs TRNSYS eQuest Difference

Heating 3318 3150 5.06%

Cooling 4627 4400 4.91%

25 Comparison of Heating and Cooling Loads of a Typical Building with TRNSYS. . . 331

Infiltration Rate

The infiltration rate of a building is very important and influences on the loads a lot.

So the parametric analysis for this is of a high importance (Figs. 25.3 and 25.4).

From Fig. 25.3 it is shown that heating loads has an increasing rate for greater

values of infiltration. On the other hand, the cooling load is lower in the cases of

greater infiltration rate. A simple explanation for these results is that the summer

heat from windows is stored in the inside air and the more air changes help fresh and

colder air to get into the house. It is obvious that the two programs give similar

results with low differences.

Building Orientation

The orientation of the building is able to influence on the loads because of the

existence on the windows. For example, a south window let greater amount of solar

irradiation to through into the house compared to a north window. Figures 25.5 and

25.6 present the heating and cooling loads for a full reverse of the building, from

�180� to þ180�. Low differences between the programs are observed from Figs. 25.5 and 25.6.

The curves are not symmetrical to the vertical line to 0�, because the East and the West irradiation is not the same. The minimum heating load is achieved when the

south wall azimuth is 0� because of the large window is located in this wall and in this case it lets the solar irradiation to through into the house with the greatest way.

On the other hand, the cooling load in this case is the maximum, because of the high

irradiation leads to a great cooling load.

Fig. 25.3 Heating loads for different infiltration rate

332 E. Bellos et al.

Fig. 25.4 Cooling loads for different infiltration rate

Fig. 25.5 Heating loads for different building orientation

Fig. 25.6 Cooling loads for different building orientation

25 Comparison of Heating and Cooling Loads of a Typical Building with TRNSYS. . . 333

Insulation Thickness

The existence of insulation is the most important parameter for the load reduction

and especially for the heating load. The thickness of this layer is an optimization

issue and it is analyzed in the following schemes (Fig. 25.7).

Figure 25.8 shows that the higher thickness of insulation lead to lower heating

energy consumption, but after 8 cm, the influence on the loads is very low.

TRNSYS and eQuest give similar results according the curves and while the

thickness is greater, the curves come very close to each other. On the other hand,

the cooling energy consumption has a strange behavior. More specifically, the

eQuest simulation proves that the greater insulation is beneficial for the building

load, by decreasing them when TRNSYS shows that the insulation layer increases

these. The values for cooling does not differs a lot as values, but the derivative of

the one is negative and of the other positive. A possible explanation is that the two

programs make the energy balance of the building with different way.

Windows Area

The existence of windows in a building changes a lot the heating and the cooling

loads. The windows let the solar energy through into the house, which means that

the indoor air is getting warmer. Simultaneously, the U-value of the windows is

greater than the wall, fact that leads to high losses in the night. The following

diagrams assume the building performance for different values of total windows

area. It is important to say that the 50% of the total windows area is located to the

south wall, the 25% to the east and the other 25% to the west (Figs. 25.9 and

25.10).

Fig. 25.7 Heating loads for different insulation layer thickness

334 E. Bellos et al.

The above diagrams show that the two programs give similar result, with the

heating load to be lower for a higher windows area and the cooling load has the

reverse behavior. The climate of Athens explains these results because of the high

summer irradiation level in the summer increases the cooling loads when greater

windows are put in the building.

Table 25.5 gives the men differences between the two energy tools for all study

cases.

Table 25.5 shows all the results by giving the mean differences between pro-

grams for the all cases. The main case, which is about the firstly building, which

Fig. 25.8 Cooling loads for different insulation layer thickness

Fig. 25.9 Heating loads for different Windows Area

25 Comparison of Heating and Cooling Loads of a Typical Building with TRNSYS. . . 335

examined, gives differences of about 5% in cooling and heating loads which is

acceptable. The difference in the orientation change is in the same proportion; while

in the other cases differences of 10–15% are observed. Finally the mean difference

of the heating load is about 10% and in the cooling 8%, assuming all the cases of

our analysis.

Conclusions

In this analysis two very known simulation tools for energy calculations in build-

ings are compared in order to validate the one from the other. The differences were

low which shows that the results are similar in the majority of the cases. More

specifically:

• It is important to state that the way that the loads are calculated are different

because of TRNSYS calculates the theoretical load every moment in order to

keep the desired temperature while eQUEST uses a heat pump system to satisfy

the preferable inside temperature.

Fig. 25.10 Cooling loads for different Windows Area

Table 25.5 Final comparison for all the studied cases

Case Heating difference (%) Heating difference (%)

Main case 5.06 4.91

Infiltration rate 11.00 13.36

Orientation 6.54 3.65

Insulation thickness 15.89 8.76

Windows area 12.61 9.24

Mean value of all the cases 10.22 7.98

336 E. Bellos et al.

• The results of this analysis are easily generated because in every parameter

typical and usual values have been selected which match with the real

constructions.

• In the main case, the difference of the loads in the two programs is very low,

about 5%.

• In other parametric cases, greater differences of about 10–15% are observed.

• It is important to state that the heating loads have greater differences between the

two programs compared to the differences in cooling loads with 10% and 8%

respectively.

• In all cases, the derivative of the curves is the same except from Fig. 25.8, which

shows the cooling energy consumption for different thickness of the insulation

layer. TRNSYS gives greater cooling load for greater thickness, while eQuest

has the gives results.

• The main conclusion of this comparison is that the two programs can be

validated by this analysis and the small difference can be explained by the

different way that the programs cover the heating and cooling loads. So the

two programs use different approximations in order to predict the loads of the

building.

• Finally it is important to state that TRNSYS is able to calculate the building

loads with greater accuracy because the material properties are able to be fully

determined by the user and calculate the exact value of the loads. So, to make a

more realistic approach for the Greek environmental conditions, TRNSYS is the

suitable choice.

References

Beausoleil-Morrison, I., Kummert, M., Macdonald, F., Jost, R., McDowell, T., & Ferguson,

A. (2012). Demonstration of the new ESP-r and TRNSYS co-simulator for modeling solar buildings, Energy Procedia, 30, 505–514.

Brahme, R., O’Neill, Z., Sisson, W., & Otto, K. (2009). Using existing whole building energy tools for designing net-zero energy buildings—Challenges and workarounds. In Eleventh interna- tional IBPSA conference, Glasgow, Scotland.

Crwley, D. B., Hand, J. W., Kummert, M., & Griffith, B. T. (2008). Contrasting the capabilities of building performance simulation programs, Building and Environment, 43(4), 661–673.

Development Ministry. (2009). The Greek energy system. Gasparella, A., & Pernigotto, G. (2012). Extensive comparative analysis of two building energy

simulation codes for southern Europe climates: Heating and cooling energy needs and peak loads calculation in TRNSYS and EnergyPlus, International High Performance Buildings Conference, 3556, Purdue.

Han, Y., Liu, X., & Chang, L. (2014). Comparison of software for building energy simulation.

Journal of Chemical and Pharmaceutical Research, 6(3), 467–471. http://en.wikipedia.org/wiki/List_of_countries_by_electricity_consumption

http://www.mpoweruk.com/electricity_demand.htm.

Kea, M.-T., Yeh, C.-H., & Jian, J.-T. (2013). Analysis of building energy consumption parameters and energy savings measurement and verification by applying eQUEST software, Energy and Buildings, 61, 100–107.

25 Comparison of Heating and Cooling Loads of a Typical Building with TRNSYS. . . 337

http://www.mpoweruk.com/electricity_demand.htm

http://en.wikipedia.org/wiki/List_of_countries_by_electricity_consumption

Terziotti, L. T., Sweet, M. L., & McLeskey Jr., J. T. (2011). Modeling seasonal solar thermal energy storage in a large urban residential building using TRNSYS 16, Energy and Buildings, 45, 28–31.

Xing, J., Ren, P., & Ling, J. (2014). Analysis of energy efficiency retrofit scheme for hotel buildings usingeQuest software: A case study from Tianjin, China. www.elsevier.com/locate/enbuild.

Zhu, D., Hong, T., Yan, D., & Wang, C. (2013). A detailed loads comparison of three building

energy modeling programs: EnergyPlus, DeST and DOE 2.1E. Building Simulation.

338 E. Bellos et al.

http://www.elsevier.com/locate/enbuild

Chapter 26

Optimum Insulation Thickness for Cooling Applications Through Exergy Analysis and Environmental Methods

Beyza Nur Daldal, _Ibrahim Sarıo�glu, Gülcan €Ozel Erol, Emin Açıkkalp, and Hasan Yamık

Introduction

In Turkey, heating and cooling applications constitute 80% of the total energy

consumption in the buildings. Also, the building sector is the second largest energy

consumer thus it is an important area for improving of energy savings and effi-

ciency (Dombaycı 2009).

Energy is basic for humankind and it one of the most important parts of the

sustainable development, however, environmental problems becomes a really seri-

ous problem, while energy needs increases. Until recently, energy conversion

systems has been only designed and improved by using the economic and efficiency

parameters. However, environmental impact analysis has gain importance with the

increasing environmental problems such as global warming, natural resource

depletion and climate changes in recent years. It is shown that some new design

and improvement parameters that provide us evaluation for environmental impact

are an obligation for the energy conversion systems. Some countries have already

obligated the environmental impact assessment with laws (Dasdemir 2011).

In the literature, there are many study about optimum insulation thickness for

cooling and heating applications (Gürel and Dasdemir 2011; Dagıdır 2011;Arslan

et. all 2010; Kurekci 2016). They are used energy, exergy and economic analysis

for determining optimum insulation thickness for different cooling applications. In

this study, it presented a novel method that combined environmental impact and the

exergy analysis to determine the optimum insulation thickness is performed. Cal-

culations are carried out for two insulation materials and wall types.

B.N. Daldal (*) • İ. Sarıo�glu • G. Özel Erol • E. Açıkkalp • H. Yamık Department of Mechanical and Manufacturing Engineering, Faculty of Engineering, Bilecik

S.E. University, Bilecik, Turkey

e-mail: [email protected]; [email protected]; [email protected];

[email protected]; [email protected]

339

mailto:[email protected]

Modeling and Analysis

In this study, exergy analysis is combined with the environmental impact analysis

for determining the optimum insulation thickness for the cooling applications. Ambi-

ent temperature is assumed as 313 K and the indoor temperature is assumed as 295 K.

Electricity is used as fuel for the cooling system (air conditioner). Optimum insula-

tion thickness is investigated for two different wall and two different insulation

materials. The investigated walls are illustrated in Fig. 26.1. All calculations are

conducted for the unit wall area and annual process (Table 26.1).Please check the

renumbering of figures/tables/equations and their citations, and correct if necessary.

equation 26.4 have been deleted and the other equatins have revised.

Annual cooling loss in unit area (kJ/m2-year) from the wall is calculated as

follow (Cengel 1998):

q ¼ 0:024ðCDDÞU ð26:1Þ

where CDD is cooling degree-days (�C.day), and U is heat transfer coefficient (W/m K). Annual energy need (kJ/m2-year) for the unit wall area is calculated as

following (Cengel and Boles 2006):

E ¼ 0:024ðCDDÞU COP

ð26:2Þ

Annual exergy loss (kJ/m2-year) is defined as (Cengel and Boles 2006):

Exloss ¼ 0:024ðCDDÞU COP

1� To Ti

! ð26:3Þ

where Ti is the indoor temperature (K) and To is the ambient temperature (K). COP is the coefficient of the performance for the cooling system. Heat transfer

coefficient (W/m K) for no-insulation and insulation wall conditions are shown in

Eqs. (26.4) and (26.5) respectively (Cengel 1998).

Fig. 26.1 Schematic of the investigated system for wall I (a) and wall II (b)

340 B.N. Daldal et al.

Unins ¼ 1 Ri þ Rw þ Ro ¼

R ð26:4Þ

Uins ¼ 1 Ri þ Rw þ Ro þ Rins ¼

Rþ x=k ð26:5Þ

Environmental impact function of the system (mPts/m2-year) is;

BT ¼ ðbf :ExlossÞ þ ðbins:ρ:xÞ ð26:6Þ

where bf is the environmental impact of the electricity (mPts/kWh), bins is the environmental impact of the insulation materials (mPts/ kg), ρ is the density of the insulation materials and x is the insulation thickness. CO2 emission is given in the environmental impact of the electricity. The net saving of the environmental impact

(mPts/m2-year) is;

S ¼ ðbf :ExlossÞ þ ðbins:ρ:xÞ

ins

� ðbf :ExlossÞnins ð26:7Þ

The net saving of the exergy loss (kJ/m2-year) is;

SEx ¼ Exlossð Þnins � Exlossð Þins ð26:8Þ

The optimum insulation thickness is calculated by taking the derivative of BT and set equal to zero. Data used in calculations can be seen in Table 26.2.

Table 26.1 Properties of walls (TS 825) used in this study

Wall types

Thickness

(m)

Thermal

conductivity (W/m K)

Overall heat transfer

coefficient (W/m2 K)

Heat

resistance

(m2 K/W)

Wall I 1.572 0.636

External

plaster

0.03 1.40

Internal

plaster

0.02 0.87

Horizontal

coring brick

0.19 0.45

Wall II 1.772 0.564

External

plaster

0.03 1.60

Internal

plaster

0.02 1

Gasconcrete 0.25 0.16

26 Optimum Insulation Thickness for Cooling Applications Through Exergy. . . 341

Results and Discussion

In this study, environmental impact analysis is combined with exergy analysis for

determining the optimum insulation thickness of a building wall. The rockwool and

glasswool are used as insulation material for the analysis. Wall I and wall II are the

investigated systems which are the most commonly used wall arrangements in

Turkey.

In Fig. 26.2a and b, variations of the total environmental impact and the net

savings of the environmental impact with insulation thickness for the glasswool are

shown for wall I and II. As appears in the graphics, initially the environmental

impact decreases dramatically and achieves a minimum point called the optimum

point. After the optimum point, it starts to increase in small steps. When glasswool

is used as the insulation material for wall 1 and 2, optimum points are calculated as

0.052 m and 0.054 m respectively. While the environmental impact decreases until

the optimum point, the net savings of the environmental impact increases contin-

uously. At optimum points for wall I and II, environmental impact points are

determined as 11.67 and 11.88 mPts/m2-year respectively.

In Fig. 26.3a and b, change of the exergy loss and the net exergy savings

according to the insulation thickness from the wall 1 and 2 is illustrated. Exergy

losses decreases with insulation thickness. At optimum points exery loss decreases

by 60.8% and 74.95% compared with the no insulation conditions. In Fig. 26.4a

and b, the variations of the total environmental effect and the net savings of the

environmental impact with insulation thickness for the rockwool are shown for wall

I and II. When the rockwool is used as the insulation material for wall I and II,

optimum points are calculated as 0.01 m and 0.015 m respectively. At these points,

the environmental impact of the system reaches its minimum. Rockwool has

relatively lower optimum points than the glasswool.

Table 26.2 Parameters used in calculations

Parameter Unit Value

Heat conduction coefficient (Izocam 2013) W/m K

Rockwool 0.04

Glasswool 0.032

Environmental impact point mpts/kg

Rockwool (Eco-indicator 99 2014) 4.2

Glasswool (Eco-indicator 99 2014) 2.1

Electricity (Eco-indicator 95 2014) 27

Mean temperature for heating period �C 22 Heating degree day (Dombaycı 2009) �C-days 661 COP (Dasdemir 2011) 2.4

Density of insulation material kg/m3

Rockwool (Dombaycı 2009) 105

Glasswool (Dombaycı 2009) 45

342 B.N. Daldal et al.

0.00 0.02 0.04 0.06 0.08 0.10 10

BT S

E nv

iro nm

en ta

l i m

pa ct

(m P

ts /m

2 - ye

ar )

E nv

iro nm

en ta

l i m

pa ct

(m P

ts /m

2 - ye

ar )

10 T

he net environm ental saving (m

P ts/m

2-year)

insulation thickness (m)

T he net environm

ental saving (m P

ts/m 2-year)

0.00 0.02 0.04 0.06 0.08 0.10

BT S

insulation thickness (m)

Fig. 26.2 Change of the environmental impact and

the net saving with

insulation thickness for

glasswool, (a) wall I, (b) wall II

0.00 0.02 0.04 0.06 0.08 0.10 -0.1

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

SEx Exloss

insulation thickness (m)

T he

n et

e xe

rg y

lo ss

s av

in g

(k J/

m 2 -

ye ar

)

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

E xergy loss (kJ/m

2-year)

0.00 0.02 0.04 0.06 0.08 0.10 -0.1

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0a b

SEx Ex

loss

insulation thickness (m)

T he

n et

e xe

rg y

lo ss

s av

in g

(k J/

m 2 -

ye ar

)

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

1.1

E xergy loss (kJ/m

2-year)

Fig. 26.3 Change of the exergy loss and the net exergy loss saving with insulation thickness for glasswool, (a) wall I, (b) wall II

In Fig. 26.5a and b, the change of the exergy loss and the net exergy saving of the

optimum insulation thickness are presented for wall I and II. Using the rockwool as

insulation material it cause to decrease the exergy saving from the wall I and II by

17% and 40% compared with the no insulation conditions

0.00 0.02 0.04 0.06 0.08 0.10 15

BT S

insulation thickness (m)

E nv

iro nm

en ta

l i m

pa ct

( m

P ts

/m 2 -

ye ar

) E

nv iro

nm en

ta l i

m pa

ct (

m P

ts /m

2 - ye

ar )

50 The net environm ental saving (m

P ts/m

2-year) T

he net environm ental saving (m

P ts/m

2-year)

0.00 0.02 0.04 0.06 0.08 0.10 20

insulation thickness (m)

BT S

Fig. 26.4 Change of the environmental impact and

the net saving with

insulation thickness for

rockwool, (a) wall I, (b) wall II

344 B.N. Daldal et al.

Conclusions

In this study, exergy based environmental impact analysis is used to determine the

optimum insulation thickness for cooling applications. As mentioned above, global

warming has gained attention in recent decades and buildings have an important

effect on energy consumption and environmental issues. Some important results

obtained from the analysis can be listed as follows:

• Environmental impacts decrease according to the optimum insulation thickness.

• For the rockwool, optimum points are as 0.052 m and 0.054 m for wall I and II

respectively.

• For the glasswool, optimum points are as 0.01 m and 0.015 m for wall I and II

respectively.

• At optimum points exergy savings increase considerably compared with the no

insulation conditions.

We get more efficient, less energy consumption and more environmental in the

optimum insulation thickness.

According to these results, the environmental effects should be investigated as

well as the economic effects to provide sustainable development.

Nomenclature

b Environmental impact point, mPts/kg-mPts/kWh

B Environmental impact rate associated with exergy, mPts

CDD Cooling degree-days, �C.day COP Coefficient of performance for the cooling system

E Annual energy need for unit wall area, kJ/m2-year

0.00 0.02 0.04 0.06 0.08 0.10 -0.1

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8 a b

SEx Exloss

insulation thickness (m)

T he

n et

e xe

rg y

lo ss

s av

in g

(k J/

m 2 -

ye ar

)

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

E xergy loss (kJ/m

2-year)

0.00 0.02 0.04 0.06 0.08 0.10

0.0

0.2

0.4

0.6

0.8 SEx Exloss

insulation thickness (m)

T he

n et

e xe

rg y

lo ss

s av

in g

(k J/

m 2 -

ye ar

)

0.2

0.4

0.6

0.8

1.0

E xergy loss (kJ/m

2-year)

Fig. 26.5 Change of the exergy loss and the net exergy loss saving with insulation thickness for rockwool, (a) wall I, (b) wall II

26 Optimum Insulation Thickness for Cooling Applications Through Exergy. . . 345

El Annual electricity consumption for unit wall area, kJ/m2year

Ex Annual heat exergy, kJ/m2-year

k Thermal conductivity, W/m K

q Annual heat loss for unit wall area, kJ/m2-year

R Heat resistance, K/W

S Annual net saving of environmental impact, mPts/m2-year

SEx Annual net saving of the exergy loss, kJ/m2-year

T Temperature, �C or K U Heat transfer coefficient, W/K

x Insulation thickness, m

Subscripts

o Ambient

f Fuel

i Indoor

ins Insulation

loss Loss

nins No-insulation

T Total

w composition

Greek Letter

ρ Density, kg/m3

References

Arslan, O., Ozgur, M. A., Yıldızay H. D., Kose, R., (2010). Fuel Effects on Optimum Insulation

Thickness: An Exergitic Approach, Energy Sources, Part A, 32, 128–147.

Cengel, Y. A. (1998). Heat transfer: A practical approach (1st ed.). Hightstown: McGraw-Hill. Cengel, Y. A., & Boles, M. A. (2006). Thermodynamics an engineering approach (5th ed.).

Hightstown: McGraw-Hill.

Dagıdır, C., (2011). Determination of Optimum Insulation Thickness by Considering Solar

Radiation in Buildings of Warm Climate Regions, M. Sc Thesis, Graduate School of Applied

and Natural Sciences, Süleyman Demirel University, Isparta, TURKEY.

Dasdemir, A. (2011). Heating and cooling applications energy saving of optimum thickness and

the effect of the flue gas emission M. Sc Thesis, Graduate School of Applied and Natural

Sciences, Karabuk University, Karabuk, TURKEY.

Dombaycı, Ö. A. (2009). Degree-days maps of Turkey for various base temperatures. Energy, 34, 1807–1812.

Goedkoop, M., & Spriensma, R. (2014, March). The Eco-indicator 99: A damage oriented method

for life cycle impact assessment. Methodology report, 2000, Amersfoort, Netherlands. http://

www.pre.nl.

346 B.N. Daldal et al.

http://www.pre.nl

Gürel, A. E., Dasdemir, A. (2011). Economical and Environmental Effects of Thermal Insulation

Thickness in Four Different Climatic Regions of Turkey, International Journal of Renewable

Energy Research, Vol.1 , No.1, 1–10.

Kurekci, N.A., (2016). Determination of optimum insulation thickness for building walls by using

heating and cooling degree-day values of all Turkey’s provincial centers, Energy and Build- ings, 118, 197–213.

Retrieved March 2013 from http://www.izocam.com.tr/tr-tr/urunler/yalitim-malzemeleri.aspx.

The Eco-indicator 95. (2014, March). http://www.pre-sustainability.com/eco-indicator-95-final-

report, http://www.pre.nl.

Turkish Standards Institution (TSE). (1998). TS 825: Thermal insulation in buildings. Ankara, Turkey: TSE Publications.

26 Optimum Insulation Thickness for Cooling Applications Through Exergy. . . 347

http://www.pre.nl/

http://www.pre-sustainability.com/eco-indicator-95-final-report

http://www.izocam.com.tr/tr-tr/urunler/yalitim-malzemeleri.aspx

Chapter 27

Novel Tungsten Bronze Nanoparticles for Shielding Near Infrared Ray and Decreasing CO2 Emission

Tsugio Sato, Chong-shen Guo, and Shu Yin

Introduction

Recently, much attention has been attracted for the smart windows to reduce the

energy consumption for air conditioning, and, thereby, to decrease the carbon

dioxide emission by shielding the heat-ray from the sunlight into the room in

summer, and from the room to the outside in winter for automobiles, buildings,

etc. In case of the smart window, the high transparency of visible light and high

shielding ability of NIR light are required. In order to cut off the heat-rays, the

shielding of the near infrared light by the electronic plasma is used (Kreibig and

Vollmer 1995). Namely, the electronic plasma frequency (Wp) of the conductive

materials is expressed by Eq. (27.1)

Wp 2 ¼ 4πne2=m ð27:1Þ

where n is free electron density and m is electronic mass. It is known that the

electromagnetic wave with the lower frequency than plasma frequency is not able

to pass the plasma. Therefore, it is possible to shield the near infrared rays by

controlling the free electron density of the conductive materials. In addition, it is

well known that the scattering of lights by the particles greatly changes depending

on the particle size, and nano particles less than 20 nm in diameter are quite

transparent, since the Rayleigh scattering intensity (s) is proportional to the particle

size (d) to the six power as shown by Eq. (27.2).

T. Sato (*) • C.-s. Guo • S. Yin Institute of Multidisciplinary Research for Advanced Materials, Tohoku University,

2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan

e-mail: [email protected]

349

mailto:[email protected]

s ¼ Kd6=λ4 ð27:2Þ

Nowadays, the thin films of various nanosized conductive compounds such as

silver (Kreibig and Vollmer 1995), indium tin oxides (ITO) (Yang et al. 2009), etc.

are widely used as solar filters (Okada et al. 2003; Hammarberg and Roos 2003;

Adachi and Miratsu 2010; Takeda et al. 1998), however, the performances of the

these materials are not satisfactory. We focused the attention on the hexagonal

tungsten bronze compounds with the chemical formula of MxWO3 consisting of the

mixed valence of W6þ and W5þ, where M is alkali metal ion which locates in the space of the WO3 layer. The free electron density of tungsten bronze can be

controlled by controlling the amounts of Mþ. There are lots of tungsten bronze compounds, but the cesium tungsten bronze shows the most excellent chemical

stability because of the adequate ionic size matched with the space size in the WO3 layer. Takeda and Adachi (2007) prepared cesium tungsten bronze nanoparticles for

near infrared light shielding by the solid state reaction under severe reaction

conditions, such as hydrogen gas atmosphere above 800 �C, followed by energy consuming milling process. Now, we tried the direct fabrication of the cesium

tungsten bronze nanocrystals by solvothermal reaction under mild conditions.

Experimental

In a typical experiment, after dissolving desired amounts of WCl6 and CsOH in

ethanol separately, both solutions were added into the ethanol and acetic acid mixed

solution to precipitate amorphous gel precursor, followed by solvothermal reactions

at a desired temperature to form CsxWO3 nanocrystals by the dissolution-

crystallization mechanism. In order to evaluate NIR shielding performance, the

product was dispersed in a collodion-ethanol mixed solution, and then, coated on a

quartz glass by a doctor-blade method using an applicator of 12.5 μm film thickness.

Results and Discussion

Figures 27.1 and 27.2 shows the X-ray diffraction patterns of the products obtained

in (a) pure ethanol and (b) 90 vol.% ethanol-10 vol.% acetic acid mixture at 240 �C. Both samples consisted of the single phase of the hexagonal cesium tungsten

bronze, but the morphology was greatly different. It can be seen that the irregularly

agglomerated large particles were formed in pure ethanol. In contrast, the samples

synthesized in 10 vol.% acetic acid contained ethanol solution consisted of well-

dispersed rod-like nanoparticles with about 15 nm in diameter and 50 nm in length.

350 T. Sato et al.

By increasing the acetic acid content up to 40 vol.%, the size of nanorods could be

decreased, but the agglomeration of particles proceeded.

Table 27.1 shows the Cs/W atomic ratio and CsxWO3 yield in ethanol mixed

with various amounts of acetic acids. It can be seen that the Cs/W atomic ratio and

CsxWO3 yield in pure ethanol were quite low, but Cs/W atomic ratio increased to

almost 0.33, which is the ideal value of tungsten bronze structure, and CsxWO3 yield increased to nearly 100% by adding acetic acid.

In order to confirm the reaction mechanism to promote the formation of tungsten

bronze by adding carboxylic acid, the chemical compositions of the reaction

solutions after solvothermal reaction were analyzed by NMR. It was found that

the peaks corresponding to not only the ethanol and acetic acid which were used as

starting solvents, but also ethyl acetate and diethyl ether were determined. These

Ref, Cs0.32WO3

2 q Cuka /deg 10 20 30 40 50 60

70 80

Fig. 27.1 XRD patterns of samples synthesized in (a) pure ethanol and (b) 90 vol. % ethanol-10 vol.% acetic

acid mixed solutions at

240 �C for 20 h (reference: Cs0.32WO3, JCPDS

No. 831334)

Fig. 27.2 Scanning electron micrographs of samples synthesized in (a) pure ethanol and (b) 90 vol.% ethanol-10 vol.% acetic acid mixed solutions at 240 �C for 20 h with a nominal Cs/W atomic ratio of 0.5

27 Novel Tungsten Bronze Nanoparticles for Shielding Near Infrared Ray. . . 351

results indicate that the esterification and etherification shown by Eqs. (27.3) and

(27.4) proceeded during the solvothermal reaction, and water generated by these

reactions played an important role to form CsxWO3 nanocrystals.

CH3CH2OH þ CH3COOH ¼ CH3CH2OOCCH3 þ H2O Esterificationð Þ ð27:3Þ

2CH3CH2OH ¼ CH3CH2OCH2CH3 þ H2O Etherificationð Þ ð27:4Þ

It is considered that water promotes the hydrolysis of WCl6, and ethanol pro-

motes the reduction of W6þ to W5þ to form CsxWO3. In case of pure ethanol, due to the low reaction rate of the dehydration condensation reaction of ethanol to

generate water, the rate of CsxWO3 formation is slow. By adding acetic acid in

ethanol, the rate of water generation increases, therefore, the formation of CsxWO3 was promoted. When excess amount of acetic acid is added in ethanol, the water-

releasing rate becomes too high to proceed the agglomeration. Therefore, the

optimum acetic acid content exists to form well dispersed nanocrystals of

Cs0.33WO3.

By the XPS analysis, it was confirmed that tungsten trioxide (WO3) consisted of

only W6þ, but cesium tungsten bronze crystal (CsxWO3) consisted of the mixed valences of W6þ and W5þ as shown in Fig. 27.3.

Transmittance spectra of CsxWO3 particles synthesized in (a) pure ethanol

(b) 90 vol.% ethanol-10 vol.% acetic acid, (c) 80 vol.% ethanol-20 vol.% acetic

acid, (d) 60 vol.% ethanol-40 vol.% acetic acid solutions at 240 �C for 20 h with Cs/W atomic ratio of 0.5 and (e) WO3 particles are shown in Fig. 27.4. As-expected,

tungsten trioxide (WO3) consisted of only W 6þ did not show NIR shielding

ability, but CsxWO3 consisted of the mixed valences of W 6þ and W5þ showed

NIR-shielding ability, where the NIR-shielding ability greatly changed depending

on the reaction conditions, indicating that well dispersed nanocrystals of CsxWO3 showed excellent heat ray shielding performance.

In order to confirm the heat-ray shielding performance of CsxWO3, the simulated

experiments were carried out by a 50 W Halogen lamp radiating to three boxes

sealed by quartz glass, CsxWO3 coated quartz glass and ITO glass. The tempera-

tures in the boxes after 1 h irradiation are listed in Table 27.2. It can be seen that the

temperature in the box covered by a quartz glass increased up to 34.2 �C after 1 h irradiation. The temperature increment could be depressed by using an ITO glass,

Table 27.1 Cs/W atomic ratio and CsxWO3 yield in

ethanol mixed with various

amounts of acetic acids

CH3COOH

content/vol.% Cs/W atomic ratio CsxWO3 yield/%

0 0.26 65.1

10 0.31 90.0

20 0.32 96.2

40 0.29 95.5

352 T. Sato et al.

WO3

40 39 38 37

Binding Energy/eV

36 35 34 33

CSxWO3

W6+ W5+ W5+W6+

Fig. 27.3 W4f core-level XPS spectra of CsxWO3 nanorods prepared in 90 vol.

% ethanol-20 vol.% acetic

acid mixed solution at

240 �C for 20 h with Cs/W atomic ratio of 0.5 and WO3

UV VIS NIR lights

300

100

600 900 1200

(e)

(a)

(d)

(c)

(b)

Wavelength/nm

T ra

n sm

it ta

n ce

1500 1800 2100 2400

Fig. 27.4 Transmittance spectra of CsxWO3 particles synthesized in (a) pure ethanol (b) 90 vol.% ethanol-10 vol.% acetic acid, (c) 80 vol.% ethanol-20 vol.% acetic acid, (d) 60 vol.% ethanol- 40 vol.% acetic acid solutions at 240 �C for 20 h with Cs/W atomic ratio of 0.5 and (e) WO3 particles

Table 27.2 Temperatures in the boxes covered by quartz

glass, ITO glass and CsxWO3 coated quartz glass after 1 h

irradiation by a 50 W

halogen lamp

Box Temperature/�C Quartz glass 34.2

ITO glass 30.0

CsxWO3 coated quartz glass 24.4

Temperature before irradiation: 20.0

27 Novel Tungsten Bronze Nanoparticles for Shielding Near Infrared Ray. . . 353

but still caused a remarkable increase in temperature up to 30.0 �C. In contrast, the temperature increment was limited to 24.4 �C by using a Cs0.32WO3 coated quartz glass, indicating the excellent heat-ray shielding performance of the CsxWO3 nanocrystals.

Conclusions

From the present results, following conclusions may be drawn. (1) The CsxWO3 nanocrystals were successfully synthesized by solvothermal process. (2) The well

dispersed CsxWO3 nanocrystals showed the excellent NIR shielding ability as well

as high transmittance in the visible light range.

References

Adachi, K., & Miratsu, M. (2010). Absorption and scattering of near-infrared light by dispersed

lanthanum hexaboride nanoparticles for solar control filters. Journal of Materials Research, 25, 510–521.

Hammarberg, E., & Roos, A. (2003). Antireflection treatment of low-emitting glazings for energy

efficient windows with high visible transmittance. Thin Solid Films, 442, 222–226. Kreibig, U., & Vollmer, M. (1995). Optical properties of metal clusters. In J. P. Toennies (Ed.),

Springer series in materials science (Vol. 25). New York: Springer. Okada, M., Yamada, Y., Jin, P., Tazawa, M., & Yoshimura, K. (2003). Fabrication of

multifunctional coating which combines low-e property and visible-light-responsive

photocatalytic activity. Thin Solid Films, 442, 217–221. Takeda, H., & Adachi, K. (2007). New infrared absorption of tungsten oxide nanoparticle

dispersions. Journal of American Ceramic Society, 90, 4059–4061. Takeda, H., Otsuka, Y., Kuno, H., & Adachi, K. (1998). Coating solution for a heat-ray shielding

film and a process for forming a heat-ray shielding film by employing the same. US Patent

No. 5,840,364.

Yang, L. L., Ge, D., Wei, H., He, F., & He, X. D. (2009). Morphology and characterization of ITO-

Ag-ITO films on fibers by layer-by-layer method. Applied Surface Science, 255, 8197–8201.

354 T. Sato et al.

Chapter 28

Modelling of a Solar Assisted Floor Heating System with TRNSYS

E. Bellos, C. Tzivanidis, A. Prassas, and K.A. Antonopoulos

Introduction

Energy consumption in buildings has a very important role with a proportion of

40% of the total energy in Europe. Especially energy consumption for heating and

cooling is responsible for 70% of building consumption which is a great percentage

(European Environment Agency 2010). More specifically, the specific heating

consumption for typical buildings varies from 15 kWh/m2 year to 100 kWh/m2

year (Asimakopoulos et al. 2012; Theodoridou et al. 2011). In order to cover this

load, many technologies are used and this research field evolves rapidly. Solar

energy utilization is very beneficial because of the zero operating cost and is able to

cover great loads in countries with high irradiation level as Greece. With a solar

potential of 1600 kWh/m2 year in Athens (Fantidis et al. 2013; Kouremenos

et al. 1985), the solar energy exploitation is a feasible solution for covering the

building heating loads.

Simultaneously, underfloor heating systems are a heating technology which is

used with an increasing rate because provide to occupants more satisfactory indoor

micro-climate (Gao et al. 2011). The first steps of this technology were in Germany

in 1970s in commercial buildings (David 1984) and in data centers of high heat and

fewer people (Sodec and Craig 1990). Nowadays, the 50% if the new constructed

Europe buildings uses this technology (Kilkis et al. 1994) because underfloor

heating systems reduces the seasonal heating about 18% (Ghali 2007) and improve

the thermal comfort conditions inside the buildings (Inard et al. 1998).

Many analyses have been done in this area, Alajmi and El-Amer developed an

underfloor-air-distribution system and proved that this system saves energy

E. Bellos (*) • C. Tzivanidis • A. Prassas • K.A. Antonopoulos Department of Thermal Engineering, National Technical University of Athens,

Zografou, Heroon Polytechniou 9, 15780 Athens, Greece

e-mail: [email protected]

355

mailto:[email protected]

compared to ceiling-based air distribution (Alajmi and El-Amer 2010). Other

studies prove the improvements in thermal comfort conditions by using an

underfloor heating system (Myhren and Holmberg 2008; Sekhar and Ching 2002;

Hasan et al. 2009). Zhai et al. (2009) studied the design and performance of the

solar-powered floor heating system in for a typical building. Badran and Hamdan

made a theoretical and an experimental study for under-floor heating system using

solar collectors and solar pond. They finally proved that the system with solar

collector is 7% more efficient than the solar pond system (Badran and Hamdan

2004). In other studies, Athienitis made a numerical model to predict the underfloor

heating load under high solar gain and conclude that controllers should be used in

order the floor temperature does not exceed the comfort limits (Athienitis 1994).

Al-Khalayleh et al. in a theoretical investigation of an underfloor heating system

coupled with solar collectors proved that solar energy is able to cover the heating

load sufficiently (Al-Khalayleh et al. 1999).

In this study the solar energy utilization is analyzed for heating a typical building

with an underfloor heating system. The combination of these is suitable for Greek

high solar potential and leads to an optimum performance. The simulation is done

by commercial software TRNSYS which uses an active layer to simulate the

underfloor heating system.

General Information

In this paragraph the building description, the underfloor system modelling and the

basic mathematical equations are presented in order to make the next analysis

feasible.

Examined Building

The building of this study is a cubic building with double glass windows in south,

east and west direction. The characteristics of the building are presented in

Table 28.1. Simultaneously the specific loads of the building are presented in the

same table.

The structure and the composition of outer walls influence on the thermal

behavior of the building. Table 28.2 presents the material properties which have

the default TRNSYS values.

The building consists of four outer same walls and a roof without having internal

walls. The roof of the building has three layers; the outer is cement with 20 cm

thickness, the intermediate is insulation of 8 cm thickness and the inner plaster of

1.5 cm thickness with a U-value equal to 0.439 W/m2 K. The outer wall is a five

layer wall with the following materials: 1.5 cm plaster, 12 cm brick, 6 cm insula-

tion, 12 cm brick and 1.5 cm plaster with a U-value equal to 0.510 W/m2 K.

356 E. Bellos et al.

The ground contains the heating pipes inside the concrete layer and also has

insulation layer of 8 cm with U-Value about 0.314 W/m2 K.

For thermal comfort conditions, the daily temperature should be greater than

22 �C which means that a control system is used to determine the operation of the heating system. The minimum theoretical heating energy to cover this thermal

comfort condition is about 5020 kWh which was calculated by TRNSYS.

Active Layer (Underfloor Heating System)

The underfloor heating system is inserted in the ground of the building as an active

layer which exchanges data with other system components. The hot water flows

inside the tubes giving heating in the house and let the house with a lower

temperature. There is a thermostat which controls when there is heating need.

Figure 28.1 shows the TRNSYS environment which related with the underfloor

heating.

In this window the parameters of the active layer are determined in order to take

data for the hot water temperature and mass flow rate. Also, the minimum desired

inlet mass flow rate is given which is a very important parameter. This parameter

determines the segmentation of the area for the underfloor system. In this figure, the

specific mass flow rate of 3 kg/h m2 separates the area in four segments as it is

shown in Fig. 28.2. By changing this parameter, the area segmentation changes in

order to improve the system operation.

Table 28.3 gives the main parameters for the tubes of the heating system.

These values are the default TRNSYS values and are realistic according the

bibliography for building cases.

Table 28.1 Building parameters

Parameter Value Parameter Value

City Athens Specific gains 14 W/m2 K

Area 100 m2 Occupants density 0.1 person/m2

Height 3 m Specific light 10 W/m2

East glass 3 m2 Infiltration rate 1 change per hour

West glass 3 m2 Thermal capacitance 720 kJ/K

South glass 6 m2 hout 17.8 W/m 2 K

Shading coefficient 70% hin 3.1 W/m 2 K

Table 28.2 Properties of structural materials

Material k (W/m K) Cp (kJ/kg K) ρ (kg/m3) Brick 0.89 1.0 1800

Plaster 1.39 1.0 2000

Insulation 0.04 0.8 40

Concrete 7.10 0.8 2400

28 Modelling of a Solar Assisted Floor Heating System with TRNSYS 357

Fig. 28.1 TRNSYS active layer environment

Fig. 28.2 Floor segmentation with four different loops. The red line shows the hot water inlet flow and the blue line the return flow (Color figure online)

358 E. Bellos et al.

Mathematical Equations

The basic equations which describe the analyzed case are presented and explained

in this section. These equations are related with the solar collectors, the system

energy balance, the auxiliary heater and the building.

Building

The thermal resistance of the structural components is given from the next

equation:

R ¼ XN j¼1

� � j

þ 1 hin

þ 1 hout

ð28:1Þ

U ¼ 1 R

ð28:2Þ

where N is the number of layers of every structural component.

The heating load of the house is approximately given from the next equation

(28.3):

Qheating ¼ ms � Cp � T Bin � T Bout � � ð28:3Þ

where Cp is the specific heat capacity of water which was taken 4.19 kJ/kg K.

Flat Plate Collectors

The following equations are the basic equations for the useful collector energy and

for the collector efficiency.

Qu ¼ _mc � Cp � Tf ,o � Tf , i � � ð28:4Þ

Table 28.3 Properties of piping

Parameter Value

Pipe wall conductivity 0.35 W/m K

Pipe spacing 0.2 m

Pipe outside diameter 2 cm

Pipe wall thickness 2 mm

Liquid specific thermal capacity 4.19 kJ/kg K

28 Modelling of a Solar Assisted Floor Heating System with TRNSYS 359

η ¼ Qu Ac � GT ð28:5Þ

η ¼ FR ταð Þ � FRUL � Tf , i � Tamb GT

� � ð28:6Þ

Storage Tank

A simple energy balance in the storage tank is given below:

Qsource ¼ Qload þ Qloss ð28:7Þ

where source is the collectors, load the heat to the building and loss the radiant

losses to the environment.

Auxiliary Heater

The auxiliary heater operation is described from Eqs. (28.8) and (28.9):

QA:H: � QA:H:,max ð28:8Þ QA:H: ¼ min QA:H:,max,ms � Cp � Tset � Tlð Þ

� � ð28:9Þ

Other System Parameters

The next equation is a simple energy balance in the total system

Qu þ QA:H: � Qloss � Qheating ð28:10Þ

The following equation gives the solar cover of the system for heating need:

f ¼ 1� QA:H: Qheating

ð28:11Þ

The last equation shows the temperature set value in the mixer and in the

auxiliary heater. This is a function of the ambient temperature and gives acceptable

results. It was able to use a constant value of 40–45 �C, but this relation leads the system to use warmer water in the colder days which covers better the heating

loads.

Tset ¼ 50� Tamb 2

ð28:12Þ

360 E. Bellos et al.

System Description

The total system is simulated with TRNSYS which is able to make a dynamic

simulation. The months from November to April are simulated because in these

months there is heating need according the simulation results. The heating is given

from the solar collectors and from an auxiliary heater and the goal is to maximize

the solar cover in order reduce the operation cost of this system. Figure 28.3 shows

the analyzed system.

The red line shows the hot water which flows in the flat plate collectors and is

stored in the tank, while the blue line shows the water stream which flows in the

underfloor heating system. More specifically, the water leaves the storage tank and

goes to auxiliary heater. After the heater this flow goes into the house and when it

leaves the house piping it returns to the storage tank. In the case that the temperature

of the water which goes to the house is great, this is mixed with the return of the

house in order to reduce the inlet temperature and to protect the piping from

destroying. It is important to say that there are different thermostats which control

the system and the heater operation in order to reduce the heater energy usage.

Controller 1

Controller 2 Heater

Mixer

Tempering Valve

Pump-2 Storage Tank

Collectors

Pump Building

Fig. 28.3 Basic components of the analyzed system

28 Modelling of a Solar Assisted Floor Heating System with TRNSYS 361

In this system is important to determine the optimum values for critical param-

eters in order minimize the auxiliary heater energy for the winter period. The

collecting area, the storage tank volume, the maximum heater power, the controller

strategy and the area segmentation are the parameters that are examined in this

study.

Table 28.4 gives the values of the system parameters. In the case that one

parameter is analyzed for different values, these are also given:

Results

In this paragraph the results of the simulation of the system are presented. The

diagrams show the system performance for different values of important parame-

ters. By evaluating these data is able to determine the optimum system which leads

to a feasible situation. The goal of the optimization is to minimize the auxiliary

heater energy by using a realistic collecting area. It is important to state that the

storage tank volume influences on the results, so in every case the suitable table is

used in order to have an optimal system.

Area Segmentation and Heater Control Strategy

First of all, is important to determine the way that the underfloor system should be

separated in parts in order to heat the building efficiently. So, the floor area is either

separated in four segments, in two segments and in one segment and the three cases

are compared. Simultaneously, the control of the thermostat temperature is ana-

lyzed; because of this is a crucial parameter for the heater energy. By reducing this

temperature, the heater energy is dramatically diminished. It is important to state

that the heater power is selected to be at 6 kW, which is close to maximum heating

load of the building (Figs. 28.4, 28.5, and 28.6).

From the above diagrams, it is obvious that the thermostat temperature of heater

is very important parameter. By using 21 �C as the critical temperature, the energy is low and the thermal comfort conditions are in preferable limits (Fig. 28.7). If the

Table 28.4 System parameters

Collector Parameters Value Other Parameters Value

FR(τα) 0.8 Heating system water flow rate 1500 kg/h FRUL 3.61 Maximum system temperature 98

�C Slope angle 45� Tank losses coefficient 0.7 W/m2 K Azimuth 0� Tank volume 1.5–6 m3

Operation hours 9:00–17:00 Heater thermostat temperature 20–22 �C Collector water mass flow rate 2000 kg/h Heater power 0–12 kW

362 E. Bellos et al.

thermostat was set at 22 �C, which is also the set temperature for the underfloor heating system, then the energy is about four times greater which leads to a high

energy consumption and is not sustainable.

It is obvious that the temperature is over 22 �C for the greater part of the winter and only a few times is lower than this limit. The next diagram (Fig. 28.8) compares

the three heating systems.

It is obvious that the segmentation of four parts gives the better results because

the heat transfer from the piping to the indoor air becomes easily. In the following

analysis, this case is selected as the optimum, but also the case of the two segments

gives similar results. Finally it is important to stat that with only one loop the

auxiliary energy is about five times greater which to an unaffordable solution.

The optimum collecting area is 30 m2 according the Fig. 28.7. More specifically,

a greater collecting area means lower heater energy, but after the 30 m2, the

0 0

1000

2000

3000

4000

5000

6000

7000

8000

9000

20 40 60 Ac(m2)

E au

x( kW

h )

80 100

Tq=20

Tq=20,5

Tq=21

Tq=21,5

Tq=22

Fig. 28.4 Heater energy for one underfloor loop (area segmentation¼ 1 part)

500

1000

1500

2000

2500

3000

3500

4000

4500

E au

x( kW

h )

0 20 40 60

Ac(m2)

80 100

Tq=20

Tq=20,5

Tq=21

Tq=21,5

Tq=22

Fig. 28.5 Heater energy for two underfloor loops (area segmentation¼ 2 parts)

28 Modelling of a Solar Assisted Floor Heating System with TRNSYS 363

reduction in the heating energy is very low. Table 28.5 gives the optimum tank

volume for every collecting area and the heater energy consumption for every case.

Heater Power Analyses

In this section a parametric analysis is presented in order to predict the value of the

auxiliary heater power. Figure 28.9 shows how the mean value and the minimum

value of the indoor temperature changes with different values of heater power.

Tq=20

Tq=20,5

Tq=21

Tq=21,5

Tq=22

500

1000

1500

2000

2500

3000

3500

4000

4500 E

au x(

kW h

)

0 20 40 60

Ac(m2)

80 100

Fig. 28.6 Heater energy for four underfloor loops (area segmentation¼ 4 parts)

30.00

27.00

24.00

T em

p er

at u

re s

[d eg

C ]

21.00

18.00

15.00

30.00

27.60

25.20

22.80

20.40

Simulation Time-11640.00[hr]

18.00

7. 30

+ 03∋

8. 02

+ 03∋

8. 38

+ 03∋

8. 74

+ 03∋

9. 11

+ 03∋

9. 47

+ 03∋

9. 83

+ 03∋

1. 01

+ 04∋

1. 05

+ 04∋

1. 09

+ 04∋

1. 12

+ 04∋

1. 16

+ 04∋

7. 66

+ 03∋

Fig. 28.7 Distribution of the indoor temperature for all over the winter period, from November to April. The thermostat set temperature of the heater is 21 �C and the floor heating system is consisted of four segments

364 E. Bellos et al.

1seg

2seg

4seg

1000

2000

3000

4000

5000

6000

E au

x( kW

h )

0 20 40 60

Ac(m2)

80 100

Fig. 28.8 Comparison of the three heating system with 1 (blue), 2 (red) and 4 (green) area segmentation (Color figure online)

Table 28.5 Results of the 4 segmentation heating

system

Ac (m 2) V (m3) 1seg 2seg 4seg f (%) for 4seg

10 1.50 5706 2569 1940 61.35

20 2.00 4159 1171 871 82.65

30 2.50 3190 689 533 89.38

40 2.50 2347 557 404 91.95

50 2.75 1886 410 314 93.75

60 4.00 1879 261 204 95.94

70 5.00 1882 217 182 96.37

80 6.00 1906 193 164 96.73

Tm Tmin

0 2 4 86 Qaux (kW)

10 12

T (°

C )

Fig. 28.9 Mean (blue line) and minimum (red line) indoor temperature for different values of heater power

28 Modelling of a Solar Assisted Floor Heating System with TRNSYS 365

From this diagram it is obvious that the mean temperature is not changes a lot for

different heating power, but the minimum temperature is influenced a lot. More

specifically, a heater of 6 or 9 kW is suitable by giving the desired indoor

conditions.

Figure 28.10 presents the operation time of the heating system and of the heater.

These times are different, because the auxiliary heater operates when there is great

need for heating.

The Solar Stand-Alone Underfloor Heating System

In this section the case that the solar collectors give all the energy to the heating

system is analyzed. It is very important to determine if this case is feasible because

the energy consumption from electricity or fuel is zero (Fig. 28.11).

heating

auxilliary

0 2 4 86

Qaux (kW)

10 12

H o

u rs

1200

1000

800

600

400

200

Fig. 28.10 Operation time of the heating system (blue line) and of the auxiliary heater (red line) (Color figure online)

Tmin

T (°

C )

13 0 20 40 8060

Ac(m2)

100

Fig. 28.11 Mean (blue line) and minimum (red line) indoor temperature for different values of collecting area in the case without heater (Color figure online)

366 E. Bellos et al.

In order to have an acceptable minimum temperature, 50 m2 of flat plate

collectors should be used. In this case the minimum temperature of the winter

period is about 18.70 �C. The mean temperature is not influenced a lot after the 20 m2 fact that shows a low collecting area is able to cover a great part of the

heating load.

Conclusions

The main conclusions of this study are the following:

• It is able to heat a building efficiently with an underfloor heating system. By

using 30 m2 flat plate selective collectors is able to cover the 90% of the heating

load. The optimum volume of the storage tank in this case is about 2.5 m3.

• A for segmentation of the building area gives better results than the other cases.

Especially, in the case of one underfloor loop, the energy consumption is five

times greater than the four loops case.

• By using two thermostats, one for heating system and one for auxiliary heater, is

able the reduction of the energy consumption. More specifically the heating

system thermostat is set to 22 �C and the heater to 21 �C which lead to a great indoor temperature profile and to a 75% auxiliary heating energy reduction.

Simultaneously, the operations hours of the heater are about the 10% of the total

operation hours of the underfloor heating system. This shows that the heater

operates in moments with high heating need.

• The optimum value for the auxiliary heater power is 6 kW, which is close to the

maximum heating load of the building. This means that the heater should be able

to cover the total building loads in the moments which solar energy is

unsufficient.

• An underfloor heating system is able to operate without auxiliary energy by

using more collecting area. More specifically, 50 m2 are able to keep the thermal

comfort condition in high levels inside the house. This leads to zero consumption

which is a feasible solution for new buildings.

• The ratio of collecting are to building area is about 1–3 for the case with heater

and 1–2 for the case with only solar collectors. For the heater case, other studies

(Zhai et al. 2009) give similar results which validate this analysis.

Nomenclature

Ac Collecting area, m 2

Cp Specific heat capacity, J/kg K

E Energy, kWh

f Solar cover

FR Heat removal factor

28 Modelling of a Solar Assisted Floor Heating System with TRNSYS 367

GT Solar titled radiation, W/m 2

h Heat transfer coefficient, W/m2 K

k Thermal conduction, W/m K

L Layer length, m

m Mass flow rate, kg/s

Q Heat flux, W

R Thermal resistance, mK/W

T Temperature, �C U Thermal transmittance, W/m2 K

UL Collector losses coefficient, W/m 2 K

V Storage tank volume, m3

Greek Letters

η Collector efficiency ρ Density, kg/m3

(τα) Transmittance–absorptance product

Subscripts

A.H. Auxiliary heater

amb Ambient

aux Auxiliary

c Collector

f,i Fluid inlet

f,o Fluid outlet

in Indoor

l Load

min Minimum

max Maximum

out Outdoor

q Heater thermostat

s Heating system

u Useful

Superscripts

B Building

References

Alajmi, A., & El-Amer, W. (2010). Saving energy by using underfloor-air-distribution (UFAD)

system in commercial buildings. Energy Conversion and Management, 51, 1637–1642. Al-Khalayleh, M. T., et al. (1999). Modelling and simulation of solar-pond floor heating system.

Renewable Energy, 18, 1–14.

368 E. Bellos et al.

Asimakopoulos, D. A., Santamouris, M., Farrou, I., Laskari, M., Saliari, M., Zanis, G.,

Giannakidis, G., Tigas, K., Kapsomenakis, J., Douvis, C., Zerefos, S.C., Antonakaki, T.,

Giannakopoulos, C. (2012). Modelling the energy demand projection of the building sector

in Greece in the 21st century. Energy and Buildings, 49(June), 488–498. Athienitis, A. K. (1994). Numerical model of floor heating system. ASHRAE Transactions, 100,

1024–1030.

Badran, A. A., & Hamdan, M. A. (2004). Comparative study for under-floor heating using solar

collectors or solar ponds. Applied Energy, 77, 107–117. David, J. (1984). Under floor air conditioning. Journal of the Charted Institution of Building

Services, 6, 29–34. European Environment Agency. (2010). Consumption and the environment—state and outlook.

Fantidis, J. G., Bandekas, D. V., Potolias, C., & Vordos, N. (2013). Cost of PV electricity—Case

study of Greece. Solar Energy, 91, 120–130. Gao, R., Li, A., Zhang, O., & Zhang, H. (2011). Comparison of indoor air temperatures of different

under-floor heating pipe layouts. Energy Conversion and Management, 52, 1295–1304. Ghali, K. (2007). Economic viability of underfloor heating system: A case study in Beirut climate.

In International conference on renewable energies & power quality, Sevilla, Spain. Hasan, A., Kurnitski, J., & Jokiranta, K. (2009). A combined low temperature water heating

system consisting of radiators and floor heating. Energy and Buildings, 41, 470–479. Inard, C., Meslem, A., & Depecker, P. (1998). Energy consumption and thermal comfort in

dwelling-cells: A zonal-model approach. Building and Environment, 33(5), 279–291. Kilkis, B. I., Sager, S. S., & Uludag, M. (1994). A simplified model for radiant heating and cooling

panels. Simulation Practice and Theory, 2, 61–76. Kouremenos, D. A., Antonopoulos, K. A., & Domazakis, E. S. (1985). Solar radiation correlations

for the Athens, Greece, area. Solar Energy, 35(3), 259–269. Myhren, J. A., & Holmberg, S. (2008). Flow patterns and thermal comfort in a room with panel,

floor and wall heating. Energy and Buildings, 40, 524–536. Sekhar, S. C., & Ching, C. S. (2002). Indoor air quality and thermal comfort studies of an under-

floor air-conditioning system in the tropics. Energy and Buildings, 34, 421–444. Sodec, F., & Craig, R. (1990). The underfloor air supply system—The European experience.

ASHRAE Transactions, 96(2), 690–695. Theodoridou, I., Papadopoulos, A. M., & Hegger, M. (2011). A typological classification of the

Greek residential building stock. Energy and Buildings, 43, 2779–2787. Zhai, X. Q., Yang, J. R., &Wang, R. Z. (2009). Design and performance of the solar-powered floor

heating system in a green building. Renewable Energy, 34, 1700–1708.

28 Modelling of a Solar Assisted Floor Heating System with TRNSYS 369

Part VII

Energy Technologies and Their Effect on Global Warming

Bioenergy–Biofuel Technologies

Novel biofuels

Chapter 29

Biogas Production from Napier Grass at Various Cutting Intervals

Nusara Sinbuathong, Yuwadee Sangsil, and Suriya Sawanon

Introduction

Anaerobic digestion can be applied to convert biodegradable wastes such as plant

biomass, energy crops and grass to produce biogas (Seppala et al. 2009). Napier

grass (Pennisetum purpureum) is known as elephant grass and is a perennial grass with high biomass. Normally it is used for cattle feeds and is cultivated as forage.

The grass has the advantage of being familiar to farmers and suitable for harvesting

and storing with existing methods and machinery. It grows fast and is highly

adaptive, hence is suitable to be grown on marginal lands. Climate, soil fertility,

cutting interval, variety and management practices may affect on chemical com-

position and digestibility of Napier grass. It is interesting to digest the grass in order

to produce biogas. However, grass is not a mature feedstock for anaerobic digestion

facilities due to its complex structure; lignin and cellulose are resistant to hydrolysis

reaction and microbial actions (Nizami et al. 2009). Previous studies about biolog-

ical pretreatment were mainly focused on use of pure cultures, such as anaerobic

bacteria, fungi, and actinomycetes, which were able to degrade lignocellulose

(Desvaux et al. 2000; Xu and Goodell 2001). However, pure cultures of

N. Sinbuathong (*) Scientific Equipment and Research Division, Kasetsart University Research and Development

Institute (KURDI), Kasetsart University, Bangkok 10900, Thailand

e-mail: [email protected]

Y. Sangsil

Department of Environmental Engineering, Faculty of Engineering, Kasetsart University,

Bangkok 10900, Thailand

e-mail: [email protected]

S. Sawanon

Department of Animal Science, Faculty of Agriculture at Kamphaeng Saen, Kasetsart

University, Kamphaeng Saen Campus, Nakhon Pathom 73140, Thailand

e-mail: [email protected]

375

mailto:[email protected]

microorganisms are difficult to maintain in an open system, and often require long

pretreatment time. In fact, it has been approved that the complete decomposition of

lignocellulose requires the combined actions of various microorganisms (Slater and

Lovatt 1984). Several studies have demonstrated the efficiency of constructed

microbial consortia for the rapid degradation of lignocellulose (Haruta

et al. 2002; Wongwilaiwalin et al. 2010)

Cows rely on rumen microorganisms to convert feed components into useable

source of energy and protein. Rumen microorganisms ferment carbohydrates to

make volatiles fatty acids and grasses. The rate of digestion of feeds depends on the

quality and composition of feed. It is affected by the number and type of microor-

ganism, pH in the rumen and nutrients. These factors limit the growth of the

microorganisms.

Hence, two phase anaerobic digestion with mixed microorganisms may enhance

the efficiency of digestion. In this study, a lab scale, two-stage anaerobic digestion

system was used for digesting Napier grass for biogas production. In the first stage,

the acidogenic condition provides acidic surroundings to digest the recalcitrant

structure and enhances digestibility. The aim of the current study is to digest Napier

grass of different cutting intervals by using mixed ruminal microorganisms from

cow rumen in semi-continuous two-stage reactor in order to minimize inhibition of

the hydrolysis phase by low pH and accumulation of inhibitors. The test was

performed under optimum hydraulic retention time (HRT). Annual CH4 yield per

hectare obtained from Napier grass at various cutting interval was investigated.

Materials and Method

Two-Stage Anaerobic Operation

Two separate bioreactors were designed specifically for the acidogenic and

methanogenic anaerobic digestion. Four set of bioreactors was constructed with a

PET plastic reactors with a working volume of 4 L and 5 L for acidogenic and

methanogenic stage respectively (Fig. 29.1). The reactor was connected to a gas

collection system, which was based on water displacement by the exiting gases

(Fig. 29.1).

Fresh Napier grass (Pakchong 1) of approximately 30 kg. was cut at various

cutting intervals (30, 45, 60 and 90 days) and then bagged and stored in a cold room.

The grass was chopped to a size of 1 cm and ground to a size of approximately

2 mm. The stems and leaves were blended thoroughly into a harmonious whole.

The ground Napier grass was stored in a refrigerator at 4 �C before use. Without pretreatment and supplement with nutrient addition, the grass was prepared with tap

376 N. Sinbuathong et al.

water at a ratio of 1:5 by weight to create a slurry. Napier grass was used as a sole

carbon source. Four systems were developed by varying the cutting intervals of the

Napier grass in the acidogenic and methanogenic reactors. A slurry of grass at

various cutting intervals at a 1:5 grass-water ratio was added to the acidogenic

reactor at a rate of 0.5 L/day for 8 days. This acidogenic reactor was operated for

2 days in batch mode before feeding once daily with the slurry semicontinuously in

an upflow mode at a feed rate of 200 mL/day in each set of reactors, giving rise to

HRT of 20 days for acidogenic and 25 days for methanogenic reactor stage. Mixed

ruminal microorganisms of approximately 10 g mixed liquor volatile suspended

solid/L were used as inoculum. The reactors were operated at ambient temperature

of 30þ 1 �C. pH was adjusted to be 7.5 for all methanogenic reactors at the start-up period. The reactors functioned without pH control during an operation period. In

this study, two-stage anaerobic digestion of Napier grass was investigated by

controlling the HRT of the two digesters. The start-up and operating period were

approximately 55 days. The study was carried out using steady-state conditions.

Slurry in

Water out

Water in

Slurry out

Gas in 3

Gas sampling point

Fig. 29.1 Two-stage anaerobic reactor with gas collection system

29 Biogas Production from Napier Grass at Various Cutting Intervals 377

Analysis of Materials

Napier grass (Pakchong 1) used in the test was cultivated in well fertilized field at

Khamphaeng Saen, Nakorn Pathom Province, Thailand. The grass at various

cutting intervals was measured for height and analysed for major (N, P, K) and

minor elements (K, Ca, Mg, Cu, Fe). These elements are nutrients in the digestion.

Nitrogen (N) was determined by the Kjeldahl methods by digesting samples to

convert organic N to NH4 þ-N and determining NH4

þ-N in the digest. Total phos- phorous (P) was determined by digesting samples with sulphuric acid and analysed

by the Vanadomolybdophosphoric Acid Colourimetric method. Methane (CH4)

was determined by employing a gas chromatograph (Model GC 14B, Shimadzu,

Japan) equipped with a thermal conductivity detector (TCD) and a molecular sieve

13X column. The temperatures of the injector, column and TCD detector were

60, 40 and 70 �C, respectively. Argon was used as the carrier gas. The slurry fed to reactors and the digested slurry from the methanogenic reactor were analysed for

Chemical Oxygen Demand (COD), Total Volatile Solids (TVS), Total Solids

(TS) and pH according to the procedures of the Standard Methods (APHA and

AWWA 2005). Organic degradation efficiency (in terms of COD and TVS) and

CH4 production from the system obtained from the Napier grass at various cutting

intervals were used as indicators of reactor performance. All experiments were

conducted in duplicate and the results are calculated using the mean of the exper-

imental values.

Results

The grass yield from the field is as shown in Fig. 29.2. A slurry of Napier grass at a

1:5 grass-water ratio was analysed for COD, TS, TVS also for the major and minor

biological nutrients (Table 29.1). The composition and quantity of Napier grass

varied on the cutting intervals (Table 29.1), thus impacts on the biogas production.

During sample preparation, it was noticeable that the higher age grass (higher

cutting interval) had more stems and had fewer leaves than the lower age. Thus, the

proportion of leaf to stem of the higher age grass was less comparing with that of the

lower age grass. Crowder and Chheda (1995) had also reported this. Napier grass is

easy in propagation and management, thus it has high yield. The data from field

found that when the cutting interval increased, the grass yield increased (Fig. 29.2).

The grass yield obtained from the Napier grass at the cutting interval of 45, 60 and

90 days was double, quadruple and penta times of that from 30 days (Fig. 29.2).

On the other hand, at higher cutting intervals, the major and minor elements by dry

weight decreased (Table 29.1). This is in accordance with the data reported by

Crowder and Chheda 1995. Nutrients are crucial that limit microbial growth in

anaerobic digestion. If the nutrients are in short supply, microbial growth is

retarded, and so is the digestibility of feed (Moran 2005).

378 N. Sinbuathong et al.

The grass was fairly high in organic substrate (Table 29.2) and therefore had

good potential for biogas generation. The COD content in the slurry of Napier grass

(Napier grass:water¼ 1:5) at the cutting intervals of 30, 45, 60 and 90 days was 19.32, 24.00, 27.32 and 30.87 g/L and TKN of the grass was 661, 343, 300, 251 mg/

L as N respectively; thus, the C:N ratio was 100:3.42, 100:1.43, 100:1.10 and

100:0.81 respectively. Microorganisms that decompose organic matter use carbon

as a source of energy and nitrogen for building cell structure. The recommended

COD:N of organic substrate is 100:2.5 in order to assimilate the microorganisms in

Fig. 29.2 Annual Napier grass yield at various

cutting intervals

Table 29.1 Characteristics of the slurry of Napier grass (Napier grass:water¼ 1:5) fed to reactors at various cutting intervals

Parameters Napier grass at various cutting interval (days)

30 45 60 90

Chemical oxygen

demand (COD, g/L)

19.32 24.00 27.32 30.87

Total solids (TS, g/L) 17.73 24.00 26.94 32.30

Total volatile solids

(TVS, g/L)

14.43 18.42 20.88 29.18

pH 5.86 7.22 6.92 6.17

Nitrogen (TKN, mg/L as

661 343 300 251

Phosphorus (PO4 3�,

mg/L as P)

2.74 1.84 2.14 3.11

Calcium (Ca, mg/L) 50.19 32.45 24.11 35.87

Copper (Cu, mg/L) 0.15 0.07 0.07 0.02

Iron (Fe, mg/L) 14.47 2.55 2.99 4.51

Potassium (K, mg/L) 1334 864 972 1017

Magnesium (Mg, mg/L) 34.79 19.79 39.50 35.47

COD:N 100:3.42 100:1.43 100:1.10 100:0.81

COD:N:P 100:3.42:0.014 100:1.43:0.008 100:1.10:0.008 100:0.81:0.010

29 Biogas Production from Napier Grass at Various Cutting Intervals 379

anaerobic digestion (Anderson et al. 2003). If the COD:N ratio is too high,

decomposition slows because the nitrogen is used up and some microorganisms

die. On the other hand, if the COD:N ratio is too low, microorganisms make full use

of the available carbon and get rid of the excess nitrogen as ammonia. Ammonia

caused toxic to microorganisms in the system (Hartmann and Ahring 2006). In this

study, the ratio of COD:N:P was 100:3.42:0.014, 100:1.43:0.008, 100:1.10:0.008,

100:0.810:010. These caused differences in the amount of carbon source and

nutrients fed to reactors.

Table 29.2 Summary of two-stage anaerobic digestion of the Napier grass as a sole carbon source at various cutting intervals

Parameters

Napier grass at various cutting

intervals (days)

30 45 60 90

Reactor volume for each acidogenic, methanogenic reactor

(L)

4, 5 4, 5 4, 5 4, 5

Daily feed (mL/day) 200 200 200 200

HRT for each acidogenic, methanogenic reactor (day) 20,

20,

Initial MLVSS (g/L) 10.0 10.0 10.0 10.0

Initial pH of substrate solution 5.86 7.22 6.92 6.17

Initial COD (g/L) 19.32 24.00 27.32 30.87

Initial TS (g/L) 17.73 24.00 26.94 32.30

Initial TVS (g/L) 14.43 18.42 20.88 29.18

OLR (kgCOD/m3.day) 0.97 1.20 1.37 1.54

OLR (kgTVS/m3.day) 0.72 0.92 1.04 1.46

CH4 produced at steady state

(mL at STP/day)

568 610 561 480

Average CH4 (%) 41.34 43.51 42.99 39.43

COD at steady state (g/L) 5.32 6.04 6.60 7.69

COD degradation efficiency (%) 72.46 74.82 75.84 75.88

TVS at steady state (g/L) 5.21 6.09 6.62 7.50

TVS degradation efficiency (%) 63.88 66.94 68.30 74.30

CH4 yield (L at STP/kgCOD added) 147 127 103 78

CH4 yield (L at STP/kgTS added) 160 127 104 74

CH4 yield (L at STP/kgTVS added) 197 166 134 82

Napier grass (DW) for pure CH4 1 m 3 (kg) 6.25 7.87 9.62 13.51

CH4 yield per area (m 3/ha/year) 2700 4763 6500 6013

Average pH of acidogenic reactor at steady state 5.20 5.24 5.35 5.35

Average pH of methanogenic reactor at steady state 7.25 7.20 7.18 7.10

380 N. Sinbuathong et al.

Biogas Production

At steady-state conditions, total biogas production and the performance of digestion

were reported. In this study, the results are reported for 25–55 days of digestion

period. The amount of CH4 production from the reactors are shown in Fig. 29.3 and

the average CH4 content are shown in Table 29.2.

Differences in the amount of CH4 production (Fig. 29.3) by the Napier grass of

each cutting interval were observed. At steady-state condition, the average daily

CH4 produced from the Napier grass at the cutting interval of 45 days was 605 mL

at STP/day and that from the cutting interval of 30 and 60 days was comparable and

was recorded at 570 mL at STP/day while that from the cutting interval of 90 days

was 480 mL at STP/day (Fig. 29.3). However, the key parameter that makes more

sense to use to consider the appropriate cutting interval is the annual CH4 yield per

area of cultivation, which is calculated by using the CH4 gas produced and the

Napier grass added to reactors including the mass of the grass yield obtained from

field.

Organic Substrate Degradation

The initial COD, TS, TVS and other parameters of the slurry of Napier grass

(Napier grass: water¼ 1:5) are summarised in Table 29.2. The COD and TVS of the slurry of Napier grass at the higher cutting interval was higher than that of the

lower (Table 29.2). Ansah et al. (2010) also reported that the higher age grass had

higher stem and higher organic matter (OM), resulted in higher COD and TVS than

0 10

800

700

600

500

400

300

200

100

20 30

30 day 45 day 60 day 90 day

Time (days)

C H

, ( m

L a

t S

T P

/d ay

)

40 50 60

Fig. 29.3 Time course of CH4 production of Napier grass slurry at various cutting intervals

29 Biogas Production from Napier Grass at Various Cutting Intervals 381

that of the lower age grass. The steady-state COD and TVS obtained from the

various cutting intervals are as shown in Table 29.2. The COD and TVS removal

efficiency were over 70% and 60%, respectively for all reactors that contained a

slurry of Napier grass of all cutting intervals (Table 29.2).

CH4 Yield

CH4 yield is the amount of CH4 produced per kilogram of organic substrate added

to reactor. For CH4 production and based on the COD, TVS and TS added to

reactors at the steady-state conditions, CH4 yield obtained at various cutting

intervals are shown in Table 29.2, respectively. Differences in the CH4 yield by

the Napier grass of each cutting interval were obviously observed (Table 29.2). The

composition and quantity of Napier grass varied on the cutting intervals (Table 29.1)

impacts on the biogas production (Fig. 29.3). Hence, the CH4 yield was influenced

by the cutting interval of the grass and the grass yield. Napier grass at the cutting

interval of 30 days showed a maximum value of CH4 yield at 147 L at STP/kg of

COD added (197 L at STP/kg of TVS added or 160 L at STP/kg DW of Napier grass

added). CH4 yield obviously dropped when the cutting intervals increased

(Table 29.2). For Napier grass of higher cutting interval (Napier grass of

90 days), grass is composed of more stems and it is not a mature feedstock for

anaerobic digestion facilities due to its complex structure; lignin and cellulose are

resistant to hydrolysis and microbial actions.

The highest CH4 yield was observed from the Napier grass at the cutting interval

of 30 days. For the Napier grass of 30 days, the CH4 yield was 160 L at STP/kg of

dry Napier grass added to the reactor (Table 29.2), which indicated that 6.25 kg of

dry Napier grass is needed to produce 1 m3 of pure CH4. COD and TVS degradation

efficiency was 72% and 64%, respectively (Table 29.2). The average pH in the

acidogenic and methanogenic reactors was 5.20 and 7.25, respectively (Table 29.2).

For the Napier grass at the cutting intervals of 45, 60 and 90 days, the highest CH4 yield was observed at 127, 104 and 74 L at STP/kg of dry Napier grass added to the

reactor, respectively (Table 29.2). The higher the cutting interval, the lower the CH4 yield obtained. Although the higher age grass had more stems, however, the higher

age grass had the more fibre and lignin (lignocelluloses) which are nonbiode-

gradable organics. Hence, the higher age grass gave less CH4 yield during digestion

than the lower age grass.

382 N. Sinbuathong et al.

Annual CH4 Gas Produced per the Napier Grass Added to Reactors

For the digestion of Napier grass at the cutting intervals of 30, 45, 60, 90 day, the

CH4 yield was 160, 127, 104, 74 L at STP/kg of dry Napier grass added to the

reactor (Table 29.2), which indicated that 6.25, 7.87, 9.62, 13.51 kg of dry Napier

grass is needed to produce 1 m3 of pure CH4 (Fig. 29.4).

However, when considering the Napier grass yield from cultivation in the field

(the grass yield at the cutting intervals of 30, 45, 60 and 90 days was 16.88, 37.50,

62.50 and 81.25 tons dry weight/hectare/year as mentioned earlier), it was found

from calculation that the CH4 yield per area of cultivation which was obtained from

the Napier grass at the cutting interval of 30, 45, 60 and 90 was 2700, 4763, 6500

and 6013 m3/hectare/year (Fig. 29.5). The annually highest CH4 yield per area of

cultivation was obtained from the Napier grass at the cutting interval of 60 days

(Fig. 29.5).

The result of this study is in accordance with that reported by Ansah et al. (2010).

Ansah et al. (2010) reported that the lower age grass gives the higher CH4 yield than

the higher age grass due to its higher crude protein and fibre. From this study, even

though the Napier grass of the cutting interval of 30 days gave the highest CH4 yield

but it gave the lowest annual grass yield per area, resulting in least annual CH4 yield

per area.

Fig. 29.4 Napier grass at various cutting intervals to

produce 1 m3 of pure CH4

29 Biogas Production from Napier Grass at Various Cutting Intervals 383

Conclusions

Napier grass (Pakchong 1) at the cutting interval of 60 days gave the highest annual

CH4 yield per area of all various cutting intervals. By two-stage anaerobic digestion

using the Napier grass as the sole carbon source and mixed ruminal microorganisms

from cow as seed source, the CH4 yield obtained was 104 L at STP/kg of dry Napier

grass added to the reactor, which indicated that 9.62 kg of dry Napier grass is

needed to produce 1 m3 of pure CH4. The grass yield obtained from the field was

62.50 tons dry weight/hectare/year, resulting in the annual CH4 yield per area

obtained was 6500 m3/hectare/year.

Acknowledgement This research was supported by the Kasetsart University Research and Development Institute (KURDI), Kasetsart University, Bangkok, Thailand.

References

Anderson, G. K., Sallis, P. J., & Uyanik, S. (2003). Anaerobic treatment processes. In D. Mara &

N. J. Horan Jr. (Eds.), Handbook of water and wastewater microbiology (pp. 391–426). London: Academic.

Ansah, T., Osafo, E. L. K., & Hansen, H. H. (2010). Herbage yield and chemical composition of

four varieties of Napier (Pennisetum purpureum) grass harvested at three different days after planting. Agriculture and Biology Journal of North America, 1, 923–929.

APHA and AWWA (American Public Health Association and American Water Works Associa-

tion). (2005). Standard methods for the examination of water and wastewater (21st ed.). Washington, DC: APHA and AWWA.

Crowder, L. V., & Chheda, H. R. (1995). Tropical grassland husbandry (1st ed.). NJ: Wiley. Desvaux, M., Guedon, E., & Petitdemange, H. (2000). Cellulose catabolism by Clostridium

cellulolyticum growing in batch culture on defined medium. Applied and Environmental Microbiology, 66, 2461–2470.

Fig. 29.5 Annual CH4 produced per hectare from

Napier grass at various

cutting intervals

384 N. Sinbuathong et al.

Hartmann, H., & Ahring, B. K. (2006). Strategies for the anaerobic digestion of the organic

fraction of municipal solid waste: An overview. Water Science and Technology, 53, 7–22. Haruta, S., Cui, Z., Huang, Z., Li, M., Ishii, M., & Igarashi, Y. (2002). Construction of a stable

microbial community with high cellulose-degradation ability. Applied Microbiology and Biotechnology, 59, 529–534.

Moran, J. (2005). How the rumen work? Tropical dairy farming: Feeding Management for small dairy farmers in the humid tropics (pp. 41–49). Collingwood: Land Links Press.

Nizami, A. S., Korres, N. E., & Murphy, J. D. (2009). A review of the integrated process for the

production of grass biomethane. Environmental Science and Technology, 43, 8496–8508. Seppala, M., Paavolla, T., Lehtomaki, A., & Rintala, J. (2009). Biogas production from boreal

herbaceous grass-specific methane yield and methane yield per hectare. Bioresource Technol- ogy, 100, 2952–2958.

Slater, J. H., & Lovatt, D. (1984). Biodegradation and the significance of microbial communities.

In D. T. Gibson (Ed.),Microbial degradation of organic compounds (pp. 439–485). New York: Marcel Dekker.

Wongwilaiwalin, S., Rattanachomsri, U., Laothanachareon, T., Eurwilaichitr, L., Igarashi, Y., &

Champreda, V. (2010). Analysis of a thermophilic lignocelluloses degrading microbial con-

sortium and multi-species lignocellulolytic enzyme system. Enzyme and Microbial Technol- ogy, 47, 283–290.

Xu, G., & Goodell, B. (2001). Mechanisms of wood degradation by brown-rot fungi: chelator-

mediated cellulose degradation and binding of iron by cellulose. Journal of Biotechnology, 87, 43–57.

29 Biogas Production from Napier Grass at Various Cutting Intervals 385

Chapter 30

Sustainability Assessment of Fuels Production via Hydrotreating Waste Lipids and Co-processing Waste Lipids with Petroleum Fractions

Stella Bezergianni and Loukia P. Chrysikou

Introduction

Considering the depletion of fossil energy resources and the increased greenhouse

gas (GHG) emissions of the transportation sector, biofuels are being extensively

explored as renewable and sustainable energy sources (Demirbas 2009). The

transportation sector contributes around 15% to the global GHG emissions, while

according to the EU targets by 2020, 10% of fuels in the transportation sector

should be biofuels (Directive 2009/28/EC). In particular, biofuels are being pro-

moted as one of the most substantial substitutes of fossil fuels, accounting their

favorable environmental performance, especially if utilizing residual biomass as

feedstock (Gnansounou et al. 2009). FAME (Fatty Acid Methyl Esters) biodiesel

constitutes the most common biofuel mainly derived from energy crops, whereas

residual biomass can be utilized in minor percentages. For instance, waste cooking

oil (WCO) generated from frying and cooking with edible oils has been investigated

as feedstock for FAME biodiesel production through transesterification and ester-

ification processes. FAME biodiesel is used as a low-blend component in transport

fuels (up to 7% v/v) in Europe. However, FAME biodiesel cultivation processes

raised significant issues, such as food-versus fuel debate, land-use alteration ren-

dering the use of bio-based feedstocks imperative, aiming to address global

warming concerns, as well (Gnansounou et al. 2009). Catalytic hydroprocessing

is an alternative conversion process of lipid feedstocks (e.g. vegetable oils, animal

wastes/fats etc.) into bio-based diesel fuels and has been applied in industrial scale

for the production of hydrotreated vegetable oils (HVOs). More specifically, HVOs

S. Bezergianni (*) • L.P. Chrysikou Chemical Process & Energy Resources Institute (CPERI), Centre for Research & Technology

Hellas (CERTH), Thermi Thessaloniki, Greece

e-mail: [email protected]; [email protected]

387

mailto:[email protected]

are produced from vegetable oils and/or grease by Universal Oil Products (UOP)

(product’s trade name green diesel) (Kalnes et al. 2009) and from vegetable oils and/or animal fats by NesteOil Corporation (product’s trade name NExBTL- acronym for “Next Generation Bio-to-Liquid) (Arvidsson et al. 2011).

WCO has been extensively explored as potential feedstock for renewable diesel

production via catalytic hydrotreatment in CPERI/CERTH (Bezergianni

et al. 2010a, b, 2011). The renewable diesel is a high quality fuel based on its

remarkable properties (Bezergianni and Dimitriadis 2013a). Nevertheless, the high

capital cost investment of hydroprocessing units of vegetable oils and/or animal fats

supports the exploration of co-hydroprocessing petroleum fractions with oils uti-

lizing existing refining facilities, since catalytic hydroprocessing units are available

in all petroleum refineries. Recently, co-hydroprocessing of petroleum fractions

with WCO was also examined in CPERI/CERTH, resulting in the production of a

new hybrid diesel. In particular, catalytic hydroprocessing of a heavy petroleum

fraction (heavy atmospheric gas oil, HAGO) with WCO (at a ratio 95/5% v/v) was

investigated towards the production of a hybrid diesel of increased sustainability

(Bezergianni and Dimitriadis 2013b; Bezergianni et al. 2014a, b). This new hybrid

diesel was evaluated as a blending component of fossil diesel (Bezergianni

et al. 2014b). In this field Garraı́n et al. (2014) studied the production of a renewable

diesel fuel from co-processing soybean vegetable oil (at variant ratios from 9 up to

13.8% v/v/) with conventional fossil fuel.

However, the environmental performance of the production processes involving

the exploitation of existing petroleum refining processes to convert vegetable oils to

renewable bio-based diesel fuels, receives also noticeable attention, accounting the

global necessity to mitigate the climate change and to promote sustainable tech-

nologies (Garraı́n et al. 2014). Life Cycle Assessment (LCA) is a commonly

applied powerful method for the global warming impact assessment of conven-

tional fuels and biofuels. LCA quantifies the environmental impacts of conven-

tional fuels and biofuels throughout their life-cycle stages, proposing concurrently

possible ways to reduce them. A noticeable amount of LCA studies related to fuels

is available in the literature, in order to identify potential sustainable fuels that

could contribute to the transportation sectors’ GHG emissions reduction (Pleanjai et al. 2009; Arvidsson et al. 2011; Kochaphum et al. 2012; Bezergianni et al. 2014c;

Garraı́n et al. 2014). Based on the large number of publications analyzing the life-

cycle of fuels and biofuels significant controversies arise, even for the same biofuel

type and conversion technology, mainly due to variant methodological assump-

tions, inventory data etc. An accurate assessment of a new biofuel technology

requires a comprehensive fuel-cycle analysis, commonly called Well-To-Wheel

(WTW) analysis, involving both the Well-To-Tank analysis (WTT), as well as the

Tank-To-Wheel analysis (TTW). The WTT approach covers the fuel’s production

chain while the TTW the vehicle’s operation. The majority of the LCA studies

separate the analysis in the WTT and TTW counterparts, whilst the WTT is

particularly appropriate if the purpose of the study is concerned with the fuel’s

production process (Malça and Freire 2011).

388 S. Bezergianni and L.P. Chrysikou

The goal of this study is to assess the environmental profile of the renewable

diesel and the hybrid diesel produced via WCO hydrotreatment and

co-hydroprocessing of petroleum fractions with WCO, respectively. In addition,

the environmental impacts of the renewable diesel’s blend (up to 7% v/v) with

fossil diesel were also investigated. A secondary goal of this study is to compare the

environmental performance of all aforementioned fuels with fossil diesel

(containing 7% v/v FAME biodiesel) in order to address the most sustainable

process and to verify the advantages of utilizing WCO as feedstock and its

prospective integration in the refinery. Aiming to establish a reliable comparison

basis of the aforementioned fuels production processes, WTT analysis was

conducted addressing their GHG intensity.

Methodology

The scope of the LCA study is to investigate the environmental impacts of

bio-based fuels produced via hydrotreating WCO and co-processing WCO with

petroleum fractions, and to compare their production processes GHG emissions

with fossil diesel, as well. The experimental procedure followed for the WCO

catalytic hydrotreatment has been previously described in detail (Bezergianni and

Dimitriadis 2013a), utilizing a large pilot plant scale hydroprocessing unit of

CPERI/CERTH. Likewise, the production process of the new hybrid diesel has

been described in authors’ previous work (Bezergianni et al. 2014b), exploiting data collected from the Hellenic Petroleum refinery in Thessaloniki as reported in

authors’ previous work (Bezergianni et al. 2014b). The experiments were carried out in a small-scale hydroprocessing plant of CPERI/CERTH, while the unit is

described extensively by Bezergianni and Dimitriadis (2013a). Apart from the real

experimental data collected for the LCA study, results reported by JRC (2014) were

also employed for comparison purposes referring to the fossil diesel’s and FAME

biodiesel’s production processes GHG intensity.

The fuels production processes examined in the study are shown in Figs. 30.1,

30.2, 30.3 and 30.4 depicting the system boundaries encompassed for each of the

examined fuels. Particularly, Fig. 30.1 presents the production process of the

renewable diesel via WCO catalytic hydrotreatment, including WCO collection

and transportation to the hydrotreating unit and the hydrotreatment process as well.

The production of the new hybrid diesel from co-hydroprocessing HAGO and

WCO in the refinery under consideration is shown in Fig. 30.2, involving the crude

oil extraction and transportation to the refinery, the refining of the crude oil for the

production of petroleum fractions (HAGO and light atmospheric gas oil-LAGO),

the co-processing HAGO with WCO (95/5% v/v), the hydrotreatment of LAGO

and finally the blending with FAME for the production of the new hybrid diesel (the

precise blending ratios are reported below). Figure 30.3 presents the production

chain of fossil diesel, encompassing the stages of crude oil extraction and trans-

portation to the refinery and the refining process based on previous studies (JRC

30 Sustainability Assessment of Fuels Production via Hydrotreating Waste Lipids. . . 389

2014). The final stage of the production process involves its blending with FAME

biodiesel (~7% v/v) as previously mentioned in the introduction. The FAME

biodiesel production chain considered is shown in Fig. 30.4 containing the energy

crops cultivation and the oil extraction from them and finally the transesterification

process, taking into consideration the transport processes as well. More details for

FAME biodiesel production process can be found on a previous thorough study

(JRC 2014).

WCO collection & transportation Hydrotreatment

WCO pretreatment Renewable diesel

Fig. 30.1 Production chain of the renewable diesel via WCO catalytic hydrotreatment

Crude oil extraction & transportation

Refining

WCO collection & transportation

HAGO

LAGO

HAGO/WCO hydrotreatment

LAGO hydrotreatment

FAME production & transportation

New hybrid diesel

Fig. 30.2 Production chain of the new hybrid diesel via co-hydroprocessing HAGO with WCO

Crude oil extraction & transportation Refining

FAME production & transportation

Fossil diesel

Fig. 30.3 Production chain of the fossil diesel

Energy crops cultivation &

transportation

Oil extraction & transportation

Transes- terification

FAME biodiesel

Fig. 30.4 Production chain of the FAME biodiesel

390 S. Bezergianni and L.P. Chrysikou

The functional unit was 1 MJ of the renewable diesel and the hybrid diesel. The

inventory data sources employed for each of the investigated fuels were reproduced

based on this functional unit. The impact category assessed in this study is the

global warming potential (GWP) expressed in CO2 equivalents (CO2 eq-), since

GHG emissions and energy use are of high interest in bio-based fuels LCA studies.

The CO2 eq-outlines the total effect of GHG emissions including related emissions

of CO2, CH4 and N2O. Emissions contributing to acidification and eutrophication

are also often considered as impact categories, yet in the present study were not

accounted, since WCO does not impose these emissions.

Inventory Data

This section includes the inventory data of the fuels production processes previ-

ously described.

Renewable Diesel

Real experimental data were collected from the production of the renewable diesel

via WCO catalytic hydrotreatment while data were derived from current literature

as well. The assumptions and considerations for the environmental evaluation of the

renewable diesel’s production process are listed below:

• the impacts associated to the collection and transportation stages of WCO are

negligible in comparison to the impacts of the hydrotreatment process, account-

ing also the short distances within the city limits.

• main energy supply systems considered were the electric power consumption

from the grid and steam generation. The inventory data referring to the energy

requirements of the hydrotreatment process (electricity and steam) and the

associated GHG emissions were adapted from literature data, considering the

production of a HVO using vegetable oils and/or animal fats (Nikander 2008).

• the GHG emissions of the H2 consumption in the hydrotreatment process have

been estimated based on data retrieved from the literature (Nikander 2008),

produced via natural gas steam reforming.

• construction and demolition phases were eliminated from this study, due to

deficiency of related GHG emissions data.

Table 30.1 gathers the main inventory data (inputs and outputs) for the produc-

tion of renewable diesel from WCO catalytic hydrotreatment, based on experimen-

tal data computed by previously evaluations (Nikander 2008).

At this point it should be underlined that the renewable diesel could be possibly

employed as a blending component to fossil diesel up to ~7% v/v, as HVOs.

Therefore the environmental profile of this blend was also addressed in order to

30 Sustainability Assessment of Fuels Production via Hydrotreating Waste Lipids. . . 391

determine the most sustainable fuel in terms of GHG intensity and the results are

presented below. Data for the GHG emissions of fossil diesel production process

were obtained from literature sources in view of a European context (JRC 2014).

Hybrid Diesel

The key inventory data for the new hybrid fuel production process for the quanti-

fication of the GHG emissions (e.g information on crude oil origin, typical catalytic

hydrotreatment operation conditions, electric power consumption, fuels used for

heat production, main input and output flows used during the production etc.) were

collected from the refinery of the Hellenic Petroleum in Thessaloniki. Secondary

data were taken from assessments previously undertaken (Nikander 2008;

Cetinkaya et al. 2012). For assessing the GHG emissions of the new hybrid diesel

profile GEMIS (Global Emission Model for Integrated Systems, Version 4.9) was

used. GEMIS is a life-cycle analysis program and database for energy, material, and

transport systems providing information for fuels, processes for electricity and

heat etc.

The primary considerations and assumptions of the LCA study are the following:

• the impacts associated with the collection and transportation of WCO to the

refinery were considered negligible, accounting short distances (within city

limits).

• the petroleum refineries are extremely complicated plants with combined and

sequenced processes and as a result the refinery process of the crude oil is often

handled as a “black box” and not partitioned into sub-processes. In this study, the

refining stage is also depicted as a “black box” and the energy consumption and

GHG emissions were allocated according to the final products distribution.

Figure 30.5 illustrates a generic flow diagram of the refinery studied. Briefly,

after crude’s oil refining process the treated petroleum fractions, HAGO and LAGO are further treated to hydrotreating units. In the HAGO hydrotreating

unit, HAGO with WCO (95/5% v/v ratio) are co-hydroprocessed for the pro-

duction of a new hydrotreated hybrid fuel. Then this fuel is mixed with

hydrotreated LAGO and with FAME biodiesel for the production of the new

Table 30.1 Inventory data for the production of

renewable diesel via WCO

catalytic hydrotreatment

Unit Input Output

WCO g/MJ 23 –

H2 g/MJ 1.268

Renewable diesel g/MJ – 20.41

Gas producta g/MJ – 1.587

Total liquid product g/MJ – 3.648

Energy MJ/MJ 0.002 –

Steam MJ/MJ 0.014 – aIncluding excess H2

392 S. Bezergianni and L.P. Chrysikou

hybrid diesel, based on the blending strategy of the refinery of the Hellenic

Petroleum in Thessaloniki. A detailed analysis of the blending followed is

presented in Fig. 30.6.

• data regarding the GHG emissions of the fossil diesel’s and FAME biodiesel’s

production processes were retrieved form scientific papers (JRC 2014) consid-

ering typical refining in the EU. Specifically, the GHG balances of FAME

biodiesel refer to farming emissions not taking account of any land use change

emissions.

• electricity used in the refinery is assumed to be taken from the local grid, while a

small quantity is produced internally by fuels combustion (fuel gas, fuel oil,

natural gas etc.). The GHG emissions from the electricity consumption were

calculated based on the Greek electricity grid mix. The combustion of carbon

containing fuels internally results in the formation of CO2 (very small amounts

of N2O and CH4 are also formed). The contribution of these emissions has been

taken into account in the refinery’s GHG emissions. The electricity power

consumption in the hydrotreatment unit of HAGO did not alter due to the

addition of WCO.

Refinery

Energy

Emissions Cultivation &

transesterification of vegetable oils

Fertilizers Pesticides

New hybrid diesel

Refinery

Emissions

Crude oil

Natural Gas

Energy

Water

Hydrotreatment Unit

HAGO

LAGO

Hydrotreated hybrid fuel

Hydrotreated light gasoilHydrotreatment

Unit

FAMEH2 Fuel gas

Emissions

Energy

Fuel gas

Water WCO

Energy

Fig. 30.5 Generic flow diagram of the refinery describing the production process of the new hybrid diesel via co-processing HAGO and WCO

New hybrid diesel

FAME biodiesel (2% v/v)

Hydrotreated mixture HAGO-WCO (49% v/v)

Hydrotreated LAGO(49% v/v)

Fig. 30.6 Blending ratios of the components for the production of the new hybrid diesel

30 Sustainability Assessment of Fuels Production via Hydrotreating Waste Lipids. . . 393

• in the examined production process of the hybrid diesel the H2 consumption of

the HAGO hydrotreating unit is increased by about 6.25%, as compared with

conventional HAGO hydrotreating, due to the addition of 5% v/v WCO. This

increase is expected, due to the more demanding WCO hydroconversion reac-

tions. The additional H2 required can be supplied without operating cost

increase, since in the examined refinery there is a surplus of H2 from the natural

gas steam reforming unit (Bezergianni et al. 2014b).

• the GHG emissions of H2 production process from natural gas steam reforming

were based on literature data (Cetinkaya et al. 2012).

• the GHG emissions of construction and decommissioning of all process steps as

well as the maintenance operations are not accounted, due to lack of detailed

related GHG emissions data.

The inventory data of the new hybrid diesel’s production process are detailed in

Tables 30.2 and 30.3.

Results and Discussion

Environmental Evaluation of the Renewable Diesel and the Hybrid Diesel

The inventory data previously presented were the basis for the calculation of the

GWP associated with the investigated fuels production processes. The results are

Table 30.2 Inventory data of the HAGO/WCO (95/5% v/v) hydrotreating unit for the production of the new hybrid diesel

Unit Inputs Outputs

HAGO m3/m3 hydrotreated hybrid fuel 0.986 –

WCO m3/m3 hydrotreated hybrid fuel 0.052 –

H2 m 3/m3 hydrotreated hybrid fuel 70.924 –

Electricity kWh/m3 hydrotreated hybrid fuel 15 –

Steam kg/m3 hydrotreated hybrid fuel 24 –

Fuel gas mmBtu/m3 hydrotreated hybrid fuel 0.238 –

Hydrotreated hybrid fuel m3/m3 hydrotreated hybrid fuel – 1

Table 30.3 Inventory data of the LAGO hydrotreating unit for the production of the new hybrid diesel

Unit Inputs Outputs

LAGO m3/m3 hydrotreated LAGO 1.04 –

H2 m 3/m3 hydrotreated LAGO 55 –

Electricity kWh/m3 hydrotreated LAGO 15 –

Steam kg/m3 hydrotreated LAGO 24 –

Fuel gas mmBtu/m3 hydrotreated LAGO 0.238 –

Hydrotreated LAGO m3/m3 hydrotreated LAGO – 1

394 S. Bezergianni and L.P. Chrysikou

given in Tables 30.4 and 30.5 for the renewable diesel and the hybrid diesel,

respectively. As it can be observed, the hybrid diesel emits lower GHG emissions

than the renewable diesel, indicative of its optimal environmental characteristics.

Since this study aims to compare the environmental impacts of the aforementioned

fuels among themselves and also relative blend of the renewable diesel with fossil

diesel and fossil diesel, further comparisons results are exhibited in the following

subsection.

The contribution of the process stages encompassed in each production chain

was accounted so as to identify the major parameters affecting the GHG emis-

sions and is depicted in Fig. 30.7. In the case of the renewable diesel, the H2 demands of the hydrotreating process arose as the main source of GHG emissions

(91.41%). This high contribution to the GWP was attributed to the increased H2

Table 30.4 GWP emissions of the renewable diesel

production process Process stage

Renewable diesel

g CO2 eq/MJ

% Contribution to

production process

WCO collection &

transportation

~0 ~0

Pretreatment

Energy 0.957 7.873

Hydrotreatment

Energy 0.088 0.724

H2 11.11 91.403

Total 12.15 100

Table 30.5 GWP emissions of the renewable diesel

production process Process stage

Hybrid diesel

g CO2 eq/MJ

% Contribution to

production process

Refinery

HAGO 3.640 39.052

LAGO 2.463 26.454

Hydrotreatment

HAGO/WCO

Energy 0.410 4.398

H2 0.736 7.896

Fuel gas 0.185 1.985

Hydrotreatment

LAGO

Energy 0.410 4.399

H2 0.572 6.137

Fuel gas 0.175 1.985

FAME 0.720 7.724

Total 9.321 100

30 Sustainability Assessment of Fuels Production via Hydrotreating Waste Lipids. . . 395

consumption required for the conversion of WCO to renewable diesel. Likewise,

the contribution of H2 production has also been identified as the core source of

GHG emissions in the production chain of HVOs from vegetable oils (Arvidsson

et al. 2011). As expected, the hybrid diesel from co-processing HAGO/WCO

mixtures showed a different contribution profile, since the emissions from the

refinery were found to be dominating (~65.4%, encompassing the stage of crude

oil extraction and transportation to the refinery), linked to crude oil refining for

the production of the petroleum fractions HAGO and LAGO. It should be noted

that the H2 requirements in the co-processing of HAGO/WCO mixtures were also

substantial (~7.896%), while FAME biodiesel was also a noticeable GHG emis-

sions source (~7.724%).

The GHG emissions of the hybrid diesel examined could be potentially further

reduced by energy efficiency improvements steps in the refinery, focusing more on

optimizing energy utilization. Improvement actions to minimize the H2 require-

ments in the co-processing of HAGO and WCO are also encouraged via incorpo-

rating H2 from renewable energy sources for instance solar energy. Based on

literature data the dominant contributor to the GWP of the fossil diesel’s production

process is the refining process (JRC 2014). Emissions from the cultivation stage

represent the highest GHG emissions source in the carbon footprint of a renewable

diesel fuel obtained from co-processing soybean vegetable oil with fossil diesel

(mainly emissions connected with nitrogen fertilizers) (Garraı́n et al. 2014). Like-

wise, cultivation processes were identified as key contributors to the GHG emis-

sions of HVOs production processes (Uusitalo et al. 2014).

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Renewable diesel Hybrid diesel

Energy H2 Refinery Hydrotreatment LAGO FAME Hydrotreatment HAGO/WCO

Fig. 30.7 Percentage contributions to the GWP of the renewable diesel and hybrid diesel

396 S. Bezergianni and L.P. Chrysikou

Comparison with Other Fuels

This section compares the GHG emissions of the bio-based renewable fuels pro-

duced via hydrotreating WCO and co-processing HAGO with WCO among them-

selves and to relative blends and also to conventional fossil diesel. The comparison

includes only the fuels production processes and in the case of fossil diesel and

FAME biodiesel literature data were retrieved (JRC 2014).

Table 30.6 contrasts the GHG emissions of the targeted fuels production pro-

cesses. As it is shown, the GWP of the new hybrid diesel was estimated as 9.321 g

CO2 eq/MJ, presenting a better environmental profile compared to the renewable

diesel and to the other fuels. This observation validates that the integration of a

bio-based feedstock in the refinery and its co-processing with petroleum fractions,

constitutes a favorable environmental production process over stand-alone biomass

conversion technologies from GHG intensity viewpoint. Furthermore, the environ-

mental superiority of the renewable diesel is also evident, while its blend (7% v/v)

with fossil diesel showed also a better environmental profile than fossil diesel

(containing 7% v/v FAME biodiesel). As a result, the blend of the renewable

diesel with fossil diesel constitutes an alternative to fossil diesel and conventional

bio-based counterparts. As regards to the fossil diesel (containing 7% v/v FAME

biodiesel) it entailed the highest GWP.

Furthermore, when comparing the renewable fuels with HVOs originating from

rapeseed, palm oil and jatropha (GHG emissions range from 20.97 to 57.57 g CO2 eq/MJ, Uusitalo et al. 2014) their sustainable environmental profile is further

validated. Although, it should be underlined that the comparison of life-cycle

studies is frequently ambiguous since a large number of publications present

sometimes contradictory results, due to variant methodological approaches and

assumptions, inventory data for key input parameters etc. The high variability of

the life-cycle results from the various assessments demonstrates the necessity to

appoint key issues used in all the studies (Malça and Freire 2011). Nevertheless, the

variability in the results presented in this study could be high and subject to various

details of all stages included in the investigated production chains.

Overall, the renewable fuels investigated in this study are environmental advan-

tageous than conventional fossil diesel in terms of GHG emissions, identifying the

utilization of WCO as a potential favorable bio-based feedstock. The integration of

WCO in the refinery for the production of fuels with high bio-content via

co-processing technology could be conducive to the global warming mitigation

contrasting to stand-alone biomass conversion technologies. These observations

Table 30.6 GWP emissions of the examined fuels production processes

Fuel type gCO2 eq/MJ

Renewable diesel (via WCO hydrotreating) 12.15

Renewable diesel’s blend (7% v/v) with fossil diesel 14.15

Hybrid diesel (via co-processing WCO with HAGO) 9.321

Fossil diesel (containing 7% v/v FAME biodiesel) 16.974

30 Sustainability Assessment of Fuels Production via Hydrotreating Waste Lipids. . . 397

could be guiding future actions towards the decarbonization of the transportation

sector and guarantee the environmental sustainability of the EU policy at this level.

According to the European legislation the Directive 2009/28/EC establishes

sustainability criteria for biofuels, setting minimum GHG saving limits. In detail,

the GHG emissions savings should be at least 35% for any biofuel. This specific

minimum limit shall be at least 50% by the year 2017 and 60% by 2018 for biofuels

and bioliquids. Therefore, the GHG emissions savings of the renewable fuels

examined were quantified and compared to those of fossil diesel. GHG emission

savings of 89.48, 86.28 and 84.03% were calculated for the hybrid diesel, the

renewable diesel and its blend with fossil diesel, respectively. In all cases the GHG

emission savings meet the sustainability criteria of the regulation for the 2017 and

2018 limits. The new hybrid diesel could be assigned as an alternative to fossil

diesel and be conducive to significant GHG emissions reductions. These results

further validate the environmental performance of renewable fuels derived from

residual biomass via the co-processing approach and the catalytic hydrotreatment

conversion technology.

Conclusions

LCA is a valuable method applied to evaluate the environmental burdens of

processes accounting the inputs and outputs on a life-cycle basis. Renewable diesel

via WCO catalytic hydrotreatment has been produced, while the co-processing of

petroleum fractions/WCO mixtures has been explored as an alternative approach to

integrate residual biomass in the refinery. This new hybrid diesel constitutes a

blending component of fossil diesel. The present study aims to provide the envi-

ronmental characterization of bio-based fuels production systems via hydrotreating

WCO and co-processing petroleum fractions with WCO utilizing existing refinery

infrastructure. A comparison of these fuels with fossil diesel (containing 7% v/v

FAME biodiesel) and the renewable diesel’s blend (7% v/v) with fossil diesel was

also conducted through a WTT analysis. In this respect, the LCA study was

performed by utilizing real experimental data and inventory data sources from

previous environmental studies in the field as well as GEMIS software. The new

hybrid diesel produced via co-processing HAGO/WCO (95/5% v/v) exhibited the

most favorable environmental performance, in terms of GHG emissions. The

renewable diesels’ production chain GHG emissions are also relatively low, whereas its blend with fossil diesel presents also environmental benefits compared

with fossil diesel, enforcing its usage as a blending component. The results also

showed that in the case of the renewable diesel the emissions for the hydrotreatment

process (H2 consumption) were the dominant contributors to the GWP of the

process. Furthermore, in the case of the hybrid diesel the emissions from the

refining processes contributed notably to its GWP, while the emissions of the

hydrotreatment unit of HAGO/WCO mixtures were also prominent. Improvements

actions targeted primarily to energy efficiency techniques in the refinery and to the

398 S. Bezergianni and L.P. Chrysikou

incorporation of H2 originating from RES could probably lead to further GHG

emissions from the hybrid diesel production chain. The GHG emission savings

calculated for the new hybrid diesel further promotes its optimal environmental

characteristics, validating that WCO constitutes a suitable feedstock for bio-based

fuels production from GHG emissions perspective. Based on these findings, it could

be inferred that the co-processing approach of petroleum fractions with WCO could

contribute to the production of sustainable and environmentally efficient fuels.

Supplementary to this observation, it may also be underlined that the integration

of residual biomass in the refinery via co-processing technology for the production

of bio-based fuels compatible with their fossil counterparts is preferable in terms of

GHG balance compared to stand-alone biomass conversion technologies. However,

future studies should also address thoroughly the issue of WCO availability in

Greece in the case the above conversion technologies become commercially viable.

Acknowledgements This work was supported by the EU-Program LIFEþ LIFE08 ENV/GR/ 000569 and by the project SustainDiesel-09SYN-32-328 which is funded 50% by the European

Commission and the Greek Government.

Nomenclature

FAME Fatty acid methyl esters

GHG Greenhouse gas

GWP Global warming potential

HAGO Heavy atmospheric gas oil

HVOs Hydrotreated vegetable oils

LAGO Light atmospheric gas oil

LCA Life cycle assessment

WCO Waste cooking oil

WTT Well-to-tank

TTW Tank-to-wheel

WTW Well-to-wheel

References

Arvidsson, R., Persson, S., Fr€oling, M., & Svanstr€omb, M. (2011). Life cycle assessment of hydrotreated vegetable oil from rape, oil palm and Jatropha. Journal of Cleaner Production, 19, 129–137.

Bezergianni, S., & Dimitriadis, A. (2013a). Temperature effect on co-hydroprocessing of heavy

gas oil-waste cooking oil mixtures for hybrid diesel production. Fuel, 103, 579–584. Bezergianni, S., & Dimitriadis, A. (2013a). Catalytic hydrotreating of waste cooking oil for

renewable diesel production. Proceeding’s of the 9th International Colloquium on Fuels Conventional and Future Energy for Automobiles (pp. 551–557). Germany: Stuttgart. Retrieved Jan 15–17, 2013.

30 Sustainability Assessment of Fuels Production via Hydrotreating Waste Lipids. . . 399

Bezergianni, S., Dimitriadis, A., Kalogianni, A., & Knudsen, K. G. (2011). Towards hydrotreating

of waste cooking oil for biodiesel production. Effect of pressure, H2/Oil ratio and liquid hourly

space velocity. Industrial Engineering Chemistry Research, 50, 3874–3879. Bezergianni, S., Dimitriadis, A., Kalogianni, A., & Pilavachi, P. A. (2010a). Hydrotreating of

waste cooking oil for biodiesel production. Part I: Effect of temperature on product yields and

heteroatom removal. Bioresource Technology, 101, 6651–6656. Bezergianni, S., Dimitriadis, A., Sfetsas, T., & Kalogianni, A. (2010b). Hydrotreating of waste

cooking oil for biodiesel production. Part II: Effect of temperature on hydrocarbon composi-

tion. Bioresource Technology, 101, 7658–60. Bezergianni, S., Dimitriadis, A., & Chrysikou, L. P. (2014a). Quality and sustainability compar-

ison of one- vs two-step catalytic hydroprocessing of waste cooking oil. Fuel, 118, 300–307. Bezergianni, S., Dimitriadis, A., & Karonis, D. (2014b). Diesel decarbonization via effective

catalytic co-hydroprocessing of residual lipids with gas–oil. Fuel, 136, 366–373. Bezergianni, S., Dimitriadis, A., & Meletidis, G. (2014c). Effectiveness of CoMo and NiMo

catalysts on co-hydroprocessing of heavy atmospheric gas oil–waste cooking oil mixtures.

Fuel, 125, 129–136. Cetinkaya, E., Dincer, I., & Naterer, G. F. (2012). Life cycle assessment of various hydrogen

production. International Journal of Hydrogen Energy, 37, 2071–2080. Demirbas, A. (2009). Political, economic and environmental impacts of biofuels: A review.

Applied Energy, Suppl 1, 108–117. Garraı́n, D., Herrera, I., Lech�on, Y., & Lago, C. (2014). Well-to-Tank environmental analysis of a

renewable diesel fuel from vegetable oil through co-processing in a hydrotreatment unit.

Biomass and Bioenergy, 63, 239–249. Gnansounou, E., Dauriat, A., Villegas, J., & Panichelli, L. (2009). Life cycle assessment of

biofuels: energy and greenhouse gas balances. Bioresource Technology, 100, 4919–4930. JRC. (2014). Well-to-Tank appendix 2—version 4a. Summary of energy and GHG balance of

individual pathways. Well-to-Wheels analysis of future automotive fuels and powertrains in

the European context.

Kalnes, T. N., Koers, K. P., Marker, T., & Shonnard, D. R. (2009). A technoeconomic and

environmental life cycle comparison of green diesel to biodiesel and syndiesel. Environmental Progress & Sustainable Energy, 28, 111–120.

Kochaphum, C., Gheewala, S. H., & Vinitnantharat, S. (2012). Environmental comparison of

straight diesel and cracked diesel. Journal of Cleaner Production, 37, 142–146. Malça, J., & Freire, F. (2011). Life-cycle studies of biodiesel in Europe: A review addressing the

variability of results and modeling issues. Renewable and Sustainable Energy Reviews, 15, 338–351.

Nikander, S. (2008). Greenhouse gas and energy intensity assessment of product chain: case

transport biofuel. Master’s Thesis. Helsinki University of Technology, Faculty of Engineering and Architecture, Department of Civil and Environmental Engineering (pp. 1–112).

Pleanjai, S., Gheewala, S. H., & Garivait, S. (2009). Greenhouse gas emissions from production

and use of used cooking oil methyl ester as transport fuel in Thailand. Journal of Cleaner Production, 17, 873–876.

Uusitalo, V., Väisänen, S., Havukainen, J., Havukainen, M., Soukka, R., & Luoranen, M. (2014).

Carbon footprint of renewable diesel from palm oil, jatropha oil and rapeseed oil. Renewable Energy, 69, 103–113.

400 S. Bezergianni and L.P. Chrysikou

Part VIII

Energy Technologies and Their Effect on Global Warming

Hydrogen Energy and Technologies

Chapter 31

Spark-Ignition Engine Fueled with Methane-Hydrogen Blends

G.M. Kosmadakis, F. Moreno, J. Arroyo, M. Mu~noz, and C.D. Rakopoulos

Introduction

Apart from engine-related techniques to meet stringent imposed emissions regula-

tions and higher efficiency over a large range of operating conditions and loads,

engine researchers have focused their interest on the domain of fuel-related tech-

niques (Rakopoulos and Giakoumis 2009). It is true that considerable attention has

been paid in the development of alternative fuel sources, with emphasis on liquid

bio-fuels that possess the added advantage of being renewable, such as vegetable

oil, bio-diesel, ethanol, butanol, and diethyl ether (Agathou and Kyritsis 2014;

Rakopoulos 2012, 2013; Wang et al. 2010). Moreover, many internal combustion

engines, usually converted from commercial compression- or spark-ignition

engines, have been fueled with various alternative gaseous fuels, such as the most

common methane (or natural gas) and liquefied petroleum gas to the most rarely

syngas and biogas, for use in power generation and transportation, showing inher-

ently clean nature of combustion with reduced emitted pollutants (Papagiannakis

and Zannis 2013; Rakopoulos and Kyritsis 2006; Rakopoulos and Michos 2009).

Finally, fuel blends show some interesting features, especially when hydrogen is

added to a conventional fuel for combustion enhancement, due to its very high

combustion speed (Kosmadakis et al. 2012).

G.M. Kosmadakis (*) • C.D. Rakopoulos Internal Combustion Engines Laboratory, Thermal Engineering Department, School of

Mechanical Engineering, National Technical University of Athens, 9 Heroon Polytechniou St.,

Zografou Campus, Athens 15780, Greece

e-mail: [email protected]; [email protected]

F. Moreno • J. Arroyo • M. Mu~noz Laboratory of Engines, Department of Mechanical Engineering, University of Zaragoza,

C/Marı́a de Luna s/n, Zaragoza 50018, Spain

e-mail: [email protected]; [email protected]; [email protected]

405

mailto:[email protected]

One promising fuel blend is the methane/hydrogen one. The addition of even a

small hydrogen quantity in methane increases the combustion speed, improving

engine efficiency, while the fuel flammability limit is extended, allowing the use of

leaner mixtures. Moreover, CO2 and HC emissions are decreased, since the initial

amount of carbon in the fuel blend is decreased (Ma et al. 2008). On the other hand,

nitrogen oxides (NOx) emissions are increased, because of the higher combustion

velocity and burned gas temperature, while the event of knock is likely to occur for

high hydrogen percentage (Moreno et al. 2012).

Various experimental facilities have been developed for the investigation of the

combustion processes of methane/hydrogen blends, and the performance of SI

engines under different operating conditions and strategies (Demuynck

et al. 2009; Moreno et al. 2012), as well as for the in-cylinder processes and their

exhaust emissions (Akansu et al. 2007). Apart from these experimental studies,

there exist many simulation works focusing mainly on the engine performance

parameters (Aliramezani, et al. 2013) and to some extent to the nitric oxide

(NO) emissions, using the thermal NO production path (Dimopoulos et al. 2007),

widely known as the “three-equation Zeldovich mechanism”.

The present study concerns the extension of the combustion model of an

in-house CFD code developed by the NTUA team. This model has been initially

developed for the simulation of the power cycle of hydrogen-fueled SI engines, and

validated over many different conditions, including variable ignition timing, com-

pression ratio, large range of equivalence ratios, and EGR (Kosmadakis et al. 2012;

Kosmadakis and Rakopoulos 2014a, b; Rakopoulos et al. 2010a, 2011). The

extension of this combustion model and of the CFD code mainly concerns the

introduction of the carbon chemistry. Three more species have been added (carbon

dioxide, carbon monoxide and methane), together with an appropriate laminar

flame speed correlation for methane fuel, making the code capable of simulating

such combustion processes.

In order to validate the CFD code, appropriate measured data are used from a

two-cylinder engine. It has been decided here to focus on the variable hydrogen

content, keeping all other parameters constant, whereas it is planned to conduct

further investigation at other conditions as well in the future. For the validation of

this model, the calculated results regarding engine performance and nitric oxide

emissions are compared with the corresponding measured ones. From the analysis it

is concluded that the presented combustion model manages to predict adequately

the engine performance within the range of examined hydrogen content. As far as

the nitric oxide exhaust emissions is concerned, the model manages to capture

qualitatively correct the trend as hydrogen is increased, while in absolute values a

small difference exists from the measured ones. Then, a detailed investigation of

flame propagation and in-cylinder combustion is implemented, revealing the capa-

bilities of the CFD code for detailed combustion analysis and engine research.

406 G.M. Kosmadakis et al.

Experimental Facilities

The experimental facilities are briefly presented next, while further details can be

found in (Moreno et al. 2012).

Engine Modifications

The experimental tests were carried out on a Lombardini LGW 523 MPI spark

ignition engine, with two cylinders and total swept volume of 505 cm3. The engine

was properly modified to work with gaseous fuels containing hydrogen. These

modifications are briefly mentioned next. First, an additional gaseous fuel supply

circuit was mounted in parallel with the original gasoline circuit. Gas injectors are

designed and manufactured by Quantum, and prevent from premature failure in dry

gas applications. To favour the homogeneity of the air-fuel mixture inside the

cylinder, a new gas injection port was designed and installed after the inlet

manifold, where the gas injectors are fitted. Both gas injectors are fed by a gas

ramp connected to the gaseous fuel supply circuit of the test rig, which is explained

next. The ignition system was also modified, adding two BERU coils to ignite two

NGK spark plugs with low enough thermal grade to prevent problems like

pre-ignition. The original engine management system has been replaced by an

AEM 30-1900U Universal Programmable Engine Management System, which

controls all working parameters of the engine. The crankshaft angle at which the

gaseous fuels are injected has a big influence on performance, and therefore the

engine was converted to sequential injection. To this end, the installation of a cam

sensor was necessary, which allowed the synchronization between the strokes of the

cylinders. Moreover, the original narrow band oxygen sensor was replaced by a

wide band universal exhaust gas oxygen sensor (BOSCH LSU 4.2) with better

control of the fuel-air equivalence ratio, especially at lean equivalence ratios.

Finally, in order to perform an analysis of the combustion behavior, a piezoelectric

pressure sensor (Kistler 6053CC60) was mounted in the combustion chamber, in

order to acquire and analyze the pressure inside the cylinder.

Experimental Procedures

The engine was coupled to a Tecner E315 dynamometer, which allows testing

engines at constant speed or load. Data acquisition system of the test bench

recorded the load, speed, temperatures, pressures and fuel and air consumptions.

Pollutant emissions were measured using a Signal Instruments exhaust gas analysis

installation. The measurement principles are based on non-dispersive infrared for

CO and CO2, flame detector ionization for HC, chemiluminescence for NOx and

paramagnetism for O2. The pressure inside the cylinder was measured with the

31 Spark-Ignition Engine Fueled with Methane-Hydrogen Blends 407

piezoelectric sensor mentioned above connected to a signal conditioning and data

acquisition system from National Instruments, controlled by a specific proprietary

software programmed in LabVIEW. The volumetric composition of the different

gaseous fuel blends tested is presented in Table 31.1.

The engine was tested at full load and at a wide range of speeds (from 2000 to

4500 rpm), but the results selected in this study to validate the model were those

corresponding to 4500 rpm. The use of hydrogen blends allows the extension of the

lean operation limits of the methane (Moreno et al. 2012), so an equivalence ratio of

0.8 was selected for all cases. The ignition timing was fixed at 33� CA BTDC, in order to focus on the combustion differences due to the different blend composition.

The injection timing was set to 15� CA BTDC during the intake stroke for all the fuel blends. According to engine valve timing, the injection at this moment ensures

that all fuel is injected, while the inlet valve is open for all cases.

All relevant measurements have been conducted at wide-open throttle (WOT), in

order to reduce the pumping losses. The main specifications of this engine are given

in Table 31.2.

Table 31.1 Composition of the gaseous fuel blends tested

H2 composition (% by vol.) CH4 composition (% by vol.)

Methane 0 100

G1 10 90

G2 30 70

G3 50 50

Table 31.2 Lombardini engine main specifications

Engine model and type

Lombardini engine, two-cylinder, naturally aspirated, four

stroke, water-cooled

Bore 72 mm

Stroke 62 mm

Swept volume (per cylinder) 252.5 cm3

Connecting rod length 107 mm

Compression ratio 10.7

Valves (per cylinder) 2

Engine speed 4500 rpm

Ignition timing 33� CA BTDC Equivalence ratio ~0.8

Number of piston rings 3

Valve timing

events

Inlet valve

opening

5� CA BTDC

Inlet valve

closure

59� CA ABDC

Exhaust valve

opening

57� CA BBDC

Exhaust valve

closure

7� CA ATDC

408 G.M. Kosmadakis et al.

CFD Code

The firing version of the CFD code developed by the NTUA team can simulate

three-dimensional curvilinear domains, using the finite volume method in a collo-

cated grid. It has been validated in previous published works (Kosmadakis

et al. 2012; Kosmadakis and Rakopoulos 2014a, b; Rakopoulos et al. 2010a,

2011), where it has been revealed that it can adequately simulate the power cycle

of hydrogen-fueled spark-ignition engines. In the next subsections the extended

combustion model is briefly presented, as applied in the present study and its main

differences with the addition of methane fuel are discussed. A detailed presentation

can be found in previous publications (Kosmadakis et al. 2012, 2013; Kosmadakis

and Rakopoulos 2014a, b; Rakopoulos et al. 2010a, b, 2011).

Combustion Model

The combustion model is briefly described in this section, which has been already

developed and applied in previous studies for hydrogen combustion. The main

difference here is that methane fuel and carbon chemistry are added in the transport

equations. Only its basic features are given, since its detailed presentation is

provided in previous publications (Kosmadakis et al. 2012; Rakopoulos

et al. 2010a).

For the calculation of the species reaction rates, the characteristic conversion

time-scale method has been followed (Abraham et al. 1985). A characteristic time-

scale (τc) is calculated, as the sum of the laminar conversion time (τl) and the turbulent mixing time (τt), which determines to what extent the combustible gas content of each computational cell has reached its chemical equilibrium during a

specific duration (equal to the computational time step). This method is followed

for the calculation of the reaction rates of all chemical species considered here,

namely H2, O2, N2, H2O, H, O, N, OH, CO, CO2, and CH4. The reaction rates for

the nitric oxide (NO) derived from three different paths (thermal NO, NNH and

N2O paths) have already been discussed in (Kosmadakis and Rakopoulos 2014a, b)

and will not be repeated here. Further details concerning the calculation of the

reaction rates with the use of the characteristic conversion time-scale method can be

found in (Rakopoulos et al. 2010a).

The correlation for the hydrogen laminar flame speed is the one proposed by

(Gerke et al. 2010), which includes stretch effects. A similar correlation for

methane is used, which is proposed by (Ouimette and Seers 2009), which is derived

under a wide range of pressure and temperature similar to the gas properties during

spark ignition. Other correlations have been examined as well (applicable over a

smaller range though), with similar results. The fuel blend laminar flame speed is

calculated using a Le Chatelier rule (Rakopoulos and Michos 2009), which is a

rather simple calculation method, but ensures that the most reliable correlations are

31 Spark-Ignition Engine Fueled with Methane-Hydrogen Blends 409

used for the two fuels (hydrogen and methane), taking into consideration stretch

effects. The laminar flame speed is used to track the computational cells, in which

the flame has propagated during the ignition phase through the calculation of the

flame radius, assuming that the flame propagation velocity is approximately equal

to the laminar flame speed during this phase. When the flame reaches a critical

radius, turbulent effects become dominant and then a turbulent burning velocity (ut)

is used to track the flame. The expression used for this velocity is the one proposed

by Zimont/Lipatnikov and Chomiak (Lipatnikov and Chomiak 1997; Zimont

2000), in which one calibration constant exists (constant “A”), which is appropri-

ately tuned for each fuel blend (Rakopoulos et al. 2010a). This correlation is given

in Eq. (31.1).

ut ¼ A u0ð Þ3=4 u1=2l D�1=4T,u L1=4t þ ul ð31:1Þ

where A is the calibration constant that needs to be tuned, u’ the rms turbulent

velocity given by u0 ¼ ffiffiffiffiffiffiffiffiffiffi2k=3p , ul the stretched laminar flame speed, DT,u the thermal diffusivity of the unburned mixture, and Lt the turbulent integral length

scale given by Lt ¼ 0:37 u0ð Þ3=ε.

Computational Details

Some initial and boundary conditions are provided from the experimental data, such

as the pressure at IVC, and the inlet air (humidity in the inlet air is neglected) and

hydrogen/methane flow rates. For the rest of the required conditions, reliable

estimations are used, such as the gas temperature at IVC (from 380 up to 405 K

as the hydrogen content increases), wall temperature at IVC (from 440 up to 450 K

as the hydrogen content increases), residual gas mass fraction (around 6–7%), and

turbulent kinetic energy at IVC (constant and equal to 55 m2/s2 for all cases).

The constructed computational mesh has (40� 40� 30) grid lines along each axis (see Fig. 31.1) and has been tested for grid independence. The addition and

removal of mesh layers according to the piston movement is also used, since during

compression the height of the cells decreases at the dead volume. The engine is

equipped with a small bowl-in-piston, and its geometry has been extrapolated with

the highest possible detail from the engine design provided by the manufacturer.

The computational time step used is equal to 1� CA, which is further decreased from the beginning of the combustion period and afterwards becoming equal to 0.4�

CA. Such time step is sufficient small, since the engine speed is high and equal to

4500 rpm. Finally, the only calibration constant used in the in-house CFD code,

which exists in the expression of the turbulent flame speed (no calibration factors

exist in the heat transfer and crevice models), has a different value for each fuel

blend, which is however in the range of 0.7 (similar with hydrogen combustion).

410 G.M. Kosmadakis et al.

Results and Discussion

Test Cases Considered

The main engine conditions and settings of the test cases examined in the current

study have been shown previously in Table 31.2. Focus is given on the effect of

hydrogen content in the fuel (four test cases considered).

CFD Code Validation

The validation of the CFD code is presented here, which includes the comparison of

the predicted performance and NO emissions with the available measured data for

the methane/hydrogen-fueled SI engine.

Fig. 31.1 Computational grid at IVC with

40� 40� 30 grid lines along the x, y, z axis. The

bowl-in-piston is depicted

at the bottom

31 Spark-Ignition Engine Fueled with Methane-Hydrogen Blends 411

Engine Performance

The CFD code has been applied for the simulation of the four test cases. In Fig. 31.2

is shown the comparison of the predicted with the measured cylinder pressure for

variable hydrogen content.

The pressure traces are predicted with high accuracy, since for every case

considered the peak pressure and its timing are very well captured, with only

some minor discrepancies. These can be partly attributed to the correlation of the

laminar flame speeds used in the CFD code, being near to their application range,

50-50%: methane-H2

120 140 160 180 200 220 240

70-30%: methane-H2

120 140 160 180 200 220 240

Crank angle degrees (ABDC)

90-10% methane-H2

120 140 160 180 200 220 240

100-0%: methane-H2

120 140 160 180 200 220 240

Crank angle degrees (ABDC)

50 Measured

Calculated

C yl

in d

er p

re ss

u re

( b

ar )

C yl

in d

er p

re ss

u re

( b

ar )

C yl

in d

er p

re ss

u re

( b

ar )

C yl

in d

er p

re ss

u re

( b

ar )

Fig. 31.2 Comparison of calculated pressure traces with the corresponding measured ones for variable hydrogen content

412 G.M. Kosmadakis et al.

and to the higher heat loss calculated during the end of combustion. Nevertheless,

the cylinder pressure numerical results can be considered reliable, providing a good

proof of the reliability of the CFD code developed and of the presented results in the

next subsections.

This conclusion is also justified with the good comparison of the net heat release

rates, which is shown in Fig. 31.3. The maximum rate is well captured from the

CFD code, together with the combustion timing and profile.

Again, the process during the expansion stroke shows some differences, which

are under further investigation. Some possible causes can be some differences with

the exact bowl geometry, a non-homogeneous gas mixture at IVC, and the uncer-

tainty on the values of the initial gas temperature at IVC and wall temperature.

50-50%: methane-H2

120 140 160 180 200 220 240

-4

70-30%: methane-H2

120 140 160 180 200 220 240

-4

90-10% methane-H2

120 140 160 180 200 220 240

-4

100-0%: methane-H2

120 140 160 180 200 220 240

Crank angle degrees (ABDC)

-4

20 Measured

Calculated

N et

h ea

t re

le as

e ra

te (

J/ o C

A )

N et

h ea

t re

le as

e ra

te (

J/ o C

A )

N et

h ea

t re

le as

e ra

te (

J/ o C

A )

N et

h ea

t re

le as

e ra

te (

J/ o C

A )

Fig. 31.3 Comparison of calculated net heat release rates with the corresponding measured ones for variable hydrogen content

31 Spark-Ignition Engine Fueled with Methane-Hydrogen Blends 413

The local increase of the heat release rates during the expansion stroke at around

200� CA ABDC is due to the rapid combustion of the end gas near the cylinder liner. This is advanced as the hydrogen content is increased, due to the more rapid

combustion. According to the measured values, a different trend exists, since this

end gas slowly burns during a larger period at the expansion stroke.

Similar comparisons have been made concerning the indicated mean effective

pressure (IMEP) and indicated efficiency. These parameters provide a more general

insight on the accuracy of the numerical results using the CFD code. It has been

shown that both IMEP and indicated efficiency are adequately predicted, since for

all cases considered a good match exists with few differences. These exist due to the

discrepancies of cylinder pressure during the exhaust stroke.

The main conclusion of this validation process is that the CFD code can predict

adequately the performance of such engine with methane/hydrogen fuel blends and

its application can be extended for the investigation of various conditions and

engine designs.

NO Emissions

After the validation of the performance, the study focuses on the NO exhaust

emissions, which are investigated for the test cases of Table 31.1. The calculated

NO values are obtained using the CFD code and are compared with the measured

values (see Fig. 31.4).

It can be observed that the trend of the NO emissions is adequately captured, as

the hydrogen content increases. Concerning the absolute emission values there is

some discrepancy, which is almost equal for all cases (around 800 ppm). For high

hydrogen content, the relevant variation is maintained lower than around 30–40%,

which can be considered acceptable, since no calibration factor is included in the

0 10 20 30 40 50

Hydrogen content (by vol. %)

1000

2000

3000

Measured Calculated

N O

e xh

au st

e m

is si

o n

s (p

p m

)

Fig. 31.4 Comparison of calculated NO emissions

with the corresponding

measured ones for variable

hydrogen content

414 G.M. Kosmadakis et al.

emissions model. Nevertheless, such prediction level is adequate, having in mind

all uncertainty factors in the calculation of NO emissions (Kosmadakis et al. 2012;

Kosmadakis and Rakopoulos 2014a).

Combustion Analysis

The validation of the extended combustion model revealed that the power cycle of a

SI engine with variable hydrogen content can be simulated with detail, while both

performance and NO emissions are adequately calculated. Therefore, the CFD code

can be then applied for further combustion analysis, by providing some insight on

the in-cylinder processes.

As the hydrogen content increases, the combustion speed is higher, increasing

the gas temperatures during combustion. This is the main reason that NO emissions

are higher, which is one of the main concerns for the use of hydrogen in blends

(Moreno et al. 2012). Such indication is provided in Fig. 31.5, where the calculated

mean gas temperature is observed. In the same figure are also shown the mean NO

reaction rates, which depend a lot on the local gas temperature and the local species

concentration.

It is observed that the maximum temperature (around 2400 K) is reached for the

50–50% blend, which is observed some CA degrees before the 100–0% blend.

Also, as the hydrogen content increases, the NO reaction rates rapidly increase,

since there is an exponential dependence from the temperature (Kosmadakis and

Rakopoulos 2014a). Moreover, even some small addition of hydrogen in the fuel

160 180 200 220 240

6 Case 1 (100-0%)

Case 2 (90-10%)

Case 3 (70-30%)

Case 4 (50-50%)

160 180 200 220 240

600

1000

1400

1800

2200

2600

Case 1 (100-0%)

Case 2 (90-10%)

Case 3 (70-30%)

Case 4 (50-50%)

M ea

n g

as t

em p

er at

u re

( K

)

Crank angle degrees (ABDC) Crank angle degrees (ABDC)

M ea

n N

O r

ea ct

io n

r at

e (k

g N

O /k

g m

ix /s

)

Fig. 31.5 Mean gas temperature and mean NO reaction rates during combustion and early expansion for variable hydrogen content

31 Spark-Ignition Engine Fueled with Methane-Hydrogen Blends 415

blend, as is the case of 90–10%, increases the maximum mean gas temperature by

more than 100 K and almost doubles the mean NO reaction rate.

Some more detailed aspects of flame propagation are presented next. The

differences observed are mainly due to the variable hydrogen content, since all

other important parameters and conditions are exactly the same for all cases. The

initial temperature and pressure at IVC show some small differences, which are

however negligible and do not introduce any important changes. In Fig. 31.6 is

shown the flame radius, calculated from the computational cells, which are located

at an axial direction crossing the spark-plug, and until the flame reaches the piston.

In the same figure is also shown the mean laminar flame speed during the early

stages of combustion and the turbulent flame speed. It should be stressed that these

speeds are mean values averaged over the cells that are inside the flame front and

therefore should be only treated as indicative ones.

The spark-timing is constant and equal to 147� CA ABDC. Therefore, for all cases the combustion starts at the same time and it is possible to identify the effect

of hydrogen addition on the flame speeds and flame propagation inside the cylinder.

It is observed that the flame radius increases more quickly for higher hydrogen

content, which is directly related with the mixture laminar flame speed (the

hydrogen laminar flame speed is many times higher than the methane one) and

turbulent flame speed. The latter mainly depends on the local turbulent properties

and the laminar flame speed. These properties are more or less the same for all

cases, since a constant value of turbulence has been considered for all cases (engine

speed is 4500 rpm). Therefore, the turbulent flame speed depends almost exclu-

sively on the laminar flame speed. For the 50–50% blend, its maximum value is

around twice the maximum value for the pure methane case. In other words, flame

propagation is around two times higher, in case hydrogen is added in methane by

50% by vol. This is verified by the combustion duration angles (0–5 and 5–95%),

but it can be better visualized by the flame images, shown in Fig. 31.7. These

images depict how the flame propagates inside the cylinder after the ignition timing,

140 150 160 170 180 190

100-0% 90-10% 70-30% 50-50%

140 150 160 170 180 190

8 100-0% 90-10% 70-30% 50-50%

140 150 160 170 180 190

12 100-0% 90-10% 70-30% 50-50%

F la

m e

ra d

iu s

(m m

)

L am

in ar

f la

m e

sp ee

d (

m /s

)

T u

rb u

le n

t fl

am e

sp ee

d (

m /s

)

Crank angle degrees (ABDC) Crank angle degrees (ABDC) Crank angle degrees (ABDC)

Fig. 31.6 Flame radius, laminar flame speed and turbulent flame speed for variable hydrogen content

416 G.M. Kosmadakis et al.

noticing the differences for the various hydrogen contents. The spark-plug is offset

from the cylinder axis, as one can guess from the location of the ignition kernel.

Owing to the high burning velocity of hydrogen, the flame has significantly

expanded at TDC for the 50–50% blend. Moreover, the flame has covered the

whole combustion chamber at around 200� CA ABDC for the 50–50% blend, and at 220� CA ABDC for the pure methane case. The main differences can be identified during early combustion, where the flame propagates with its laminar

flame speed, which is much lower for the pure methane case, as mentioned

previously.

Fig. 31.7 In-cylinder flame images for 50–50% hydrogen/methane blend and pure methane

31 Spark-Ignition Engine Fueled with Methane-Hydrogen Blends 417

Summary and Conclusions

In the present work, the combustion model of a 3D-CFD code has been extended.

This was originally developed for pure hydrogen combustion, while this extension

allowed it to simulate the power cycle of hydrogen/methane blends. The first step

was to validate the code. Therefore, detailed measurements on a SI engine have

been used for that purpose. The experimental data are for constant equivalence ratio

and load, while only the hydrogen content is varied within the range 0–50% by vol.

The validation has been conducted for both performance and NO emissions. This

procedure showed that the CFD code is capable of predicting the performance

parameters of such engine for variable hydrogen content, while the NO emissions

are adequately predicted and closely following the same trend as the measured

ones. Such conclusions are encouraging, in order to apply the CFD code for further

combustion analysis. Some first relevant tasks have been presented in the second

part of this work, where focus has been given on the flame propagation for variable

hydrogen content. It has been shown that the addition of even a small amount of

hydrogen can substantially increase the flame speed, especially during the early

combustion period.

In conclusion, the results obtained so far are encouraging, by showing that the

simulation of SI engines fueled with hydrogen/methane blends using a detailed

numerical tool, such as the one presented here, can yield reliable results, with the

use of just one calibration constant per blend. However, a more extended study

should be conducted in the future, covering a wider range of operating conditions

(such as variable equivalence ratio and speed), to justify the validity of the model

and its ability to capture combustion phenomena without adjusting the value of the

calibration constant.

Acknowledgement Dr. G.M. Kosmadakis (NTUA) wishes to thank the Greek State Scholarships Foundation for granting him an “IKY Fellowship of excellence for postgraduate studies in

Greece—Siemens Program, years 2013–2015.”

References

Abraham, J., Bracco, F. V., & Reitz, R. D. (1985). Comparison of computed and measured

premixed charge engine combustion. Combustion and Flame, 60(3), 309–322. Agathou M. S., & Kyritsis, D. C. (2014). Experimental study of steady, quasi cone-jet electrostatic

sprays of bio-butanol for engine applications. Journal of Energy Engineering 140(3). doi: 10. 1061/(ASCE)EY.1943-7897.0000141, A4014008.

Akansu, S. O., Kahraman, N., & Ceper, B. (2007). Experimental study on a spark ignition engine

fuelled by methane-hydrogen mixtures. International Journal of Hydrogen Energy, 32(17), 4279–4284.

Aliramezani, M., Chitsaz, I., & Mozafari, A. A. (2013). Thermodynamic modeling of partially

stratified charge engine characteristics for hydrogen-methane blends at ultra-lean conditions.

International Journal of Hydrogen Energy, 38(25), 10640–10647.

418 G.M. Kosmadakis et al.

http://dx.doi.org/10.1061/(ASCE)EY.1943-7897.0000141

Demuynck, J., Raes, N., Zuliani, M., De Paepe, M., Sierens, R., & Verhelst, S. (2009). Local heat

flux measurements in a hydrogen and methane spark ignition engine with a thermopile sensor.

International Journal of Hydrogen Energy, 34(24), 9857–9868. Dimopoulos, P., Rechsteiner, C., Soltic, P., Laemmle, C., & Boulouchos, K. (2007). Increase of

passenger car engine efficiency with low engine-out emissions using hydrogen–natural gas

mixtures: A thermodynamic analysis. International Journal of Hydrogen Energy, 32(14), 3073–3083.

Gerke, U., Steurs, K., Rebecchi, P., & Boulouchos, K. (2010). Derivation of burning velocities of

premixed hydrogen/air flames at engine-relevant conditions using a single-cylinder compres-

sion machine with optical access. International Journal of Hydrogen Energy, 35(6), 2566–2577.

Kosmadakis, G. M., Pariotis, E. G., & Rakopoulos, C. D. (2013). Heat transfer and crevice flow in

a hydrogen-fueled spark-ignition engine: Effect on the engine performance and NO exhaust

emissions. International Journal of Hydrogen Energy, 38(18), 7477–7489. Kosmadakis, G. M., & Rakopoulos, C. D. (2014a). Computational fluid dynamics investigation of

alternative nitric oxide emission mechanisms in a hydrogen-fueled spark-ignition engine.

International Journal of Hydrogen Energy, 39(22), 11774–11791. Kosmadakis, G. M., & Rakopoulos, C. D. (2014b). Computational fluid dynamics study of

alternative nitric-oxide emission mechanisms in a spark-ignition engine fueled with hydrogen

and operating in a wide range of exhaust gas recirculation rates for load control. Journal of Energy Engineering C4014008. DOI: 10.1061/(ASCE)EY.1943-7897.0000229.

Kosmadakis, G. M., Rakopoulos, C. D., Demuynck, J., De Paepe, M., & Verhelst, S. (2012). CFD

modeling and experimental study of combustion and nitric oxide emissions in hydrogen-fueled

spark-ignition engine operating in a very wide range of EGR rates. International Journal of Hydrogen Energy, 37(14), 10917–10934.

Lipatnikov, A. N., & Chomiak, J. (1997). A simple model of unsteady turbulent flame propagation.

Transactions SAE Journal of Engines 106:2441–2452 [SAE Paper no. 972993]. Ma, F., Liu, H., Wang, Y., Li, Y., Wang, J., & Zhao, S. (2008). Combustion and emission

characteristics of a port-injection HCNG engine under various ignition timings. International Journal of Hydrogen Energy, 33(2), 816–822.

Moreno, F., Mu~noz, M., Arroyo, J., Magén, O., Monné, C., & Suelves, I. (2012). Efficiency and emissions in a vehicle spark ignition engine fueled with hydrogen and methane blends.

International Journal of Hydrogen Energy, 37(15), 11495–11503. Ouimette, P., & Seers, P. (2009). Numerical comparison of premixed laminar flame velocity of

methane and wood syngas. Fuel, 88(3), 528–533. Papagiannakis, R. G., & Zannis, T. C. (2013). Thermodynamic analysis of combustion and

pollutants formation in a wood-gas spark-ignited heavy-duty engine. International Journal of Hydrogen Energy, 38(28), 12446–12464.

Rakopoulos, D. C. (2012). Heat release analysis of combustion in heavy-duty turbocharged diesel

engine operating on blends of diesel fuel with cottonseed or sunflower oils and their bio-diesel.

Fuel, 96, 524–534. Rakopoulos, D. C. (2013). Combustion and emissions of cottonseed oil and its bio-diesel in blends

with either n- butanol or diethyl ether in HSDI diesel engine. Fuel, 105, 603–613. Rakopoulos, C. D., & Giakoumis, E. G. (2009). Diesel engine transient operation—principles of

operation and simulation analysis. London: Springer. Rakopoulos, C. D., Kosmadakis, G. M., Demuynck, J., De Paepe, M., & Verhelst, S. (2011). A

combined experimental and numerical study of thermal processes, performance and nitric

oxide emissions in a hydrogen-fueled spark-ignition engine. International Journal of Hydro- gen Energy, 36(8), 5163–5180.

Rakopoulos, C. D., Kosmadakis, G. M., & Pariotis, E. G. (2010a). Evaluation of a combustion

model for the simulation of hydrogen spark-ignition engines using a CFD code. International Journal of Hydrogen Energy, 35(22), 12545–12560.

31 Spark-Ignition Engine Fueled with Methane-Hydrogen Blends 419

http://dx.doi.org/10.1061/(ASCE)EY.1943-7897.0000229

Rakopoulos, C. D., Kosmadakis, G. M., & Pariotis, E. G. (2010b). Critical evaluation of current

heat transfer models used in CFD in-cylinder engine simulations and establishment of a

comprehensive wall-function formulation. Applied Energy, 87(5), 1612–1630. Rakopoulos, C. D., & Kyritsis, D. C. (2006). Hydrogen enrichment effects on the second law

analysis of natural and landfill gas combustion in engine cylinders. International Journal of Hydrogen Energy, 31(10), 1384–1393.

Rakopoulos, C. D., & Michos, C. N. (2009). Generation of combustion irreversibilities in a spark

ignition engine under biogas-hydrogen mixtures fueling. International Journal of Hydrogen Energy, 34(10), 4422–4437.

Wang, S., Ji, C., & Zhang, B. (2010). Effect of hydrogen addition on combustion and emissions

performance of a spark-ignited ethanol engine at idle and stoichiometric conditions. Interna- tional Journal of Hydrogen Energy, 35(17), 9205–9213.

Zimont, V. L. (2000). Gas premixed combustion at high turbulence. Turbulent flame closure

combustion model. Experimental Thermal and Fluid Science, 21(1–3), 179–186.

420 G.M. Kosmadakis et al.

Chapter 32

Hydrogen Fueled Airplanes, Test Case: Aviation in Libya

Satya P. Bindra, Ali Alwafi, Ashour Saasi, Elbahlul Musa Abogrean,

Mohsen Masaud A. Maatugh, and Khaled Khalifa

Introduction

World over CO2 emission from aviation is on the rise. See Fig. 32.1 Hydrogen

fueled airplane offers the most promising zero-emission alternative to conventional

aircraft since they have a similar flying range and refueling time. While Hydrogen

fueled airplanes require massive investment and government subsidies for fuelling

stations, it is noted that hydrogen—the most abundant element in the universe—

could be extracted from many different sources and had the advantage of being

portable and more easily stored than electricity. The example is the southern

Japanese city of Fukuoka that recently completed a fuelling station that uses

hydrogen made from sewage. Of course, there are technological hurdles that need

to be cleared to make this commercially viable.

Low carbon environmental friendly science and technology for sustainable civil

aviation in new Libya is being planned in line with UNCSD Rio+20 Focal Point

Libya (Bindra 2012; Bindra et al. 2012) objectives (a) To Make the airport

environment friendly and achieve higher level of customer satisfaction; (b) To

lay special emphasis on the development of infrastructure for remote and inacces-

sible areas; (c) To provide airport capacity ahead of demand; (d) To encourage

greater efficiency in Airport Operations on ground and in the air; (e) To provide

multi-modal linkages for flexibility. The focus regarding the internal infrastructure

lies on the vehicles moving at, in, on and around the airport as well as an innovative

taxiway and runway constellation using: (1) CAV: Clean Air Vehicles; (2) ITC:

Innovative Taxiway Constellation; (3) ERS: Efficient Runway system. The purpose

S.P. Bindra (*) UNCSD Rio+20 Focal Point, Sbia, Libya

e-mail: [email protected]

A. Alwafi • A. Saasi • E.M. Abogrean • M.M.A. Maatugh • K. Khalifa

Civil Aviation and Meteorology Technical College, Sbia, Libya

421

mailto:[email protected]

is to meet and exceed ICAO guidelines issued to its Member States. The idea is to

commit the country to help develop solutions for the sustainable future of interna-

tional civil aviation, in cooperation with industry, sister United Nations agencies

and Non-governmental Organizations. It would serve as a catalyst for economic and

social development. Therefore, air transport work force needs to be equipped with

tools, techniques and technologies that focus on help reduce environmental foot-

print, in line with the guidance and leadership of Environmental General Authority

and ICAO. Its goal is to strike a balance among the three pillars of sustainability—

social, economic and environmental so that air transport grows in an environmen-

tally sustainable manner, while continuing to ensure freedom to travel by air.

Policy of Libya is helping establish democratization of air travel by access to

sustainable air transport in a guaranteed manner for its future generations. Libyan

national UNCSD Rio+20 Focal Point has set clear objectives and provides frame-

work to address the new energy challenges as we transition to a green economy

(Bindra 2014; Robertson 2008). This includes use of sustainable alternative fuels as

one of the most promising win-win-win solutions for aviation’s future. Our Green Airport Concept [4.5] is based on a Clean Air Vehicle Policy. The fleet operating at

or near the airport consists of:- Compressed Natural Gas Vehicles (CNG);- Electric

Vehicles;- Hybrid-Electric Vehicles;- Green Airport TRAIN powered by hydro

electricity.

Furthermore it supports Diesel Vehicles Filters for all transporter and charter bus

operators and shuttles. Libya is committed to make available of these fuels through

policies that incentivize their development and their deployment. This paper after

review of the situation is designed to show that how the civil aviation industry in the

country is committed to meet its environmental commitments through its own

0 1950

M ill

io n

B ar

re ls

p er

D ay

1960

Transportation sector leads in petroleum use Carbon emissions from global aviation exceed the total output of many countries

Aviation Contribution to CO2

Electric Power1

1970 1980 1990

Industrial

Transportation

Residential and Commercial

2000

Fig. 32.1 Aviation contribution to CO2

422 S.P. Bindra et al.

resources. For this the country policy is devised based on better co-ordination of

Libyan national Civil aviation activities at the international level by elimination of

duplication in all areas, and to build upon the work of specialized agencies and

existing sustainable development frameworks.

An Overview of Civil Aviation and Airports in Libya

Civil aviation in Libya in 1987 was the responsibility of the Secretariat of Com-

munications, which operated all airports, and the Civil Aviation Institute, which

trained all personnel. The three international airports in 1985 were located at Tripoli

(Al Aziziyah), Benghazi (Benina), and Sabha. Smaller airfields were located at

Marsa al Burayqah, Tobruk Ghat, Ghadamis, Al Kufrah, and several other loca-

tions. Most civil air personnel went abroad for training. Britain suspended its air

traffic control training program for Libyans in 1985, but Pakistan subsequently

agreed to train about 78 Libyan air traffic controllers (Bindra 2014).

The national air carrier, Libyan Arab Airlines (LAA), was nationalized in 1973.

Possessing only a dozen aircraft in 1977, it grew rapidly, expanding its fleet to

25 aircraft in 1985. The main aircraft in service were manufactured by Boeing,

Hawker Siddeley, Caravelle, and Fokker. In 1980, LAA carried 1.17 million

passengers. A new carrier called United African Airlines (UAA) was created in

1985 in association with LAA.

Airports in New Libya

Currently air transportation is one of the most pressing issues for the new Libya.

The country’s infrastructure has suffered from decades of neglect and the transport network is essential to rebuilding the economy. The ports and the airports, in

particular, have been neglected and underdeveloped. In a country which imports

some 80% of its food, the freight sector requires urgent attention. Despite some

damage to facilities and aircraft, Libya’s airports steadily reopened after the revolution. Most recently Sirte airport reopened at the end of October, following

extensive repair and maintenance work to address damage sustained during the

fighting. Even before the airports were fully-functional, airlines resumed flights to

Libya, with the very first being Turkish Airlines, which restarted daily Istanbul to

Benghazi flights from 13 September 2011.

Concerns have been raised about safety, not least by the European Union. In

accordance with the International Civil Aviation Organisation (ICAO), in March

the EU banned Libya’s two state-owned carriers, Afriqiyah Airways and Libyan Airlines from flying to Europe, on the grounds of flight safety and airport security.

Both carriers were obliged to wet-lease aircraft to maintain services to some

European destinations. The EU said when it imposed the ban last April that it

32 Hydrogen Fueled Airplanes, Test Case: Aviation in Libya 423

would review it this month. The ban is expected to remain in force for some further

while. Aviation freight at Libya’s 18 main airports faces similar to the ports, in particular limited and obsolete equipment. For smaller-scale cargo, air freight is

often more straightforward and cheaper, as well as faster, than sea freight, because

the airports do not have the congestion problems of the ports. Urgent cargo, such as

medicine, hospital equipment and essential equipment for the oil industry usually

comes via air freight. A state monopoly operates at all airports, where only one

company, the state-run Shorooq Handling and Ground Services company, can deal

with freight deliveries. “The country’s airports need to be rebuilt to accommodate big planes,” said Mohamed Douas, CEO of Libya Shipping Line “and the services

need to be liberalised, because the current state-run services are inadequate, inef-

ficient and totally under-equipped.” Recently Civil Aviation Authority of Libya

(LCAA) has launched a pioneering program to perform a fundamental country-

wide upgrade of the existing Aeronautical Fixed Telecommunication Network

(AFTN) and Automatic Identification System (AIS) infrastructure in order to

enhance flight safety. LCAA have been effectively operating COMSOFT’s highly dependable AIDA-NG and CADAS products since 2004, and have again put their

full confidence in the German expert to address Libya’s high technical and opera- tional expectations. With the upgrade Libya will join the still exclusive club of Air

navigation service provider (ANSPs) processing the aeronautical information data

in line with the ICAO Roadmap AIS to AIM. In addition, LCAA will benefit from

the fast and highly reliable Aeronautical Message Handling System (AMHS) that

already connects many countries in the Arab peninsula and North African Region.

Home to the world’s hottest desert, The Sahara, Libya’s expansive sandy land- scape makes air travel essential in order to facilitate Libya’s transportation infra- structure; meanwhile a number of national airports are of growing importance.

COMSOFT’s innovative AMHS and AIM solutions will be provided to the central site in capital city Tripoli and countrywide messaging and information

management services will also be delivered via remote installations at Metiga,

Mistrata, Sahba, Benina.

During the course of the ambitious project LCAA will upgrade their NOTAM,

OPMET, Briefing and Flight Plan Management facilities and simultaneously inte-

grate the components in a state-of-the-art AIXM 5.1-based AIM concept (Bindra

2012; Bindra et al. 2012). This includes the central handling of static data and the

fully integrated ability to generate electronic AIP and aeronautical charts directly

from the central AIXM 5.1 database contents.

Tripoli International Airport is a public airport serving international and domes-

tic passengers from most European and Arab airlines, and handling over three

million travelers per year. With the installation of two new terminals they hope to

increase this capacity to 20 million passengers annually, therefore, increasing the

need for advanced and reliable message handling. Installation of an end around

taxiway, which is based on the newest developments regarding safety and effi-

ciency: ITC—Innovative Taxiway Constellation is planned to ensure that:

424 S.P. Bindra et al.

• Aircraft will be allowed to taxi around the end of the runway instead of waiting

to cross them.

• Even if aircraft have to expect a longer taxi, it can be another way of avoiding a

lengthy queue at the holding point.

• New taxiway constellation significantly decreases runway crossings thereby

increasing safety and efficiency, thereby reducing the probability of an runway

incursion.

• Airlines, passengers and the environment are the ultimate benefactors of the new

taxiway, because it will safe time, fuel and fumes.

Hydrogen Powered Airplanes

Hydrogen powered aircraft are usually designed with the liquid hydrogen fuel

carried inside the fuselage, in order to minimize surface-area and reduce boil-off.

The future of low carbon science & technology airplanes are assessed, evaluated &

its findings are being implemented & monitored after a fact finding mission. The

information was gathered to help assess and create three new concentration curric-

ulums. One of the current green sky initiative related curriculum objectives being

developed is the specialty in Aviation Management as the first of its kind in Libya

(Bindra et al. 2012). It is based on the meetings with industry & academia leaders

representing a vast cross-section of the Libyan aviation industry. This includes the

Civil Aviation Authority, Libyan Airlines, Air Libya, ICAO—International Civil

Aviation Organization, Airport Company of Libya, local airport managers, and

local and regional government agencies. The overall impression is that there is a

great need for greener aviation in the higher education system of Libya. This paper

examines the needs assessment for aviation fuel curriculum in the higher educa-

tional system and also explores the content of this curriculum.

Rationale for Change and Development

Aviation management encompasses a multitude of aviation interest since the

industry has delineated itself into various categories such as airline, airport, civil

aviation, air traffic control, and piloting (as evident by the number of professional

associations). All these represent the planning and managing of a business that

brings people together with a specific mission and need to accomplish a specific

organizational goal. Aviation helps contribute to growth in many other areas:

tourism hinges on airports and the airlines to deliver passengers to resort locations,

corporate enterprises depend on civil aviation businesses to maintain and fuel their

aircraft and to take care of their flying customers. All these aviation services require

a strong regulatory body like the Libyan Civil Aviation Authority (CAA) and a

strong airport management system.

32 Hydrogen Fueled Airplanes, Test Case: Aviation in Libya 425

The current state of the Libyan Aviation Industry is in turmoil and requires a

growing and prospering environment for great strides to modernize and expand. A

move by the country to become a North African hub requires participation at the

highest forum with regards to aviation matters. There is a need for better trained

individuals to work in this dynamic industry. In the Libyan Civil Aviation

Authority’s Strategic Plan in line with Ministry of planning 2013–2030 3rd gener- ation planning requires, strategic mapping process (Bindra 2012, 2014). This out-

lines the new strategic objective to attract, develop, and retain human capital. The

critical issues outlined in this process include: establishing competitive remunera-

tion structures, favorable working environments, and commitment by management

to training development, creation of a management development program, and staff

Morale. It is hoped that these issues will assist in accomplishing one of its main

priorities that is aviation safety, security, transformation and growth.

UNCSD RIO+ 20 Libya Focal Point for Sustainable Development

Rio + 20, like the past Rio Earth Summit & Johannesburg Conferences, did provide

an opportunity for the international community to assess achievements and progress

since 1992 together (Bindra et al. 2012). It also gave a forum to highlight the unmet

objectives and gaps that have hindered implementation of the decisions and rec-

ommendations of the two previous summits, with a view to making the improve-

ments needed for the post-2012 global agenda. This agenda acknowledges the

legitimate expectations by incorporating economic, social and environmental con-

cerns, in order to better respond to the necessity for growth and progress that can

ensure a decent standard of living for citizens in a context of multidimensional

international crisis. New Libya’s input to the United Nations Conference on Sustainable Development held in Rio de Janeiro in June 20–22, 2012 is part of

the both national New Libya rebuilding efforts in line with international

community’s global effort to promote support and enhance development that is respectful of the environment. It is the outcome of a non-exhaustive analysis of

New Libya’s socio-economic and environmental achievements as a result of the commitments made at the 1992 Rio Summit, Johannesburg Summit and numerous

subsequent events & conferences. It also reflects the concerns that free Libyan

society emerging out of the recent crisis and faced with formidable task of rebuild-

ing the nation shares with its neighbour regional and international partners in the

Mediterranean & Euro Med region, Maghreb Union, African Union, the League of

Arab States and the Group of 77 and BRICS, which it shared once again in 2012.

Libya has initiated a revitalized national environment strategy (NES) and a

national plan of action for environment and sustainable development (NPAE-SD)

in the context of a participatory approach involving all stakeholders as national

actors. The national environmental strategy aims to achieve sustainable economic

426 S.P. Bindra et al.

growth both during and after rebuilding by putting in place public policies to

improve health and quality of life, conserve and increase the productivity of natural

resources especially its Oil & Gas reserves, reduce economic losses and increase

competitiveness and, lastly, protect the environment. It is committed to put into

practice through the rebuilding New Libya laws on sustainable development.

A number of initiatives (Bindra et al. 2012; Bindra 2014) have also been created,

including the First Libyan Environmental Engineering & Sciences Center (EESC),

Libyan Business Council for Sustainable Development (LBCSD), Libyan 350 org,

Libyan National Platform for Risk Reduction, Care Libya Brand Foundation

(CLBF), Green Sky Initiative, Desert Prosperity Initiative, Sustainable Solid

Waste Management Initiative. The national, regional rebuilding schemes, and

initiatives provide a policy framework for a wide range of environmental protection

and regional rebuilding development after the Arab Spring aimed at sustainable

development.

The country is committed to implement many initiatives to foster education and

training on sustainable development. Authors as focal point in Libya have set up a

network of technical institutions committed to education and training on

Eco-Efficiency and sustainable development in the country (Bindra 2014).

Greener Skies Initiative in Libya

The green skies initiative by a team of leading former and serving professors and

experts in Libya is based on principles that govern both ecological systems and

control economic systems. Airspace design for the Environment considerations are

shown below:

It considers that “If you violate ecological principles you might be able to make a

fast buck on the short term,” “but long-term, you’ll have an economic disaster” It is

based on UNCSD Rio +20 Future we want that advocates and requires the need to

use citizen power backed by intelligent management of the ecosystems and nature-

based infrastructure (Bindra et al. 2012). It provides a way forward to think about

pragmatic and realistic approaches to the challenges of climate change and envi-

ronmental sustainability, and the critical role of innovation and greening of indus-

try. Equity, the right to development and the principle of common but differentiated

responsibilities are the basis of Libyan approach.”

In addition even for external infrastructure there is plan to introduce Inherently

Low Emission Vehicle Program (ILEAV). The purpose of the Program is to

evaluate airport use of alternative fuel vehicles (AFV) and infrastructure to deter-

mine their reliability, performance, and cost-effectiveness in the airport environ-

ment (Robertson 2008; Maniaci 2006). The Requirements are:

• Public-use airports in areas that do not meet federal air quality standards

designed to protect public health.

32 Hydrogen Fueled Airplanes, Test Case: Aviation in Libya 427

• Vehicles operating exclusively on six alternative fuels: Compressed Natural Gas

(CNG); Liquefied Natural Gas (LNG); Liquefied Petroleum Gas (LPG); elec-

tricity, hydrogen, or methanol-85. See Fig. 32.2 below with H2 Tanks of liquid

hydrogen study plane.

Being an alternative to traditional jet fuel, hydrogen has a higher energy density

per unit mass but a lower energy density per unit volume, and containing the hydrogen at high pressure requires a heavy container. In aircraft heavy containers

are not an option, and therefore regular carbon fibre tanks are often used, which can

only sustain a pressure of about 350 bar. This is significantly lower compared to

steel hydrogen containers (used in cars and ships) which can sustain 500–700 bar.

This limitation decreases the amount of energy that can be spent on the propulsion

by about half. Alternatively, as with some rockets, cryogenic liquid hydrogen could

be employed. Libya being a country blessed with highest solar radiation intensity

supports the recent Si2 as the first sun-powered aircraft able to stay aloft for several

days and nights. That is powered by more than 17,000 solar cells built into wings

that, at 72 m (236 feet), are almost as long as those of an Airbus A380 superjumbo.

This is an innovative design, the light-weight carbon fibre aircraft weighs only 2.3-

tonnes, about the same as a family 4� 4 and less than one percent of the weight of the A380. The propellor craft has four 17.5 horsepower electric motors with

rechargeable lithium batteries. It is planned to land 12 times on the trip lasting

about 25 days spread over five months.

The longest single leg allows a lone pilot fly non-stop for 5 days across the

Pacific Ocean between Nanjing, China and Hawaii, a distance of 8500 km (5270

miles) (Fig. 32.3).

From the Gulf Si2 it did cross the Arabian Sea to India before heading on to

Myanmar, China, Hawaii and New York. Landings are also earmarked for the

Mid-Western United States and either southern Europe or North Africa, depending

on weather conditions.

Fig. 32.2 H2 tanks of liquid hydrogen study plane

428 S.P. Bindra et al.

Si2 is the successor to Solar Impulse, a smaller craft that notched up a 26-h flight

in 2010, proving its ability to store enough power in the batteries during the day to

keep flying at night. It travels at 50–100 km per hour, with the slower speeds at

night to prevent the batteries from draining too quickly.

Libyan Strategy

The Libyan strategy includes a project to use information and communications

technologies to reform the technical education and scientific research system,

which has the potential to become a model for the proper integration of ICTs in

cleaner and greener skies using fuels like Hydrogen in the country.

Libya has also helped the country in developing system level improvement,

institutional level improvement and individual level improvement based on key

principles for GEF-UNDP supported national capacity self assessment (NCSA).

These principles are (1) Ensuring national ownership, leadership and policy com-

mitment, (2) Using existing mechanisms and structures whenever possible, (3) Pro-

moting multi-stakeholder participation, (4) Adopting a holistic approach to capacity

building, (5) Adopting a long-term approach to capacity building, (6) Considering

obligations of the three Rio Conventions; (7) Balance Between Process and Product

so that (a) The process should increase stakeholders buy-in and (b) The Product

should be of high quality so that government take recommendations/actions as

priorities into national budgeting and donor can support it.

The current proposal under the form of civil aviation cleaner and greener

airplanes fuels aims at ensuring at relatively short notice, access to and progressive

Wingspan: 72.3 m

Planned world tour to promote alternative energy Solar Impusle 2

Distance: 35,000 km 500 hours flight time A 5-month missionLength: 22.4 m

Weight: 2,300 kg Ave. speed: 70 kph Max. altitude : 8,500 m Carbon fibre: 80%

17,000 solar cells spread across

Propulsion: 4 electric engines

Propellers 4 m in diameter

Cockpit: 3.8 m3 - Non-pressurised cabin - No heating or air conditioning - Insulating foam

Thickness of cells: 35 microns

Source: solarimpulse.com

270 m2 of wings and fuselage

Fig. 32.3 Factfile on the new solar-powered aircraft solar impulse 2

32 Hydrogen Fueled Airplanes, Test Case: Aviation in Libya 429

ownership by the Libyans, of the required technical and instrumental capacities.

This would also provide opportunities for implementation of practical steps like

rapid diffusion of economic data, information on best practices through networking.

At the international level, Libya intends to help in not only in transfer, adapt,

adopt, absorb and embrace advanced technology and governance practices but also

access to most up to date and unbiased scientific data and information to confront

challenges of future. This would help country to play an effective and leading role

in promoting international cooperation with organizations of the UN System,

among others ICAO, UNEP, UNESCO, FAO, as well as, regional counterparts

(Mediterranean, Euro-Med, Maghreb Union, Arab, Sahel and other African) and

also other multi- and bilateral funding or assistance providing sources.

Discussion of Case Study Survey Results from Respondents

Based on pilot scale surveys, interviews and meetings with stakeholders it is found

that every civil aviation entity has offered advice and input to the potential new

airplanes fuels & alternative Fuels See Figs. 32.2 and 32.4 and expressed immediate

support of the new program in Libya. All organizations express that they are

struggling to find relevant personal with appropriate aviation qualifications to hire

for entry level positions. Presently they are spending much time and money to

introduce the basic knowledge of aviation to new hires. They both agree there is a

0.9

0.8

0.7

0.6

0.5

0.4

0.3 0.6 0.7 0.8 0.9

Relative Fuel Carried

Advanced Technology

Design J Min Fuel

Design K Min NOx

Design C Min NOx

R el

at iv

e LT

O N

O x

Design B Min Fuel

1.1 1.2 1.31

Aerospace Design for the Environment • 60% laminar wing • 20% composite weight reduction • 10% vortex drag saving

Fig. 32.4 Airspace design for the environment

430 S.P. Bindra et al.

need for greener aviation management curriculum in higher education (Figs. 32.5

and 32.6).

Many respondents suggest that new Libya needs airport and airline managers

who are able to communicate with the public, understand their needs and deliver a

product to meet these needs within budget. They all feel that professional aviation

management skills must be help to coordinate elements of marketing, media,

sponsorship, budgets, financial management, public speaking, planning, and

Fig. 32.5 Jet fuel alternatives

Fig. 32.6 Alternative fuels for aviation

32 Hydrogen Fueled Airplanes, Test Case: Aviation in Libya 431

complying with regulatory bodies. Most stakeholders say that new Libya needs

more of sophisticated IT systems. These systems are required along with skill sets

needed for financial management, logistics, reservations, and certification.

Concluding Remarks

Hydrogen-fueled airplanes use hydrogen as a power source. Hydrogen is either

burned in jet engine, or internal combustion engine, or used to power a fuel cell to

generate electricity to power a propeller. The science & technology of hydrogen

fuelled airplanes for aviation industry impacted by low carbon requirement in new

Libya is in the process of change. The appraisal of existing situation and needs

assessment surveys of industry and government officials in Libya clearly indicate

the need for improved hydrogen fuelled airplanes. Survey results indicate that new

aviation fuel is feasible alternative similar to Toyota Mirai sedan—powered by

hydrogen and emitting nothing but water vapour from its tailpipe. The hydrogen

fuelled airplane like Mirai car can travel without refuelling, some three times

further than an electric car, and its tank can be filled in a few minutes like gasoline

engine vehicles. However, aircrafts need to be configured in such a fashion that the

current low energy output from hydrogen propulsion (a result of the low-pressure

hydrogen tanks) do not pose a problem due to its volume and high volatility. Finally

the paper demonstrates that in order to achieve aviation sustainability it is possible

to meet the challenges of 4� larger fuel tanks, higher drag, higher empty weight, H2 production issues, new infrastructure, affordable cost, high technical risk, passenger

acceptance and environmental effects.

References

Bindra, S. P. (2012). Rio+20 Libyan National Report. UNCSD. Brazil: Rio. Retrieved June 2012.

Bindra, S. P. (2014). Civil aviation technical college on low carbon sky related science &

technology education in Libya, Istanbul Turkey.

Bindra, S. P., et al. (2012). Change and development in civil aviation. ICERI 5th International Conference of Education, Research an Innovation 19th–21st of November, 2012. Madrid, Spain: IATED.

Maniaci, D. C. (2006). Operational performance prediction of a hydrogen-fueled commercial

transport. 2006 Symposium.

Robertson, D. (2008). Boeing tests first hydrogen powered plane. London: The Times.

432 S.P. Bindra et al.

Chapter 33

Perspectives of Hydrogen Automotive Applications in Croatia

Ankica Đukić, Ivan Güttler, and Robert Pašičko

Introduction

Global Warming

The warming signal in the global near-surface air and ocean temperature began to

emerge from the middle of the 20th century. Up to then, it was masked by the

internal variability of the Earths climate system and influences of the events such as

changes in the solar energy output and volcanic activities. Globally averaged

surface temperature change was estimated to equal 0.85 �C over the period from the 1880 to the 2012. However, the rate of this warming is increasing in recent

decades and regionally warming can acquire even higher levels. The changes in the

climate system are not limited only to temperature changes. Other changes in the

climate system include the melting of the Arctic sea ice, melting of the most of

the worlds glaciers, reduction of the land ice over Greenland and Antarctica.

Furthermore, the increasing rates of the sea level rise as well as the ocean heat

content, various changes in the hydrological system (this can regionally and locally

A. Đukić (*) Faculty of Mechanical Engineering and Naval Architecture, University of Zagreb, Ivana

Lučića 5, Zagreb 10000, Croatia

e-mail: [email protected]

I. Güttler

Meteorological and Hydrological Service of Croatia, Grič 3, Zagreb 10000, Croatia

e-mail: [email protected]

R. Pašičko

United Nations Development Programme, Radnička cesta 41, Zagreb 10000, Croatia

e-mail: [email protected]

433

mailto:[email protected]

emerge either as a positive or negative change in the precipitation, runoff and soil-

moisture signal) and other changes that put pressure to the biosphere and society

(IPCC 2014).

Observed and projected temperature and precipitation changes over Croatia

were assessed in (Branković et al. 2013) and (MZOIP 2014). Various human

activities related to economic activities and population growth are intrinsically

related to the energy production and emission of various combustion products.

Although there are human related impacts such as changes in the land types and

land use practices (this can locally and regionally change the energy, momentum

and mass flows), most important impact is related to the changing the chemical

composition of the atmosphere, primarily through the emission of the GHG such as

CO2, CH4, N2O etc., and secondly through emission of different aerosols. Current

GHG emissions are approximately 50 Gt CO2 eq. per year, and rising.

Therewithal, oceans and biosphere are still net sinks of the additional CO2, but

the amount of CO2 is accumulating in atmosphere and currently equals approxi-

mately 400 ppmv in standard conditions. In nutshell, although different human

activities can induce warming and cooling effects, the current net impact on the

state of the climate system is substantial warming related to the GHG emissions.

IPCC AR5 presented estimates indicating that in order to constrain anthropogenic

warming to less than 2 �C (relative to 1861–1880) would require cumulative CO2 emissions since 1870 to amount below approximately 3000 GtCO2. At the same

time, by the year 2011, about 2000 GtCO2 was already emitted, strongly controlling

the available time period and the scale of the changes that are needed to be

implemented in order to keep the global mean temperature increase below 2 �C (IPCC 2014). Of course, the most of these estimations are also constrained by the

various uncertainties. However, independent studies indicate the need for rapid and

large-scale upgrade of the existing energy, transport, housing and food production

systems.

Transition to Low-Carbon Society and Hydrogen Economy

Concepts of green economy, low emission development, Hydrogen Economy or

achieving a 100% renewable energy systems became increasingly important after

2008 both in the number of published studies, analyses or papers as well as in the

attention it gained on an international level (Pašičko 2014). It also became clear that

the existing model of economic development needs to change and transition

towards different foundations is needed. There are several reasons that can be

found and understood or that were mentioned in the literature: (1) Economic crisis

that started in 2008 was heavily influenced by the energy crisis (record high prices

of oil and gas) and combined and / or alone resulted in other crises such as food

crisis, political crisis etc; (2) Increased warnings that society is in danger of

transgressing a number of planetary boundaries or ecological limits (Raworth

2012); contrary to economic philosophy that resources come from the market, it

434 A. Đukić et al.

is more and more clear they come from nature. Every incident including a deep oil

drilling is a reminder that harm to society and environment are increasing as fewer

fossil fuels are available; (3) Global warming is becoming more evident while on

the other side there is a clear lack of political decision on the global level to tackle

this issue; (4) Avoid the trap of ‘growing first, cleaning up later’ (Atkisson 2012); (5) Growing pressure from people excluded from economic growth (1.3 billion still

do not have access to the electricity, 2.6 billion do not have access to the sanitation

and 900 million lack access to the clean drinking water); (6) Given the fact that

fossil fuels are still heavily subsidized by governments (Kovacevic 2011), in a

much higher share than renewable energy or energy efficiency, the present eco-

nomic model represents a sort of lock-in against low emission development;

(7) Energy security issues—with higher and higher energy import dependences,

renewable energy and energy efficiency are becoming more and more important.

The term of Green Economy was first coined in 1989 in a pioneering report for

the Government of the United Kingdom by a group of leading environmental

economists, entitled Blueprint for a Green Economy (Pearce et al. 1989). In 2008

the term was revived in the context of discussions on the policy response to

the multiple global crises. The United Nations Environment Programme (UNEP)

introduced Green Economy, which it defines as one that ‘results in improved human well-being and social equity, while significantly reducing environmental risks and

ecological scarcities’ (UNEP 2011). During the financial crisis it inspired several governments to implement signif-

icant ‘green stimulus’ packages as part of their economy recovery efforts. The concept of Green Growth has its origins at the Fifth Ministerial Conference on

Environment and Development (MCED) held in March 2005 in Seoul. 52 Govern-

ments and other stakeholders from Asia and Pacific agreed to move beyond the

sustainable development rhetoric and pursue a path of Green Growth. As with

Green Economy, Green Growth attracted significant attention as a way out of

economic problems in the aftermath of the 2008 financial crisis. Green Growth is

principally a ‘top-down’ approach, driven by government initiatives. It can also be criticized for being ‘green’ in relatively limited ways, but it emerged as a serious and very mainstream alternative to Growth as Usual with both environmental and

social dimensions.

To define Sustainable Development, an international exercise was performed that catalogued, analyzed, and synthesized: written submissions and expert testi-

mony from ‘senior government representatives, scientists and experts, research institutes, industrialists, representatives of non-governmental organizations, and

the general public’ held at public hearings throughout the world, in 1987, the United Nations released the Brundtland Report, that included what is now one of

the most widely recognized definitions: ‘Sustainable development is development that meets the needs of the present without compromising the ability of the future

generations to meet their own needs’ (UNWCED). The concept of Low Carbon Development has its roots in the United Nations Framework Convention on Climate

Change (UNFCCC) adopted in Rio in 1992. In the context of this convention, Low

Carbon Development is now generally expressed using the term Low‐Emission

33 Perspectives of Hydrogen Automotive Applications in Croatia 435

Development Strategies (LEDS). Though no formally agreed definition exists,

LEDS are generally used to describe forward‐looking national economic develop- ment plans or strategies that encompass low‐emission and / or climate‐resilient economic growth.

Whilst the concepts of Green Economy, Green Growth, Sustainable Develop-

ment and Low Carbon Development emerged from different sources, through the

work of different organizations and with different target audiences, the distinctions

among them became blurred and they are now being used almost interchangeably.

A main driver behind the development of these concepts was the move towards a

more integrated and holistic approach to incorporating environment in policies,

economic decision making and planning.

Croatia has recently joined the growing number of countries in the world that

have already started to develop a long-term strategy for low-carbon development

and thereby firmly embarked on the road to sustainable development. The approach

that determines impacts of Hydrogen Economy in the context of low emission

development was the core for the methodology used in this work. The design of the

low-carbon society requires innovative energy systems considering a trans-

disciplinary approach that integrates multi-dimensional elements, related to

the social, economic, and environmental aspects (Nakata et al. 2011). Development

of energy and transportation sector is complex and increasingly often evaluated as a

part of society-biosphere-climate-economy-energy system (Akhtar et al. 2013).

Description of Croatian Power System and Renewable Energy

Croatia is currently importing around 50% of its energy of which 80% is oil.

Almost all electricity generation capacity is in ownership of Croatian Electrical

Utility, HEP Group. From 3993 MW installed, 2056 MW is in hydro, 1589 MW in

thermal power plants and 348 in Croatian part of nuclear power plant Krsko.

Specificity of Croatian power system is large percentage of installed power in

hydro (52%) that requires reserve capacity during summer period when water

level is low. Ever growing electricity consumption is not offset with new generation

capacities and electricity import is rapidly rising. That emphasizes need for new

generation capacities. Currently, LEDS is in progress—with focus up to 2030 and

outlook to 2050.

Hydrogen in Transport

Based on today’s global climate changes, the main goal of this work was to research how new technologies application can help in mitigation of GHG. Due to

the increasing of the GHG concentrations, this work focuses on climate change

analysis, transition of energy, and transportation sector towards low carbon

436 A. Đukić et al.

paradigm. As one of the most critical barriers to achieve 100% renewable energy

system is intermittent nature of renewable energy such as solar and wind, demand

for energy storage becomes important (Moriarty and Honnery 2009; Najjar 2013).

And that’s the point where hydrogen as the great energy carrier can be implemented. This is where the focus of this work was positioned, related to the

transport sector as the highest energy consumer and polluter (Shafiei et al. 2014).

Given the intermittent nature of renewables, energy peaks from wind and solar

energy can be transferred to the hydrogen for later use and / or utilize in transport

sector (Đukić 2015). This also provides more flexibility in the power system network to offset production peaks to energy for use when needed (Cipriani

et al. 2014).

A global trend of population growth leads to the increasing of energy demands,

resulting in decreasing of fossil fuels reserves, increasing of CO2 emission and

increasing of the temperature, respectively. Here is where the transfer to the Hydro-

gen Economy has to be applied. The drivers of Hydrogen Economy in the countries

worldwide are energy safety, climate changes, air pollution, and competitiveness in

the world market (Andrews and Shabani 2012). Hydrogen technologies and their

applications are investigated worldwide, from the aspect of sustainable develop-

ment, cleaner technologies, energy efficiency and energy savings. A transport

sector is the leader of energy consumption and air pollution, the most evident in

urban cities. Due to that hydrogen fuel cells powered vehicles present one of the

rare technologies capable to switch over internal combustion engines vehicles

(Biswas and Thompson 2013). As it is written above importance of involving of

hydrogen fuel cells powered vehicles is recognized not just in Europe but all over

the world. US Department of Energy predicts demands for hydrogen of 150 Mt until

2040 (Hamad et al. 2014). Thus, countries of Asia such as Japan, China, Korea,

India, Malaysia, and Taiwan invest millions dollars to make green transport sector

(Lu et al. 2013). For instance, Japan set the goal to have each new vehicle as

hydrogen fuel cells powered until 2020. In India the goal is to have 1 million

hydrogen fuel cells powered vehicles. A rapid implementation of hydrogen fuel

cells powered vehicles in Asia also started because 13 of 20 the most polluted cities

are located in China (Pudukudy et al. 2014).

The goal of EU is set to be the first Hydrogen based Economy in the world. In

order to realize this plan the list of legislatives has to be set. In other words, EU

country states need to reform their statutes to ensure successful transition to the

hydrogen technologies (Apak et al. 2012). Nowadays EU Commission applied

directive in order to approve hydrogen fuel cells powered vehicles. Furthermore,

EU established platform for hydrogen and fuel cells to encourage the development,

making strategy, and introduction of standards and legislatives. Aside of legisla-

tives, public-private partnership should be highlighted as a step forward in

the financing major projects. These partnerships is going to be applied within

several years. During that time period both parties should invest 470 millions

euros each. As the result, future EU investment in hydrogen technologies will be

around one billions euros.

33 Perspectives of Hydrogen Automotive Applications in Croatia 437

Croatia as a full member of EU should aim to shift to the new technologies as

soon as it can. Meeting this demand the increased investment in hydrogen technol-

ogies is required. Croatia is a touristic country with large amount of motorized

vehicles during the year with trend of double / triple increasing in summer months.

It is important to highlight that hydrogen as a fuel is clean as much as is clean

energy and processes used for its production. To satisfy this claim hydrogen

production via water electrolysis using renewable energy sources is unquestionable

(Đukić and Firak 2011). In Croatia there are around 1.9 millions vehicles. From this number, approximately 1.5 millions belong to the passenger cars. To accomplish

hypothesis of clean and environmentally friendly hydrogen, there were performed

calculations for the systems that include use of solar and / or wind energy,

i.e. photovoltaic cells and / or wind turbines (Nowotny and Veziroglu 2011).

Given results represent directions in the system development based on installed

power of solar and wind energy, taking into account demands for hydrogen

amounts. Conclusions and recommendations are based on analyzing three different

scenarios with hydrogen as the energy storage in Croatia; in what extent can

hydrogen be used as the energy carrier to store excessive energy from intermittent

renewable energy sources. In order to estimate potential savings in CO2 emissions,

in this study some methodological approaches from (Pascala and Socolow 2004)

were applied. These options are related to the improved fuel economy, reduced

reliance on the vehicles and the use of the renewable hydrogen in the transportation

sector.

Methodology

Following potential changes in the transportation system were analyzed in this

study: (1) A fraction of the hydrogen powered vehicles was assumed to be equal

10%, 50 %, and 75% by the year of 2030. Starting fraction of the hydrogen fuel

cells powered vehicles in Croatia was assumed as 0%; (2) The kilometers values

were assumed to be equal 600, 700 or 800 km / 5 kg of H2 by the year of 2030 with

starting kilometers value assumed to be equal 500 km / 5 kg of H2 as an average

value of 500 km that can be traveled by the current generation hydrogen fuel cells

powered vehicles. Total number of scenarios in this set was 9, where all combina-

tions of the fraction of the hydrogen fuel cells powered cars and the average

efficiency were evaluated. It was also applied following 3 constants in this set of

scenarios: the number of the passenger cars was assumed to be equal 1448229 (DZS

2014) and constant by the year of 2030. Also, average number of kilometers

traveled per year was assumed to be equal 11000 km / year and constant in this

set of scenarios, while the average gasoline consumption used to estimate potential

savings was assumed to be equal 10 km / L.

Although various assumptions in this set of scenarios were subject to the various

uncertainties and limitations, they provided simple and realistic framework to

evaluate possible hydrogen production and storage needs in Croatia. In order to

compare hydrogen scenarios in this work to potential savings in the gasoline

438 A. Đukić et al.

consuming cars, next set of scenarios was also evaluated. There were additionally

constructed 9 scenarios based on the following options: (1) The average distance

was assumed to decrease up to the year of 2030. Starting from 11000 km / year,

potential reductions in the gasoline consumptions and reductions in the CO2 emissions, when distance was reduced to the 9000 km, 7000 km or 5000 km per

year, were evaluated; (2) The average distance was assumed to reach 11 km, 15 km

or 20 km per liter by the year 2030. In this set of scenarios the same number of

passenger cars as in the hydrogen scenarios and the same starting average distance

and gasoline consumption were assumed. All changes in the projections

were assumed to vary as a linear function of time, and were estimated on the yearly

time scale. Scenarios were compared in term of the CO2 emission saved by the year

of 2030 and in the year of 2030. Some other details related to the various conversion

factors and comparisons were introduced in the results and discussion sections

where needed.

Results and Discussion

Due to the described methodology, two cases were evaluated. First one was related

to the hydrogen demands till the end of 2030 and second one was related to the

saved gasoline till the end of 2030. Case of hydrogen was consisted of the fraction

of the hydrogen fuel cells powered vehicles (included scenarios 1A: 10%, 1B: 50%

and 1C: 75%), and average efficiency of the fuel cells, i.e. kilometers per 5 kg of

hydrogen (included scenarios 2A: 600, 2B: 700 and 2C: 800). Further discussion of

these scenarios was given in the Table 33.1 with conversion factors included.

In the Fig. 33.1 there is given a projected increase of the hydrogen fuel cells

powered vehicles in Croatia by the end of 2030 (a) and average kilometers range

with 5 kg of hydrogen by the end of 2030.

Due to the average kilometers per 5 kg of hydrogen, Fig. 33.1b presents

projected ranges of 600 km, 700 km, and 800 km. However these approximations

are related to the expected improving of hydrogen storage that allows to have these

ranges. From the Fig. 33.2a it is seen how much hydrogen is needed per year from

the 2015 to the 2030. Related to the hydrogen automotive application, Fig. 33.2b

brings amounts of saved gasoline. Given results promise CO2 emissions reducing.

All Scenarios were compared in term of the CO2 emission saved by the year of

2030. The results are given in the Table 33.2

In the Table 33.3 are given results of calculations for saved gasoline within

Scenarios 1A, 1B, and 1C. Accumulated gasoline not spent / L for Scenario 1A is

1.27� 109 L, for Scenario 1B is 6.37� 109 L, and for Scenario 1C is 9.56Eþ 09 L. Table 33.4 presents data within 6 Scenarios for gasoline of average kilometers

per year and average kilometers per litre started from the 2015 to the end of

the 2030.

To compare savings in CO2 emissions and gasoline, further calculations based

on current needs of gasoline were performed. Figures 33.3a and 33.3b give view

on average kilometers per year and average kilometers per liter of gasoline.

33 Perspectives of Hydrogen Automotive Applications in Croatia 439

Both calculations results were presented in term of accumulated CO2 not released

and accumulated C not spent including 25% overheads.

In the Fig. 33.4 the combined Scenarios included in the Fig. 33.3

were presented that gives overall data of amount of gasoline needed per year.

Results were grouped into 3 additional Scenarios with group of 3 discussed

above. Calculated values of each grouped Scenarios were given in the Table 33.5.

Table 33.1 Hydrogen by the end of the 2030

Starting number of the hydrogen powered cars 0

Starting efficiency of fuel cells (km / 5 kg H2) 500

Number of passenger cars (assumed constant) 1448299

Average kilometers per year (assumed constant) 11000

Average kilometers per litre of gasoline (km / L) (assumed constant) 10

Fraction of hydrogen fuel cells powered vehicles by the end of 2030

Scenario 1A 10%

Scenario 1B 50%

Scenario 1C 75%

Average kilometers (km / 5 kg H2) by the end of 2030

Scenario 2A 600

Scenario 2B 700

Scenario 2C 800

Conversion factors

1 gal of gasoline>X kg of C 2.40

1 L of gasoline>X kg of C 0.63

1 kg of C corresponds to X kg of CO2 3.67

kWh needed in the electrolyzer to get 1 kg of H2 52.5

Peak power output produced by a windturbine (MWp) 3

Peak power output produced by a photovoltaic array (MWp) 0.01

Capacity factor for the windturbine 30%

Capacity factor for the photovoltaic cells 15%

1,200,000 900 800 700 600 500 400 300 200 100

1,000,000

800,000

600,000

400,000

200,000

20 10

20 15

20 20

20 25

Year

a b

N u

m b

er o

f h

yd ro

g en

f u

el c

el ls

p o

w er

ed v

eh ic

le s

A ve

ra g

e ki

lo m

et er

s p

er 5

k g

o f

h yd

ro g

20 30

20 35

20 10

20 15

20 20

20 25

Year

20 30

20 35

Scenario 1A

Scenario 1B

Scenario 1C

Scenario 2A

Scenario 2B

Scenario 2C

Fig. 33.1 Hydrogen fuel cells powered vehicles: 10 %, 50 %, and 75% (a); Average kilometers per 5 kg of hydrogen (b)

440 A. Đukić et al.

The main Scenarios studied within this work were based on the hydrogen and

gasoline calculations. Results give good directions to the shift to the hydrogen fuel

cells powered vehicles. A stronghold is basically in high CO2 saving as well as

savings in fuel cell consumption. Hence, as a very rich with renewables such as

solar and wind energy, Croatia has a good potential to follow trends of Hydrogen

based Economy what gives tailwind to its transport sector.

a b 1.20E+08

1.00E+08

8.00E+07

6.00E+07

4.00E+07

2.00E+07

0.00E+00

20 10

20 15

20 20

20 25

Year

A m

o u

n t

o f

h yd

ro g

en n

ee d

ed p

er ye

ar \

20 30

20 35

Scenario: 1A+2A

Scenario: 1A+2B

Scenario: 1A+2C

Scenario: 1B+2A

Scenario: 1B+2B

Scenario: 1B+2C

Scenario: 1C+2A

Scenario: 1C+2B

Scenario: 1C+2C

1.40E+09

1.20E+09

8.00E+08

1.00E+09

6.00E+08

4.00E+08

2.00E+08

0.00E+00

A m

o u

n t

o f

sa ve

d g

as o

lin e

20 10

20 15

20 20

20 25

Year

20 30

20 35

Scenario 1A

Scenario 1B

Scenario 1C

Fig. 33.2 Amount of hydrogen needed per year (a); Amount of saved gasoline (b)

Table 33.2 Amount of H2 needed per year (kg)

Scenario 1Aþ 2A 1Aþ 2B 1Aþ 2C Accumulated H2 (1000 t) 112.23 100.53 91.22

2030 - demand for H2 (1000 t) 13.28 11.38 9.96

Electricity needed in 2030 for H2 production (MWh) 696.994 597.423 522.745

Installed power of the windturbines needed in 2030

(MW)

265.2 227.3 198.9

Installed power in the photovoltaic array needed in

2030 (MW)

530.4 454.6 397.8

Scenario 1Bþ 2A 1Bþ 2B 1Bþ 2C Accumulated H2 (1000 t) 561.13 502.64 456.08

2030 - demand for H2 (1000 t) 66.38 56.90 49.79

Electricity needed in 2030 for H2 production (MWh) 3484969.47 2987116.69 2613727.10

Installed power of the windturbines needed in 2030

(MW)

1,326.1 1,136.6 920.9

Installed power in the photovoltaic array needed in

2030 (MW)

2,652.2 2,273.2 1,841.8

Scenario 1Cþ 2A 1Cþ 2B 1Cþ 2C Accumulated H2 (1000 t) 841.70 753.97 684.13

2030 - demand for H2 (1000 t) 99.57 85.35 74.68

Electricity needed in 2030 for H2 production (MWh) 5227454.20 4480675.03 3920590.65

Installed power of the windturbines needed in 2030

(MW)

1989.1 1705 1491.8

Installed power in the photovoltaic array needed in

2030 (MW)

3978.2 3410 2983.7

33 Perspectives of Hydrogen Automotive Applications in Croatia 441

Table 33.3 Amount of gasoline saved in Scenarios 1A, 1B, and 1C

Scenario 1A 1B 1C

Accumulated gasoline not spent (L) 1.27Eþ 09 6.37Eþ 09 9.56Eþ 09 Accumulated C not spent (kg) 8.08Eþ 08 4.01Eþ 09 6.02Eþ 09 Accumulated C not spent (kg)þ 25% overheads 1.01Eþ 09 5.02Eþ 09 7.53Eþ 09 Accumulated C not spent (1000 t)þ 25% overheads 1010.06 5018.36 7527.53 Accumulated CO2 not released (1000 t)þ 25% overheads

3706.94 18417.37 27626.05

2030 - not released CO2 (1000 t)þ 25% overheads 463.37 2316.84 3475.25

Table 33.4 Gasoline by the end of 2030 (Mt CO2¼ 3.71Eþ 00 for the 2015) Number of passenger cars (assumed constant) 1448299

Starting average kilometers per year 11000

Starting average kilometer per liter of gasoline (km / L) 10

Average kilometers per year by the end of the 2030

Scenario G1A 9000

Scenario G1B 7000

Scenario G1C 5000

Average kilometers per liter of gasoline (km /L) by the end of the 2030

Scenario G2A 11

Scenario G2B 15

Scenario G2C 20

Conversion factors

1 gal of gasoline>X kg of C 2.40

1 L of gasoline>X kg of C 0.63

1 kg of C corresponds to X kg of CO2 3.67

12,000

10,000

8,000

6,000

4,000

2,000

0A ve

ra g

e ki

lo m

et er

s p

er y

ea r

A ve

ra g

e ki

lo m

et er

s p

er li

tr e

o f

g as

o lin

Scenario G1A

Scenario G1B

Scenario G1C

Scenario G2A

Scenario G2B

Scenario G2C

20 10

20 15

20 20

20 25

Year 20

30 20

35 20

10 20

15 20

20 20

Year 20

30 20

25.00

20.00

15.00

10.00

5.00

0.00

a b

Fig. 33.3 Average kilometers per year: 9000, 7000, and 5000 km (a); Average kilometers per liter of gasoline: 11 km, 15 km, and 20 km (b)

442 A. Đukić et al.

Conclusions and Future Work

Croatia as a touristic country has a great potential for hydrogen automotive appli-

cation. The number of motorized tourists is rapidly increasing during summer

months. This fact opens enough room to the hydrogen fuel cell powered vehicles

shift starting with 10%, 50%, and 75% up to the end of the 2030. Due to the EU

directives flows of hydrogen powered vehicles should be set for every 300 km.With

G as

o lin

e n

ee d

ed p

er y

ea r/

1.20E+09 1.40E+09 1.60E+09 1.80E+09

1.00E+09 8.00E+08 6.00E+08 4.00E+08 2.00E+08 0.00E+00

20 10

20 15

20 20

20 25

Year 20

30 20

Scenario: G1A+G2A

Scenario: G1A+G2B

Scenario: G1A+G2C

Scenario: G1B+G2A

Scenario: G1B+G2B

Scenario: G1B+G2C

Scenario: G1C+G2A

Scenario: G1C+G2B

Scenario: G1C+G2C

Fig. 33.4 Amount of gasoline needed per year

Table 33.5 Gasoline needed per year (L)

Scenario G1AþG2A G1AþG2B G1AþG2C Accumulated gasoline not spent (L) 3.36Eþ 09 6.52Eþ 09 9.13Eþ 09 Accumulated C not spent (kg) 2.13Eþ 09 4.13Eþ 09 5.79Eþ 09 Accumulated C not spent (kg)þ 25% overheads 2.66Eþ 09 5.17Eþ 09 7.23Eþ 09 Accumulated C not spent (1000 t)þ 25% overheads

2664.48 5167.12 7234.84

Accumulated CO2 not released (1000 t)þ 25% overheads

9778.63 18963.33 26551.85

Scenario G1BþG2A G1BþG2B G1BþG2C Accumulated gasoline not spent (L) 5.53Eþ 09 8.26Eþ 09 1.05Eþ 10 Accumulated C not spent (kg) 3.51Eþ 09 5.24Eþ 09 6.68Eþ 09 Accumulated C not spent (kg)þ 25% overheads 4.38Eþ 09 6.55Eþ 09 8.35Eþ 09 Accumulated C not spent (1000 t)þ 25% overheads

4383.50 6545.02 8347.89

Accumulated CO2 not released (1000 t)þ 25% overheads

16087.43 24020.21 30636.75

Scenario G1CþG2A G1CþG2B G1CþG2C Accumulated gasoline not spent (L) 7.70Eþ 09 1.00Eþ 10 1.19Eþ 10 Accumulated C not spent (kg) 4.88Eþ 09 6.34Eþ 09 7.57Eþ 09 Accumulated C not spent (kg)þ 25% overheads 6.10Eþ 09 7.92Eþ 09 9.46Eþ 09 Accumulated C not spent (1000 t)þ 25% overheads

6102.51 7922.92 9460.94

Accumulated CO2 not released (1000 t)þ 25% overheads

22396.23 29077.10 34721.65

33 Perspectives of Hydrogen Automotive Applications in Croatia 443

area of 56594 km2 (89810 km2 with associated coastal see) starting point

was suggested to be installation of hydrogen refueling stations along the seaside.

With seaside of 1777 km (over 6000 km including islands) number of demanded

hydrogen refueling stations was calculated to be 6. Hydrogen production technol-

ogy is water electrolysis using solar energy installed on-site during transition period

of infrastructure construction. Obtained results are talking of 27626.05 accumulated

CO2 not released (1000 tones) plus 25% overheads. Energy needed for fuel cells

was calculated as it comes from renewable energy—wind power plants (3 MW each

unit, with 30% capacity factor) and PV systems installed on the roof (10 kW each,

15% capacity factor). However, methodology used in this work can be easily

applied in every country for calculations of demands, taking into account total

number of internal combustion engines vehicles. Future work of the authors will be

adjusted by changing the time horizon from the year of 2030 to the year of 2050. It

will produce two additional sets of Scenarios each including nine of them.

References

Akhtar, M., Wibe, J., Simonovic, S., & MacGee, J. (2013). Integrated assessment model of

society-biosphere-climate-economy-energy system. Environmental Modelling & Software, 49, 1–21.

Andrews, J., & Shabani, B. (2012). Re-envisioning the role of hydrogen in a sustainable energy

economy. International Journal of Hydrogen Energy, 37, 1184–1203. Apak, S., Atay, E., & Tuncer, G. (2012). Renewable hydrogen energy regulations, codes and

standards: Challenges faced by an EU candidate country. International Journal of Hydrogen Energy, 37, 5481–5497.

Atkisson, A. (2012)). Life beyond growth, annual survey report of the institute for studies in

happiness, economy, and society, Japan.

Biswas, W. K., & Thompson, B. C. (2013). Environmental life cycle feasibility assessment of

hydrogen as an automotive fuel in Western Australia. International Journal of Hydrogen Energy, 38, 246–254.

Branković, Č., Güttler, I., & Gajić-Čapka, M. (2013). Evaluating climate change at the Croatian

Adriatic from observations and regional climate models’ simulations. Climate Dynamics, 41, 2353–2373.

Cipriani, G., Di Dio, V., Genduso, F., La Cascia, D., Liga, R., Miceli, R., et al. (2014). Perspective

on hydrogen energy carrier and its automotive applications. International Journal of Hydrogen Energy, 39, 8482–8494.

Đukić, A. (2015). Autonomous hydrogen production system. International Journal of Hydrogen Energy, In Press, Corrected Proof, http://dx.doi.org/10.1016/j.ijhydene.2015.02.003.

Đukić, A., & Firak, M. (2011). Hydrogen production using alkaline electrolyzer and photovoltaic (PV) module. International Journal of Hydrogen Energy, 36, 7799–7806.

DZS, (2014). Registered road vehicles and road traffic accidents 2013. http://www.dzs.hr/Hrv_

Eng/publication/2014/05-01-08_01_2014.htm. Retrieved Mar 24, 2014.

Hamad, Y. M., Hamad, T. A., Agil, A. A. A., Bapat, S. G., Bauer, C., Clum, A., et al. (2014). A

design for hydrogen production and dispensing for northeastern United States, along with its

infrastructural development timeline. International Journal of Hydrogen Energy, 39, 9943–9961.

444 A. Đukić et al.

http://www.dzs.hr/Hrv_Eng/publication/2014/05-01-08_01_2014.htm

IPCC. (2014). Climate change 2014: Synthesis report. Contribution of Working Groups I, II and III to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change [Core Writing Team, R. K. Pachauri & L. A. Meyer (Eds.)]. IPCC, Geneva, Switzerland, 151 pp.

Kovacevic, A. (2011). Fossil fuel subsidies in the Western Balkans, A report for UNDP. p. 18.

Lu, J., Zahedi, A., Yang, C., Wang, M., & Peng, B. (2013). Building the hydrogen economy in

China: Drivers, resources and technologies. Renewable and Sustainable Energy Reviews, 23, 543–556.

Moriarty, P., & Honnery, D. (2009). Hydrogen’s role in an uncertain energy future. International Journal of Hydrogen Energy, 34, 31–39.

MZOIP. (2014). Sixth National Communication and First Biennial Report of the Republic of Croatia under the United Nation Framework Convention on the Climate Change. Republic of Croatia Ministry of Environmental and Nature Protection (MZOIP), Zagreb, p. 247.

Najjar, Y. S. H. (2013). Hydrogen safety: The road toward green technology. International Journal of Hydrogen Energy, 38, 10716–10728.

Nakata, T., Silva, D., & Rodionov, M. (2011). Application of energy system models for designing

a low carbon society. Progress in Energy and Combustion Science, 37(4), 462–502. Nowotny, J., & Veziroglu, T. N. (2011). Impact of hydrogen on the environment. International

Journal of Hydrogen Energy, 36, 13218–13224. Pascala, S., & Socolow, R. (2004). Stabilization wedges: Solving the climate problem for the next

50 years with current technologies (review). Science, 305, 968–972. Pašičko, R. (2014). Optimization of power system operation and development under emission

trading scheme. PhD dissertation: University of Zagreb. Pearce, D., Markandya, A., & Barbier, E. (1989). Blueprint for green economy. U.K.: Earthscan. Pudukudy, M., Yaakob, Z., Mohammad, M., Narayanan, B., & Sopian, K. (2014). Renewable

hydrogen economy in Asia—opportunities and challenges: An overview. Renewable and Sustainable Energy Reviews, 30, 743–757.

Raworth, K. (2012). A Safe and Just Space for Humanity. Oxfam Discussion Paper. http://policy-

practice.oxfam.org.uk/publications/a-safe-and-just-space-for-humanity-can-we-live-within-

the-doughnut-210490.

Shafiei, E., Davidsdottir, B., Leaver, J., Stefansson, H., & Asgeirsson, E. I. (2014). Potential

impact of transition to a low-carbon transport system in Iceland. Energy Policy, 69, 127–142. UN WCED. (1987). Our Common Future—The Brundtland Report, Report of the World Com-

mission on Environment and Development.

UNEP. (2011). Towards a green economy: Pathways to sustainable development and poverty eradication. France: UNEP.

33 Perspectives of Hydrogen Automotive Applications in Croatia 445

http://policy-practice.oxfam.org.uk/publications/a-safe-and-just-space-for-humanity-can-we-live-within-the-doughnut-210490

Part IX

Energy Technologies and Their Effect on Global Warming

Fossil Fuels and Climate Change

Chapter 34

Contribution to Multi-Criteria Evaluation of the Impacts of Air Pollution: Case of Cement Plant (Ain Touta- ALGERIA)

Lylia Bahmed, Samia Daas, Mourad Chebila, and Loubna Khadoudja Aggabou

Introduction

The implementation of a strategy or an Environmental Management Plan (EMP), to

minimize air pollution that results from the manufacture of a product, fall within the

scope of the EMS policy of most of the cement companies in Algeria, and in

accordance with the requirements of the ISO14001 standard (Hariz and Bahmed

2013; Bahmed et al. 2009), in terms of improving their EMS, and depending on the

environmental context and legal restrictions that subject the companies regarding

the dust releases’ limits and their technical capacity to address the problems of air pollution (Hariz 2009).

In this article and after presenting the proposed methodology for the quantitative

assessment of the impacts of air pollution of cement by means of a multi-criteria

approach, a state of play on the life cycle of the cement product modeled by the

SADT method of the process of the cement plant of Ain-Touta, and its environ-

mental impacts will be quantified by the AHP method before concluding on the

prospects and expectations from this study.

L. Bahmed (*) • S. Daas • M. Chebila • L.K. Aggabou Laboratory of Research in Industrial Prevention- Industrial Health and Safety Institute,

University of Batna 2, Batna, Algeria

e-mail: [email protected]; [email protected]; [email protected]; loubna.

[email protected]

451

mailto:[email protected]

Method and Material

This study allows the proposition of a first perspective of the different actions

required to implement an effective management of the EMS. These objectives

constitute the indices that permit the assessment and evaluation of the impacts of

air pollution related to the manufacturing of a product.

Proposed Methodology

LCA is a global approach standardized according to the ISO 14040 standard, which

quantifies the impacts of a product. LCA encrypts the impacts of each component of

the product from the extraction of raw materials to the end of the cycle. The final

result is presented according to the specific impacts on climate change, human

health, ecosystems and non-renewable resources (ISO 14044 2006).

The phase of the LCA and its standardized methodology and high precision, is

an internationally recognized tool for decision support, it allows the reduction of the

impacts of the new products on the environment, the identification of what can be

improved in the already existing products, avoiding the improvement of an aspect

that creates more serious problems to another stage of the product’s life and the comparison of the environmental performances of products with the same utility

(Fig. 34.1).

In order to evaluate the environmental impacts associated with the manufacture

of cement, we have chosen the multi-criteria approach to decision support AHP,

taking into account the product life cycle and at the same time the two steps of the

LCA method (Bouhidel 2009): evacuation of the environmental impacts and

interpretation of the results.

The articulation of these tools in a methodological approach is of great impor-

tance especially for the quantitative evaluation of the environmental impacts.

Interpretation

Definition of the objectives and the

field of study

Inventory analysis

Impacts evaluation

Direct applications:

- Development and improvement of products - Strategic planning - Public policies - Marketing

Fig. 34.1 Framework of a LCA according to ISO 14040 (2006)

452 L. Bahmed et al.

Hence, the major stages of the proposed methodology are based on the multi-

criteria approach to decision support (Fig. 34.2).

The Analytic Hierarchy Process (AHP) method of T.L. Saaty (1994) was

developed in the 70 to facilitate the decision making in the complex situations

using a structured approach (Rousval and Bouyssou 2009). The AHP method takes

into consideration qualitative and quantitative criteria. This method is simple to use,

very flexible, as it is a computerized method by software called Expert Choice.

The AHP method consists of representing a decision problem for evaluating the

impacts of air pollution by a hierarchical structure reflecting the interactions

between the various phases of the life cycle of cement, then to make paired

comparisons of the criteria of the evaluations of the hierarchy, and finally to

determine the priorities of the environmental impacts.

Presentation of the AHP Method

The multi-criteria hierarchy method (MHM) or Analytic Hierarchy Process (AHP)

of T.L. Saaty (1994) was developed in the 70s to facilitate the decision making in

the complex situations using a structured approach (Aull-Hyde et al. 2006). The

AHP method allows taking into account qualitative and quantitative criteria. This

method is simple to use, very flexible, as it is a computerized method by software

called Expert Choice. Actually, several steps compose the AHP method. These

steps are sequentially detailed hereinafter.

• Step 1: Hierarchical decomposition of the complex problem into simple elements.

This essential step aims to pose the problem to be solved, to position it in its

environment in order to accurately identify its various aspects and features and

Fig. 34.2 The proposed methodology

34 Contribution to Multi-Criteria Evaluation of the Impacts of Air Pollution. . . 453

also to identify the stakeholders or experts of the decision-making process

(Fig. 34.3).

• Step 2: Comparison of criteria by means of binary comparison matrix.

The preferences of experts reflecting the relative importance between the criteria

are expressed by the weights ajj resulting from pair-wise comparison matrices between the criteria of the same hierarchical level according to a scale of

linguistic ratio. The aggregation and evaluation of weights is done from the

roots to the leaves according to a principle that akin to a weighted sum.

Configure a reciprocal square matrix formed by the evaluations of the weight

ratios N∗Nð Þ where, N represents the number of the compared elements. In this way, we obtain:

a ¼ aijWithajj ¼ 1

Let A ¼ aij to be a pair-wise comparison matrix:

A ¼ a11 a12 a1n a21 a22 a2n an1 an2 ann

0 @

1 Aaij ¼ 1

aji ,8i, j ¼ 1, 2, ::::n

The values of aij can be determined through the scale of Saaty (Table 34.1.).

Fig. 34.3 Hierarchical structure of the problem (Aull-Hyde et al. 2006)

454 L. Bahmed et al.

The reciprocal comparison according to (Saaty 1994) can be:

– Favorable and positive, the appreciation will correspond to an integer value.

– Unfavorable and therefore negative, the appreciation will be expressed using

a fraction.

• Step 3: Determine the relative importance of the criteria.

The determination of the elements’ priorities of each matrix is done by solving the eigenvector problem. The relative importance of the different criteria is

expressed by the values of the normalized vector that is equal to 1.

So the priorities are determined by solving a system of equations (Saaty

1994):

A:w ¼ λmax:w ð34:1Þ

Where:

A: is the comparison matrix of dimension N∗Nð Þ. w ¼ w1,w2, :::::::::wnð Þ Is an eigenvector of dimension N∗1 associated with

the eigenvalue.

λmax: The maximum Eigen value of the matrix. Therefore,

A:w ¼ λmax:w ) A:w ¼ Xn j¼

aij:wj

" # ,8i ¼ 1, :::::n ð34:2Þ

Then, we obtain:

λmax ¼ 1 n : Xn i¼1

Xn j¼1

aij: wj wi

ð34:3Þ

This step of the appreciations’ collect is the most controversial. Indeed, a major criticism pronounced towards AHP method concerns the scale of judg-

ment on the lack of consideration of the uncertainty in the opinions and percep-

tions of experts (Vincke 1998).

• Step 4: Consistency of judgments.

Table 34.1 Weighting scale of the AHP method (Saaty and Hu 1998)

Numerical scale Verbal scale

1 Importance equals to the two elements

3 One element is a little more important than the other

5 An element is more important than the other

7 An element is much more important than the other

9 An element is absolutely more important than the other

2, 4, 6, 8 Intermediate values between two judgments used to refine the judgment

34 Contribution to Multi-Criteria Evaluation of the Impacts of Air Pollution. . . 455

The obtained answers often exhibit some degree of inconsistency. The method

does not require that judgments neither be consistent nor transitive, contrariwise

the method to define an index of consistency IC (Saaty and Hu 1998).

IC ¼ λmax � 1 n� 1 ð34:4Þ

Where:

λmax: is the maximal eigenvalue corresponding to the matrix of pair-wise comparisons.

n: number of the compared elements.

The ratio of coherence can be interpreted as the probability that the matrix is

completed randomly. The ratio of coherence is given by the following formula:

RC ¼ IC IA

ð34:5Þ

Where:

RC: is the ratio of coherence. IA: is a random index. IC: is the index of coherence (Table 34.2). The overall coherence of appreciation is evaluated using the ratio of coher-

ence RC. Still according Saaty, the value of this latter must be at most equal to

10%.

In the case where this value exceeds 10%, the appreciations may require some

revisions.

• Step 5: Establish the relative performance of each criterion.

This last step aims to assign a performance rating for each action Pai, which will be multiplied by a weighting coefficient wi. The sum over n actions gives an aggregated performance results expressed in an overall rating (Saaty 1994):

Pci ¼ Xn i¼1

Paji � wi ð34:6Þ

Where:

Pci: Rating of performance for the criterion cj. Paji: Rating of performance for the action ai of the criterion cj. wi: Weighting coefficient for the action ai of the criterion cj.

Table 34.2 Table of the acceptable coherency’s ratios (Saaty 1994)

Size of the matrix (n) Ratio of the acceptable coherence

3 0.05

4 0.08

5 et þ 0.10

456 L. Bahmed et al.

Application of the Methodology

Our case study is applied to the life cycle of cement manufacturing of the cement

plant Ain-Touta Batna.

The application of the SADT method allows us to model the cement life cycle

and determine its major phases and their interactions (Fig. 34.4).

This method facilitates the passage of the environmental impacts’ evaluation during the analysis of the life cycle of the cement product, by the application of

normative LCA methods and AHP method.

This method facilitates the passage of the environmental impact evaluation in

the analysis of the life cycle of the cement product, by the application of normative

LCA methods and the AHP method.

The characterization of environmental impacts in the cement plant of Ain Touta

results in an approach which consists of developing the hierarchical structure of our

multi-criteria system (Fig. 34.5).

Three criteria are determined; the extraction of raw materials, cement

manufacturing and transport of cement. Each criterion is defined by several

sub-criteria, and each sub-criterion is divided into three alternatives (air pollution,

soil pollution and depletion of the natural resources).

The evaluation of the overall environmental impacts in the cement plant of Ain

Touta implies an evaluation of the impacts of the extraction, manufacturing,

transport of cement, and each criterion has sub criteria. Three types of impacts

Citizens

Robot

Truck

Control room

Clinker crusher

Oven

Crusher at raw

Worker

Borehole’s engines

Hammer crusher

Cement use

Cement transport

Cement manufacturing

Extraction of RM

End of life

Dust

Waste

Dust

CO2 Clinker’s waste

Dust Heat

Noise

Dust

Cement

R.M cracked

R.M

Explosive

Weight control

Dater Cement quantityTemperature

Pressure

Standards of manufacturing

1000 t/h (clay)

500 t/h (limestone) Quality

control

Fig. 34.4 Phase of the life cycle by the method SADT

34 Contribution to Multi-Criteria Evaluation of the Impacts of Air Pollution. . . 457

(air pollution, soil pollution and depletion of the natural resources) were selected as

alternatives.

In order to evaluate the environmental impacts of cement in the cement plant of

Ain Touta, a survey was conducted to consolidate the various opinions of the

judgment of the services’ heads of the different specialties of the cement plant of Ain Touta (SCIMAT 2015).

The table below presents the results of the evaluation of the environmental

impacts related to the cement product by means of the decision support multi-

criteria AHP method (INERIS, 2009).

Results and Discussion

The main objective of this study is to evaluate the environmental impacts related to

the manufacture of cement. Several steps compose the AHP method. These steps

will present the results obtained using the Expert Choice software, through the

cement life cycle. Therefore, The obtained results using the AHP method

(Table 34.3) revealed that the highest pollution levels at the manufacturing stage

in which we must take all preventive and corrective measures to reduce this critical

Fig. 34.5 Hierarchical structure for the evaluation of the environmental impacts in the cement plant of Ain touta

458 L. Bahmed et al.

and significant rate (65% atmospheric pollution). Pollution level of other steps

(extraction of raw materials and transport of cement) is not negligible, but remains

less than that of manufacturing.

Sensitivity analysis is a good tool that allows us to validate the robustness of an

environmental decision. To do this, we can change the weight of our criteria to

determine the limits of our best choice. This permits us to check the shift thresholds

of our results regarding the importance of our criteria. The Expert Choice software

skillfully synthesizes the results by graphics of weights of life phases and the

associated impacts.

The Fig. 34.5 illustrates hierarchical structure for the evaluation of the environ-

mental impacts in the cement plant of Ain touta, through analysis of the life cycle.

The Fig. 34.6 illustrates the performance graph in the basis of the final eigen-

vectors of the three impacts per cycle phase, we notice that the alternative of

winning solution is either, the “air pollution” before the resources depletion and

soil pollution at all stages of the life cycle of the cement except the phase

“extraction of RM” where we can see that “transport of cement” has less impact

on the environment in the same criterion performances better than the others.

Conclusion

The main objective of this study is the evaluation of the environmental impacts of

different life cycle’s phases of cement of the cement plant of Ain-Touta Batna. For this, we have applied the LCA method combined with the method of multi-criteria

hierarchy AHP which allows the quantification of the different categories of

environmental impacts of the cement product, particularly when the software

Expert Choice is used (www.expertchoice.com 2015).

The results of the application of LCA and AHP method in this study show that

the environment is seriously threatened by the environmental impacts. It is affected

Table 34.3 The obtained results using the AHP method (SCIMAT 2015)

Phase of the cement life cycle

Criteria of the hierarchy Results

Extraction of raw materials Felling 32% Atmospheric pollution 48% Soil pollution

20% Depletion of natural

resources

Transport of MP

Crushing

Storage of MP

Cement manufacturing Raw grinding 65% Atmospheric pollution 23% Depletion of natural

resources

12% Soil pollution

Baking

Cement grinding

Transport of cement Bagging 38% Soil pollution 55% Atmospheric pollution

7% Depletion of natural resources Expedition

34 Contribution to Multi-Criteria Evaluation of the Impacts of Air Pollution. . . 459

http://www.expertchoice.com/

by the impacts of air pollution generated throughout the different stages of the life

cycle of the cement such as the phase of cement manufacturing and this in the

sub-step of raw grinding of semi finished product, extraction in the sub-step of

felling of raw materials and the sub-step of bagging the cement.

Therefore, special attention should be paid to these problems:

From an environmental viewpoint and for the problem of air pollution, the

current remedy is to ensure the capture of dust during the cement manufacturing

phase to reduce dust levels released into the air, in order to avoid environmental

problems.

Despite the fact that many of the dust collection techniques such as the electro-

bag filters are implemented, unfortunately they are ineffective. For this reason, it is

necessary to proceed preventive maintenance plans, to make the best environmental

decision as well as the regulatory compliance.

The regulatory texts play a key role in this area, which will require companies to

take serious decisions about the environment. Therefore, to improve the conserva-

tion of the environment and to respect the principles of the sustainable develop-

ment, the strategic environmental planning must be implemented to meet the needs

of green products and also the needs of the future generations.

The study has allowed us to expand our knowledge on methods and tools for

assessment of environmental impacts related to air pollution from cement plants,

based on a multi-criteria evaluation and analysis of the life cycle by method SADT,

which has allowed us to develop an original analytical approach on the basis of

which we will in future perspective make further quantitative assessments.

Fig. 34.6 The final eigenvectors of the three impacts per cycle phase

460 L. Bahmed et al.

References

Aull-Hyde, R., Erdogan, S., & Duke, J. M. (2006). An experiment on the consistency of aggre-

gated comparison matrices in AHP. European Journal of Operational Research, 171, 290–295. Bahmed, L., Djebabra, M., Boubakeur, L., & Boukhalfa, A. (2009). Implementing the ISO 14001

certification—an empirical study of an Ajgerian company in the process of certification.

Journal of Management of Environmental Quality: An International Journal, 20(2), 155–164. Emerald Group Publishing Limited ISSN 1477-7835.

Bouhidel, M. (2009). Application d’analyse du cycle de vie (ACV) pour un développement durable: cas des cimenteries Algériennes. Mémoire de Magister. Institut d’Hygiène et Sécurité Industrielle, Université Hadj Lakhdar de Batna.

Hariz, S. (2009). Etude critique du système de management environnemental au niveau des

entreprises Algériennes, Mémoire de Magister, Institut d’Hygiène et Sécurité Industrielle, Université Hadj Lakhdar de Batna.

Hariz, S., & Bahmed, L. (2013). Assessment of environmental management system performance

in the Algerian Companies Certified ISO 14001. Management of Environmental Quality: An International Journal, 24(2), 228–243. Emerald Group Publishing Limited ISSN 1477-7835.

INERIS. (2009). Panorama des méthodes d’analyse multicritère comme outils d’aide �a la décision. ISO 14040. (2006). Environmental management: Life-cycle assessment. Principles and frame-

work. International Organization for Standardization.

ISO 14044. (2006). Environmental management: Life-cycle assessment. Requirements and guide-

lines. International Organization for Standardization.

Rousval, B., & Bouyssou, D. (2009). De l’aide multicritère �a la décision �a l’aide multicritère �a l’évaluation Un cadre et une application aux transports et �a l’environnement. Cahier du Lamsade. (p. 293).

Saaty, T. L. (1994).Décider face �a la complexité—Une approche analytique multicritères d’aide �a la décision. Paris: Collection Université-Entreprise, Entreprise Moderne d’Edition. 232p.

Saaty, T. L., & Hu, G. (1998). Ranking by eigenvector versus other method in the analytic

hierarchy process. Applied Mathematics Letters, 11(4), 121–125. SCIMAT. (2015). Technical report. Algeria: Cemet Plant Ain Touta. Vincke, P. (1998). L’aide multicritères �a la décision. Editions de l’université de Bruxelles,

Editions Ellipses, 179 p. www.expertchoice.com. Retrieved February 12, 2015.

34 Contribution to Multi-Criteria Evaluation of the Impacts of Air Pollution. . . 461

http://www.expertchoice.com/

Chapter 35

Environmental Impact Assessment of Electricity Production, A Case Study of Turkey

Fatih Yılmaz, M. Tolga Balta, Reşat Selbaş, and Do�gan Demiral

Introduction

Energy has significant effects in the evolution of economy and technology.

Electricity was the major actor during the transition from the industrial to the

technological revolution, almost all the financial and economic activities depend

directly on it and any development coincides with an increasing demand of electric

energy. Recent year’s electricity energy majority is produced from fossil fuels. Fossil fuels have historically been the world’s primary source of energy and will continue to dominate the world in the next few decades. Combustion of fossil fuels

results in carbon dioxide (CO2). The bigger contributor to global warming from

fossil fuel combustion is CO2. In recent years, the problem of air pollution has

reached limits of remarkably dangerousness both for the environment and human

health (Nicoletti 2001; Churchill 1997). Greenhouse gases are causing climate

change and increasing the world’s average temperatures. Electricity production accounts for 32% of total global fossil fuel use and

around 41% of total energy-related CO2 emissions. Improving the efficiency with

which electricity is produced is therefore one of the most important ways of

F. Yılmaz (*) Department of Energy, Vocational School of Technical Sciences, Aksaray University, Aksaray

68100, Turkey

e-mail: [email protected]

M.T. Balta • D. Demiral

Department of Mechanical Engineering, Faculty of Engineering, Aksaray University, Aksaray

68100, Turkey

R. Selbaş

Department of Energy Systems Engineering, Faculty of Technology, Suleyman Demirel

University, Isparta 32100, Turkey

463

mailto:[email protected]

reducing the world’s dependence on fossil fuels, thus helping both to combat climate change and improve energy security (IEA 2007).

Fossil fuel comprises from coal, natural gas, petroleum shale oil and bitumen.

They all contain carbon. Coal usage of for a long time to generate heat and electrical

energy. But natural gas since 19985 year, it has been usage for heat and electrical

energy in Turkey.

Currently, Turkey is turn into utilizing electric power in a clean energy resource

because of the coal-based thermal power with the high occurrence of environmental

pollution. Figure 35.1 shows the electricity generation mix in Turkey from 1970 to

2010.

An increase in the use of hydropower, renewable energy, and natural gas has

been observed over the years in Fig. 35.1.

When examining the literature, several studies are available. Mukhopadhyay and

Forssell 2005, stated that empirical investigation of air pollution from fossil fuel

combustion and its impact on health in India during 1973–1974 to 1996–1997. The

study categorizes the changes in the amount of CO2, SO2 and NOx emissions into

four factors: the pollution intensity or eco-efficiency, technology or input-mix,

composition of final demand, and the level of final demand. The main factors for

these changes were the pollution intensity, technology, and the volume of final

demand. A number of studies concentrate on energy and environment (greenhouse

gas emissions) by applying input–output structural decomposition analysis. Lin and

Chang 1996, used the divisia index approach to examine emissions of CO2, NOx and SO2 from major economic sectors in Taiwan during 1980–1992. They found

that economic growth had the greatest impact on the variation of emission intensi-

ties during this period, while the influence of fuel mix was limited.

1970

70.000

Lignite Other termal Hydraulic + Renewable Natural gas

60.000

50.000

40.000

30.000

20.000

10.000

0 1980 1990

Years

P o

w er

( M

W )

2000 2010

Fig. 35.1 Electricity production in Turkey from 1970 to 2013 (TEİAS 2015)

464 F. Yılmaz et al.

Zhang 2000, analyzed the relationships of fuel mix, energy saving, economic

productivity and population expansion to the increase of China’s CO2 emissions during 1980–1997. Paul and Bhattacharya 2004, clear that, paper selected pollution

coefficient, energy intensity, structural changes and economic activity as primary

input to identify the major factors affecting the energy-related CO2 emissions from

the major economic sectors in India from 1980 to 1996. Their results showed that

economic growth was the most important component of CO2 emissions.

Wier 1998, illustrate that paper explores the anatomy of Danish energy con-

sumption and emissions of carbon dioxide (CO2), sulphur dioxide (SO2) and

nitrogen oxides (NO2). Changes in emissions between 1966 and 1988 were inves-

tigated using input-output structural decomposition analysis. Hayami et al. (1993),

stated that paper estimation of air pollutions and evaluating CO2 emissions from

production activities: using Japan’s 1985. The aim of this research is to extend the input-output tables for environmental analysis in the most detailed classification

possible. It can also be shown that it plays an important role in evaluating accurately

the emissions of CO2, NOx and SOx.

Liaskas et al. (2000), stated that his paper aims at identifying the factors that

have influenced changes in the level of industrial CO2 emissions. By means of an

algebraic decomposition method the observed changes are analyzed into four

different factors: output level, energy intensity, fuel mix and structural change.

The application study refers to the industrial sector of European Union countries.

Proops et al. (1996), illustrate that paper examines the UK economy wide, lifecycle

implications of eight forms of electricity generations for the emission of three air

pollutants, CO2, SO2 and NO, The lifecycle of the generating stations is considered

in three phases: construction, operation and decommissioning.

Felix and Grewal (2012), stated that environmental assessment of electricity

production in Tanzania. They paper presents the environmental assessment of the

centralized grid-connected electricity production in Tanzania using a life cycle

approach for the years 2000, 2015, 2020, 2026 and 2030, according to the Tanzania

Electricity Supply Company Limited, TANESCO’s, plans for power system expan- sion (power system master plan of the year 2009). The results of their study show

that in all the chosen impacts categories, based on the absolute annual electricity

production, environmental impacts increase significantly with time when compar-

ing the years 2000, 2015, 2020, 2026 and 2030.

Kim 2007, illustrated that evaluation of negative environmental impacts of

electricity generation: Neoclassical and institutional approaches. This paper

focuses on three dimensions: theoretical and methodological backgrounds; critical

review of specific studies: methodologies, results, and limitations; and discussing

their results and implications for environmental policy and further research.

In the literature research is understood that in the Turkey almost isn’t on this topic. This study focuses on the environmental impacts associated with the atmo-

spheric emissions and other wastes that are produced from fossil fuels from elec-

tricity generation. And also a case study is presented for Turkey from 1975 to

2011, according to the TUİK (2015) data.

35 Environmental Impact Assessment of Electricity Production, A Case Study. . . 465

Materials and Methods

The world energy demand has increased rapidly during the last decades with the

increase in the industrialization and population (Balta and Eke, 2011). There has

been a continuous increase in the utilization of electricity produced from consump-

tion of fossil fuels, which further causes several problems such as increased CO2 emissions mainly from fossil fuel combustion products and leads to the global

problems. The ongoing growth in fossil fuels consumption suggest that global

carbon dioxide emission are still rising (Yilanci et al. 2008) The combustion of

fossil fuels for generating electricity is the largest source of CO2 emissions.

The environmental impacts associated with the electricity generated and sup-

plied in Turkey from 1975 to 2011 were evaluated and compared for comparison

purposes. This study mainly focused on the assessment of Turkey’s electricity

production. Electricity production from fossil fuels such as coal, liquid fuels and

natural gas are considered, in this study. Table 35.1 illustrates that between 1975

and 2011 year’s electricity production and energy resource in Turkey.

Table 35.1 1975–2011 years electricity production and shares by energy resources in Turkey (TUIK 2015)

Years Coal (TJ)

Liquids Fuel (TJ)

Natural gas (TJ)

Hyro (TJ) Renewable energy (TJ)

1975 36.97964 55.30073 0 22.98182 3.936996

1976 38.99764 55.52474 0 32.58676 2.961846

1977 44.05023 70.68396 0 33.37282 4.07187

1978 50.0567 68.6559 0 36.35603 2.346408

1979 57.97163 58.00001 0 40.0545 2.432376

1980 53.6256 59.93918 0 44.20157 2.5137

1981 55.29219 59.48907 0 49.06492 1.776456

1982 58.06922 61.02287 0 55.17809 0

1983 77.28262 76.31782 0 44.16579 0

1984 91.19911 72.24292 0 52.30134 0.551052

1985 135.1993 72.675 0.447913 46.87466 0

1986 175.055 71.67964 8.833058 46.18864 0.71451

1987 158.8724 56.42766 16.54605 72.49374 0.798354

1988 112.4347 34.01581 21.06956 112.7535 0.864882

1989 182.2025 43.78482 62.33182 69.87304 0.936774

1990 181.7783 40.73699 66.65951 90.0216 1.035774

1991 194.1126 33.99682 82.40829 88.38891 2.168856

1992 221.2185 53.89246 70.95913 103.5169 2.424312

1993 213.8956 53.00891 70.52656 132.1264 2.657088

1994 253.7633 57.05444 90.21792 119.176 2.819592

1995 252.2725 59.28791 108.3781 138.2832 6.209784

1996 274.0563 67.1566 112.3744 157.6334 5.122548

1997 304.9298 73.12737 144.6751 154.7649 7.437312

(continued)

466 F. Yılmaz et al.

The Table 35.2 is given from combustion resulting factor GHG emission values.

It is clear that from the Table 35.2 coal of CO2 emission is much higher than liquid

fuels and natural gas. Therefore, if we want to reduce GHG emissions, we should

decrease the usage of coal.

GHG emission values which are given in Table 35.2, used for calculating the

CO2, CH4 and NOx emissions in Table 35.3. The average values are used [14-16],

while calculating the CO2, CH4 and NOx emissions.

Table 35.3 illustrates that the electricity production emission values from 1975

to 2011 in Turkey. It is obviously seen that CO2 emissions are the highest energy

resource is coal as expectedly.

Total electricity productions 1975–2011 is shown in Table 35.1. Table 35.2

show that between 1975 and 2011 years emission release into atmosphere in

Turkey. Coal emission release CH4 and NOx values could not be found. As the

approached the 2000s years, because of increase in population growth and electric-

ity demand, has increased emissions released into the atmosphere. Table 35.1 and

Table 35.2 data’s for this paper has been collected from the Turkish Statistical Institute (TUİK) database (TUIK 2015).

Figure 35.2 shows that the electricity production percent of distribution from

years 1980 to 2010 in Turkey [13]. In 1980 year, electricity production as percent of

Table 35.1 (continued)

Years Coal (TJ)

Liquids Fuel (TJ)

Natural gas (TJ)

Hyro (TJ) Renewable energy (TJ)

1998 320.7426 80.87509 162.7622 164.1802 5.995188

1999 333.2513 82.43253 237.7679 135.0351 6.28776

2000 344.0352 96.12748 302.5081 120.0782 6.745788

2001 345.7163 105.7693 324.4971 93.60894 6.62715

2002 288.8208 110.1945 343.8402 130.929 6.9876

2003 289.7374 93.75347 415.8737 137.3183 5.060916

2004 310.5886 78.85424 407.3371 179.4556 5.425128

2005 389.1803 56.49673 480.1662 153.7854 5.830416

2006 420.4755 45.22095 528.4625 172.2084 6.3468

2007 481.0021 66.82309 621.8396 139.4024 13.79218

2008 519.6567 77.35921 645.4072 129.7235 21.42914

2009 501.4487 49.96953 628.581 140.2548 42.07961

2010 596.6564 23.53593 698.1251 218.7148 78.45309

2011 612.1543 9.828957 711.6268 212.502 112.0846

Table 35.2 GHG emissions values (IPCC 1996; CIPEC

2002; Hepbasli 2010)

Fuel type CO2 (t/TJ) CH4 (kg/TJ) NOx (kg/TJ)

Natural gas 49.68 0.13–1.27 0.62

Liquid Fuelsa 59.84–74 0.16–121.11 3.11–12.5

Coal 93.8–95 – –

t ton, kg kilogram, TJ terajoule aGasoline, kerosene, jet fuel, LPG, diesel, jet fuel, aircraft

35 Environmental Impact Assessment of Electricity Production, A Case Study. . . 467

T a b le

3 5 .3

E m is si o n re le as e v al u es

b et w ee n th e y ea rs

1 9 7 5 – 2 0 1 1 in

T u rk ey

(T U İK

, 2 0 1 5 )

Y ea rs

C o a l

L iq u id s F u el

N a tu ra l g a s

C O

(t /y ea r)

C H

(t /y ea r)

N O

(t /y ea r)

C O

(t /y ea r)

C H

(k g /y ea r)

N O

(k g /y ea r)

C O

(t /y ea r)

C H

(k g /y ea r)

N O

(k g /y ea r)

1 9 7 5

3 5 0 5 .6 7

– –

3 7 0 0 .7 2 5

3 3 5 1 .2 2 4

4 3 1 .3 4 5 7

0 0

1 9 7 6

3 6 9 6 .9 7 6

– –

3 7 1 5 .7 1 6

3 3 6 4 .7 9 9

4 3 3 .0 9 3

0 0

1 9 7 7

4 1 7 5 .9 6 2

– –

4 7 3 0 .1 7 1

4 2 8 3 .4 4 8

5 5 1 .3 3 4 9

0 0

1 9 7 8

4 7 4 5 .3 7 6

– –

4 5 9 4 .4 5 3

4 1 6 0 .5 4 7

5 3 5 .5 1 6

0 0

1 9 7 9

5 4 9 5 .7 1

– –

3 8 8 1 .3 6

3 5 1 4 .8

4 5 2 .4

0 0

1 9 8 0

5 0 8 3 .7 0 7

– –

4 0 1 1 .1 3

3 6 3 2 .3 1 4

4 6 7 .5 2 5 6

0 0

1 9 8 1

5 2 4 1 .7

– –

3 9 8 1 .0 0 9

3 6 0 5 .0 3 8

4 6 4 .0 1 4 7

0 0

1 9 8 2

5 5 0 4 .9 6 2

– –

4 0 8 3 .6 5

3 6 9 7 .9 8 6

4 7 5 .9 7 8 4

0 0

1 9 8 3

7 3 2 6 .3 9 3

– –

5 1 0 7 .1 8 9

4 6 2 4 .8 6

5 9 5 .2 7 9

0 0

1 9 8 4

8 6 4 5 .6 7 5

– –

4 8 3 4 .4 9 6

4 3 7 7 .9 2 1

5 6 3 .4 9 4 8

0 0

1 9 8 5

1 2 ,8 1 6 .8 9

– –

4 8 6 3 .4 1 1

4 4 0 4 .1 0 5

5 6 6 .8 6 5

2 2 .2 5 2 3 2

0 .3 1 3 5 3 9

0 .2 7 7 7 0 6

1 9 8 6

1 6 ,5 9 5 .2 1

– –

4 7 9 6 .8 0 2

4 3 4 3 .7 8 6

5 5 9 .1 0 1 2

4 3 8 .8 2 6 3

6 .1 8 3 1 4 1

5 .4 7 6 4 9 6

1 9 8 7

1 5 ,0 6 1 .1 1

– –

3 7 7 6 .1 3 9

3 4 1 9 .5 1 6

4 4 0 .1 3 5 8

8 2 2 .0 0 7 6

1 1 .5 8 2 2 3

1 0 .2 5 8 5 5

1 9 8 8

1 0 ,6 5 8 .8 1

– –

2 2 7 6 .3 3 8

2 0 6 1 .3 5 8

2 6 5 .3 2 3 3

1 0 4 6 .7 3 6

1 4 .7 4 8 6 9

1 3 .0 6 3 1 3

1 9 8 9

1 7 ,2 7 2 .8

– –

2 9 3 0 .0 8

2 6 5 3 .3 6

3 4 1 .5 2 1 6

3 0 9 6 .6 4 5

4 3 .6 3 2 2 7

3 8 .6 4 5 7 3

1 9 9 0

1 7 ,2 3 2 .5 9

– –

2 7 2 6 .1 1 9

2 4 6 8 .6 6 2

3 1 7 .7 4 8 5

3 3 1 1 .6 4 5

4 6 .6 6 1 6 6

4 1 .3 2 8 9

1 9 9 1

1 8 ,4 0 1 .8 8

– –

2 2 7 5 .0 6 7

2 0 6 0 .2 0 7

2 6 5 .1 7 5 2

4 0 9 4 .0 4 4

5 7 .6 8 5 8

5 1 .0 9 3 1 4

1 9 9 2

2 0 ,9 7 1 .5 1

– –

3 6 0 6 .4 8 3

3 2 6 5 .8 8 3

4 2 0 .3 6 1 2

3 5 2 5 .2 4 9

4 9 .6 7 1 3 9

4 3 .9 9 4 6 6

1 9 9 3

2 0 ,2 7 7 .3

– –

3 5 4 7 .3 5 6

3 2 1 2 .3 4

4 1 3 .4 6 9 5

3 5 0 3 .7 5 9

4 9 .3 6 8 5 9

4 3 .7 2 6 4 6

1 9 9 4

2 4 ,0 5 6 .7 6

– –

3 8 1 8 .0 8 3

3 4 5 7 .4 9 9

4 4 5 .0 2 4 7

4 4 8 2 .0 2 6

6 3 .1 5 2 5 4

5 5 .9 3 5 1 1

1 9 9 5

2 3 ,9 1 5 .4 3

– –

3 9 6 7 .5 4 7

3 5 9 2 .8 4 8

4 6 2 .4 4 5 7

5 3 8 4 .2 2 5

7 5 .8 6 4 6 8

6 7 .1 9 4 4 3

1 9 9 6

2 5 ,9 8 0 .5 4

– –

4 4 9 4 .1 2

4 0 6 9 .6 9

5 2 3 .8 2 1 5

5 5 8 2 .7 5 8

7 8 .6 6 2 0 5

6 9 .6 7 2 1

1 9 9 7

2 8 ,9 0 7 .3 4

– –

4 8 9 3 .6 8 4

4 4 3 1 .5 1 9

5 7 0 .3 9 3 5

7 1 8 7 .4 5 7

1 0 1 .2 7 2 5

8 9 .6 9 8 5 3

1 9 9 8

3 0 ,4 0 6 .3 9

– –

5 4 1 2 .1 6 1

4 9 0 1 .0 3

6 3 0 .8 2 5 7

8 0 8 6 .0 2 4

1 1 3 .9 3 3 5

1 0 0 .9 1 2 5

468 F. Yılmaz et al.

1 9 9 9

3 1 ,5 9 2 .2 2

– –

5 5 1 6 .3 8 5

4 9 9 5 .4 1 2

6 4 2 .9 7 3 8

1 1 ,8 1 2 .3 1

1 6 6 .4 3 7 5

1 4 7 .4 1 6 1

2 0 0 0

3 2 ,6 1 4 .5 4

– –

6 4 3 2 .8 5 1

5 8 2 5 .3 2 5

7 4 9 .7 9 4 3

1 5 ,0 2 8 .6

2 1 1 .7 5 5 7

1 8 7 .5 5 5

2 0 0 1

3 2 ,7 7 3 .9 1

– –

7 0 7 8 .0 8 2

6 4 0 9 .6 2

8 2 5 .0 0 0 6

1 6 ,1 2 1 .0 1

2 2 7 .1 4 8

2 0 1 .1 8 8 2

2 0 0 2

2 7 ,3 8 0 .2 1

– –

7 3 7 4 .2 1 3

6 6 7 7 .7 8 4

8 5 9 .5 1 6 7

1 7 ,0 8 1 .9 8

2 4 0 .6 8 8 2

2 1 3 .1 8 0 9

2 0 0 3

2 7 ,4 6 7 .1 1

– –

6 2 7 3 .9 8 2

5 6 8 1 .4 6

7 3 1 .2 7 7 1

2 0 ,6 6 0 .6

2 9 1 .1 1 1 6

2 5 7 .8 4 1 7

2 0 0 4

2 9 ,4 4 3 .8

– –

5 2 7 6 .9 2 5

4 7 7 8 .5 6 7

6 1 5 .0 6 3

2 0 ,2 3 6 .5

2 8 5 .1 3 5 9

2 5 2 .5 4 9

2 0 0 5

3 6 ,8 9 4 .2 9

– –

3 7 8 0 .7 6 1

3 4 2 3 .7 0 2

4 4 0 .6 7 4 5

2 3 ,8 5 4 .6 6

3 3 6 .1 1 6 4

2 9 7 .7 0 3 1

2 0 0 6

3 9 ,8 6 1 .0 8

– –

3 0 2 6 .1 8 6

2 7 4 0 .3 9

3 5 2 .7 2 3 4

2 6 ,2 5 4 .0 2

3 6 9 .9 2 3 7

3 2 7 .6 4 6 7

2 0 0 7

4 5 ,5 9 9

– –

4 4 7 1 .8 0 1

4 0 4 9 .4 7 9

5 2 1 .2 2 0 1

3 0 ,8 9 2 .9 9

4 3 5 .2 8 7 7

3 8 5 .5 4 0 5

2 0 0 8

4 9 ,2 6 3 .4 6

– –

5 1 7 6 .8 7 8

4 6 8 7 .9 6 8

6 0 3 .4 0 1 8

3 2 ,0 6 3 .8 3

4 5 1 .7 8 5 1

4 0 0 .1 5 2 5

2 0 0 9

4 7 ,5 3 7 .3 3

– –

3 3 4 3 .9 6 1

3 0 2 8 .1 5 4

3 8 9 .7 6 2 4

3 1 ,2 2 7 .9

4 4 0 .0 0 6 7

3 8 9 .7 2 0 2

2 0 1 0

5 6 ,5 6 3 .0 3

– –

1 5 7 5 .0 2 4

1 4 2 6 .2 7 7

1 8 3 .5 8 0 2

3 4 ,6 8 2 .8 6

4 8 8 .6 8 7 6

4 3 2 .8 3 7 6

2 0 1 1

5 8 ,0 3 2 .2 3

– –

6 5 7 .7 5 3 8

5 9 5 .6 3 4 8

7 6 .6 6 5 8 6

3 5 ,3 5 3 .6 2

4 9 8 .1 3 8 8

4 4 1 .2 0 8 6

35 Environmental Impact Assessment of Electricity Production, A Case Study. . . 469

rate respectively coal 25.6%, liquid fuels 25.1%, natural gas 0%, hydro 48.8% and

renewable energy 0.6%. Moreover, in 2000 years, while from coal and natural gas

increase in for electricity production, hydro and liquids fuels usage of decreased

shows that from Fig. 35.1. Approximately, percentage of the electricity production

from coal and natural gas at about 72% in 2010 year. As can be seen in this figure

that electricity production from natural gas increases from 1988 in Turkey.

Results and Discussion

In this paper CO2, CH4 and NOx emissions are calculated from 1975 to 2011 for

Turkey. The Turkish Statistical Institute (TUİK) database is considered (TUIK

2015) while calculating these emission values.

Figure 35.3 shows that CO2 emissions from electricity production in Turkey

between 1975 and 2011. The CO2 emission values from liquid fuels did not change

too much, between 1975 and 2011. But, an increase is seen for coal and natural gas

CO2 emission values in this figure. As expected that CO2 emissions values from

coal are higher than that of others. CO2 emissions values from coal and natural gas

were observed sharply changes in 2002. CO2 emissions values from coal decreased

while the CO2 emissions values of natural gas increased at 2002.

Figure 35.3 illustrates the change of electricity production resource in Turkey

from 1975 to 2011. Especially, the usage of natural gas subsequently increase after

1998. The usage of liquid fuels decrease because of the commonly usage of the

natural gas after 1998. The use of natural gas is better than coal in terms of

emissions. In 2001 year was observed that from natural gas electricity production

is higher than coal (Fig. 35.4).

0 1980 1990 2000

years

E le

ct ri

ci ty

p ro

d u

ct io

n r

es o

u rc

es (

% )

2010

Caol (%)

Liquid Fuels (%)

Natural Gas (%)

Hydro (%)

Renewable Energy (%)

Fig. 35.2 Electricity production resources of Turkey from 1980 to 2010

470 F. Yılmaz et al.

CH4 emission values from 1975 to 2011 for electricity production resource is

given in Fig. 35.5. While resulting from natural gas emissions quite a few, but liquid

fuels are higher. Also as can be seen in this figure that, CH4 emissions from liquid

fuels decreases, while CH4 emissions from natural gas increases after than 2003.

NOx emission values from 1975 to 2011 for electricity production resource is

given in Fig. 35.6. Also as can be seen in this figure that, NOx emissions from liquid

fuels decreases, while NOx emissions from natural gas increases after than 1988.

1979

Coal Liquid Fuels Natural gas

65000 60000 55000 50000 45000 40000 35000 30000 25000 20000 15000 10000 5000

−5000 0

1987 1995

Years

C O

2 em

m is

io n

( t/

ye ar

)

2003 20111971

Fig. 35.3 Between 1975 and 2011 from electricity production release CO2 emission

750 700 650 600 550 500 450 400 350 300 250 200 150 100

−50 0

Years

T J

Coal Liquid Fuels Natural gas

1979 1987 1995 2003 20111971

Fig. 35.4 Between 1975 and 2011 electricity production resource (TUİK 2015)

35 Environmental Impact Assessment of Electricity Production, A Case Study. . . 471

Conclusions

In this study, an environmental impact assessment of electricity production was

investigated and compared for CO2, CH4 and NOx emissions in Turkey.

Some concluding remarks from this study can be extracted as follows:

(a) In 2011, the electricity production from coal is 642.15 TJ, and corresponding

CO2 emission is 58032.23 t/year. And 711.62 TJ for natural gas and

corresponding CO2 emission is 498.13 kg/years.

Liquid Fuels

7000

6000

5000

4000

3000

2000

1000

Years

C H

4 em

is si

o n

Natural gas

19 75

19 77

19 79

19 81

19 83

19 85

19 87

19 89

19 91

19 93

19 95

19 97

19 99

20 01

20 03

20 05

20 07

20 09

20 11

Fig. 35.5 Between 1975 and 2011 from electricity production release CH4 emission

1971

1000

900

800

700

600

500

400

300

200

100

0 1979 1987 1995

Years

N O

x em

is si

o n

( t/

ye ar

)

2003 2011

Liquid Fuels Natural gas

Fig. 35.6 Between 1975 and 2011 from electricity production release NOx emission

472 F. Yılmaz et al.

(b) It has been observed a continuous increase in electricity production from coal

and natural gas from 1975 to 2011.

(c) It has been observed that most of the CO2 emissions arise from coal and CH4 emissions from liquid fuels higher than natural gas.

(d) Until 2009 year, it has been observed that from liquid fuels NOx emissions

higher than that of natural gas, but after this year this situation is reversed.

As can we concluded that, in Turkey the electricity produced mostly from coal

and natural gas. The usage of liquid fuels decreased while the usage of the natural

gas increased.

Nomenclature

GHG Greenhouse gas

MW Megawatt

TJ Terajoule

t Ton

kg Kilogram

References

Balta, M.O., & Eke, F. (2011). Spatial reflection of urban planning in metropolitan areas and urban

rent; A case study of Cayyolu, Ankara. European Planning Studies, 19 (10), 1817–1838.

Churchill, S.W. (1997). The reduction of air pollution by improved combustion. Energy Conver- sion and Management 38, 1335–1341.

CIPEC. (2002). Canadian Industry Program for Energy Conversation. “Energy Efficiency Plan-

ning and Management Guide” the Office of Energy Efficiency of Natural Resource Canada,

Ottawa.

Felix, M., & Grewal, S. H. (2012). Environmental assessment of electricity production in Tanza-

nia. Energy for Sustainable Development, 16, 439–447. Hayami, H., et al. (1993). Estimation of air pollutions and evaluating CO2 emissions from

production activities: using Japan’s 1985 input–output tables. Journal of Applied Input–Output Analysis, 1(2), 29–44.

Hepbasli, A. (2010). Enerji Verimlili�gi ve Y€onetim Sistemi Yaklaşımlar Ve Uygulamalar. Schneider Electric Enerji Verimlili�gi Serisi, 1, 45–63.

IEA. (2007). Fossil fuel-fired power generation. Case studies of recently constructed coal- and gas-fired power plants. Paris: IEA/OECD.

IPCC. (1996). Intergovernmental panel on climate change, climate change 1995; The Science of

Climate Change (Türkiye İstatiitik Kurumu, 2015). (p. 120). Cambridge, UK: Cambridge

University Press. Tablo 2-9 “Radiative Forcing of Climate Change.”

Kim, S. H. (2007). Evaluation of negative environmental impacts of electricity generation:

Neoclassical and institutional approaches. Energy Policy, 35, 413–423. Liaskas, K., et al. (2000). Decomposition of industrial CO2 emissions: the case of European

Union. Energy Economics, 22, 383–394. Lin, S. J., & Chang, T. C. (1996). Decomposition of SO2, NOx and CO2 emissions from energy

use of major economic sectors in Taiwan. The Energy Journal, 17, 1–17.

35 Environmental Impact Assessment of Electricity Production, A Case Study. . . 473

Mukhopadhyay, K., & Forssell, O. (2005). An empirical investigation of air pollution from fossil

fuel combustion and its impact on health in India during 1973–1974 to 1996–1997. Ecological Economics, 55, 235–250.

Nicoletti, G. (2001). Limpatto ambientale dei combustibili generalmente impiegati peril

riscaldamento urbano degli edifici. In: Proceeding of Italian Conference 56 Congresso Nazionale ATI, Naples.

Paul, S., & Bhattacharya, R. N. (2004). CO2 emission from energy use in India: A decomposition

analysis. Energy Policy, 32(5), 585–593. Proops, J. L. R., et al. (1996). The life time pollution implications of various types of electricity

generation: an input–output analysis. Energy Policy, 24(3), 229–237. TEİAŞ. Turkish electricity transmission company. http://www.teias.gov.tr/. Retrieved February

16, 2015.

TUIK. (2015). Turkish Statistical Institute. www.turkstat.gov.tr. Retrieved March 2, 2015.

Wier, M. (1998). Sources of changes in emissions from energy: A structural decomposition

analysis. Economic Systems Research, 10(2), 99–112. Yilanci, A., Dincer, I., & Ozturk, H. K. (2008). A review on solar-hydrogen/fuel cell hybrid energy

systems for stationary applications. Progress in Energy and Combustion Science. doi:10.1016/ j.pecs.2008.07.004.

Zhang, Z. (2000). Decoupling China’s carbon emissions increase from economic growth: An economic analysis and policy implications. World Development, 28(4), 739–752.

474 F. Yılmaz et al.

http://dx.doi.org/10.1016/j.pecs.2008.07.004

http://www.turkstat.gov.tr/

http://www.teias.gov.tr/

Chapter 36

Hybridization of Parabolic Trough Power Plants with Natural Gas Through Integration of Industrial Gas Turbines

Tobias Vogel, Gerd Oeljeklaus, and Klaus G€orner

Introduction

The operation of concentrating solar power (CSP) plant concepts without thermal

energy storage is completely dependent on the course of the sun. Because of this

dependency such power plants have only a limited capability of regulating the

electrical grid. The operation temperature is also very closely linked to collector

technology and available solar radiation. The input of fossil fuel, however, can be

controlled and therefore used according to needs. Through the systematic combi-

nation of solar and fossil energy a more flexible power plant is created. Even from

financial standpoint hybrid plants offer in mid-term a cost reduction potential and

thereby lessen economic inhibitions.

The total electricity consumption will grow until 2035 by roughly 65%, as

predicted in (BP 2014) based on the reference year 2012, whereas the absolute

share of natural gas will be approximately constant at 20.5% (BP 2014). This

indicates that natural gas will play in mid-term an important role. In terms of the

combined usage of natural gas and concentrated solar thermal energy in one power

plant the most common solution is the ISCC (Integrated Solar Combined Cycle).

Due to technical reasons the amount of integrable solar energy is strongly limited,

for instance the annual solar share is relatively low at 2–8% (Turchi et al. 2011). An

alternative approach is to integrate smaller gas turbines, like industrial or

aeroderivative gas turbines, into a CSP plant. A fairer performance ratio and a

comparatively lower natural gas usage are achievable, for what reason this idea is

increasingly studied in the last years (e.g. Turchi et al. 2011; Vogel et al. 2013;

Servert et al. 2014).

T. Vogel (*) • G. Oeljeklaus • K. G€orner LUAT, University of Duisburg-Essen, Leimkugelstrasse 10, Essen 45141, Germany

e-mail: [email protected]

475

mailto:[email protected]

For this case study the configuration of the parabolic trough power plant Shams

One (cf. Goebel 2010), located Madinat Zayed in Abu Dhabi part of the United

Arab Emirates (UAE) has been used. The power plant itself as well as the region

fulfills all requirements to make such an analysis worthwhile.

The UAE have the world’s seventh largest proved reserves of natural gas (BP 2014). For that reason natural gas covers roughly 63% of the UAE’s primary energy consumption and thus represents their main energy source (BP 2014). In

2011 the installed gross electricity capacity has been divided into 18.5 GWel of

combined cycle, 5.4 GWel gas turbine and 2.3 GWel steam turbine (UAE 2012). But

in Abu Dhabi itself are still 0.4 GWel of open cycle gas turbine capacity installed,

which indicates a potential of combining such gas turbines with Shams One. Due to

an expected rising energy consumption and sharper summerly load transients the

local grid operator TRANSCO is forecasting an amount of 1.3 GWel installed gross

capacity of open cycle gas turbines until 2020 (TRANSCO 2014).

In addition it should be noted, that there is one additional power plant located in

Madinat Zayed with the name “Madinat Zayed Power Plant,” owned by the Al

Mirfa Power Company. It consists out of four open cycle gas turbines with an

installed gross capacity of 0.1 GWel (Al Mirfa Power Company 2014). Altogether it

can be assumed that at least for this application example from outer perspective a

market potential for the developed hybridization configuration exists.

The Site

As site for the calculations Madinat Zayed in the United Arab Emirates was chosen,

where also Shams One is located. The weather profile was taken in hourly time

resolution from the meteonorm database (version 7.0). This averaged dataset has a

yearly total direct normal irradiance (DNI) of 1889 kWh/(m2a), which corresponds

well with the number of 1925 kWh/(m2a), published in (Goebel 2010), whose value

is based on ground data collected during the project development of Shams One.

The sorted distribution curve and the interval frequency of the aperture effective

DNI (cosine correction included) are shown in Fig. 36.1, whereas for the interval

frequency only all hours with an aperture effective DNI greater than 1 Wh/(m2h)

are considered.

Within respect of the cosine correction the yearly available aperture effective

DNI is lowered by 8.5% to 1729 kWh/m2. An average aperture effective DNI of

over 700 Wh/(m2h) appears only in 204 h, which underpins the medium insolation

quality for the analyzed site.

The design point was set to be on 21st March at solar noon, because of the

comparatively low aerosol charge of the air in spring compared to the summer

month. Referring to (Goebel 2010) the DNI for the design point is 750 W/m2.

476 T. Vogel et al.

The Base Case Power Plant

The layout of the base case power plant is shown in Fig. 36.2 and the main technical

performance data from the design point are given in the diagram in the lower left

part of Fig. 36.2. The thermodynamic model can be divided into the solar-heat-

transfer-fluid-cycle (solar-HTF-cycle) and the water/steam cycle. The main param-

eters were primarily taken from publications or otherwise estimated based on

typical values and design guidelines.

Solar-HTF-Cycle

The solar-HTF-cycle has the following two main tasks:

• transform the solar irradiation into heat.

• transfer the gained heat to a power generation process.

Therefore the solar-HTF-cycle consists out of the main components solar field,

HTF-pump, HTF-heater and the connecting solar steam generator (SSG).

As heat transfer fluid (HTF) the thermal oil Therminol VP1 has been used,

similar to Shams One. It is thermally stable up to 400 �C, whereas the related vapor pressure is 10.9 bar (SOLUTIA 2013). For security reasons a HTF-evaporation

should be avoided at any time. In order to fulfill this requirement the minimum

pressure (position: suction HTF-pump) in the solar-HTF-cycle has been set to

15 bar. The pressure loss over the complete solar field is assumed to be 5.25 bar

(Balan 2014) for nominal conditions and in the SSG 2.5 bar, so that the HTF-pump

discharge pressure overall amounts to 22.75 bar.

Fig. 36.1 Sorted distribution curve and interval frequency of the aperture effective DNI for the used weather profile from Madinat Zayed

36 Hybridization of Parabolic Trough Power Plants with Natural Gas Through. . . 477

The solar field of Shams One consists out of 768 ASTRØ 150 collectors (Goebel

2010), in a typical 4 collectors per loop arrangement. Due to the fact that the solar

library (Pawellek et al. 2009) of the power plant simulation program Ebsilon®

Professional includes only a model of the EUROTrough ET 150 collector, this

comparable collector type has been used. In order to serve a sufficient thermal heat

input even in case of low solar insolation, e.g. due to cloud passing, the solar-HTF-

cycle is additionally furnished with a HTF-heater, which is fuelled with natural gas.

At nominal conditions 1061.6 kg/s of HTF are circulating, whereby its temper-

ature is elevated from 296.6 �C (HTF-side outlet of SSG) to 393 �C (HTF-side inlet of SSG) while passing the solar field.

Water/Steam Cycle

The main components in the water/steam cycle are the SSG, the booster, the turbo-

generator (steam turbine and generator), the air-cooled condenser, condensate and

feedwater pump as well as the low and the high pressure feed heaters.

The solar heat is transferred to the water steam cycle via the SSG. By that heat

input the feedwater entering the SSG at 219.46 �C and 111 bar is preheated, evaporated and superheated up to 380 �C at 102.5 bar. Subsequently, the steam is further superheated in a natural-gas-fired booster. At live steam parameters of

540 �C and 100 bar (Reuß 2012) the steam enters a 35-staged, single flow steam turbine (MAN 2014). The 35 turbine stages can be arranged for the thermodynamic

solar-HTF-cycle

solar field

natural gas inlet

flue gas outlet

air inlet

solar steam

generator

natural gas inlet

air inlet

flue gas outlet booster steam turbine

technical data

main HTF pump

LP feed heaters

feed water tank

feed water pump

condensate pump

air cooled condenser air

inlet

air outlet

H P

fe ed

h ea

te rsheat input 303.97 MWth

heat input solar steam generator 249.95 MWth heat input booster 54.02 MWth heat input heater 0.00 MWth gross power output 120.70 MWel auxiliary power demand 6.50 MWel net power output 114.20 MWel water/steam cycle gross efficiency 39.70 % net plant efficiency 21.65 % live steam flow 120.00 kg/s live steam temperature 540.00 °C live steam pressure 100.00 bar condenser pressure 0.13 bar

HTF-heater 1 2

34 5

678

34 5

6 78

Fig. 36.2 Process flow diagram of the base case power plant based on the configuration of Shams One

478 T. Vogel et al.

modelling related to the required extractions for the feedwater preheating into

7 stage groups. Through passing the steam turbine the steam is expanded to the

condenser pressure of 0.13 bar (Reuß 2012), while six partial flows are extracted for

the feedwater preheating. For the last 3 stage groups the wetness correction for the

isentropic efficiency was used because of the present steam wetness. Following, the

discharge steam streams through an air-cooled condenser (ACC). Then the fully

condensed water is delivered by the condensate pump to the feedwater tank, while

passing two low pressure (LP) feed heaters. From the feedwater tank the feedwater

is led through the feedwater pump to the SSG, while passing three high pressure

(HP) feed heaters. The extraction pressure levels have been chosen in order to

enable a temperature step of 28 K in each preheater (regulation cf. Schr€oder 1966). All assumed machinery efficiency data are given in Table 36.1.

At nominal conditions with a heat input of 301 MWth 120 kg/s of water/steam

circulates in the system. The power plant therefore generates 120.7 MWel of gross

electricity, which represents a water/steam cycle gross efficiency of 39.45%. In part

load the live steam pressure level is set in general by the steam generator while the

pressure entering the first stage of the turbine undergoes the Stodola’s law. Because of that coherence for part load operation a modified sliding pressure mode was

assumed for the steam generator.

Technical Boundary Conditions

An important basis for the development of the operating logic of a power plant

represents the knowledge of the elementary technical boundary conditions,

whereby for reasons of presentation a differentiation into the three areas solar

field, water/steam-cycle and natural-gas-firing has been made.

For the solar field off-design operation a minimum circulating HTF mass flow of

200 kg/s has been considered, while the outlet temperature is limited to 393 �C. In case of high solar insolation when the heat-entry oversteps the nominal value, the

troughs are defocussed automatically until the heat-entry achieves the allowed

nominal value.

Table 36.1 Efficiency data (isentropic, mechanical and electrical) for the process machinery

Component ηs (%) ηmech (%) ηel (%) Electric motor – 99.80 97.00

Generator – – 98.55

Pump 80.00 99.80 –

Blower 86.00 99.80 –

HP steam turbine (1. stage group) 84.00 99.80 –

IP steam turbine (2.-6. stage group) 90.00 99.80 –

LP turbine (7. stage group) 86.00 99.80 –

36 Hybridization of Parabolic Trough Power Plants with Natural Gas Through. . . 479

Regarding the water/steam cycle the SSG and the steam turbine are in general

the limiting components, whereby in this work the steam turbine has been used as

benchmark. For that reason an industry-related, steam turbine model has been

developed, whose technical boundary conditions mainly occur during the

off-design operation. The following main technical boundary conditions for the

steam turbine with maximum allowable steam wetness (15%), maximum turbine-

exhaust pressure (0.23 bar), smoothed live steam temperature and permissible

temperature gradients for heating (5 K/min) and cooling (�2 K/min) have been identified in (Vogel et al. 2013), thus this reference is referred for further explana-

tion. It has to be mentioned, that as specific state point for the steam wetness at the

steam turbine outlet the expansion line end point has been used. Furthermore the

maximum turbine-exhaust volume flow factor is limited to the factor 1.5 of the

nominal value for the volume flow at the turbine-exhaust. Besides, the live steam

temperature is smoothed by the booster until 3 O’clock pm, in order to avoid negative temperature gradients during main steam turbine operation time.

According to (Goebel 2010) the amount of natural gas is limited to 600,000

MMBTU/a. From that the booster has an approximated contribution share of 81.8%

and the HTF-heater one of 18.2% (Goebel and Luque 2012). Due to the fact that the

composition of natural gas fluctuates and is not clear defined, in this case study

methane was used as reference fuel with a lower heating value of 50,015 kJ/kg.

Based on these boundary conditions the heater has in total a potential of 2,301.3

tmethane/a and the booster one of 10,355.6 tmethane/a. In addition the booster’s min-load is set to 5% of nominal fuel mass flow.

Operational Logic

The power plant operation can be divided in four main operating states, namely:

night, below min-load, normal day and heater operation. During night no insolation

is available and the power plant is out of operation. In exceptional situations the

grid operator can prescribe power plant operation during night by using the fossil-

only mode (Goebel and Luque 2012), but that exception has been neglected for the

performed case study. The other three operating states are during the day. If the

insolation is too low to provide the minimum amount of circulating HTF-mass flow

the power plant is out of operation as well. If the DNI is high enough the power

plant is in typical normal day operation. Is the power plant in normal operation and

it appears a sudden (or forecasted) short-term insolation drop in the next time step,

for example caused by cloud passing, the power plant should still operate in order to

avoid start-up and shut-down losses by using the HTF-heater.

The following three identification criteria need to be fulfilled for HTF-heater

operation. At first the HTF-heater shall operate only up to 16 o’clock to follow the typical diurnal variation of the insolation. Secondly the insolation drop compared to

the previous DNI must be higher than 250 W/(m2h). As third criteria for HTF-heater

480 T. Vogel et al.

operation the DNI must be lower than 400 Wh/(m2h). When HTF-heater operation is

identified, the HTF-heater can be operated with its load in different ways. For this

case study the HTF-heater operates in order to enable the same load, meaning

entering the SSG with the same HTF-mass flow, as in the time step before.

The booster operates in respect to the given technical boundary conditions.

When the steam generator achieves a load level close to full load in the previous

and the actual hour the booster goes to full load and delivers live steam at 540 �C and 100 bar, as long as none of the named boundary conditions are opposed.

In case of the necessity to reduce the power plant load, e.g. due to the turbine-

exhaust pressure limitation, firstly the fossil-firing is reduced to the technical lowest

limit, e.g. booster min-load or smoothed live steam temperature. Secondly, the load

of the solar field is reduced through defocussing.

The Base Case Power Plant with Front End Gasturbine

Concept Layout

Figure 36.3 shows the process flow diagram of the developed concept with the

additional integration of a gas turbine into the base case power plant.

In general there are different ways for the integration of the gas turbine’s waste heat possible, for instance the integration into the booster’s air flow or directly into the water/steam-cycle. In order to avoid technical changes of the installed booster

arrangement the waste heat has been integrated directly through two heat

LP-FH 2

condensate pump

air-cooled condenser

feedwater pump

feed- water tank

HP-FH 3

fan

LP-FH 1

HP-FH 2

HP-FH 1

economizer

evaporator

superheater

booster

HTF-pump

HTF-heater

steam turbine generator

solar f ield G~

GT-SH

GT-FH stack

gas turbine (GT)

Fig. 36.3 Process flow diagram of the base case power plant added with a front end gas turbine

36 Hybridization of Parabolic Trough Power Plants with Natural Gas Through. . . 481

exchangers into the water/steam cycle. The waste heat at high temperature level is

firstly integrated through the gas turbine waste heat recovery superheater (GT-SH),

located between the SSG-superheater and the booster, in order to lower the

booster’s load. The remaining waste heat with a temperature of up to 390 �C can be used part vise further for preheating the feed water. Replacing HP bled off steam

is thermodynamically favorable. For that reason secondly the gas turbine waste heat

recovery feed heater (GT-FH) is installed in parallel to the HP feed heaters

(HP-FH). Thus, the required amount of bled steam is reduced and consequently a

higher steam turbine power output reveals. In terms of corrosion by the cause of

condensation of exhaust gas components it has to be mentioned, that through the

chosen arrangement the stack temperature stays above 100 �C even in low load due to the minimum pressure in the feedwater tank of 1.15 bar. A displacement of the

HP-FH 3 was not undertaken in order to secure always the required feed water

temperature at the inlet of the economizer.

Gas Turbine Selection

In respect to the developed concept layout the following specification requirements

have been used for the gas turbine selection:

• grid frequency: 50 Hz

• gas turbine performance class: 10–20 MWel • emission reduction technology: dry, resp.no water/steam injection

• exhaust gas temperature: at least 540 �C

Based on the market review, given in (Gas Turbine World 2011), out of the

276 listed gas turbines only four gas turbines fulfill the above mentioned require-

ments. Namely: THM 1304-14 (MAN), L20A (Kawasaki), H-15 (Hitachi) and

SGT-400 (Siemens). In order to cover the complete range of electrical efficiency

the THM 1304-14 (31.0%) and the SGT-400 (34.8%) have been chosen for the

conducted case study. The technical data of these two gas turbines at nominal

conditions (cf. ISO 2314-2009) are summed up in Table 36.2.

The operation of gas turbines has a strong dependence on the ambient condi-

tions. For example, a change in the elevation level (resp. ambient pressure) or the

Table 36.2 Technical data for the two gas turbines

for generation drive at

nominal conditions

(GTW-Performance

Specs 2011)

Parameter Unit GTa) GTb)

Type THM 1304-14 SGT-400

Electric power kWel 12,680 12,900

Heat rate kJ/kWh 11,610 10,355

Electric efficiency % 31.0 34.8

Exhaust temperature �C 545.0 555.0 Exhaust mass flow kg/s 49.0 39.4

Pressure ratio – 11.0 16.9

482 T. Vogel et al.

ambient temperature have a strong influence on the performance of the gas turbine.

For that reason the operating characteristic of the gas turbines need to be taken into

account for the annual yield simulation. Therefore two different approaches have

been used. For the GTa) a full thermodynamic model has been developed based on

the design point data and the instructions given in (Lechner and Seume 2010),

which covers the part load and operating behavior. Contrary for the GTb) charac-

teristic curves provided by the manufacturer have been used. It should be noted, that

GTb) has a customized design referring to the studied site. For both gas turbines the

same site boundary conditions with an ambient pressure at the design-point of

99.9 kPa and pressure losses at gas turbine inlet and gas turbine outlet (due to waste

heat recovery) of 1 and 2.5 kPa have been used.

Figure 36.4 shows for GTa) the distribution of the electrical efficiency for each

operating point as subject to the ambient temperature.

The operating points of GTa) are arranged in Fig. 36.4 as a passel. That means

that even for operating points with an equal ambient temperature different efficien-

cies occur, due to various ambient pressure and ambient humidity. With decreasing

ambient temperature the GT-efficiency is raised. Summarizing, the developed

thermodynamic model for GTa) enables a typical operating behavior.

The Solar Only Bench Mark Model

For the closing assessment of the concepts in terms of power generation efficiency

from natural gas it is necessary to perform the annual yield simulations as well with

a, so called, solar only model. Using the base case power plant and operating it in

solar only mode is not feasible, because for example technical limitations like steam

turbine wetness could not be fulfilled with the given design of the components. For

Fig. 36.4 Annual operating behavior of the gas turbine GTa)

36 Hybridization of Parabolic Trough Power Plants with Natural Gas Through. . . 483

that reason a solar only benchmark model has been developed, whose process flow

diagram and technical data for the design-point are given in Fig. 36.5.

In comparison to the base case power plant, shown in Fig. 36.5, the booster has

been removed. With the objective to fulfill still the steam turbine wetness limitation

the power plant has been additionally equipped with a reheating. Therefore the

superheated steam leaving the first turbine stage group at 225.54 �C and 25.75 bar is reheated up to 380 �C. Following the reheated steam is returned to the steam turbine for the further expansion. Through this arrangement the steam turbine-exhaust

wetness limitation could be fulfilled, e.g. at the design-point the steam wetness is

11.4%. The solar field and the nominal HTF-mass flow are still the same as for the

base case power plant. But the HTF-mass flow is now split up between the solar

steam generator and the reheating. For that reason the transferred heat into the

water/steam cycle through the solar steam generator is lowered to 252.27 MWth,

while heat input in reheating amounts to 39.38 MWth. As consequence the circu-

lating steam mass flow is lowered to 102.02 kg/s. Using the efficiency data given

Table 36.1 altogether a net power output of 88.96 MWel at the design-point could be

generated. Whereas the gross efficiency is 37.5%, which represents a reduction of

2.2%-points related to the base case power plant.

Results and Discussion

For all in the previous chapters mentioned configurations, namely

• solar only bench mark model: abbr.: solar only

• base case power plant: abbr.: BC

solar-HTF-cycle solar field

natural gas inlet

flue gas outlet

air inlet

solar steam

generator

reheating

HTF-heater 1 2

34 5

678

M main HTF pump

steam turbine

condensate pump

air cooled condenser air

inlet

air outlet

feed water tank

feed water pump LP feed heaters

H P

fe ed

h ea

te rs

technical data

heat input 252.27 MWth heat input solar steam generator 212.89 MWth heat input reheating 39.38 MWth heat input heater 0.00 MWth gross power output 94.60 MWel auxiliary power demand 5.64 MWel net power output 88.96 MWel water/steam cycle gross efficiency 37.50 % net plant efficiency 18.89 % live steam flow 102.02 kg/s live steam temperature 380.00 °C live steam pressure 100.00 bar

condenser pressure 0.13 bar

reheating steam temperature 380.00 °C reheating steam pressure 25.75 bar

Fig. 36.5 Process flow diagram of the solar only benchmark model

484 T. Vogel et al.

• base case power plant plus GTa) (THM1304-14): abbr.: BCþGTa) • base case power plant plus GTb) (SGT-400): abbr.: BCþGTb),

annual yield simulations have been performed in hourly time resolution, based

on the given information regarding the operational logic and the used exemplary

annual weather profile.

In order to enable a fundamental understanding of the power plant model at first

the behavior of the base case power plant is analyzed. Therefore initially the daily

behavior is discussed based on two example daily curves, before subsequently the

attention is given to the annual behavior.

Base Case Power Plant

In Fig. 36.6 the daily variation for process parameters (steam turbine inlet temper-

ature, steam turbine outlet pressure and DNI), shown as curves, and performance

values (heat input through SSG, HTF-heater and booster, generated net electricity),

shown as bars, are displayed exemplary for (a) 25th March (spring) and (b) 17th

July (summer).

Figure 36.6a shows with the 25th March an ideal sunny day in spring. The DNI is

very constant and lies during the day at around 600 W/m2. The power plant starts in

solar only mode, wherefore the steam turbine inlet temperature without booster-

operation is roughly 380 �C. In the next hour the solar heat input raises analog to the DNI and the daily shape of the incidence correction. Following, the steam mass

flow is increasing and so the shape of the process in the T,s-diagram is moving to

the left. Assuming a similar expansion in the steam turbine the steam wetness is

increasing and the steam turbine wetness limitation moves into focus. As a result,

the steam turbine inlet temperature is raised by the booster to 524 �C. Also in the following hour through the SSG a heat input of nearly 250 MWh/h is transferred to

the water steam cycle. Thus, the booster goes into full load and delivers steam at

300

Q_SSG Q_Heater

W_net Q_Booster

200

100

0 1

800

400

600

200

0 3 5 7 9

local time

o u

tp u

t [M

W h

/h ]

(b ar

D N

I [ W

/m 2 ]

; p

S T ,o

u t [

m b

ar ]

T S

T ,in

[ °C

] (c

u rv

es )

11131517192123

T_ST_in p_ST_out DNI

800

400

600

200

0 D N

I [ W

/m 2 ]

; p

S T ,o

u t [

m b

ar ]

T S

T ,in

[ °C

] (c

u rv

es )

o u

tp u

t [M

W h

/h ]

(b ar

local time

1 3 5 7 9 11131517192123

300

200

100

Fig. 36.6 Performance values (bars) and process parameters (curves) for the (a) 25th March and (b) 17th July

36 Hybridization of Parabolic Trough Power Plants with Natural Gas Through. . . 485

540 �C. Despite the later on slight reduction of the in the SSG transferred heat into the water steam cycle the steam temperature at steam turbine inlet is constant at

540 �C, due to the approach of smoothed live steam temperature. During night the steam turbine is cooling out. In spring the ambient temperature is on a moderate

level, wherefore the steam turbine outlet pressure is obvious lower than the limi-

tation of 230 mbar.

A summer day with a short-term insolation drop is shown in Fig. 36.6b with the

17th July. In comparison with Fig. 36.6a it is easy to identify that for that summer

day the maximum electrical net output is not reached. This is caused by the hot

ambient temperature (at that day roughly 39 �C) and is typical for the chosen design of the power plant with an ACC, whereby a solution could be to overdesign the

ACC. The high ambient temperature yields to a large steam turbine outlet pressure

with an ACC. For the shown example the maximum steam turbine outlet pressure is

reached. For that reason the fossil input is lowered to the technical lowest level,

e.g. steam turbine wetness limitation. Therefore the steam turbine inlet temperature

is even at high DNI not at 540 �C but rather at 490 �C (12:00), which is typical for the summer period. The drop in the transferred heat through the SSG between 12:00

and 13:00 indicates that supportive the solar field is defocussed in order to lower the

power plant load. After 13:00 there is a sudden insolation drop (753 Wh/(m2h)! 111 Wh/(m2h)), which is why the HTF-heater starts its operation and enables a

steady transferred heat to the water/steam cycle. In the late afternoon the DNI is

raising again, so that the HTF-heater is turned off.

The distribution of all base case power plant operating points with a positive net

power output are shown in Figs. 36.7 and 36.8. Based on these two diagrams the

functionality of the developed operational logic will be discussed in detail.

In Fig. 36.7 the steam turbine exhaust pressure is plotted against the ambient

temperature. Due to the different part load status of the power plant a certain

ambient temperature leads to different steam turbine exhaust pressures. The

steam turbine exhaust pressure increases with rising power plant load. For that

Fig. 36.7 Annual distribution of steam turbine

(ST) outlet pressure with

respect to the ambient

temperature

486 T. Vogel et al.

reason two curves form out, which represent the curve for min load (point 3) and

curve for full load (point 2) of the power block as function of the ambient

temperature. As already mentioned the maximum tolerable turbine exhaust pressure

is 0.23 bar. This limitation is trespassed at high ambient temperatures with concur-

rent high load status of the power block. Through the operating logic these critical

operating points are transferred into an operating point where this limitation is

satisfied. Herefrom the perpendicular in the upper right part of the passel in

Fig. 36.7 indicated by point 1, is formed out. The volume factor of the volume

flow at steam turbine outlet is limited to 1.5. This limitation is most critical at low

condenser pressure with simultaneously high part load status and is depicted in

Fig. 36.7 by the notch in the passel at point 4.

Figure 36.8 shows the dependency of live steam pressure versus steam quality at

steam turbine outlet at ELEP for the operating points. The steam quality describes

the share of saturated steam (vapor) in a saturated condensate (liquid) and saturated

steam (vapor) mixture. The passel at point 1, with operating points corresponding to

a steam turbine inlet pressure of lower than 40 bar and a steam quality at steam

turbine outlet of lower than 0.87, located in the lower left part in Fig. 36.8

represents the solar only operating points. In the morning as long as the steam

wetness limitation is satisfied the power plants runs in solar only mode. When the

load is increasing due to higher solar insolation with respect to the simultaneously

raising live steam pressure, caused by the sliding pressure mode of the steam

generator, the steam wetness is also increasing. For that reason the booster goes

into operation. The minimum allowed steam wetness at ELEP is 15%, which

corresponds with a steam quality of 0.85. Because of the booster’s min load of 5% the set point of the controller regulating the boosters load is set to adapt the

booster load in order to enable a steam quality at ELEP of 0.86. For that reason is at

a steam quality of 0.86 a perpendicular (point 2). But when the booster is already at

full load and delivers a live steam temperature of 540 �C and owing to a relatively low ambient temperature a low condenser pressure arises the booster cannot fulfill

the steam wetness limitation. In order to fulfill the requirement the load of the

Fig. 36.8 Annual distribution of steam quality

at the steam turbine

(ST) outlet with respect to

the live steam pressure

36 Hybridization of Parabolic Trough Power Plants with Natural Gas Through. . . 487

power block must be reduced for example by reducing the solar heat through

defocussing. The upper end of the passel at 100 bar (point 4) indicates the power

blocks full load. There the steam quality is only depending on the ambient

temperature.

In conclusion the annual yield simulation for the base case power plant has

shown so far, that due to the chosen operating logic and the process layout nearly all

operating points differ from each other. Therefore it is very important to perform

the annual yield simulations with a fully thermodynamically model and not by

characteristic curves.

Cross Comparison

A cross comparison of the results from the annual yield simulation for the four

examined configurations of the case study is given with their main performance

parameters in Table 36.3.

As a common constraint the incident solar energy is in all configurations the

same, owing to the identical solar field and the uniform site. The yearly operating

hours of all configurations are very similar and lay in a range of 3231–3246 h per

year. For that reason the theoretical as well as the used solar heat input to the HTF

are also in a similar magnitude. Referring to the incident solar energy the amount of

Table 36.3 Comparison of the simulation results of the annual yield analysis for the configura- tions of the case study

Simulation results Solar only BC BCþGTa) BCþGTb) Units Available DNI 1889.38 1889.38 1889.38 1889.38 kWh/(m2 a)

Net aperture area 627,786.55 627,786.55 627,786.55 627,786.55 m2

Incident solar energy 783.72 783.72 783.72 783.72 GWhth/a

Operating hours 3241 3231 3243 3246 h

Theoretical available

solar heat input to HTF

682.63 682.27 683.30 683.51 GWhth/a

Used solar heat input to

HTF

636.46 635.99 637.26 637.54 GWhth/a

Total gross electricity

steam turbine

234.57 282.45 286.84 285.64 GWhel/a

Total net electricity gas

turbine

0.00 0.00 26.05 28.98 GWhel/a

Net electricity 220.65 266.55 296.99 298.72 GWhel/a

Supplied energy from

natural gas

13.38 126.05 198.29 195.22 GWhth/a

Design-point net plant

efficiency

18.89 21.65 22.75 22.66 %

Annual net plant

efficiency

18.40 20.31 21.45 21.62 %

Annual solar fraction 97.94 83.46 76.27 76.56 %

488 T. Vogel et al.

used solar heat input to HTF ranges between 81.2% (solar only) to 81.3%

(BCþGT configurations). The gross electricity of the BCþGT configurations is elevated based on the BC model by 3.2–4.4 GWhel/a owing to the gas turbine’s waste heat integration. Comparing the BCþGT configurations, the larger available waste heat amount for GTa) yields to a 1.2 GWhel/a larger steam turbine gross

electricity output. Due to the better electrical efficiency of GTb) the benefit of GTa)

in terms of steam turbine gross electricity output has been overcompensated so that

the overall produced net electricity of GTb) is 1.7 GWhel/a larger than the one for

GTa). The net electricity output of the solar only system amounts to 220.65 GWhel/

a. The BC offers a 20.8% higher net electricity output whereby the supplied energy

from natural gas is raised by the factor 9.4. Through an additional GT-integration

the net electricity output is additional raised by 11.4–12.1%, while the gas con-

sumption is increased by 50%. The solar only model has because of the lower live

steam temperature the lowest design-point net efficiency of 18.89%. Following the

hybridization the live steam temperature is elevated from 380 to 540 �C which leads for the BC to a 2.76%-points higher design-point net efficiency. Through the

further combination with gas turbines the design-point net efficiency could be

raised by additional 1–1.1%-points. For the solar only model the design point net

plant efficiency and the annual net plant efficiency differ with absolute 0.5%-points

not that much, owing to very constant process parameters. For the hybrid config-

urations the difference between design-point and the annual value is larger and

ranges between 1- and 1.3%-points. This is especially caused by different process

parameters between different operating states, e.g. the live steam temperature varies

during operation between 380 and 540 �C. In analogy to the supplied energy from natural gas the annual solar fraction decreases beginning with 97.9% for the solar

only model upon further hybridization to 83.5% (BC) and finally round about

76.3–76.6% for the BCþGT configurations. For the energetic comparison between the hybrid configurations the conversion

efficiency of fuel into electricity ηfuel is introduced, which is defined by Eq. (36.1).

ηf uel ¼ ΔPnet,hybrid�solar Δ _Q hybrid�solar

¼ Pnet,hybrid � Pnet, solar _Q hybrid � _Q solar

ð36:1Þ

Therefore the difference of the produced net electricity of the hybrid power plant

and the solar only benchmark model is divided by the difference of the used fuel,

whereby also the hybrid case is subtracted from the solar only benchmark model.

The resulting ηfuel for the hybrid configurations is visualized in Fig. 36.9. Referring to the solar only bench mark model described in chapter 5 and the

results of the performed annual yield simulation the ηfuel amounts for the base case power plant to 40.74%. Through integrating industrial gas turbines the overall

conversion efficiency of fuel into electricity could be elevated compared to the base

case power plant. The highest increase, with absolute 2.20%-points could be

achieved by integrating GTb) in the BC. But even with the configuration

BCþGTa) an enhancement of ηfuel could be realized with a plus of 0.55%-points. Comparing these numbers, while taking the 3.8%-points better electrical efficiency

36 Hybridization of Parabolic Trough Power Plants with Natural Gas Through. . . 489

of GTb) at the design-point into account, the absolute advantage is lessened through

the integrated configuration. This effect is mainly caused by the fact, that the gas

turbine GTa) with a lower electrical efficiency offers at design point a 19% higher

waste heat potential than the GTb). Following this, the amount of bled steam for the

configuration BCþGTa) could be lowered, which leads to the higher steam turbine gross electricity of round about 1.2 GWhel/a.

As mentioned in the introduction a certain amount of peaker gas turbines is

installed in the UAE. For the evaluation of the advantage of a combined usage in

comparison to a separated configuration the electricity to fuel ratio is used. For the

separated production the gas turbine’s waste heat is not integrated into the base case power plant. Due to missing information on the operation scheme of the peaker gas

turbines in UAE, this evaluation was simplified in that way, that the operating hours

of the peaker gas turbine are similar with the base case power plant. The following

values are also based on the yearly values.

As Fig. 36.10 shows, within a combined production the electricity to fuel ratio

could be elevated depending on the configuration round about 0.17–0.19 MWhel/

Fig. 36.9 Annual conversion efficiency of fuel into electricity for the three hybrid configurations BC, BCþGTa) and BCþGTb) of the case study

Fig. 36.10 Fuel to efficiency ratio for the two BCþGT configurations for separated and com- bined production

490 T. Vogel et al.

MWhth. Based on the above mentioned assumptions for the two BCþGT config- urations 4.4–5 MtCO2/a could be saved towards a separated production.

Conclusions

In the present publication the hybridization of parabolic trough power plants using

state of the art thermal oil as HTF with natural gas has been evaluated based on the

power plant configuration of Shams One. In a first step for this base case model a

detailed operational logic has been developed in order to fulfill all technical

constraints. In a second step a further hybridization through integrating gas turbines

in the performance class of 10–20 MWel has been done, whereby two different gas

turbines has been used in order to cover the range. For this purpose of evaluating the

fuel to electricity conversion efficiency in addition a solar only reference model has

been prepared. For all these configurations annual yield simulations have been

performed.

It is shown, by example of the base case model, that through the developed

operational logic the identified main technical boundary conditions are satisfied.

Through the hybridization done in the base case model, based on Shams One, the

net efficiency could be raised by 2.76%-points for design-point and 1.92%-points

for annual view in comparison to the solar only reference model. The annual fossil

fuel to electricity conversion efficiency amounts to 40.74%. By integrating addi-

tionally a gas turbine this efficiency value could elevated by another 2.2%-points

up to 42.94%. Supplementary to this absolute efficiency improvement, the com-

bined production has versus to the separate production a better electricity to fuel

ratio and thereby saves CO2. Here it should be noted, that therefore the assumptions

for gas turbine operation are deciding. Furthermore, the operation flexibility of the

peaker gas turbine is in the combined approach not affected.

All in all the hybridization of parabolic trough power plants using a HTF limited

to 400 �C with natural gas offers the opportunity to improve the power plant in terms of live steam parameters, efficiency and flexibility.

As brief outlook on the economy it has to be noted, that a gas turbine integration

in the evaluated arrangement offer a reduction potential for the levelized costs of

electricity, which amounts with the used assumptions to round about 5–6%.

Acknowledgements The authors would like to thank the German Federal State of North Rhine- Westphalia and the European Regional Development Fund for the financial support of the project

TURIKON in the frame of the program progress. NRW and the goal 2-program 2007–2013, Phase

VI (Grant No. 64.65.69-EN-2019).

36 Hybridization of Parabolic Trough Power Plants with Natural Gas Through. . . 491

Nomenclature

ACC Air-cooled condenser

BC Base case

CSP Concentrating solar power

DNI Direct normal irradiance, W/m2

ELEP Expansion line end point

GT Gas turbine

HTF Heat transfer fluid

HP High pressure

FH Feed heater

IP Intermediate pressure

ISCC Integrated solar combined cycle

LP Low pressure

p Pressure, bar or kPa

P Power output, W

Q Thermal output, W

SSG Solar steam generator

ST Steam turbine

T Temperature, �C UAE United Arab Emirates

Greek Letters

Δ Difference ηel Efficiency, %

Subscripts

out Outlet

in Inlet

hybrid Hybrid configuration

net Net

solar Solar configuration

el Electrical

fuel Fuel

mech Mechanical

s Isentropic

492 T. Vogel et al.

References

Al Mirfa Power Company. http://www.ampc.ae/en/production/. Retrieved November 27, 2014.

Balan, R. (2014). Simulation des transienten Verhaltens von Parabolrinnenkraftwerken. Master thesis. Essen: University of Duisburg-Essen.

BP. (2014). BP energy outlook 2035. bp.com/energyoutlook. Retrieved March 16, 2015. Gas Turbine World. (2011).Gas turbine world 2011-Performance Specs. Pequot Publishing. ISSN

0746–4134, (27th ed., Vol. 41 No.1).

Goebel, O. (2010). Shams one 100 MW CSP plant in Abu Dhabi—Update on Project Status.

Proceedings of the SolarPACES 2010 Conference. Perpignan, France. Goebel, O., & Luque, F. (2012). Shams One 100 MW CSP Plant in Abu Dhabi. Update on

Proceedings of the SolarPACES 2012 Conference. Marrakesch: Marocco.

Lechner, C., & Seume, J. (2010). Station€are Gasturbinen. e-ISBN 978-3-540-92788-4. (2nd ed.). Heidelberg: Springer-Verlag Berlin.

MAN. http://www.corporate.man.eu/man/media/content_medien/images/global_corporate_website/

presse_und_medien/mdt/2013_2/T_Turbinenlaeufer.jpg. Retrieved December 29, 2014.

Pawellek, R., L€ow, T., & Hirsch, T. (2009). EbsSolar—a solar library for Ebsilon®Professional. Proceedings of the SolarPACES 2009 Conference. Berlin, Germany.

Reuß, N. (2012). Modern gas and steam turbines in solarthermic applications. 14th International Symposium on Transport Phenomena and Dynamics of Rotating Machinery (ISROMAC).

Honolulu, HI, USA.

Schr€oder, K. (1966). Große—Dampfkraftwerke—Planung Ausf€uhrung und Bau, Dritter Teil A. Berlin: Springer.

Servert, J. F., Cerrajero, E., Lopez, D., Yagüe, S., Gutierrez, F., Lasheras, M., & San Miguel, G.

(2014). Base case analysis of a HYSOL power plant. Proceedings of the SolarPACES 2014 Conference. Bejing, China.

SOLUTIA. Product data sheet—therminol VP-1. http://twt.mpei.ac.ru/TTHB/HEDH/HTF-VP1. PDF. Retrieved May 6, 2013.

TRANSCO. (2014). Seven year electricity planning statement (2014–2020)—report. http://www. transco.ae/media/docs.htm. Retrieved November 27, 2014.

Turchi, C. S., Ma, Z., Erbes, M. (2011).Gas turbine/solar parabolic trough hybrid designs. ASME Turbo Expo 2011. Vancouver, Canada.

United Arab Emirates. (2012). Annual statistical report—electricity and water 2012. Ministry of Energy. Abu Dhabi, Dubai.

Vogel, T., Oeljeklaus, G., G€orner, K. Dersch, J., & Polklas, T. (2013). Hybridization of parabolic trough power plants with natural gas. Energy Procedia 49 (2014)—Proceedings of the SolarPACES 2013 Conference. (pp. 1238–1247). Las Vegas, USA.

36 Hybridization of Parabolic Trough Power Plants with Natural Gas Through. . . 493

http://www.corporate.man.eu/man/media/content_medien/images/global_corporate_website/presse_und_medien/mdt/2013_2/T_Turbinenlaeufer.jpg

http://www.ampc.ae/en/production/

Part X

Energy Technologies and Their Effect on Global Warming

Thermodynamic System Analysis and Optimization

Specific cases of system analysis and optimization

Chapter 37

Performance Analyses of CO2-N2O Cascade System for Cooling

Fatih Yılmaz, Reşat Selbaş, Arif Emre €Ozgür, and M. Tolga Balta

Introduction

Because of environmental issues associated with the global warming and ozone

layer depletion attributed to the application of synthetic refrigerants chlorofluoro-

carbons (CFC’s), hydrochlorofluorocarbons (HCFC’s) and hydrofluorocarbons (HFC’s), the return to the usage of natural materials for cooling system appears to be an appropriate alternative. Accordingly, the natural refrigerants such as

ammonia, carbon dioxide and hydrocarbons, have recently received increasing

attentions (Dopazo et al. 2009). Amongst the natural refrigerants, the suggested

of the use of CO2 seems to be the most promising especially as the natural

refrigerant (Lorentzen and Petterson 1993). The CO2 including that non-toxic,

easily available, excellent thermophysical properties and not explosive. N2O refrig-

erant, which is alternative of CO2 in terms of thermophysical properties. N2O

refrigerants’ disadvantage is, its global warming potential (GWP) is higher than CO2.

The cooling systems involving a high temperature difference between the

condenser and the evaporator, employing a single stage cooling system is not

F. Yılmaz (*) Department of Energy, Vocational Schools of Technical Sciences, Aksaray University,

68100 Aksaray, Turkey

e-mail: [email protected]

R. Selbaş • A.E. Özgür

Department of Energy Systems Engineering, Faculty of Technology, Suleyman Demirel

University, 32100 Isparta, Turkey

e-mail: [email protected]; [email protected]

M.T. Balta

Department of Mechanical Engineering, Faculty of Engineering, Aksaray University,

68100 Aksaray, Turkey

e-mail: [email protected]

499

mailto:[email protected]

economical because of the corresponding high pressure ratio leads to a low volu-

metric efficiency of the compressors and consequently low coefficient of perfor-

mance of the system. In conditions cascade cooling cycle is more appropriate.

Cascade cooling cycles are generally in low evaporating temperature applications,

which is evaporating temperature between�40 �C and�130 �C. A commonly used refrigerants pair in the past has been R12, R502 in high temperature cycle and R13

in low temperature cycle of cascade refrigeration system. These refrigerants have

been phased out since 1996 in the developed countries, and should be totally phased

out by 2010 in developing countries as per Montreal Protocol and its amendments

from the United Nations Environment Programme (UNEP 1987, 2007). Currently,

many manufacturers tend to use natural refrigerants due to environmental problems

and harmful effects synthetic refrigerants. CO2/N2O cascade system uses N2O in

the high temperature cycle and CO2 in the low temperature cycle. N2O is natural

refrigerant.

Ratts and Brown (2000) shows that the entropy generation method to analyze the

cascade cycle. In their work, relationships were developed for the specific heat and

temperature ratio terms and the results were investigated for a cascade system in

two low temperatures of 0.684 and 0.681, with the refrigerant R-134a and finally,

the optimum temperature distribution was found. The study the optimum temper-

ature in a cascade condenser, maximized the coefficient of performance and

minimized the exergy destruction of the system, CO2 is using the evaporation

temperature and NH3 is condensation temperature carried out by (Lee et al. 2006).

Energy and irreversibility analysis of a cascade refrigeration system employing

various refrigerant couples using a computer code carried out by (Kilicarslan and

Hosoz 2010). Bansal and Jain (2007) shown that evaluated the optimum cascade

condensing temperature of CO2 when different refrigerants such as NH3, propane,

propylene and ethanol are used in the high temperature circuits of a subcritical

cascade system. Bhattacharyya et al. (2005) shows that an optimization research of

the CO2/C3H8 cascade system for cooling and heating. Analyzed a vapor compres-

sion heat pump working with R11 and a vapor compression refrigeration system

operating with R12 cascaded to produce heating and cooling effects simultaneously

carried out by (Murthy and Murthy 1985). Bhattacharyya et al. (2009) give in that

thermodynamic analysis and optimization of a novel N2O–CO2 cascade system for

refrigeration and heating. They study, a natural refrigerant based cascaded system,

with nitrous oxide as the low temperature fluid and carbon dioxide as the high

temperature fluid, is analyzed for simultaneous cooling and heating applications.

In literature generally CO2 and NH3 refrigerants in cascade cooling system were

compared. In this study, a cascade system for cooling with N2O as the high

temperature fluid and CO2 as the low temperature fluid is theoretical analyzed.

Thermodynamic analysis of cooling system as evaporator temperature variations

and pumps inlet pressure variations are investigated. Also, the effects of operating

parameters on system performance are studied and illustrated in tables. The effect

on the system performance of the heat exchangers are also investigated and given in

figures.

500 F. Yılmaz et al.

Performance Analyses of CO2-N2O Cascade

A schematic diagram of a cascaded CO2 and N2O cooling system is given in Fig. 37.1

and the corresponding P–h diagram is shown Fig. 37.2. This cooling system includes

two separate circuits, one high temperature circuit (HTC) with N2O as the refrigerant

and the other one, low temperature circuit (LTC) with CO2 as the refrigerant. The

analysis was carried out as subcritical cycle. HTC of condenser as water cooler

condenser is discussed. These two circuits are thermally coupled using a heat

exchanger which acts as an evaporator for the HTC and a condenser for the LTC.

The natural fluid N2O has a triple point �90.82 �C. Furthermore similarity between critical temperature N2O and CO2. Table 37.1 given in thermodynamic

properties of CO2 and N2O.

Each refrigeration system consists of a compressor, a condenser, an expansion

valve, and an evaporator. In this study N2O is the refrigerant in HTC, whereas CO2 is the refrigerant in LTC. The circuits are thermally connected to each other through

a heat exchanger, which acts as an evaporator for the HTC and a condenser for the

LTC. The evaporator of LTC absorbs the cooling load from the cooling space. The

condenser in HTC rejects heat flow at condensing temperature.

The cascade cooling system components shown in Fig. 37.1 can be treated as a

control volume. The thermodynamic analysis of the cascade cooling system was

performed based on the following general assumptions;

Fig. 37.1 Schematic diagram of the CO2-N2O cascade refrigeration system

37 Performance Analyses of CO2-N2O Cascade System for Cooling 501

• Refrigerants at the cascade heat exchanger and outlet for HTC cycle and

evaporator for LTC cycle outlet are saturated.

• The changes in kinetic and potential energy are negligible.

• Adiabatic and irreversible compression in HTC with an isentropic efficiency of

0.8.

• Negligible pressure and heat losses in the pipe networks or system components.

• All system components operate under steady-state conditions.

• NH3Heat transfer processes in cascade heat exchanger, condenser and evapora-

tor are isobaric.

• Ambient (dead state) temperature (T0) 21 �C and ambient pressure (P0) 1 bar.

The thermodynamic properties of CO2 and NH3 were determined using Engi-

neering Equations Solver (EES). EES can generate publication-quality plots, do

optimization, provide linear and non-linear regression, solve equations and simplify

uncertainty analyses.

Taking into account the assumptions previously made, mass and energy balances

are given by Eqs. (37.1) and (37.2), respectively.

For the steady-state process, the mass, energy and exergy balance for the each

control volume can be expressed as follows;

N2O

CO2

102

0.2 0.4 0.6 0.8

7 6

2 5

1 1

103

h [kJ/kg]

P [

B ar

] 104

Fig. 37.2 A schematic P-h diagram of the CO2-N2O cascade refrigeration system

Table 37.1 Thermodynamic properties of CO2 and N2O

Property CO2 N2O

Critical pressure (bar) 73.77 72.45

Critical temperature (�C) 30.98 36.37 Triple point temperature (�C) �56.56 �90.82 Molecular weight (kg/kmol) 44.01 44.01

502 F. Yılmaz et al.

X _m in ¼

X _mout ð37:1Þ

where _m: is the mass flow rate, and the subscript in stands for inlet and out for outlet. The mass balance equation can be expressed in the rate form as with all energy

terms as follows (Cengel and Boles 2008)

_Q � _W þ X

_m inh� X

_mouth ¼ 0 ð37:2Þ

The general exergy balance can be expressed in the rate form as;

_Exin � _Exout ¼ _Exdest ð37:3Þ _Exheat � _Exwork þ _Exmass, in � _Exmass,out ¼ _Exdest ð37:4Þ

Using Eq. (37.4), the rate form of the general exergy balance can also be written

X 1� T0

� � _Q k � _W þ

X _m inψin �

X _moutψout ¼ _Exdest ð37:5Þ

where _Q k is the heat transfer rate through the boundary at temperature, Tk at

location k, _W: is the work rate, I ? is the flow (specific) exergy, h is enthalpy, s is entropy, and the subscript zero indicates properties at the restricted dead state of P0 and T0.

The specific exergy (flow exergy) of refrigerant (or water) is calculated by;

ψ ¼ h� h0 � T0 s� s0ð Þ ð37:6Þ

The exergy rate is calculated by;

_Ex ¼ _m ψ ð37:7Þ

Energy (or first law) efficiency of the cascade cooling system and exergy

efficiency are determined as follows, respectively,

COP ¼ _Q ev

_WN2O þ _WCO2 ð37:8Þ

ε ¼ _Exout _Exin

ð37:9Þ

where out refers to “net output” or “product” or “desired value”, and in refers to

“given” or “used”.

For LTC compressor (I);

37 Performance Analyses of CO2-N2O Cascade System for Cooling 503

_mCO2 ¼ _m1 ¼ _m2 ð37:10Þ

PrCO2 ¼ P2

P1 ð37:11Þ

ηCO2 isen ¼ 0, 815þ 0, 022 * PrCO2 � 0, 0041 * P2rCO2 þ 0, 0001 * P3rCO2 ð37:12Þ

ηCO2 isen ¼ h2s � h1 h2 � h1 ð37:13Þ

where the heat transfer versus the environment was neglected. Equation (37.12)

depending on the LTC of compressor isentropic efficiency the compressor outlet

enthalpy is calculated (Robinson and Groll 1998).

_WCO2 ¼ _mCO2 h2 � h1ð Þ ð37:14Þ _Exdest, comp ¼ _mCO2 ψ1 � ψ2ð Þ þ _WCO2 ð37:15Þ

For LTC condenser–HTC evaporator (heat exchanger) (II);

_mCO2 ¼ _m2 ¼ _m3 ð37:16Þ _mN2O ¼ _m8 ¼ _m5 ð37:17Þ

_Q hexc ¼ _mN2O h5 � h8ð Þ ¼ _mCO2 h2 � h3ð Þ ð37:18Þ _Exdest, hexc ¼ _mCO2 ψ3 � ψ2ð Þ þ _mN2O ψ8 � ψ5ð Þ ð37:19Þ

The heat rate exchanged and exergy destruction from LTC to HTC in the heat

exchanger is called _Q hexc and can be calculated by Eqs. (37.18) and (37.19). For expansion valve (III)

_mCO2 ¼ _m3 ¼ _m4 ð37:20Þ h3 ¼ h4ð Þ ð37:21Þ

_Exexp ¼ _mCO2 ψ3 � ψ4ð Þ ð37:22Þ

The expansion valve exergy destruction is calculated with Eq. (37.22). Where

expansion valve of heat transfer is neglected.

For LTC evaporator (IV);

_mCO2 ¼ _m4 ¼ _m1 ð37:23Þ _Q ev ¼ _mCO2 h1 � h4ð Þ ð37:24Þ

_Exdest, evap ¼ _mCO2 ψ4 � ψ1ð Þ þ _Q ev 1� To

TEV

� � ð37:25Þ

504 F. Yılmaz et al.

The evaporator heat rate and exergy destruction is calculated with Eqs. (37.23)

and (37.24). Where is the T0 is ambient temperature (dead state), TE is evaporator

temperature.

For HTC compressor (v);

_mN2O ¼ _m5 ¼ _m6 ð37:26Þ _WN2O ¼ _mN2O h6 � h5ð Þ ð37:27Þ

_Exdest, comp ¼ _mN2O ψ6 � ψ5ð Þ þ _WN2O ð37:28Þ

The HTC compressor exergy destruction is calculated with Eq. (37.28).

For HTC condenser (VI);

_mN2O ¼ _m6 ¼ _m7 ð37:29Þ _Q con ¼ _mN2O h6 � h7ð Þ ð37:30Þ

_Excon ¼ _mN2O ψ4 � ψ1ð Þ � _Q con 1� To

TCON

� � ð37:31Þ

The condenser heat rate and exergy destruction is calculated with Eqs. (37.30)

and (37.31). Where is the T0 is ambient temperature (dead state), Tc is condenser

temperature.

For expansion valve (VII)

_mN2O ¼ _m7 ¼ _m8 ð37:32Þ h7 ¼ h8ð Þ ð37:33Þ

_Exexp ¼ _mN2O ψ7 � ψ8ð Þ ð37:34Þ

The expansion valve exergy destruction is calculated with Eq. (37.34). Where

expansion valve of heat transfer is neglected.

Results and Discussion

A performance analysis of the cascade cooling with CO2-N2O system is investi-

gated using energy and exergy analysis. Under the assumptions, the calculated

properties for cascade cooling system are given in Table 37.2. The cooling coeffi-

cient of performance and exergy efficiency of the cascade system (COP) is calcu-

lated from Eqs. (37.8) and (37.9) and is found to be 2.061% and 35%, respectively.

Figure 37.3 displays the effect of evaporator temperature on COP and exergy

efficiency cycle. As can be seen in Fig. 37.3. The cycle of evaporator temperature

25 �C, by increasing evaporator temperature the system of COP and exergy efficient has increased. While evaporator temperature �50 �C, COP and exergy efficiency

37 Performance Analyses of CO2-N2O Cascade System for Cooling 505

are 1.055% and 25%, respectively. In Fig. 37.3, the systems are represented COP

and the exergy efficiency trends with increases in evaporator temperature.

The systems of the COP and exergy efficiency effect on condenser temperature

can be observed in Fig. 37.3.

Table 37.2 Exergy analysis results of the cascade cooling system studied for one representative unit

State

no Fluid Phase

Temperature

(�C) Pressure

(bar)

Specific

enthalpy

(kJ/kg)

Specific

entropy

(kJ/kg K)

Exergy

rate

(kW)

1 CO2 saturated

vapor

�23 14.28 �62.17 �0.7095 11.81

2 CO2 Super-

heated

vapor

66.58 45.02 0.2552 �0.6806 14.28

3 CO2 Comp.

liquid

15.72 45.02 �264.6 �1.596 20.42

4 CO2 Mixture �30 14.28 �264.6 �1.542 19.28 5 N2O saturated

vapor

10 33.7 408.9 1.594 13.45

6 N2O Super-

heated

vapor

52.14 56.51 435.4 1.611 14.88

7 N2O Comp.

liquid

20 56.51 212.5 0.87 15.58

8 N2O Mixture 3 33.7 212.5 0.8839 15.29

-50 -45 -40 -35 -30 1

1.2

1.4

1.6

1.8

2.2

0.24

0.26

0.28

0.3

0.32

0.34

0.36

C O

TEV (°C)

TCON = 25 (°C)

Fig. 37.3 Effect of evaporator temperature on COP and exergy efficiency

506 F. Yılmaz et al.

In this system with increases condenser temperature, COP and exergy efficiency

is decreases shown in Fig. 37.3. While evaporator temperature �30 (�C) and the condenser temperature is 20 (�C), the cycle of COP and exergy efficiency are shown 2.28% and 39%, respectively.

Figure 37.4 given in the effect of N2O compressor isentropic efficiency on the

cycle COP and exergy efficiency. While condenser and evaporator temperature are

fixed respectively 25 (�C), �30 (�C), with HTC compressor isentropic efficiency increases, COP and exergy efficiency are increases can be observed in Fig. 37.5. As

the compressor isentropic efficiency up to 90% on, the cycle of COP value rise up

to 2.14. The figurate result in understand that if the compressor isentropic efficiency

is increases, the system of increases COP and exergy efficiency.

The system effect of heat exchanger efficiency on COP and exergy efficiency

illustrated in Fig. 37.6. When the refrigeration cycle of heat exchanger efficiency is

rise up from 60% to 95%, the system of increases COP and exergy efficiency.

Figure 37.5 shows that evaporator temperature and condenser temperature are fixed

“�30 (�C), 25 (�C)”, while heat exchanger efficient is 75%, the systems of COP and exergy efficiency are calculated 1.986 34%, respectively.

Figure 37.6 shows that heat exchanger efficiency and evaporator temperature

changed on the system COP and exergy efficiency. The system of condenser

temperature 25 (�C) is fixed, as the heat exchanger efficiency is increases, which is fixed evaporator temperature, the system increases of COP. When the system of

heat exchanger efficiency and evaporator temperature are increased, the system is

increases of COP value observed in Fig. 37.6.

Figure 37.7 demonstrates the variation in the exergy destruction of different

components of the cascade refrigeration system. According to this figure, the

Fig. 37.4 Effect of condenser temperature on COP and exergy efficiency

37 Performance Analyses of CO2-N2O Cascade System for Cooling 507

highest amount of exergy destruction rate takes place in the evaporator (18.08 kW).

The lower amount of destruction rate take place in HTC and LTC expansion valves

is are calculated 0.029 and 0.06 respectively.

The effect on evaporator temperature on the exergy destruction at the system

components and COP the whole system at different evaporator temperature values

are demonstrated at Fig. 37.9. The exergy destruction occurs given in figurate HTC

0.8 0.82 0.84 0.86 0.88 0.9 2.06

2.08

2.1

2.12

2.14

2.16

0.355

0.36

0.365

0.37

0.375

C O

ηcomN2O

TCON = 25 (°C)

TEV = -30 (°C)

Fig. 37.5 Effect of N2O compressor isentropic efficiency on COP and exergy efficiency

0.6 0.65 0.7 0.75 0.8 0.85 0.9 0.95 1.6

1.7

1.8

1.9

2.1

2.2

2.3

0.28

0.3

0.32

0.34

0.36

0.38

0.4

h hexc

C O

TCON = 25 (°C)

TEV = −30 (°C)

Fig. 37.6 Effect of heat exchanger efficiency on COP and exergy efficiency

508 F. Yılmaz et al.

compressor, LTC compressor and heat exchanger. The system COP increases from

1.33 to 2.88 with evaporator temperature increase from �40 �C to �10 �C. But the system of HTC and LTC compressor exergy destruction rate are decreases with

increase of evaporator temperature shown that Fig. 37.9.

Fig. 37.7 Effect of heat exchanger efficiency and evaporator temperature on COP and exergy efficiency

Fig. 37.8 The exergy destruction values in different components of cascade refrigeration system

37 Performance Analyses of CO2-N2O Cascade System for Cooling 509

Conclusion

In this paper, a cascade system for cooling is with N2O-CO2 fluids as theoretical

performance analyzed according to thermodynamic assessment in order to investi-

gate cascade system COP and exergy analysis. According to condenser and evap-

orator temperature exchanges the system of COP and exergy efficiency are

investigated. This paper as a refrigerants environmentally friendly fluids CO2 and

N2O are used. The main concluding remarks have been given as follows;

• This cascade refrigeration cycle is subcritical and therefore water-cooled con-

denser was adopted.

• While the system of condenser temperature at 25 (�C) is fixed, evaporator temperature�30 (�C), the system of COP and exergy efficiency are respectively 2.1% and 36%.

• As the system of evaporator temperature is increased, COP and exergy efficiency

are increases.

• Evaporator temperature in �30 (�C), if the condenser temperature is increases the system of COP and exergy efficiency are decreased.

• Exergy efficiency have been calculated to be between 28% and 39%.

• COP and exergy efficiency are increased as the heat exchanger efficiency is

increased. Therefore, the more highly efficient heat exchanger are used, the more

exergy efficiency highly.

-45 -40 -35 -30 -25 -20 -15 -10 -5 0

1.5

2.5

3 E

xe rg

y D

es tr

uc tio

n R

at e

(k W

)

Heat exchanger LTC comp.HTC comp.

C O

COP

TEV(°C)

Fig. 37.9 Exergy destruction at the system components and COP the whole system at different evaporator temperature values

510 F. Yılmaz et al.

http://tureng.com/search/theoretical

Nomenclature

COP Coefficient of performance

Ex Exergy flow rate (kW)

Exdes Exergy destruction

h Specific enthalpy (kJ/kg)

_m Mass flow rate (kg/s) _Q Heat flow rate (kW)

s Specific entropy (kJ/kg K)

T Temperature (K or �C) _W Work rate or power (kW)

ψ Specific exergy (kJ/kg) η Efficiency (dimensionless) ε Exergy (second law) efficiency (dimensionless) in Inlet

out Outlet

des Destruction

ev Evaporator

con Condenser

exp Expansion valve

comp Compressor

hexc Heat exchanger

isen Isentropic

LTC Low temperature cycle

HTC High temperature cycle

References

Bansal, P. K., & Jain, S. (2007). Cascade systems: Past, present, and future. ASHRAE Trans- actions, 113(1), 245–252.

Bhattacharyya, S., Garai, A., & Sarkar, J. (2009). Thermodynamic analysis and optimization of a

novel N2O–CO2 cascade system for refrigeration and heating. International Journal of Refrig- eration, 32, 1077–1084.

Bhattacharyya, S., Mukhopadhyay, S., Kumar, A., Khurana, R., & Sarkar, J. (2005). Optimization

of a CO2–C3H8 cascade system for refrigeration and heating. International Journal of Refrig- eration, 28, 1284–1292.

Cengel, Y. A., & Boles, M. A. (2008). Thermodynamics: An engineering approach (6th ed.). New York: McGraw-Hill.

Dopazo, J. A., Fernández-Seara, J., Sieres, J., & Uhı́a, F. J. (2009). Theoretical analysis of CO2-

NH3 cascade refrigeration system for cooling applications at low temperatures. Applied Thermal Engineering, 29, 1577–1583.

Kilicarslan, A., & Hosoz, M. (2010). Energy and irreversibility analysis of a cascade refrigeration

system for various refrigerant couples. Energy Conversion and Management, 51(12), 2947–2954.

37 Performance Analyses of CO2-N2O Cascade System for Cooling 511

Lee, T. S., Liu, C. H., & Chen, T. W. (2006). Thermodynamic analysis of optimal condensing

temperature of cascade-condenser in CO2/NH3 cascade refrigeration system. Refrigeration, 29, 1100–1108.

Lorentzen, G., & Petterson, J. (1993). A new efficient and environmentally benign system for car

air-conditioning. International Journal of Refrigeration, 16(1), 4–12. Murthy, S. S., & Murthy, M. V. K. (1985). Experiments on a cascaded R11–R12 vapour

compression system for cogeneration of heat and cold. Journal of Heat Recovery Systems, 5 (6), 519–526.

Ratts, E. B., & Brown, J. S. (2000). A generalized analysis for cascading single fluid vapor

compression refrigeration cycles using an entropy generation minimization method. Refriger- ation, 23, 353–365.

Robinson, D. M., & Groll, E. A. (1998). Efficiencies of transcritical CO2 cycles with and without

an expansion turbine. International Journal of Refrigeration, 21(7), 577–589. UNEP. (1987). Montreal protocol on substances that deplete the ozone layer. United Nations

Environment programme.

UNEP. (2007). Assessment report of the technology and economic assessment panel. Nairobi, Kenya: UNEP Ozone Secretariat.

512 F. Yılmaz et al.

Chapter 38

Comparison of Thermal Repowering Alternatives for Thermal Power Plants

M. Zeki Yilmazoglu

Introduction

Electricity consumption increases rapidly due to the increasing population and

industrialization. Greenhouse gas emissions, mainly CO2, increase in order to offset

the increasing energy demand. Approximately half of the electricity demand is

obtained from fossil fuels combustion. Efficient use of energy, renewable energy,

clean energy generation systems, CO2 capture and storage, energy harvesting

systems etc. current research topics in power generation. Many regulations have

been implemented by the governments to decrease the greenhouse gases. On the

one hand, the energy demand increases rapidly, and on the other hand GHGs have

to be decreased. In Turkey, low rank lignite is generally used for power generation

in thermal power plants which most of them were installed in 80s. These old

thermal power plants are still in operation with lower net electrical efficiencies.

The net electrical efficiency of these power plants decrease with time due to the

aging and operational problems. Therefore, repowering of these power plants can

increase their energy efficiency and reduce their contribution to the global warming

potential.

Repowering can be defined as increasing the installed capacity, the net electrical

efficiency, and decreasing the emissions per installed capacity of an existing

thermal power plant (Yilmazoglu et al. 2012, 2013a, b). Generally, a gas turbine

is added to the cycle in thermal repowering applications. Feedwater heating, hot

windbox and parallel repowering are three of the most commonly implemented

repowering options (Escosa and Romeo 2009; Yilmazoglu and Durmaz 2013a, b).

M.Z. Yilmazoglu (*) Department of Mechanical Engineering, Faculty of Engineering, Gazi University,

Maltepe, Ankara, Turkey

e-mail: [email protected]

513

mailto:[email protected]

In feedwater heating, steam turbine extraction points are repealed and heating of

feedwater is supplied from a heat recovery steam generator or a solar field (Popov

2011; Yilmazoglu et al. 2012). In thermal power plants, repowering reduces CO2 emissions per installed capacity (Schenk and Ehren 2003; Walters 2008). The most

important parameter in repowering applications is the expected life time of the

equipment. Therefore, a detailed life expectancy analysis has to be carried out

before repowering. In addition, gas turbine and heat recovery steam generator

selection are crucial for the operation of thermal power plant after repowering

(D’Yakov et al. 1998; Mathieu 1998).

Gas turbine leverage and repowering efficiency are the decisive parameters in

the analysis of a repowering application. Repowering efficiency can be defined as

the rate of increment in electricity generation to increment in heat added to the

cycle which is given in Eq. (38.1). The subscripts, ar and br symbolize after

repowering and before repowering, respectively. After repowering the electricity

generation is increased due to the additional power from gas turbine and steam

turbine. Moreover, the natural gas consumption and consequently, the heat added to

the cycle are increased. Gas turbine leverage can be defined as the rate of increment

in electricity generation to the gas turbine installed capacity which is given in

Eq. (38.2). In a typical combine cycle power plant with an installed capacity of

400 MWe, approximately 67% of electricity generation capacity is supplied from

the gas turbine. However, in the case of repowering it is approximately 10–25% as

a result of smaller gas turbine selection.

ηrep ¼ ΔPel ΔQg

¼ Par � Pbr Qin,ar � Qin,br

ð38:1Þ

λGT ¼ ΔPel Pel,GT

¼ Par � Pbr Pel,GT

ð38:2Þ

Lignite is the main fuel source in electricity generation in Turkey and low rank

lignite is used generally for power generation. Most of the thermal power plants are

firstly operated in mid 80s. Therefore, the net electric efficiency and availabilities of

these power plants are decreased with time due to the ageing of components.

In this study, Soma A thermal power plant was examined and the application of

different repowering alternatives, feedwater heating, hot windbox, and parallel

repowering, were compared by a commercial software, Thermoflex. Soma A

thermal power plant was decommissioned in 2010. Currently, the installed capacity

of the power plant is 44 MWel with two units. One unit of the power plant was

simulated for different repowering alternatives. This study sums up and summarizes

the results of previous studies and compares different alternatives in terms of the

installed power increment, CO2 reduction potential per installed capacity and unit

electricity generation price.

514 M.Z. Yilmazoglu

Repowering Alternatives

Feedwater Heating

In Fig. 38.1, the connection schema for feedwater heating repowering application is

shown.A gas turbine and two feedwater heaters are added to the thermal power plant.

Dashed lines indicate components added to the thermal power plant after repowering.

Bled steam is only taken for deaerator and others are repealed. The waste heat of gas

turbine is utilized by two economizers. Natural gas or syngas can be used as the fuel

source in gas turbine. Also, a gasifier island can be added to the cycle to obtain

syngas. In this study natural gas is accepted as the fuel source in gas turbine.

Hot Windbox

Hot windbox repowering can be implemented in three different methods. In the first

method, the exhaust gas of gas turbine is fed to the burners. In this method, feedwater

heating is supplied by two economizers installed after the boiler. In direct hot windbox

application, burners and other related components have to bemodified due to the high

temperatures of exhaust gases of gas turbine. As a result, first investment cost of

repowering increases. In addition, due to the low O2 content which is approximately

13–14%, some combustion problems i.e. flame stabilization, can occur in the steam

boiler. Therefore, fresh air dilution is a necessity to lower the investment cost and

Fig. 38.1 Feedwater repowering of a thermal power plant

38 Comparison of Thermal Repowering Alternatives for Thermal Power Plants 515

prevent combustion problems. The fresh air dilution application is shown in Fig. 38.2.

In thismethod fresh air ismixedwith flue gases ofGT to increase theO2 content and to

decrease the burner inlet temperature. In the third method, a pre-cooling system is

installed after the gas turbine. This precooling system acts as an evaporator and

produces extra steam for the steam turbine. It is directly connected to the drum. The

temperature of the flue gas of GT is reduced to an acceptable range. However, the first

investment cost of pre-cooling system is higher than fresh air dilution application.

Therefore, fresh air dilution is used in the simulations.

Parallel Repowering

In parallel repowering, a gas turbine and a HRSG are installed and additional steam

is fed to the steam turbine. Parallel repowering application with additional gas

turbine stack brings the power plant operation flexibility (Yilmazoglu and Durmaz

2011). In all applications installed capacity of the power plant is increased with a

properly selected gas turbine and heat recovery steam generator (HRSG) combina-

tion (Carapellucci 2009; Elmasri 2008).

Design Parameters of Soma A Thermal Power Plant

Soma A thermal power plant was designed according to the data, given in

Table 38.1, in 1957. The power plant was operated at constant maximum load, at

Fig. 38.2 Hot windbox repowering with fresh air dilution

516 M.Z. Yilmazoglu

operation #4. The ultimate analysis of coal, used in the power plant, is given in

Table 38.2. The lower heating value and ash melting temperature of the coal are

3550 kcal/kg and 1400 �C, respectively. Three closed type feed water heaters and a deaerator is designed to preheat the condensed working fluid. Condenser pressure is

0.063 bar and a cross flow type cooling tower with fans is used to transfer the

condenser heat to the environment. An air preheater unit is also designed to send the

air into the combustion chamber at 220 �C. Flue gases are emitted to the atmosphere by a 55 m stack at 160 �C. The thermal efficiency of the boiler is 87.2% and stack losses are 8.4% of the total energy input. Bled steam, for preheating of the water in

feed water heaters, are taken from 4th, 8th, 11th and 13th stages, of a 15 stage

turbine. First bled steam is taken from 10–13 bar at 350 �C. The others are taken 4.5–4.8 bar at 250 �C for 8th stage, 1.7–1.8 bar at 175 �C for 11th stage and 0.3–0.35 bar at 110 �C for 13th stage (Fig. 38.3).

Table 38.1 Design data of Soma A thermal power plant

Operation conditionsa 1 2 3 4 5

Turbine power [MW] 7 12 17 22 NA

Water/steam pressures [bar]

Inlet of economizer 62 62.6 65.7 70 72

Outlet of dome 59.6 61.5 64 68 69.8

Outlet of superheater 59.4 60.7 62.4 65 66.2

Temperatures [�C] Steam temperature at outlet of superheater 489.7 487.7 487 486.5 486.4

Water temperature at inlet of economizer 139 165 180 192 196

Water temperature at outlet of economizer 197 216 230 242 245

Gas temperature at inlet of superheater 826 872 922 980 1000

Gas temperature at outlet of economizer 239 261 278 296 302

Air temperature at outlet of air pre-heater 206.5 213 222.5 226.5 228

Stack temperature 129 142 152 160 162.5

Mass flow rates [t/h]

Fuel 6.96 11.4 15.6 20.3 22

Combustion gas 60.6 93.3 121.4 150.8 161.5

Steam mass flow rate 30 51 72 96 105 aOperation conditions—1: Technical minimum, 2: Constant minimum load, 3: Normal load, 4:

Constant maximum load, 5: Transient maximum load

Table 38.2 Ultimate analysis of Soma coal

Ultimate analysis [wt.%] As received Dry

C 39.48 52.8

H 2.95 3.94

O+N 13.42 18

S 0.53 0.71

W 25.22 0

A 18.4 24.55

38 Comparison of Thermal Repowering Alternatives for Thermal Power Plants 517

Results

Aero-derivative type gas turbines, with a capacity of 12–35% of the existing power

plant, give the optimum results for feedwater heating repowering applications. The

limit is determined by the condenser mass flow rate increment percentage which is

taken as 20% greater than the initial total mass flow rate for all repowering

applications. In Figs. 38.4, 38.5, and 38.6 the effects of the feedwater repowering

application was presented. The ratio of gas turbine power to initial power indicates

the installed power or capacity of the selected gas turbine for repowering. For

instance, 20% ratio means that the GT installed power is 4.4 MWel. It is clear from

Fig. 38.4 the net power of the TPP was increased substantially after repowering.

Also, the condenser mass flow rate was increased due to the repealing of extraction

points of the steam turbine which also increased the mass flow rate of steam

entering the steam turbine and consequently, a 10% increment in net power

generation was obtained by steam turbine. For 30% GT ratio the total plant

capacity was found to be 30.2 MWel and the net electrical efficiency was increased

from 31.7% to 33.87%. Around 5% GT ratio ST net power and net electrical

efficiency was decreased as shown in Fig. 38.4. The reason of this decrement can be

explained by the lower capacity GT selection. Repowering efficiency and GT

leverage for different ratios were given in Fig. 38.5. It is shown that the minimum

gas turbine capacity has to be greater than 10% of the initial power. Figure 38.6

shows the CO2 emissions of the TPP after repowering. In the modeling of the

current state the CO2 emission was found to be 7.019 kg/s. After repowering with a

30% GT ratio, the CO2 emission was found to be 8.146 kg/s. It is an expected result

that the installed capacity of the TPP was increased. However, the CO2 emission per

installed capacity shows an interesting result. In the current state the CO2 emission

per installed capacity was found to be 0.321 and after repowering it was found to be

0.27 which indicates that repowering of old TPP can be used to decrease the CO2 emissions in short term.

Fig. 38.3 Parallel repowering application

518 M.Z. Yilmazoglu

For hot windbox repowering application a GT was installed. Flue gas was

diluted by fresh air to support combustion or flame stability. The results were

given in Figs. 38.7, 38.8, and 38.9. In Fig. 38.7 the effects of hot windbox

repowering application on TPP performance was shown. The net electrical effi-

ciency was slightly changed. However, when Figs. 38.4 and 38.7 were compared

The ratio of GT power to initial power [%]

0 10 20 30 40

V ar

ia tio

n pe

rc en

ta ge

[% ]

-10

50 Net power Heat rate variation ST net power variation Condenser mass flow rate Net electrical efficiency

Fig. 38.4 Effects of the feedwater heating repowering application in TPP

The ratio of GT power to initial power [%]

0 5 10 15 20 25 30 35

R ep

ow er

in g

ef fic

ie nc

y [%

]

0,0

0,2

0,4

0,6

0,8

1,0

1,2

1,4

G T

le ve

ra ge

[- ]

0,0

0,2

0,4

0,6

0,8

1,0

1,2

1,4

Repowering efficiency [%] GT leverage [-]

Fig. 38.5 Variation of repowering efficiency and gas turbine leverage

38 Comparison of Thermal Repowering Alternatives for Thermal Power Plants 519

The ratio of GT power to initial power [%]

0 5 10 15 20 25 30 35

C O

2 em

is si

on v

ar ia

tio n

pe r

in st

al le

d po

w er

[% ]

-20

-15

-10

-5

CO2 mass flow rate [kg/s]

CO2 emission per installed power [kg/MW.s]

Decrement percentage of CO2 emission [%]

Fig. 38.6 Variation of CO2 emissions and fuel consumption

8 10 12 14 16 18 20 22 24

V ar

ia tio

n [%

]

-4

-2

Gas turbine power ratio [%] vs Rate of increase in net power [%] Gas turbine power ratio [%] vs Variation of net heat rate [%] Gas turbine power ratio [%] vs Rate of increase in steam turbine power [%] Gas turbine power ratio [%] vs Rate of increase in condenser mass flow rate [%] Gas turbine power ratio [%] vs Variation of net electric efficiency [%]

Gas turbine power ratio[%]

Fig. 38.7 Effects of hot windbox repowering application in TPP

520 M.Z. Yilmazoglu

the increment in net electrical efficiency is distinctive in feed water heating

application. The auxiliary power consumption of the hot windbox application is

greater than feed water heating application due to the increased forced draught fan

power. GT leverage and repowering efficiency was found to be 1.3 and 0.32,

respectively for 22% GT ratio. In the case of CO2 emissions the coal consumption

was increased due to the increased mass flow rate of air. Approximately half of the

total mass flow rate of inlet air was selected as fresh air to decrease the temperature

of the flue gas and increase the O2 content of the inlet air. It is also obvious from

Fig. 38.9 that CO2 emission per installed power was decreased.

Parallel repowering of TPP was also investigated and the effects of repowering of

TPP performance were presented in Fig. 38.10. In parallel repowering it is clear that

the selection range of GT power was significantly increased. Because of the structure

of the system steam was generated separately via a heat recovery steam generator

(HRSG), located after the GT. Therefore, steam mass flow rate increment is the

limiting factor in this kind of repowering application. Steam can be produced with

different pressure levels in a multi-pressure HRSG. However, in this case initial and

operational costs will be significantly increased. Instead of multi-pressure HRSG,

single pressure HRSGwas located and same pressure with live steamwas obtained in

order to mix these streams before steam turbine inlet. According to Fig. 38.10 the net

power of the TPP was doubled and the net electrical efficiency was increased from

31.7% to 38.26%. In this case repowering efficiency and GT leverage were found to

be 47.3% and 1.174, respectively. CO2 mass flow rate was increased. However, CO2 emission per installed power was significantly decreased (Fig. 38.11).

Gas turbine power ratio [%]

8 10 12 14 16 18 20 22 24

V ar

ia tio

n [%

]

0,2

0,4

0,6

0,8

1,0

1,2

1,4

Gas turbine power ratio [%] vs Repowering Efficiency*100 [%] Gas turbine power ratio [%] vs Gas turbine leverage [-]

Fig. 38.8 Variation of repowering efficiency and gas turbine leverage

38 Comparison of Thermal Repowering Alternatives for Thermal Power Plants 521

The ratio of GT power to initial power [%]

0 20 40 60 80 100 120

V ar

ia tio

n pe

rc en

ta ge

[% ]

-40

-20

100

120 Net power Heat rate ST net power variation Condenser mass flow rate Net electrical efficiency

Fig. 38.10 The effects of parallel repowering application in TPP

Gas turbine power ratio [%] 0 2 4 6 8 10 12 14 16 18 20 22 24

V ar

ia ti on

[ %

]

-10

-8

-6

-4

-2

Gas turbine power ratio [%] vs Rate of decrease in CO2 emissions per MWel [%] Gas turbine power ratio [%] vs Rate of increase in coal consumption [%] Gas turbine power ratio [%] vs Variation of coal consumption [kg/s]

Fig. 38.9 The variation of CO2 emissions and fuel consumption

522 M.Z. Yilmazoglu

According to the results given above, repowering of the old TPPs can signifi-

cantly increase the net electrical efficiency, net energy generation and decrease the

CO2 emissions per installed power. Repowering offers a short term solution for CO2 decrement while new power plants have been installed.

An economical comparison was carried out to determine the unit electricity cost.

Table 38.3 summarizes the situation after repowering for different cases. The cost

of repowering, specific cost of repowering, unit electricity generation cost and with/

without first investment costs were given. According to the limiting factors best GT

ratios were compared. For feed water heating, hot windbox and parallel repowering

applications GT ratios were selected as 30%, 22% and 100%, respectively.

The ratio of GT power to initial power [-]

0 20 40 60 80 100 120

C O

2 em

is si

on v

ar ia

tio n

pe r

in st

al le

d po

w er

[% ]

-40

-30

-20

-10

CO2 mass flow rate [kg/s] CO2 emission per installed power [kg/MWs] Decrement percentage of CO2 emission [%]

Fig. 38.11 The variation of CO2 emissions and fuel consumption

Table 38.3 Economic comparison of repowering alternatives

Technoeconomic parameters Current case FWH HWB PR

Net power [MW] 21.877 30.207 27.67 45.5

Net electrical efficiency [%] 31.70 33.87 31.68 38.26

Heat rate [kJ/kWh] 11,355 10,609 11,363 9410

CO2 mass flow rate [kg/s] 7.02 8.15 8.17 9.18

CO2 mass flow rate per inst. power [kg/s/MW] 0.321 0.270 0.295 0.202

Coal consumption [kg/s] 4.843 4.821 5.033 3.813

First investment cost (FIC) [1000�USD] 10,940 5,700 4,210 15,940 Specific repowering cost [USD/kWel] 500 685 726.4 674.6

Unit electricity generation cost [cent/kWh] 4.24 5.38 5.36 6.57

Unit electricity gen. cost without FIC [cent/kWh] 0.00 4.9 4.83 6.24

38 Comparison of Thermal Repowering Alternatives for Thermal Power Plants 523

It is clear from the table that CO2 mass flow rate increases. However, CO2 mass

flow rate per installed power decreases. In parallel repowering application coal

consumption was found to be the lowest. However, it must be noted that natural gas

consumption was found to be four times more than FWH and HWB repowering. In

the economic analyses first investment cost of the TPP was calculated according to

the design data with specific investment cost value. After, additional costs of each

repowering application were calculated. It is obvious that the calculated highest

repowering investment cost is parallel repowering application due to GT and HRSG

costs. Unit electricity generation costs were also calculated with and without FIC.

According to the results, HWB repowering with fresh air dilution slightly increases

the unit electricity cost when compared to current case costs.

Conclusions

In this study comparison of repowering applications were performed. Net power, net

electrical efficiency, CO2 emissions and unit electricity generation costs were com-

pared. Feedwater heating, hot windbox and parallel repowering applications were

simulated in order to compare the results. SomaA thermal power plant with a capacity

of 2� 22MWelwas selected as the case study. According to the results, net power and net electrical efficiency were increased. Total CO2 mass flow rate was increased.

However, CO2 mass flow rate per installed capacity was sharply decreased. There-

fore, repowering of old thermal power plants can be a short term solution in decreas-

ing the CO2 emissions while the electricity demand increasing continuously.

Nomenclature

P Electric power, kW

Q Thermal power, kW

FWH Feedwater heating

HWB Hot windbox

PR Parallel repowering

Greek Letters

η Efficiency, % λ Leverage, –

Subscripts

El Electricity

ar After repowering

524 M.Z. Yilmazoglu

br Before repowering

rep Repowering

GT Gas turbine

g Inlet

References

Carapellucci, R. (2009). A unified approach to assess performance of different techniques for

recovering exhaust heat from gas turbines. Energy Conversion and Management, 50, 1218–1226.

D’Yakov, A. F., Nechaev, V., Olkhovsky, R., & Gurgen, G. (1998). Repowering existing thermal

power stations. Proceedings of the American Power Conference, 2, 1033–1037. Elmasri, M. A. (2008). Design of gas turbine combined cycle and cogeneration systems. Milan,

Italy: Thermoflow Inc. Seminar.

Escosa, M. J., & Romeo, M. L. (2009). Optimizing CO2 avoided cost by means of repowering.

Applied Energy, 86, 2351–2358. Mathieu. P. F. (1998). Repowering options for existing power plants. In Proceedings of the NATO

advances study institute on thermodynamics and optimization of complex energy systems (pp. 251–260).

Popov, D. (2011). An option for solar repowering of fossil fuel fired thermal power plants. Solar Energy, 85, 344–349.

Schenk, H., & Ehren, G. (2003). Gas turbine based power plants repowering reduces emissions and

increase efficiency of existing plants while re-utilizing available assets. In Proceedings of the international gas turbine congress.

Walters, A. B. (2008). Power plant topping cycle repowering. Energy Engineering, 92, 49–71. Yilmazoglu, M. Z., & Durmaz, A. (2011). Parallel repowering of Soma A thermal power plant, 18.

In National conference on thermal science and technology, Zonguldak, Turkey. Yilmazoglu, M. Z., & Durmaz, A. (2013a). Hot windbox repowering of coal-fired thermal power

plants. Turkish Journal of Engineering and Environmental Sciences, 37, 33–41. Yilmazoglu, M. Z., & Durmaz, A. (2013b). Technoeconomic analysis of feed water heating

repowering of Soma A thermal power plant. Journal of Science and Technology of Dumlupınar University, 32, 79–90.

Yilmazoglu, M. Z., Durmaz, A., & Baker, D. (2012). Solar repowering of Soma A thermal power

plant. Energy Conversion and Management, 64, 232–237.

38 Comparison of Thermal Repowering Alternatives for Thermal Power Plants 525

Chapter 39

Experimental Study of Heat Transfer for a Non-Newtonian Fluid in a Heated Cylindrical Pipe

Mounir Mellal, Hacina Abchiche, and Sabrina Ait Ouazzou

Introduction

During these last decades, the authors were interested in analyzing the problem of

transfer of heat during the flows of the non-Newtonian fluids, in cylindrical pipes

[Benslimane, 2012]. Thanks to its implication in numerous natural phenomena and

industrial process, the researchers are more and more interested in this problem and

more specifically in the transfers of heat which develop in the cylindrical pipes, in

forced convection. Numerous researchers dealt with the understanding of the

phenomenon of transfer of heat in laminar flow which the object of our work.

Materials and Methods

The setup of eviction which was of use to our experiment was specially designed

within our laboratory, for the rheologic, thermo-rheologic study of the laminar

flows of the various fluids. It consists of:

A storage tank made of stainless steel with a capacity of 15 L in double wall

(isotherm) equipped with a sensor of pressure (manometer) with a membrane, an

electric resistance, two gates of subjection, followed by a 3 m long cylindrical

conduct, a heating conduct in the form of a tube in stainless steel altered by five

prickings of temperature and two prickings of pressure, an electric resistance is

wrapped around the tube to maintain a constant flow at the end of this installation.

M. Mellal (*) • H. Abchiche • S. Ait Ouazzou Laboratoire des Phénomènes de Transfert, Faculté de Génie Mécanique et Génie des Procédés,

Université des Sciences et de la Technologie Houari Boumediene (USTHB), BP 32 El Alia,

Bab Ezzouar, 16111 Algiers, Algeria

e-mail: [email protected]

527

mailto:[email protected]

A recycling tank for the product is placed out of the section of measure provided

with a centrifugal pump allowing to feed again the main tank through a feeding pipe

and a conduct of expulsion allowing the mixture of the product before its use, also, a

thermo regulator is there in order to regulate and to fix the temperature of the

external wall of the heating conduct (Fig. 39.1).

Conception of the Heating Conduct

We designed a heating conduct with resistance to warm the model fluid we had used

for the thermo-rheologic study also to favor the flow by reducing the effects of

sliding into the conduct; it is also convenient with the study of the transfer of heat to

make a heating conduct which answers our expectations, we used a number of

equipments, which the most important are:

A 2 m tube in stainless steel with prickings of pressure and temperature, around

the tube we, a heat insulator was placed which is the Teflon in the form of an

adhesive tape, afterward it was wrapped into an electric resistance of first class type

Nickel/Chrome, then aluminum in the form of an adhesive tape, we provided the

tube with electric cables for the supply, plastic and metallic rings for the tightening,

Fig. 39.1 The installation of eviction

528 M. Mellal et al.

then we wrapped up the whole system in an insulating material which is the

glass wool and for the new conducts we put the foam rubber, then sheets of

aluminum, also, a sensor for thermocouple and finally of two transformers and a

thermoregulator.

Our study was made on three heating conducts of different diameters, one of the

conceptions was later changed; the main insulating material, the glass wool was

replaced by the foam rubber, a comparative study was also made. The conception of

two new heating conducts was made according to one method as follows:

We began with the making of the prickings, then we set up sensors of thermo-

couple, followed by a primary insulation then the implantation of the resistance,

then we placed the secondary insulation, then we prepared the grips of supply we

finalized the whole by a tertiary insulation.

Figure 39.2 represents a generalized plan by the heating conduct which was of

use to our thermo-rheologic study, it to study the thermal transfer which occurs

there.

Used Product

The product used for the thermo-rheologic study which was of use to the study of

the thermal transfer is the Carboxymethyl Cellulose. The study was made on

concentrations of 0.5%, 0.8%, 1% and 1.5%.

Results and Discussion

Rheological Characterization of the Flowing Suspension

Having drawn the graphs of the logarithm of the difference of pressure according to

the flow, we deducted that the fluid presents a rheo-fluidifying behavior of Oswald’s model. The results which follow were obtained from the relations of Rabinowitch

Résistance

P T

0,5m 0,49m 0,49m 0,23m 0,15m 0,14m

T T T T P

Mousse de caoutchouc

Téflon

Sortle Entrée

Fig. 39.2 Generalized plan by the heating conduct

39 Experimental Study of Heat Transfer for a Non-Newtonian Fluid in a Heated. . . 529

Mooney, from there we succeeded in drawing rheogrammes giving the evolution of

the constraint of parietal cutting according to the speed of parietal cutting for

various concentrations to several temperatures and various diameters.

Figures 39.3, 39.4, 39.5, and 39.6 represents the evolution of the constraint of

parietal cutting according to the speed of parietal cutting for a diameter of 10 mm

“we chose to present the results of a single diameter of 10 mm”.

From the results shown on Figs. 39.4, 39.5, and 39.6 we notice ascending curves

passing by the origin towards an asymptotic value, these curves take a look in the

form of curve of power which answers the mathematical model which follows

τp ¼ K _γ n 0 ð39:1Þ

From this equation we can deduct the type of the rheologic model which follows

the used fluid, this model is the model of OSTWALD.

The treatment of the experimental results by the relation of Rabinowitch

Mooney shows that the suspension in the range of the rate of studied cutting can

have a behavior rheo-fluidizing of Oswald’s model.

Fig. 39.3 Evolution of the constraint of cutting

according to the speed of

parietal cutting for a 0.5%

concentration, a diameter

10 mm

Fig. 39.4 Evolution of the constraint of cutting

according to the speed of

parietal cutting for a 0.8%

concentration, a diameter

10 mm

530 M. Mellal et al.

This behavior can be modeled using the following relation:

τ ¼ k€γn ð39:2Þ

The pile of curves shows that the more we increase in the temperature of the

regulator; the more there is decrease of the speed of cutting, thus the viscosity

decreases.

Heat Transfer of in the Flow of Non Newtonien Fluids

Because of the number of Richardson, we were able to demonstrate that it is the

forced convection which takes the flow on the natural convection.

The correlation Nu ¼ 11 48 � 1

X1 m¼1

exp �γ2m xþð Þ Am γ4m

" #�1 allowed us to confirm the con-

stant parietal flow, we found a value of Nu¼ 4,36 with one m varying from 1 to 1000 where m represents a constant of precision, the higher m is, the better the

Fig. 39.5 Evolution of the constraint of cutting

according to the speed of

parietal cutting for a 1%

concentration, a diameter

10 mm

Fig. 39.6 Evolution of the constraint of cutting

according to the speed of

parietal cutting for a 1.5%

concentration, a diameter

10 mm

39 Experimental Study of Heat Transfer for a Non-Newtonian Fluid in a Heated. . . 531

precision will be, thus according to the literature this value of Nusselt found using

FORTRAN (software), is represented for a flow of telling heat.

The thermal study was made on typical correlations for a forced convection on

Oswald’s fluid to constant parietal flow and it to study the evolution of the number of Nusselt according to the length, to Graetz and to the indication of the flow.

Nusselt Number Effect

Having calculated the number of Nusselt and the number of Graetz, we were able to

draw graphs Figs. 39.7 to 39.8, which represents the evolution of the number of

Nusselt according to the length for a diameter of 10 mm.

The number of Nusselt represents the total thermal transfer with regard to the

thermal transfer by conduction throughout the conduct, thus according to the graphs

of Figs. 39.8, 39.9, and 39.10, we notice the decrease of the number of Nusselt with

the increase of the length, also we distinguish two zones. The first zone into which

the number of Nusselt drops until a value of L¼ 0,7 m, this is because of the consequent exchange which is made in the entry of the zone with the aim of the

Fig. 39.7 Evolution of the number of Nusselt

according to the distance for

a 0.5% concentration and

one diameter of 10 mm

Fig. 39.8 Evolution of the number of Nusselt

according to the distance for

a 0.8% concentration and

one diameter of 10 mm

532 M. Mellal et al.

importance of the gradient of temperature, between the fluid and the wall. The

second zone where the number of Nusselt stabilizes until an asymptotic value, we

also notice that according to these graphs the number of Nusselt is important with

the increase of the temperature. Thus the warmer it is, the bigger the exchange is.

Profile of the Number of Nusselt According to the Number of Graetz

According to Figs. 39.11, 39.12, 39.13, and 39.14 the evolution of the number of

Nusselt according to the number of Graetz, we notice an increase of the number of

Nusselt with the increase of the number of Graetz, also a superimposing of curves

with various temperatures, concentrations and various diameters. We deduct that

the length has no effect, seen that Graetz depends of the length. It confirms the

works done before which also concluded that the length has no influence on the

thermal transfer.

Fig. 39.9 Evolution of the number of Nusselt

according to the distance for

a 1% concentration and one

diameter of 10 mm

Fig. 39.10 Evolution of the number of Nusselt

according to the distance for

a 1.5% concentration and

one diameter of 10 mm

39 Experimental Study of Heat Transfer for a Non-Newtonian Fluid in a Heated. . . 533

Determination of the Number of Asymptotic Nusselt

We studied the number of asymptotic Nusselt according to the index of the flow for

all the concentrations, the temperatures and the diameter, the following results

(profits) concern all the concentrations for a diameter of 10 mm.

Fig. 39.11 Evolution of the number of Nusselt

according to the number of

Graetz for a 0.5%

concentration and one

diameter of 10 mm in

various temperatures

Fig. 39.12 Evolution of the number of Nusselt

according to the number of

Graetz for a 0.8%

concentration and one

diameter of 10 mm in

various temperatures

Fig. 39.13 Evolution of the number of Nusselt

according to the number of

Graetz for a 1%

concentration and one

diameter of 10 mm in

various temperatures

534 M. Mellal et al.

Figures 39.15, 39.16, 39.17, and 39.18 express the variation of the number of

asymptotic Nusselt for the case “isoflux” according to the index of flow n, for the

concentrations of 0.5, 0.8, 1 and 1.5%, diameter 10 mm and for various tempera-

tures of the thermoregulator, we notice that n is between 0< n< 1, which corre- sponds to the pseudoplastic fluids, we also notice that Nu1 decreases with the increase of the index of flow (n) until stabilization. We can confirm that the rate of

transfer of heat is more important within the pseudoplastic fluids n< 1.

Fig. 39.14 Evolution of the number of Nusselt

according to the number of

Graetz for a 1.5%

concentration and one

diameter of 10 mm in

various temperatures

Fig. 39.15 Evolution of the number of Nusselt

according to the index of

flow for a 0.5%

concentration and one

diameter of 10 mm

Fig. 39.16 Evolution of the number of Nusselt

according to the index of

flow for a 0.8%

concentration and one

diameter of 10 mm

39 Experimental Study of Heat Transfer for a Non-Newtonian Fluid in a Heated. . . 535

Study of the Conduction

For this study, we proceeded by the method of harbinger’s Law, for reasons of

non-availability of all the parameters to study the conduction of the source towards

the ambient air, we made an reverse study, we studied at first the flow absorbed by

the fluid, by using harbinger’s law of the source towards the fluid, afterward

knowing the loose flow we proceeded with a subtraction to find the lost flow

through insulations. The results are grouped in Table 39.1.

Fig. 39.17 Evolution of the number of Nusselt

according to the index of

flow for a 1% concentration

and one diameter of 10 mm

Fig. 39.18 Evolution of the number of Nusselt

according to the index of

flow for a 1.5%

concentration and one

diameter of 10 mm

Table 39.1 Flux lost through insulation

T¼ 70 �C C % D mm

8 10 « rubber foam

10 « glass wool

0.5 3.8535 11.0690883 11.6255

0.8 3.3732 8.8967 10.8866

1 3.3843 11.9229125 9.2730

1.5 3.1618 10.8272789 3.239845 10.4824

536 M. Mellal et al.

Figure 39.19 represents a multi-cylindrical conduct sleep, where, Rint internal

radius of the conduct and Rext the external radius, the distance between them

representing the thickness of the teflon, eR the thickness of the resistance and finally

eMC the thickness of the foam rubber. The following table represents the lost flow

through insulations in different diameters and concentrations as well as the com-

parison of both insulations made on a diameter of 10 mm and for a concentration of

1.5% in 70 �C. Another study was made to confirm that the insulating material of glass wool is

more successful than the foam rubber. We compared the temperatures of the fluid

and the wall of two various insulations according to the distance, for a temperature

of the thermoregulator of 50 and 60 �C [Gacem, 2010]. Figures 39.20 and 39.21 represent the evolution of the temperature of the fluid

and the wall for both cylindrical conducts, we notice an increase of the temperature

with the increase of the length, on the other hand we notice that for the temperature

of the fluid and the wall for the glass wool, insulation is higher than foam rubber,

thus the fluid stores more heat in glass wool insulation than foam rubber this is the

same for the temperature of the wall, what leads us to say that the glass wool is more

hermetic.

Fig. 39.19 Plan representing a cylindrical

conduct

Fig. 39.20 Evolution of the fluid temperature and the

wall for the glass wool and

foam rubber according to

the distance x, to a

concentration of 1.5%, a

diameter of 10 mm to

TTR¼ 50 �C

39 Experimental Study of Heat Transfer for a Non-Newtonian Fluid in a Heated. . . 537

Figures 39.22 and 39.23 represent the evolution of the average temperature of

wall according to the length for two various insulations “Foam rubber” and “Glass

wool”. We notice an increase of the temperature with the increase of the length by

both insulations, we also notice that the curve which represents the glass wool

insulating material is higher than the one which represents the foam rubber insu-

lating material to the temperature of 50 �C and 60 �C of the thermoregulator, that leads us to confirm that the glass wool insulation is more hermetic.

Figures 39.24 and 39.25 present the evolution of the average temperature of the

wall according to the flow, for both insulations “glass wool” and “foam rubber”, for

a 1.5% concentration, one diameter of 10 mm and the temperature of the thermo-

regulator of 50 and 60 �C, these curves present a decrease of the temperature of the

Fig. 39.21 Evolution of the fluid temperature and the

wall for the glass wool and

foam rubber according to

the distance x, to a

concentration of 1.5%, a

diameter of 10 mm to

TTR¼ 60 �C

Fig. 39.22 Evolution of the wall temperature averages

according to the distance x,

for both insulations “glass

wool” and “foam rubber”,

for a 1,5% concentration,

one diameter of 10 mm and

TTR¼ 50 �C

538 M. Mellal et al.

wall average with the increase of the flow, we also notice that the temperature of

wall average for the glass wool insulation is bigger than that of the foam rubber

insulation, it can be explained by the fact that the glass wool isolates better that the

foam rubber, thus heat losses are lesser.

Fig. 39.23 Evolution of the wall temperature averages

according to the distance x,

for both insulations “glass

wool” and “rubber foam”,

for a 1,5% concentration,

one diameter of 10 mm and

TTR¼ 60 �C

Fig. 39.24 Evolution of the temperature of wall

averages according to the

outflow, for both insulations

“glass wool” and “foam

rubber”, for a 1,5%

concentration, one diameter

of 10 mm and TTR¼ 50 �C

Fig. 39.25 Evolution of the temperature of wall

averages according to the

outflow, for both insulations

“glass wool” and “foam

rubber”, for a 1.5%

concentration, one diameter

of 10 mm and TTR¼ 60 �C

39 Experimental Study of Heat Transfer for a Non-Newtonian Fluid in a Heated. . . 539

Conclusion

The thermo-rheological study allowed us to show that the non-Newtonian fluid

used, can be defined by establishing Oswald Devaele pseudoplastic type.

The testing made in the heated cylindrical pipe (HCP) has allowed us to promote

transfer mode through the relation of Richardson, which happens to be less than

1, so it is the forced convection that outweighs the natural convection.

Therefore, this study was conducted on a forced convection using Oswald fluid

for a laminar flow regime in a cylindrical pipe with constant heat and parietal flux at

different concentrations 0.5%, 0.8%, 1% and 1.5% and different diameters 8, 10

and 12 mm. From these results we were able to assess the Nusselt number with

different correlations, from one correlation we confirmed that we are in constant

flux compared with the literature, we obtained a value. We have also plot graphs of

the Nusselt number depending upon the length, and the Graetz number of flow.

To study the evolution of the Nusselt number in reference to the length, we found

that the Nusselt number drops with increasing length, and then stabilizes at an

asymptotic value. This result in the exchange therefore occurs at the entrance to the

heating pipe and caused by the elevation of the temperature gradient in the etching

area between fluid and wall.

The study of the evolution of the Nusselt number according to Graetz, allowed

us to observe an increase in the Nusselt number with the increase in the number of

Graetz, as we noticed a stack of curves at different temperatures the temperature

controller we found that the length of the pipe has no effect on the thermo-

rheological behavior.

Two of our pipes were insulated with two different insulation at the main

insulation, one insulated glass wool, the other rubber foam, for this we have

made a comparative study between the two insulators, by studying the fluid

temperature, the wall and the flow lost through these insulators, the results allowed

us to infer that the glass wool insulation is more airtight than the foam rubber.

Acknowledgement Thermal transfer, thermo rheology, carboxymethylcellulose, cylindrical pipe.

References

Benslimane, A. (2012). « Rhéologie et Ecoulement de Fluides Chargés: Application aux Réseaux

d’Assainissement Urbains. Etude Expérimentale et Modélisation ». Mémoire de Doctorat, décembre 2012.

Gacem, M. (2010/2011). « comparaison entre l’isolation thermique Extérieure et Intérieure d’une pièce d’un Habitat situé dans le Site de Ghardaı̈a », mémoire de magister, 2010–2011 (convection forcée).

Lachemet, A. (1997). « Rheologie et Transfert de Chaleur en Milieu non-Newtonien », mémoire

Magister, avril 1997.

540 M. Mellal et al.

Sacadura, J. F. (1995). « Initiation aux Transferts Thermiques ». Centre d’Actualisation Scientifique et Technique INSA de LYON, janvier 1995.

Taine, J., Iaconna, E., Petit, J. P. (2009). « Transfert Thermique », 4eme Edition.

39 Experimental Study of Heat Transfer for a Non-Newtonian Fluid in a Heated. . . 541

Chapter 40

The SOC Estimation of LCO Battery Based on BP Neural Network

Sy-Ruen Huang, Yen-Huai Ma, Jheng-Shyun Li, and Jun-Han Chan

Introduction

Improvements in battery technology have led to the development of batteries with

greater energy yield, efficacy, and capacity. Currently, the weight and energy

density of batteries, in addition to battery capacity and weight, have facilitated in

providing sufficient energy for machines requiring high-power output (e.g., electric

vehicles, electric boats, and power motors). Previous batteries for use in high

energy-consumption machines were generally too heavy or large for most practical

applications. However, the energy density of conventional lithium batteries can

exceed 120 W·h/kg. Consequently, this type of battery has been used as an energy

source in various types of machine.

Current battery technologies have led to the development of lithium ion batteries

that provide up to 190 W·h/kg in energy density and 1000 charge cycles (80%

depth of discharge). The lifetime of a lithium ion battery varies according to how it

is used. State of charge (SOC) is typically used to represent battery capacity and is

equivalent to the percentage of energy stored in a battery. Generally, maintaining

the SOC of a lithium ion battery at 20–80% can prolong its lifetime. Therefore,

accurately determining battery SOC is a crucial goal in battery research. Previous

studies on batteries have indicated that accurately estimating a battery’s SOC is a crucial topic in the fields of battery balancing and battery management systems

(Burkett et al. 1970; Linden and Reddy 2007).

S.-R. Huang • J.-S. Li • J.-H. Chan

Department of Electrical Engineering, Feng Chia University, No. 100, Wenhwa Road,

Seatwen, Taichung 40724, Taiwan, ROC

Y.-H. Ma, Ph.D. (*) Ph. D. Program of Electrical and Communications Engineering, Feng Chia University,

No. 100, Taichung 40724, Taiwan ROC

e-mail: [email protected]

543

mailto:[email protected]

Artificial neural networks (ANNs) are a family of equation models and algo-

rithms proposed by McCulloch and Pitts in 1943. These mathematic models imitate

the neuron structures and behaviors of organisms, and perform calculations

according to a network comprising numerous artificial neurons. ANNs are a type

of parallel calculation system that utilizes equations to emulate the processes of a

biological neural system and various types of numerical estimation, including

classification, identification, and prediction. Previous studies have used ANNs in

numerical analysis in various fields such as engineering, science, finance, and

literature. An ANN is composed of an input layer, one or more hidden layers, and

an output layer. Each hidden layer consists of a parallel array of neurons, in which

an input is multiplied by the weights assigned to the layer, added to the bias values

of the layer, and then transferred to the next layer through a transfer function. The

hidden layers of an ANN continually transfer input values to the lower layers until

the value reaches the output layer, at which point the calculated result is obtained

(Hagan).

Types of Lithium Ion Batteries

The prevalent use of lithium ion batteries have led to improvements to the charac-

teristics of such cathode materials as lithium cobalt oxide (LCO), lithium manga-

nese oxide, lithium iron phosphate, and lithium nickel manganese cobalt oxide.

Table 40.1 illustrates a comparison of various cathode materials. The safety of

lithium ion batteries has been improved, and the charge cycle of such batteries can

exceed 1000 charges. Consequently, lithium ion batteries have been applied in

electric cars and hybrid electric cars. Studies on lithium ion batteries have been

conducted since 1980. The oxide structure of such batteries is classified as an

α-NaFeO2 layered structure, which is relatively stable compared with other battery types. Characteristics such as high battery density, low discharge rate, absence of

memory effect, long cycle life, antioxidation, and acid-corrosion resistance enable

various types of electrolyte to be used in lithium ion batteries. Additionally, such

batteries have a long storage life when not in use. Lithium ion batteries have

become a mature and primary cathode material product that features higher capac-

ity and more stable performance compared with other cathode material products.

However, lithium ion batteries also possess several disadvantages. Overcharging

such a battery can permanently fixate lithium ions in its crystal lattices, thereby

Table 40.1 Comparisons of cathode materials

LiCoO2 LiMn2O4 LiMnO2 LiFeO4

Density of energy 190–240 100–120 200 130–140

Voltage 3.6 3.8–3.9 3.4–4.3 3.2–3.7

Cut-off voltage 4.2 4.2 4.2 3.6

Life cycle >500 >500 Bad >1000

544 S.-R. Huang et al.

reducing the lifetime of the battery. By contrast, overdischarging such batteries can

release excess lithium ions and collapse the crystal lattices, thereby decreasing the

battery lifetime. Therefore, when charging and discharging a lithium ion battery, its

SOC must be accurately measured for the protection mechanism to prevent

overcharging and overdischarging.

Methods for Measuring SOC

Current methods for measuring SOC include the discharge method, open circuit

voltage (OCV) method, coulomb counting method (CC method), direct current

(DC) impedance method, and ANNs. The discharge method is advantageous

because of its accuracy; under a constant current, a battery is discharged and its

current and voltage are then multiplied by time duration to measure the amount of

energy expended by the battery for a specific period (W·h). However, the discharge

method is an offline approach, and thus cannot be applied to measure the SOC while

a battery is in use. The OCV method involves measuring the relationship between a

battery’s capacity and voltage. Under an open-circuit condition, battery voltage represents the battery’s remaining capacity. To measure the OCV of a battery, the target battery must stand until the reaction of the battery plate is complete, and then

the voltage becomes stable and is measured as the OVC of the battery. This method

is time-consuming and cannot be applied to measure the SOC of a battery in real

time. The discharge method and OCV method are commonly used to estimate the

full capacity of a battery (Lee et al. 2007).

The CC method is a simple and prevalent method that involves multiplying

battery current by time duration to measure the cumulative capacity (A·h), which

represents the amount of electric charge in a battery for 1 A of current to flow for 1 h

discharge. However, this method can build up cumulative errors that reduce its

accuracy. Specifically, when the CC method is applied to continually estimate the

SOC of a battery, the method can yield values exhibiting small but consistent errors;

eventually, the cumulative error reduces the accuracy of the method (Leksono

et al. 2013). The DC impedance method involves measuring how the functioning

region of a battery equivalent circuit is reduced when the electrolyte level

decreases. This method is commonly used to determine a battery’s state of health (SOH).

ANNs involves various methods. Generally, a battery’s voltage, current, and capacity can be used as training data for an ANN. Battery capacity can serve as a

target matrix for training the weight and bias value of each neuron, and an ANN can

then be constructed to estimate the SOC of the battery (Liu et al. 2011; Eddahech

et al. 2011; Sarvi and Adeli 2010).

40 The SOC Estimation of LCO Battery Based on BP Neural Network 545

Battery Charge/Discharge Test and Experimental Data Storage

NCR18650 LCO batteries were used in the present study. The output voltage of

LCO batteries is stable and relatively high compared with that of other lithium

batteries. The rated capacity and maximum voltage of an NCR18650 are 3200 mAh

and 4.2 V, respectively (Table 40.2).

This study employed the constant current–constant voltage (CC–CV) method to

charge the target battery. During the initial stage of charging, a constant current was

applied to the battery, and the voltage of the battery increased. Once the battery

voltage value reached the preset voltage value, the CC–CV charging method was

initiated, during which the current decreased until reaching the preset minimum

value, at which point the charging process was completed.

To accurately measure the capacity of the target battery, the OCV method and

CC method were applied to acquire its basic data. Specifically, we plotted the

current–voltage curve of the battery. The OCV values of the battery estimate the

corresponding capacity values. The cumulative capacity values of the battery were

determined using the CC method to measure the current flowing through the

battery. LabVIEW was used to collect the data during the process of charging.

Figure 40.1 depicts the configuration of the system architecture and the human

machine interface. During the charging process, 0.34 A of current was applied to

charge the battery from 2.8 V (the minimum voltage of the battery) to 4.2 V. The

voltage of a battery can increase or decrease during the process of charging and

discharging. Consequently, the current was set at a low value (0.34 A) to ensure that

the differences in voltage were sufficiently small to approximate an OCV–capacity

curve. Figure 40.1 illustrates the current–voltage curve of the battery.

The arithmetic mean of the charging curve and discharging curve were applied

to plot the average voltage–capacity curve, in which the voltage values can be

perceived as the OCV values of the target battery (Fig. 40.2). The capacity values

(A·h) in Fig. 40.2 were calculated using the CC method to determine the battery’s cumulative current across a time duration. During the charging process, the initial

capacity value of the battery was incremented. By contrast, the initial capacity

Table 40.2 Battery parameters of NCR18650B

Rated capacity 3200 mAh

Capacity Min: 3250 mAh

Std: 3350 mAh

Rated voltage 3.6 V

Charger condition CC-CV, 1625 mA, 4.20 V, 4.0 h

Weight 48.5 g

Temperature Charging: 0 toþ 45 �C Discharging: �20 to þ 60 �C Steady: 20 to þ 50 �C

Density of energy Capacity: 676 Wh/l

Weight: 243 Wh/kg

546 S.-R. Huang et al.

value was decreased during the discharging process. Equation (40.1) illustrates how

the capacity values of the battery were determined through the CC method.

Ah tnð Þ ¼ Ah t0 � ð itdt ð40:1Þ

Design and Training of Back Propagation Neural Network

In a back-propagation neural network (NN), an input unit is multiplied by the

weights of the layer and the error of the target value. Next, a stochastic gradient

descent method is applied to minimize the input-value error, and then the input

Fig. 40.1 Battery charging, discharging, and average voltage curves at 0.34 A

Fig. 40.2 OCV–capacity curve

40 The SOC Estimation of LCO Battery Based on BP Neural Network 547

value is multiplied by the learning rate. Subsequently, the modified input value is

transferred to the previous layer to correct the weights and bias values of that layer.

The input value propagates backward in the network until it reaches the input layer,

thereby modifying the overall network and ensuring that the errors of the network

are within a given tolerance range. The initial weights of the neurons can be

modified through the backward propagation of the input value; hence, such a

network learning process is called a back-propagation NN.

A back-propagation NN can be regarded as a multilayer network (Fig. 40.3).

Such NNs can be used to accurately train any continuous function, of which the

accuracy is determined according to the number of neurons present in the hidden

layers of the network. Generally, a network with 10 nodes of neurons can result in

undesirable training errors. Increasing the number of neurons can improve the

accuracy of the output functions. Specifically, the presence of 20–50 neurons in a

network can effectively increase the training speed and ensure that the accuracy of

output functions is within a given tolerance range. However, a high amount of

memory is required to process a network containing many neurons. Therefore, a

network comprising 20 neurons was used in the present study.

This study employed a single-layer NN. The data were inputted through the

input layer, and then transferred through the neurons of the hidden layers and

modified according to the neuron weights. Through a hyperbolic tangent transfer

function, the data were successively transferred to the subsequent layers until

reaching the output layer. Finally, the data were modified according to the output

layer weights, yielding the output function a3, which is expressed as (40.2).

a3 ¼ f3 W3f2 W2f1 W1Pþ b1� �þ b2� �þ b3� � ð40:2Þ Expanding the hidden layers of the network yields (40.3):

amþ1 ¼ fmþ1 wmþ1am þ bmþ1� � m ¼ 0, 1, . . . ,M � 1 ð40:3Þ

where M is the number of layers in the NN.

n2 f1

n3 f3

a1 a2 a3

)( 1111 bpWfa += )( 21222 baWfa += )( 12333 baWfa +=

Fig. 40.3 The architecture of a multilayer ANN

548 S.-R. Huang et al.

Through training, a back-propagation NN can generate accurate functions. The

NN training parameters are inputted into the network and the mean squared error

(MSE) of the training samples can then be obtained using (40.4). The MSEs are

used to modify the weights and bias values of the neurons.

F xð Þ ¼ E eTe � ¼ E t� að ÞT t� að Þh i ð40:4Þ Through network back-propagation, the updated weights and bias values are

obtained using (40.5) and (40.6).

sM ¼ �2 _FM nM� � t� að Þ ð40:5Þ sm ¼ _Fmþ1 nmð Þ Wmþ1� �Tsmþ1 m ¼ M � 1, . . . , 2, 1 ð40:6Þ

The least mean squares (LMS) algorithm and an estimated gradient value was

used to approximate the LMS value. As shown in (40.7) and (40.8), this method is

similar to the least gradient descent method and is used to update the weights and

bias values of the layers (Fig. 40.4).

Wm kþ 1ð Þ ¼ Wm kð Þ � αsm am�1� �T ð40:7Þ bm kþ 1ð Þ ¼ bm kð Þ� / sm ð40:8Þ

where α is the learning rate. Figure 40.5 depicts the MSE of the training process. When the number of

iterations reached 240, the LMS was reduced to 9.41� e�0.9. Network training took 1 min and 26 s to complete.

0 10−6

10−4

10−2

100

50 100

Iterations

M ea

n S

q u

ar ed

E rr

o r

(M S

E )

150 200

Fig. 40.4 The MSE curve of the iteration number

40 The SOC Estimation of LCO Battery Based on BP Neural Network 549

Estimation of Battery SOC Through ANN

The weights and bias matrices obtained through the back-propagation training

method were inputted into the NN, and a mathematical model for estimating the

SOC of the target battery was then obtained. The current and voltage of the battery

were measured and then inputted into the NN to estimate its real-time capacity.

Subsequently, the real-time capacity was divided by the peak capacity to obtain the

SOC of the target battery, as expressed in (40.9).

SOC ¼ a V; Ið Þ Q0

ð40:9Þ

a(V, I): Real-time capacity

Q0: Maximum capacity

To evaluate the applicability of the proposed estimation method, we used a 1-A

constant current to charge the NCR18650 battery. Subsequently, the NN estimation

and CC methods were applied to obtain the SOC of the target battery. Figure 40.5

shows the voltage–SOC curves, in which the red curve represents the SOC values

(estimated through the NN), whereas the black curve indicates the actual SOC

values (measured through the CC method). The estimated and actual curves

exhibited similar trends, indicating that the proposed NN method can accurately

estimate battery SOC. Table 40.3 lists the numerical values for plotting the voltage–

SOC curves. The errors of the estimated SOC values and the actual SOC values

were negligible (Table 40.3).

3 3.2

Estimate SOC

Actual SOC

100

0 3.4 3.6 3.8 4.24

Voltage (V)

S O

C (%

)

Fig. 40.5 Estimated capacity versus actual capacity of the target battery

550 S.-R. Huang et al.

Conclusion

The present study was conducted to develop a back-propagation NN for estimating

battery SOC. The proposed model can be employed to estimate the SOC of a battery

in a closed-loop system. Specifically, the measured voltage and current of a target

battery can be inputted into the model to calculate the real-time capacity of the

battery, and the SOC of the battery can then be estimated. Compared with the CC

method, the NN method is more complex; however, the NN method can be applied

to continuously measure battery SOC without generating cumulative errors. The

results of the present study show that the errors of the estimated SOC and actual

SOC are within the tolerance range. Consequently, increasing the number of

neurons in the NN is unnecessary unless the number of input items is increased.

Through measuring various types of battery parameters for modifying the

weights and bias values of a trained NN, a mathematical model can be obtained

for estimating battery capacity. Such an estimation method can be applied to

measure the capacity of batteries of various characteristics. Future studies should

consider applying temperature parameters to estimate a change in battery capacity

relative to a change in temperature. In addition, the number of parameters can be

increased to improve the accuracy of battery capacity estimation.

Acknowledgement This study received financial support from the Ministry of Science and Technology under the grants NSC101-2632-E-035-001-MY3.

References

Burkett, W. B., Palisades, P., & Jackson, R. V. (1970, June). Rapid charging of batteries.

U.S. Patent 3,517,219.

Eddahech, A., Briat, O., & Vinassa, J.-M. (2011). Neural networks based model and voltage

control for lithium polymer batteries. In IEEE international symposium, 5–8 Sept 2011. Hagan, M. T., Demuth, H. B., & Beale, M. H. Neural network design. Princeton University Press.

Lee, S. J., Kim, J. H., Lee, J. M., & Cho, B. H. (2007). The state and parameter estimation of an

li-ion battery using a new OCV-SOC concept. In IEEE power electronics specialists confer- ence, 17–21 June, 2007.

Table 40.3 Estimated capacity versus actual capacity of the target battery

Voltage (V) Current (A) Estimate SOC Actual SOC Error

3.34 0.9887 2.10% 2.20% 0.10%

3.57 0.9885 21.70% 21.40% 0.30%

3.68 0.9824 40.50% 40.30% 0.20%

3.86 0.9881 59.70% 59.20% 0.50%

4.08 0.9879 80.00% 79.90% 0.10%

40 The SOC Estimation of LCO Battery Based on BP Neural Network 551

Leksono, E., Haq, I. N., Iqbal, M., Nugroho Soelami, F. X., &Merthayasa, I. G. N. (2013). State of

charge (SoC) estimation on LiFePO4 battery module using Coulomb counting methods with

modified Peukert. In Rural information & communication technology, 26–28 Nov 2013. Linden, D., & Reddy, T. B. (2007). Battary Handbook

Liu R.-h., Sun Y.-k., & Ji X.-f. (2011). Battery state of charge estimation for electric vehicle based

on neural network. In IEEE 3rd international conference (p. 493–496). Sarvi, M., & Adeli, S. (2010). A neural network method for estimation of battery available

capacity. In UPEC2010, 31st Aug–3rd Sept 2010.

552 S.-R. Huang et al.

Chapter 41

Investigating the Effect of Different Refrigerants on the Performance of a Supercritical Organic Rankine Cycle

Duygu Melek Çakıcı and Can €Ozgür Çolpan

Introduction

Consumption of fossil fuels leads to some environmental problems such as pollu-

tions, depletion of the ozone layer and global warming. There has been a high

interest in the renewable energy resources after the oil crisis in the 1970s. Geother-

mal, biomass, wind, solar, and ocean energy resources instead of fossil fuel such as

coal, natural gas, and oil are preferred as they are domestic, clean, economic, and

sustainable resources. One of these renewable energy sources is geothermal energy.

Geothermal energy is thermal energy under the earth. The thermal energy (heat)

from the Earth’s core continuously flows outward. Temperature close to the center of the Earth is around 5500 �C. Scientists estimate that 42 million megawatts (MW) of power flow through the Earth’s interior (http://www.geothermal.org/ what.html). The potential of geothermal energy in Turkey is 31,500 MW (http://

www.eie.gov.tr/yenilenebilir/turkiyede_jeo.aspx). Turkey lies in a highly active

tectonic region. It is located on the Alpine-Himalayan orogenic belt, which has

high geothermal potential. In Turkey, there are high enthalpy grabens and high

reservoir temperature fields. Some of these fields are Büyük Menderes Graben,

Gediz Graben and Simav Graben (DiPippo 2012).

Geothermal energy has been used for different purposes since ancient times such

as bathing, cooking, balneological and health spas, district heating, cooling, green-

houses heating, heat pump and power generation. Geothermal energy can be

classified according to the temperature of the resources. Geothermal resources

can be divided into three groups according to the temperature: Low temperature

fields (<70 �C), moderate temperature fields (70–150 �C), and high temperature

D.M. Çakıcı (*) • C.Ö. Çolpan Department of Mechanical Engineering, Dokuz Eylul University,

Tınaztepe Yerleskesi, Buca, Izmir 35397, Turkey

e-mail: [email protected]

553

mailto:[email protected]

fields (more than 170 �C) (Acar 2010). High temperature fields are suitable for electricity generation applications. However, it is possible to generate electricity at

lower temperatures with the new technologies. Most of the world’s geothermal power plants were built in the 1970s and 1980s after the oil crisis. The first

geothermal researches in Turkey were started by Directorate of the Mineral

Resource and Exploration of Turkey (called MTA in Turkey) in 1962 (Acar

2010). In Turkey, the first geothermal power plant was built in Kızıldere, in Denizli,

in 1984. According to 2013 data, total installed generating capacity in the world is

11,772 MWe (http://www.geothermal-energy.org/electricity_generation.html).

The potential for electricity generation from these fields are 1500 MWe in Turkey

(http://www.eie.gov.tr/yenilenebilir/turkiyede_jeo.aspx). The short-term forecast

indicates an installed capacity of 18,500 MWe by the year 2015 (Zarrouka and

Moon 2014). The major types of power plants are as follows: Dry-steam power

plants, flash-steam power plants and binary power plants. Binary power plants are

appropriate for electricity production from low and medium temperature geother-

mal sources. Binary power plant consists of two different cycles. In these plants, it

is aimed to increase the efficiency by increasing the temperature of the geothermal

fluid. Organic Rankine cycle and Kalina cycle can be given as examples to this

cycle. Organic Rankine cycle (ORC) is a Clausius Rankine cycle in which an

organic working fluid is used instead of water-steam. In the last years it has become

quite popular due to its suitability for electricity generation in the low-medium

temperatures fields. The processes in ORC are similar to the processes in the

Rankine cycle with steam as the working fluid. In the cycle, thermal energy of

geothermal brine is transferred to the second working fluid.

Some parameters must be considered for optimization of organic Rankine cycle

such as energy and exergy efficiencies of the cycle, the type of the working fluid,

mass flow rate of a working fluid, temperature, pressure and chemical composition

of the geothermal fluid, the reinjection temperature, the ambient temperature, heat

supplied at evaporator or heat exchanger, heat transfer coefficients, pressures drops,

net work output of turbine, cooling load of the condenser, subcritical and super-

critical parameters. The reason for the consideration of these parameters is to find

the optimum operating condition. Franco and Villani (2008) studied medium and

low-temperature water-dominated system. The authors introduced the geothermal

field analyzed, and proposed a methodology for optimizing the geothermal binary

plants. They considered the fundamental variables as follows: Selection of the

working fluid; temperature, pressure and chemical composition of the geothermal

fluid, the reinjection temperature, the ambient temperature and the maximum rate

of energy destruction. Borsukiewicz-Gozdur and Nowak (2007) studied several

ways of increasing the power output of a geothermal power plant based on organic

working fluid. Several types of organic working fluid were used in the analysis.

Hettiarachchia et al. (2007) presented optimum design criterion for organic Ran-

kine cycle using the low temperature geothermal sources. During the optimization

process, objective function is minimized by varying evaporation and condensation

temperature, geothermal water velocity in the evaporator and the cooling water

velocity in the condenser. After their analyses, heat rejection at the condenser, the

554 D.M. Çakıcı and C.Ö. Çolpan

Rankine cycle efficiency, working fluid mass flow rate, heat supplied at evaporator,

exergy efficiency for binary power plant, heat transfer coefficients, pressures drops,

total heat exchanger area, geothermal and cooling water pumping power and

net-power for the cycle were found.

Fluid selection is important for design of the organic Rankine cycle. Basaran and

Ozgener (2013) investigated different refrigerants on the performances of the cycle.

Energy and exergy efficiency were calculated for 12 refrigerants on binary cycle

R236ea, R600, R600a and R227ea (dry type fluid) showed higher energy and

exergy efficiencies. R143a, R415A, R290, and R413a that are wet fluids indicated

lower energy and exergy efficiencies. However, the investigation of supercritical

fluid parameters is high importance. Schuster et al. (2010) compared subcritical and

supercritical fluid parameters. They chose more than one refrigerants for geother-

mal power plant using organic Rankine cycle such as R134a, R227ea, R152a,

isobutane, isopentane. Calculations showed supercritical cycle yields better than

efficiency subcritical cycle. Vetter et al. (2012) worked with different refrigerants

for comparing subcritical and supercritical parameters. In another study,

Borsukiewicz-Gozdur and Nowak (2010) presented theoretical calculations of an

Organic Rankine cycle power plant with supercritical parameters. The temperature

of geothermal water ranged from 95 �C to 120 �C and mass flow rate was taken as 15 kg/s. Four organic fluids were selected as the working fluids in ORC (R115,

R125, R143a, and Propylene). As a result of the calculations, propylene was found

to give the best performance.

In this study, the effect of different refrigerants on performance of supercritical

organic Rankine was investigated. Power output and electrical efficiency of the

supercritical cycle were found for different refrigerants (R134a, R143a, R142b,

R124, R227ea). The equations based on the energy balances of the components of

the system were solved using Engineering Equations Solver (EES). The refrigerant

giving the best performance for the organic Rankine cycle was found.

System Description

Gümüşk€oy geothermal power plant is located in Aydın, Turkey. The plant has been operated and managed by BM Holding since 2013. The geothermal fluid is pro-

duced at a temperature of 178 �C and a pressure of 7.1 bar and the net power output is 5.5 MW. Power plant is based on a supercritical organic Rankine cycle in which

R134a is the working fluid. Operating data is given Table 41.1.

Working principle is as follows: Geothermal wells produce a mixture of steam-

liquid. The temperature of brine is 178 �C and 7.1 bar, respectively. High pressure geothermal fluid from the well is separated as saturated liquid and superheated

vapor in a separator. Superheated vapor enters the heat exchanger. The geothermal

brine transfers its heat to R134a stream in the heat exchanger. The temperature of

R134a reaches the supercritical state before entering the turbine. Then R134a enters

the turbine at a temperature of 151.8 �C and a pressure of 43.7 bar, and power is

41 Investigating the Effect of Different Refrigerants on the Performance. . . 555

produced. R134a leaves the turbine and enters the desuperheater (regenerator). The

aim of desuperheater is to increase the efficiency of the ORC by increasing the

temperature of the working fluid entering the heat exchanger. Working fluid then

enters the air cooled condenser and leaves as saturated liquid. Air enters the

condenser at 18 �C and air leaves at 30 �C. The R134a enters the pump with the 9.47 bar pressure. R134a is pumped into the desuperheater. Then refrigerant enters

the heat exchanger group. Finally, geothermal liquid is sent back to the reinjection

wells. Reinjection wells provide the longevity of geothermal resources. Process

flow diagram is shown in Fig. 41.1.

Modeling

Mathematical modeling of the system is presented in this section. The equations

developed were programmed using Engineering Equations Solver (EES). The input

data in the code used the actual operating data taken from the power plant.

Modeling of the heat exchanger is presented first. Then the energy analysis of the

overall system is presented.

Three shell and tube heat exchangers are used in the system. ε-NTU (effectiveness-number transfer units) method is used in the modeling of the heat

exchanger. To define effectiveness of heat exchanger, we must determine the

maximum possible heat transfer rate, _qmax for the heat exchanger. In the ε-NTU method (Bergman et al. 2006; Ramesh and Dušan 2003), the heat transfer rate from

the hot fluid to the cold fluid in the exchanger is defined as:

_qmax ¼ Cmin � ðTh, i � Tc, iÞ ¼ Cmin � ΔTmax ð41:1Þ

Table 41.1 Operating data of Gümüşk€oy power plant

Parameter Value

Temperature of production well 178 �C Temperature of geothermal fluid entering the heat exchanger-1 164 �C Temperature of R134a entering the turbine 151.8 �C Temperature of geothermal fluid entering the heat exchanger-2 160.6 �C Temperature of air entering the air cooled condenser 18 �C Temperature of air outlet the air cooled condenser 30 �C Pressure of geothermal fluid entering the heat exchanger-1 6.82 bar

Pressure of geothermal fluid entering the heat exchanger-2 7.8 bar

Pressure of R134a entering the turbine 43.7 bar

Pressure of R134a outlet the turbine 9.47 bar

Mass flow of R134a 213.33 kg/s

Mass flow of air 3240 kg/s

Isentropic efficiency of the turbine 0.8

Isentropic efficiency of the pump 0.8

556 D.M. Çakıcı and C.Ö. Çolpan

Th,i is inlet temperature of hot fluid, Tc,i is inlet temperature of cold fluid. Cmin is equal to Cc or Ch, whichever is smaller.

Cc ¼ _mwf � cp,wf ð41:2Þ

Ch ¼ _mgeof luid � cp,geof luid ð41:3Þ

Cc is heat capacity of cold fluid, and Ch is heat capacity of hot fluid. Cold fluid is R134a and hot fluid is the geothermal brine. Effectiveness ε is a measure of thermal performance of a heat exchanger. ε is define as a ratio of the actual heat transfer rate from the hot fluid to the cold fluid to the maximum possible heat transfer rate:

ε ¼ q qmax

ð41:4Þ

Then, for any heat exchanger it can be shown that:

ε ¼ f NTU; Cmin Cmax

� � ð41:5Þ

Cmin Cmax

is equal to CcCh or Ch Cc

. NTU is dimensionless parameter that is widely used for

heat exchanger analysis and is defined as:

NTU ¼ A � U Cmin

ð41:6Þ

HX-1

HX-2

HX-3

Production well

Reinjection well

Turbine

5 4

Air cooled condenser

Desuperheater

Pump

Geothermal fluid Working fluid

Air

8 32

Fig. 41.1 Schematic diagram of Gümüşk€oy geothermal power plant

41 Investigating the Effect of Different Refrigerants on the Performance. . . 557

A is area; U is overall heat transfer coefficient.

U ¼ 1

ho þ do

di � 1 hi

� � þ ln do

� � � do

2ktube

� � ð41:7Þ

do is outer diameter of the tube, di inner diameter of the tube, ktube is conductivity of the tube, hi is convection heat transfer coefficient inside the tube, ho is convection heat transfer coefficient outside the tube.

The main assumptions made in the energy analysis are as follows:

• The system runs at steady state conditions.

• Pressure drop and heat loss in pipeline are all neglected.

• Kinetic and potential energies are ignored.

The supercritical organic Rankine cycle is modeled based on the mass and

energy conservation laws. Energy balance of the control volume can be given as:

_Q � _W ¼ X e

_m � _h � X i

_m � _h ð41:8Þ

The power output of the turbine is given by:

_WT ¼ _mwf � h1 � h2ð Þ ð41:9Þ

In the air cooled condenser, _Wfan is calculated as follows:

_Wfan ¼ _mwf � h4 � h3ð Þ þ _mair � h8 � h7ð Þ ð41:10Þ

The power output of the pump is given by:

_WP ¼ _mwf � ðh5 � h4Þ ð41:11Þ

Net work output the system:

_Wnet ¼ _WT � _WP � _Wfan ð41:12Þ

The total heat input of the system:

_Qin ¼ _mgeo � ðha � hbÞ ð41:13Þ

The net electric power generated is defined as:

nel ¼ _Wnet _Qin

ð41:14Þ

558 D.M. Çakıcı and C.Ö. Çolpan

Results and Discussion

The effect of different fluids on the performance of the system is studied. R134a,

R143a, R124, R227ea, and R142b are chosen as the working fluids. Selection

of working fluid has been done considering the turbine inlet temperature as super-

critical. In addition, reinjection well temperature should be at least 60 �C as the minerals found in the brine precipitate below this temperature (Yıldırım and

Şimşek 2003). T-s diagrams for these working are shown fluids in Figs. 41.2, 41.3,

41.4, 41.5, and 41.6.

Thermal analysis was conducted separately for each fluid type. Result of calcu-

lations, reinjection well temperature (Tb), entering temperature of the turbine (T1),

net work output of the system, power input of the pump, power output of the

turbine, electrical efficiency of the system were found. These results are shown in

Table 41.2 for all working fluid.

A parametric study was done with EES. In Fig. 41.7, the effect of condenser

pressure on the work output of the system is shown. Wnet values were calculated for

condenser pressure between to 9 and 15 bars. It is found that as condenser pressure

increases, power output is decreased for all chosen working fluid. The effect of

condenser pressure on the electrical efficiency of the system is shown in Fig. 41.8.

The results show that R143a gives the best performance in Figs. 41.7 and 41.8.

R227ea, R124 and R142b are similar values in Fig. 41.8. R227ea gives the worst

performance. Condenser pressure increases and net fan work increases for the cool.

So that net work output and electrical efficiency decreased.

Fig. 41.2 T-s diagram of the ORC that uses R134a as the working fluid

41 Investigating the Effect of Different Refrigerants on the Performance. . . 559

The effect of production well temperature on the net work output of the system

was studied. Wnet values were calculated for temperature of production well

between 100 and 200 �C in Fig. 41.9. The results show that as the production well temperature increases; power output also increases for all working fluid. The

effect of production well temperature on the electrical efficiency of the system is

Fig. 41.3 T-s diagram of the ORC that uses R143a as the working fluid

Fig. 41.4 T-s diagram of the ORC that uses R142b as the working fluid

560 D.M. Çakıcı and C.Ö. Çolpan

Fig. 41.5 T-s diagram of the ORC that uses R124 as the working fluid

Fig. 41.6 T-s diagram of the ORC that uses R227ea as the working fluid

Table 41.2 The results of the thermal analysis

Working fluids Tb [ �C] T1 [�C] Tcritic [�C] P1 [bar] Pcritic Wnet [Mw] ηel

R134a 77.57 147.7 101 43.7 40.59 6.49 0.1522

R143a 78.55 149.3 72.7 43.7 37.61 8.29 0.1969

R142b 79.06 150 137.1 43.7 40.55 5.30 0.1266

R124 90.77 158.9 122.3 43.7 36.24 4.62 0.1286

R227ea 97.78 159.8 102.8 43.7 29.99 3.94 0.1218

Fig. 41.7 The effect of condenser pressure on the net work output

Fig. 41.8 The effect of condenser pressure on the electrical efficiency

562 D.M. Çakıcı and C.Ö. Çolpan

given in Fig. 41.10. The results show that R143a gives the best performance. The

electrical efficiency of system was calculated for different temperatures of the

production well. This efficiency decreases because of the increase in the reinjection

well temperature.

Fig. 41.9 The effect of production well temperature on the net work output

Fig. 41.10 The effect of production well temperature on the electrical efficiency

41 Investigating the Effect of Different Refrigerants on the Performance. . . 563

Conclusions

In this study, the effect of different working fluids on the performance of an existing

geothermal power plant is investigated. Energy balances developed were

programmed using EES. Using this code, the power output of the turbines, the

power demand of the pumps, the heat input to the heat exchanger, and the net power

output and the electrical efficiency of the cycle are determined. The main conclu-

sions derived from the results of the analyses conducted are listed below:

• The results for net work of the system and electrical efficiency, entering tem-

perature of the turbine and reinjection well temperature are given in Table 41.2.

It is found that R143a gives the best performance.

• Electrical efficiency from highest to lowest, respectively, is as follows: R143a,

R134a, R124, R142b, R227ea.

• As production well temperature increases, electrical efficiency decreases for all

working fluids. As condenser pressure increases electrical efficiency decreases

for all working fluid.

• Although R143a gives the best performance, we suggest that R134a that gives

the second highest performance should be selected as the working fluid in the

Gümüşk€oy power plant. This is due to the fact that the working fluid R134a is non-flammable, non-toxic and yields better performance compared to other

refrigerants (R124, R142b, R227ea).

Acknowledgments The author would like to thank Anıl Erdo�gan, G€okhan Fidan, Ömer Katırcı and the engineers and managers in the Gümüşk€oy plant for their technical contributions.

Nomenclature

A Heat exchanger area, m2

c Specific heat capacity, kJ/kg K

d Diameter of heat exchanger tube, mm

ε Effectiveness hi Convection heat transfer coefficient inside the tube, W/m

2 K

ho Convection heat transfer coefficient outside the tube, W/m 2 K

hair Specific enthalpy of air, J/kg hgeo Specific enthalpy of the geothermal fluid, J/kg k Conductivity of exchanger tube

_m Mass flow rate, kg/s NTU Number transfer units

U Overall heat transfer coefficient, W/m2 K _Wnet Net work output of the system, W

_WT Power output of the turbine, W

_WP Power input of the pump, W

564 D.M. Çakıcı and C.Ö. Çolpan

_Wfan Power input of the fans in the air cooled condenser, W

_q Heat transfer rate per tube area, W/m2

_Q Net heat gain rate, W

Qin Total heat input rate, W nel Electrical efficiency wf Working fluid

References

Acar, H. I. (2010). A review of geothermal energy in Turkey. Energy Sources, 25, 111083–111088.

Basaran, A., & Ozgener, L. (2013). Investigation of the effect of different refrigerants on

performances of binary geothermal power plants. Energy Conversion and Management, 76, 483–498.

Bergman, T. L., Lavine, A. S., Incropera, F. P., & DeWitt, D. P. (2006). Fundamentals of heat and mass transfer. New York: Wiley.

Borsukiewicz-Gozdur, A., & Nowak, W. (2007). Maximising the working fluid flow as a way of

increasing power output of geothermal power plant. Applied Thermal Engineering, 27, 2074–2078.

Borsukiewicz-Gozdur, A., & Nowak, W. (2010). Geothermal power station with supercritical

organic cycle. In Proceedings world geothermal congress, Bali, Indonesia. DiPippo, R. (2012). Geothermal power plants: Principles, applications, case studies and envi-

ronmental impact. Amsterdam: Elsevier. Franco, A., & Villani, M. (2008). Optimal design of binary cycle power plants for water-

dominated, medium-temperature geothermal fields. Geothermics, 38, 379–391. Hettiarachchia, H. D. M., Golubovica, M., Woreka, M. W., & Ikegamib, Y. (2007). Optimum

design criteria for an organic Rankine cycle using low-temperature geothermal heat sources.

Energy, 32, 1698–1706. Ramesh, K. S., & Dušan, P. S. (2003). Fundamentals of heat exchanger design. New York: Wiley. Retrieved December 5, 2014, from http://www.geothermal.org/what.html.

Retrieved December 5, 2014, from http://www.eie.gov.tr/yenilenebilir/turkiyede_jeo.aspx.

Retrieved November 30, 2014, from http://www.geothermal-energy.org/electricity_generation.

html.

Schuster, A., Karellas, S., & Aumann, R. (2010). Efficiency optimization potential in supercritical

Organic Rankine Cycles. Energy, 35, 1033–1039. Vetter, C., Wiemer, H., & Kuhn, D. (2012). Comparison of sub- and supercritical Organic Rankine

Cycles for power generation from low-temperature/low-enthalpy geothermal wells, consider-

ing specific net power output and efficiency. Applied Thermal Engineering, 51, 871–879. Yıldırım, N., & Şimşek, Ş. (2003). Determination of appropriate injection conditions for Kizildere

geothermal waste fluid to avoid scale formation and cooling. In European geothermal conference.

Zarrouka, S. J., & Moon, H. (2014). Efficiency of geothermal power plants: A worldwide review.

Geothermics, 51, 142–153.

41 Investigating the Effect of Different Refrigerants on the Performance. . . 565

http://www.geothermal-energy.org/electricity_generation.html

http://www.eie.gov.tr/yenilenebilir/turkiyede_jeo.aspx

http://www.geothermal.org/what.html

Part XI

Environmental Technologies Related to Global Warming

Carbon Capture and Storage (CCS) and Geotechnology Issues

Chapter 42

CaO-Based Sorbents for Post Combustion CO2 Capture via Carbonate Looping

Zinovia Skoufa, Andy Antzara, Ioannis Milios, Eleni Heracleous,

and Angeliki A. Lemonidou

Introduction

In 2007, the Intergovernmental Panel on Climate Change (IPCC) concluded that

worldwide temperature rise is primarily caused by the increase in anthropogenic

greenhouse gases. CO2 is by far the most important of these gases, mainly due to its

abundance (Blockstein and Shockley 2006, Fan 2010). Among several industrial

processes, electricity production sector holds the lion share in CO2 emissions; in

Greece its contribution in CO2 emissions climbs to ~50% (United Nations 2012). In

that context, research aiming at mitigating CO2 emissions particularly from power

plants has received a lot of attention, so that a pure stream of CO2 is collected from

flue gases and subsequently sequestrated in appropriate geological formations.

Among several available processes for carbon dioxide capture, CO2 capture with

amines is a well-established technology that however suffers from serious problems

Z. Skoufa (*) • A. Antzara • I. Milios Department of Chemical Engineering, Aristotle University of Thessaloniki, Thessaloniki

54124, Greece

e-mail: [email protected]; [email protected]; [email protected]; [email protected]

E. Heracleous

Chemical Process and Energy Resources Institute (CPERI), Centre for Research and

Technology Hellas (CERTH), 6th km Charilaou-Thermi Road, P.O. Box 361, Thessaloniki

57001, Greece

e-mail: [email protected]

A.A. Lemonidou

Department of Chemical Engineering, Aristotle University of Thessaloniki, Thessaloniki

54124, Greece

Chemical Process and Energy Resources Institute (CPERI), Centre for Research and

Technology Hellas (CERTH), 6th km Charilaou-Thermi Road, P.O. Box 361, Thessaloniki

57001, Greece

e-mail: [email protected]

571

mailto:[email protected]

of energetic/economic and environmental importance. First of all, high energy

demands, leading to high operational costs, are associated with the regeneration

of the amine solution. Moreover, there are problems associated with the degrada-

tion of sorbents at higher temperatures, the reactions of amines with compounds

present in the flue gases such as oxygen and SO2 and finally the corrosive nature of

amines and their degradation products (Mandal and Bandyopadhyay 2006, Blamey

et al. 2010, Wang et al. 2014). Therefore, alternative processes for CO2 separation

are extensively investigated, including reactive CO2 separation using dry, solid

sorbents such as limestone, alkali zirconates/silicates and sodium carbonates

(White et al. 2003, Park et al. 2010). Unlike liquid adsorbents, solid adsorbents

can be used over a wider temperature range from ambient temperature to 700 �C. Moreover, they yield less waste during cycling, while the spent solid adsorbents can

be disposed more easily and in an environmentally friendly way (Harrison 2005).

The choice of suitable materials depends mainly on the type of the application that

CO2 capture is intended for. Considering CO2 removal from flue gases, sorbent

properties such as heat tolerance, sorption capacity and stability, fast kinetics are

very important for the economic viability of the process. Cost is also a major factor

for such large scale applications. In this context, calcium oxide is a very attractive

material for carbon dioxide capture, mainly due to high theoretical CO2 capture

capacity of 0.786 g CO2/g sorbent (17.8 mmol CO2/g sorbent) and fast kinetics of

the CO2 capture and release reaction (Broda et al. 2014). Carbonate Looping (CaL)

is an ex-situ, post-combustion CO2 capture technology in which CO2 from flue

gases is captured by a CaO-based sorbent in the carbonator. The carbonate cycle for

post combustion CO2 capture has been chosen by The Technology Task Force of

the European Technology Platform for Zero-Emission Power Plants as one of the

two highest priorities for future research and development (EU 2014). Moreover,

preliminary techno-economic calculations show that calcium looping can separate

CO2 from flue gases at a cost of 25 USD/ton CO2 compared to 50 USD/CO2 that

removal with amine scrubbing currently costs (Epple 2010).

CO2 capture with calcium looping (CaL) is based on the reversible reaction of

calcium oxide with carbon dioxide to produce calcium carbonate, according to the

following reaction:

CaOþ CO2 Ð CaCO3

In a calcium looping cycle (CaL), the CaO-based sorbent is continuously

transferred between two reactors: the carbonator, where the flue gases are stripped

from CO2 by the forward reaction of CO2 uptake, and the calciner, where the

formed CaCO3 is decomposed to regenerated CaO producing at the same time a

concentrated CO2 stream ready to be sequestrated or used as raw material in

downstream chemical processing units. The carbonation reaction is exothermic

and the heat released can be integrated for the realization of the endothermic

reverse reaction (calcination) for sorbent regeneration. The optimal operating

temperatures of both steps are thermodynamically determined from CO2 partial

pressure. Achieving fast CO2 sorption and desorption rates is also a matter of

572 Z. Skoufa et al.

concern. The conditions in the carbonator must strike a balance between the

increased equilibrium conversion obtained at lower temperatures and the faster

reaction rate at higher temperatures. The conditions in the calciner must compro-

mise between the increased rate of the decomposition reaction at higher tempera-

tures and the reduced rate of degradation of sorbent at lower temperatures (Blamey

et al. 2010). Based on the above, the typical temperature window for CO2 capture

from a gas-fired flue gas stream ranges between 600 and 650 �C in the carbonator and above 850 �C in the calciner (Park et al. 2010; Broda et al. 2014).

Key for the large scale deployment of this process is sorbent development. In

view of the carbonation reaction, CO2 sorption process can be divided into two

distinct steps: (1) an initial fast surface reaction controlled by the reaction kinetics

and (2) a slower reaction restricted by the diffusion of CO2 in the CaCO3 product

(Mandal and Bandyopadhyay 2006). An important aspect of the carbonation reac-

tion is the difference in the molar volume of CaO and the product CaCO3.

Therefore, the formation of CaCO3 results in the formation of a product layer of

high molar volume which in turn leads to pore blockage (Broda et al. 2014). Taking

the above into consideration, it is obvious that the sorption capacity of a CaO-based

material greatly depends on its morphological and structural characteristics, mainly

its surface area and porosity. Moreover, taking into account that in practice such a

process comprises several consecutive carbonation/calcination cycles, sorbent

cyclic stability in multi-cycle operation is prerequisite for the successful industrial

implementation of the calcium looping process. Good mechanical properties are

also required for an efficient sorbent material, due to a number of important issues

of solids handling, associated with cohesive particles, attrition and agglomeration,

electrostatic charge effects, etc. (White et al. 2003). CaO derived from the decom-

position of naturally occurring limestone, although cheap, has the major drawback

of rapidly decreasing CO2 capture capacity with a number of repeated carbonation

and calcination cycles (Grasa and Abanades 2006). Several efforts to enhance

physicochemical and sorption characteristics of calcium oxide have been

employed: preparation of synthetic CaO, improvements in the synthesis methods

and synthesis of CaO-based mixed oxides. These efforts, recently reviewed thor-

oughly (Liu et al. 2012), include preparation of synthetic pure CaO sorbents via

different Ca-precursors, different preparation methods as well as doping with a

second metal and/or incorporation of inert materials. These efforts have indeed

proved to be efficient, especially in terms of cyclic stability enhancement

(Martavaltzi and Lemonidou 2008; Angeli et al. 2014).

The majority of published literature on the field reports multi-cyclic evaluation

of novel synthetic and/or natural sorbents in a thermogravimetric apparatus (TGA),

while a few recent papers concern pilot-scale operation of a carbonator/calciner

system (Diego et al. 2014; Dieter et al. 2014; Str€ohle et al. 2014). It is generally accepted that operating conditions, including for example reactor system employed,

carbonation/calcination temperature and feed composition, affect to a significant

extent the evaluation results on sorption capacity and stability (Alonso et al. 2014).

Steam, which is anyway present in flue gases, is reported to enhance sorption

capacity (Manovic and Anthony 2010; Kavosh et al. 2014), whereas no positive

42 CaO-Based Sorbents for Post Combustion CO2 Capture via Carbonate Looping 573

effect was reported in other studies (Sun et al. 2008). Steam has been also used for

regeneration attempts of the sorbents, usually via the incorporation of a hydration

step in the calcium looping cycle (Sun et al. 2008; Li et al. 2014; Coppola

et al. 2014).

In this work, we report the development, preliminary evaluation and bench-scale

testing of synthetic and natural mixed CaO-based sorbents for post-combustion

CO2 capture from industrial plants flue gases. The synthetic materials consist of

CaO-based mixed oxides with Al, Zr, La and Mg, prepared via sol-gel auto-

combustion synthesis using citric acid as a combustion agent. Concerning the

natural CO2 sorbents, we investigated the effect of different pre-treatments on the

sorption capacity and stability of industrial hydrated lime. Mixing with inert

minerals, such as kaolin, bauxite and magnesia, was attempted in an effort to reduce

sintering and degradation under consecutive sorption/desorption cycles. The most

promising materials were further studied at bench-scale in a fixed bed reactor, under

a flow of CO2, O2, H2O and N2 simulating typical flue gases composition from a

power plant. The possibility of hydration-induced regeneration and the effect of

steam in flue gases are also investigated for selected materials.

Experimental

Sorbent Preparation

Four CaO-based powders promoted with Al, Zr, La and Mg were prepared by

sol-gel auto-combustion synthesis using citric acid as combustion agent. The

starting material was Ca(NO3)2·4H2O (J.T. Baker) and the corresponding precursor

for each promoter (Al(NO3)3·9H2O (Carlo Erba), La(NO3)3·6H2O (Merck), Mg

(NO3)2·6H2O (J.T. Baker) and ZrO(NO3)2·xH2O (Acros)). All sorbents were pre-

pared with a constant 66 wt% concentration of free CaO. The required amounts of

calcium nitrate and the precursor of each promoter were dissolved in distilled water

under continuous heating and stirring. Subsequently, the required amount of citric

acid was added to the aqueous solution in order to maintain a constant nitrate salts/

combustion agent molar ratio of 3. The new solutions were heated on a heating plate

to promote water evaporation. After gelation occurred, the formed gel was trans-

ferred to a preheated furnace at 300 �C, where after a few minutes the gel was combusted in a self-propagating combustion manner. The as synthesized powders

were then calcined at 900 �C for 1.5 h under air flow. The sorbents are denoted as Ca-X, where X refers to the promoter (Zr, La, Mg or Al).

Hydrated lime, Ca(OH)2, provided by CaO Hellas was investigated as CaO source for natural CO2 sorbents. Three different pre-treatment protocols were tested

for the activation of raw Ca(OH)2: Protocol 1: the raw material was calcined at 900 �C for 1.5 h under air flow (Ca(OH)2-C900), Protocol 2: the calcined sample was then hydrated with water at 70 �C for 4 h to increase the surface area and as a

574 Z. Skoufa et al.

result the sorption capacity, and was finally recalcined at 600 �C for 3 h in order to decompose the formed Ca(OH)2 during hydration (Ca(OH)2-W-C600) and Proto- col 3: same as protocol 2, excluding final calcination step which was conducted at 900 �C (Ca(OH)2-W-C900). Three natural heat resistant binders were used as means to increase cyclic stability, namely kaolin, bauxite and magnesia obtained

from Prolat, S&B and Grecian Magnesite respectively. Three methods were inves- tigated for the incorporation of the binders: Protocol 4: Ca(OH)2-W-C600 sample obtained from protocol 2 was mixed with Kaolin (Ca(OH)2-KAOL), Bauxite (Ca (OH)2-Baux) or MgO (Ca(OH)2-MgO) in distilled water at 70

�C under continuous stirring for 4 h. The materials were filtered, dried overnight at 120 �C and calcined at 900 �C for 1.5 h under air flow; Protocol 5: raw Ca(OH)2 instead of Ca(OH)2-W- C600 was used as the CaO-precursor, and MgO (Ca(OH)2-MgO-RW) or Bauxite

(Ca(OH)2-Baux-RW) was added following the same procedure as in protocol 4; Protocol 6: raw Ca(OH)2 and MgO were grinded in a mortar for 20 min and the resulting mechanical mixture was calcined at 900 �C for 1.5 h under air flow.

Mixed natural sorbents were all prepared with a constant 66 wt% concentration

of free CaO. Kaolin is a mineral composed mainly of Al2O3 and SiO2 with a general

formula of Al2O3·2SiO2·2H2O, bauxite is composed mainly of Al2O3 and Fe2O3 while the magnesia was mainly MgO with less than 3% impurities, as tabulated in

Table 42.1.

Physicochemical Characterization

Surface areas of the samples were determined by N2 adsorption at 77 K, using the

multipoint BET analysis method, with an Autosorb-1 Quantachrome flow apparatus.

Prior to the measurements, the samples were dehydrated in vacuum at 250 �C overnight.

X-Ray diffraction (XRD) patterns were obtained using a Siemens D500 diffrac-

tometer, with Cu-Kα radiation. The morphology of the synthesized materials was examined by scanning electron microscopy (SEM) on a JEOL 6300 microscope,

coupled with energy-dispersive X-ray analysis (EDX; Oxford Link ISIS-2000) for

local elemental composition determination.

Table 42.1 Chemical composition of MgO, Kaoline and Bauxite binders

MgO-Grecian Magnesite wt% Kaoline-Prolat wt% Bauxite-S&B wt%

MgO 97.30 SiO2 46.55 SiO2 0.87

SiO2 0.50 Al2O3 39.50 Fe2O3 15.27

CaO 1.90 H2O 13.95 TiO2 3.12

Fe2O3 0.05 CaO 0.09

Al2O3 0.25 L.O.I. 14.46

Al2O3 65.77

S 0.03

Zn (ppm) 26

42 CaO-Based Sorbents for Post Combustion CO2 Capture via Carbonate Looping 575

Preliminary Evaluation in TGA

An SDT Q600 (TA Instrument) thermal gravimetric analysis (TGA) instrument was

used for the preliminary evaluation of all sorbent in 100 consecutive carbonation/

calcination experiments. SDT Q600 works in conjunction with a controller and

associated software to make up a thermal analysis system. A small quantity of the

material (5–10 mg), placed in an aluminum sample cup, was pretreated at 850 �C, in the presence of 100 cm3/min pure N2, for 10 min to remove possible humidity and

CO2 absorbed. The CO2 capacity of the sorbents was tested under 15% CO2 flow in

N2 for 30 min at 650 �C while desorption took place under 100% N2 flow for 5 min

at 850 �C. Results are presented in terms of sorption capacity of the materials (mol CO2/kg of sorbent) and CaO conversion. CaO conversion can be expressed as a

function of the weight increase of the sorbent due to CO2 absorption:

X tð Þ,% ¼ MWCaO MWCO2

*%weight increase tð Þ* 1 wCaO

ð42:1Þ

where MWCaO and MWCO2 are the molecular weight of CaO and CO2 respectively,

and wCaO is the weight fraction of free CaO present in the sorbent.

Bench-Scale Testing

The most promising synthetic and natural sorbents according to preliminary eval-

uation in TGA were tested in a bench scale flow unit for 20 consecutive CO2 sorption/desorption cycles. A fixed bed quartz reactor with 18 mm external diam-

eter of the reactor tube in the reaction zone and equipped with coaxial thermocouple

for temperature monitoring was used for testing. The reactor was heated electrically

by a tubular furnace, with three independently controlled temperature zones.

Carbonation was conducted at 650 �C under a 10% CO2/20% H2O/3.2% O2/N2 feed. Calcination was conducted at 800 �C in a 30%H2O/N2 flow. The CO2 concentration in the reactor exit was monitored online by a CO2 analyzer (Horiba,

VIA 510). Sorption capacity of the sorbents, expressed as mol CO2/kg of sorbent, %

CaO conversion and sorption rate (mmol CO2/kg/s) were calculated as follows:

Sorption capacity, molCO2=kgsorbent ¼

ð t 0

MCO2dt

winit ð42:2Þ

X tð Þ,% ¼

ð t 0

MCO2dt

nCaO *100% ð42:3Þ

576 Z. Skoufa et al.

Sorption rate, mmol=kgsorbent= sec ¼ MCO2*10

winit ð42:4Þ

where MCO2 are the moles of CO2 captured (mol CO2/s), winit is the initial weight of

the sorbent material (kg) and nCaO are the initial moles of CaO in the sorbent

sample.

Results and Discussion

Physicochemical Characterization

According to XRD analysis (not shown here for brevity), the main crystal phase

formed in all synthetic CaO-based sorbents is CaO, accompanied by minor peaks of

low intensity corresponding to Ca(OH)2 in Ca-Mg, Ca-Al and Ca-Zr samples.

Formation of mixed Ca3Al2O6 and CaZrO3 was observed in Ca-Al and Ca-Zr

sorbents, respectively. On the contrary no mixed phase was formed between CaO

and Mg or La, where the precursor nitrate salts decomposed to MgO and La2O3 respectively (Antzara et al. 2015). Concerning the textural properties of the syn-

thetic sorbents, summarized in Table 42.2, it can be observed that the nature of the

dopant affects the surface area of the final material. Surface areas ranging from

28 m2/g for Mg-doped CaO to 9 m2/g for La-doped CaO were recorded.

The as delivered industrial material (Ca(OH)2) is composed of almost pure

calcium hydroxide, presenting only a small XRD reflection corresponding to

calcium carbonate. After thermal pre-treatment at 900 �C (Ca(OH)2-C900), Ca (OH)2 was almost completely decomposed to CaO with minor Ca(OH)2 reflections.

When the calcined sample was subjected to water treatment and calcined, only

Table 42.2 BET surface area and pore volume of the synthetic and natural CaO-based sorbents

Sorbent Surface area (m2/g) Pore volume (cm3/g)

Ca-Mg 28.37 0.112

Ca-La 8.78 0.138

Ca-Zr 15.28 0.051

Ca-Al 11.93 0.062

Ca(OH)2-C900 5.04 0.041

Ca(OH)2-W-C600 17.24 0.181

Ca(OH)2-W-C900 16.82 0.149

Ca(OH)2-KAOL 3.22 0.023

Ca(OH)2-Baux 5.22 0.0198

Ca(OH)2-MgO 23.25 0.427

Ca(OH)2-Baux-RW 5.29 0.029

Ca(OH)2-MgO-RW 25.49 0.199

Ca(OH)2-MgO-GM 18.7 0.13

42 CaO-Based Sorbents for Post Combustion CO2 Capture via Carbonate Looping 577

reflections at the angular positions of Ca(OH)2 appear, despite the high temperature

used in calcination either at 600 �C or at 900 �C, that was expected to favor hydroxide decomposition to CaO. The addition of kaolin leads to the formation of a mixed phase

Ca3Al2Si2, together with pure Al2O3 and SiO2. Regardless of the preparation method,

in the case of the use of bauxite or MgO as binders, the XRD patterns revealed the

existence of CaO and MgO or Al2O3 crystalline phases, together with low intensity

peaks corresponding to Ca(OH)2 in the case of Ca(OH)2-Baux and Ca(OH)2-Baux-

RW samples, without any formation of mixed components. The surface area and pore

volume of all natural CaO-based sorbents is presented in Table 42.2. Hydration of the

calcined sample leads to an increase in surface area and porosity compared to Ca

(OH)2-C900 sample (Li et al. 2014). Concerning the mixedmaterials, the nature of the

binder seems to affect the textural properties of the final sorbent. The introduction of

kaolin or bauxite in industrial hydrated lime decreases the surface area. On the

contrary, the use of MgO greatly increases the surface area to ~25 m2/g which can

be partly attributed to the high surface area of pure MgO (70 m2/g). Overall, it can be

concluded that basic physicochemical characterization of the natural sorbents

revealed no important effect of the preparation method, whereas doping with MgO

seems to greatly affect both surface area and porosity.

Preliminary Evaluation in TGA

The performance of the four promoted synthetic CaO sorbents is presented in

Fig. 42.1. Although a wide range of surface areas was observed, all the promoted

sorbents (with the exception of Ca-La) achieved very high CaO conversions

Fig. 42.1 CO2 sorption capacity of the synthetic CaO-based sorbents as a function of the number of cycle in TGA

578 Z. Skoufa et al.

(>80%) that could be attributed mainly to the nature of the dopants and the formed structure of the final materials during combustion synthesis (Antzara et al. 2015).

All of the doped sorbents, except Ca-La, exhibit a very stable performance during

the first 70 cycles, unlike the pure CaO prepared with citric acid which deactivates

very fast in the first 20 cycles. Among the different dopants, doping with Zr leads to

the development of the most stable sorbent, followed closely by Al. Moreover, Al

exhibits the highest initial sorption capacity.

Natural sorbents consisting of pure CaO were tested in TGA for 50 carbonation/

calcination cycles. It can be observed (Fig. 42.2a) that water treatment of the

industrial hydrated lime greatly increases the initial CO2 sorption capacity com-

pared to the sample directly calcined at 900 �C, but unfortunately in expense of stability. Sample Ca(OH)2-C900 which presents the highest sorption capacity after

50 cycles was further tested for 100 cycles and the results are compared to those

obtained with doped natural sorbents in Fig. 42.2b. The use of kaolin, bauxite and

MgO binders leads to a decrease initial CO2 sorption capacity due to the lower

content of CaO in the materials, with the exception of Ca(OH)2-MgO-RW and Ca

(OH)2-MgO-GM samples. Nevertheless, CaO conversion increases for all doped

sorbents, indicating the beneficial effect of binders that seem to increase the

accessibility of active calcium oxide surface. Overall, the most promising results

were recorded for samples Ca(OH)2-C900 and Ca(OH)2-MgO-GM, that were

prepared via a solvent-free method. These two sorbents, together with Ca-Al and

Ca-Zr synthetic materials were chosen for further testing in a fixed bed reactor.

Table 42.3 summarizes the preliminary evaluation results for the above sorbents. It

becomes clear that the synthetic CaO-based sorbents exhibited almost twice the

initial sorption capacity of the natural sorbent and a very stable performance with

much lower deactivation after the same number of sorption/desorption cycles.

However, the use of natural sorbents presents important economic and environ-

mental advantages, since they are based on naturally occurring minerals. A feasi-

bility study of the use of either natural or synthetic sorbents exceeds the scope of the

present paper, and should in any case be based on sorbent properties derived after

tens of thousands of cycles (Abanades et al. 2004).

Fig. 42.2 CO2 sorption capacity of the natural CaO-based sorbents as a function of the number of cycle in TGA

42 CaO-Based Sorbents for Post Combustion CO2 Capture via Carbonate Looping 579

Bench-Scale Testing in a Fixed Bed Reactor

After initial sorbent screening in TGA, the most promising synthetic and natural

sorbents were tested in a fixed bed reactor, under realistic feed conditions.

Figure 42.3 presents the results for Ca-Al and Ca-Zr testing in 20 consecutive

carbonation/calcination experiments. It should be noted that the sorption capacity

refers to the amount of CO2 captured in the pre-breakthrough period, i.e. in the

carbonation stage controlled by surface reaction as will be discussed later on. Both

synthetic sorbents present high sorption capacity and satisfactory stability. Given

the differences between experimental set-ups, the sorption capacity recorded in

these experiments is similar to the results obtained in TGA, which refer to the

overall sorption capacity (not just in the pre-breakthrough period. Al-doped CaO

based sorbent presents only 12.5% deactivation after 20 cycles, compared to 23%

deactivation for Ca-Zr.

Carbonation profiles for the 1st and 20th cycle for Ca-Zr sorbent are presented in

Fig. 42.4, where CO2 concentration in reactor outlet and sorption rate, defined as

mmol CO2/kg/s, are plotted versus time. According to the carbonation profiles, CO2 capture proceeds via two distinctive stages. In the first stage, also known as the

pre-breakthrough period, the rate determining step of carbonation is the surface

reaction between CO2 and CaO. During this period, the CO2 concentration is

maintained at very low levels (<2%vol.), indicating a constantly high CO2 capture rate. In the experimental conditions used, both synthetic sorbents approach ther-

modynamic equilibrium CO2 conversion per pass. In the first cycle the duration of

Table 42.3 Preliminary evaluation results obtained from TGA the most promising synthetic and natural sorbents

Ca-Al Ca-Zr Ca(OH)2-C900 Ca(OH)2-MgO-GM

Initial capacity (mol CO2/kg sorbent) 11.64 10.63 5.22 4.54

Initial CaO conversion, % 99 90.3 29.6 38.6

Deactivation after 100 cycles (%) 20.7 13.7 36.5 30.9

Fig. 42.3 Sorption capacity versus number of

cycle for Ca-Zr

(GHSV¼ 318 h�1) and Ca-Al (GHSV¼ 311 h�1) synthetic sorbents in fixed

bed experiments

580 Z. Skoufa et al.

pre-breakthrough period for Ca-Zr sample is ~127 min (Fig. 42.4-left). At that time

~80% CaO conversion is achieved, corresponding to a sorption capacity of

9.02 mol CO2/kg sorbent. As the formation of CaCO3 proceeds, the overall CO2 capture process is governed by diffusion of CO2 through the CaCO3 layer. This step

is generally slower, and Fig. 42.4, it is characterized by fast decrease in the reaction

rate, accompanied by a fast increase of CO2 concentration in reactor outlet. As

already discussed, in a possible industrial implementation of the CaL concept, the

sorbent would exit the carbonator before gradual diffusion becomes rate-

controlling.

As shown in Fig. 42.4-right for Zr-doped CaO-based sorbent, after 19 cycles the

duration of the kinetically controlled period has decreased to 100 min in the 20th

cycle, leading to sorbent deactivation by 23%. Characterization of the spent

sorbent evidenced a 50% reduction in surface area (surface area of used sample:

11.1 m2/g). Characterization of the fresh and used samples with SEM revealed

significant agglomeration of the material after 20 cycles. As shown in Fig. 42.5a,b,

the fresh material is composed of small particles in the range of 10 μm, whereas in the used sample agglomeration led to the formation of larger particles, some of

which are as large as 500 μm (Fig. 42.5e). Nevertheless, it seems that the porous structure of the sorbent is retained to a significant extent, in line with the moderate

degree of deactivation that was recorded for Ca-Zr sorbent. Formation of CaZrO3 mixed phase seems to be the key for the avoidance of extended sintering phenom-

ena, as previously reported (Reddy et al. 2014), due to its high Tamman temperature

(Ruff et al. 1929). Characterization results of the used and fresh samples may

constitute the basis for enlightening the deactivation mechanism of the sorbent.

Due to surface area reduction, the carbonation reaction more quickly falls into

diffusion-controlled regime. Nevertheless, total sorption capacity, calculated as the

total amount of CO2 that was captured throughout carbonation and not just in the

pre-breakthrough period, is the same as in the first cycle. This result indicated that

sorbent did not suffer any loss of intrinsic activity. The stable porous structure

enables CO2 diffusion to the bulk of Ca-Zr particles, even if this step is completed

in a longer time after 20 cycles, as evidence by comparing the diffusion-controlled

period in the 1st and 20th cycle (Fig. 42.4).

Fig. 42.4 Carbonation profiles for the 1st (left) and 20th (right) cycle for Ca-Zr synthetic sorbent

42 CaO-Based Sorbents for Post Combustion CO2 Capture via Carbonate Looping 581

Ca-Al synthetic sorbent presented high sorption capacity, equal to 9.49 mol

CO2/kgsorbent in the pre-breakthrough period which lasted for 110 min, as shown in

Fig. 42.6-left. Compared to Ca-Zr sample, Ca-Al presents higher sorption rate,

leading to higher sorption capacity despite the smaller pre-breakthrough period. In

the 20th cycle, the surface reaction controlled step is reduced to 90 min. As

discussed for the Zr doped sample, the deactivation of Ca-Al sorbent is attributed

to a decrease in surface activity. The total active sites of the sorbent material do not

decrease judging from the fact that the same total amount of CO2 was captured in

cycles 1 and 20. Characterization of the used sample showed a marginal decrease in

surface area (from 12.5 m2/g to 9.3 m2/g) in line with a small deactivation rate of

12.5% after 20 carbonation/calcination cycles. The porous structure of the material

seems to remain almost intact, despite the formation of small agglomerates, as

shown in SEM micrographs (Fig. 42.7).

Fig. 42.5 SEM micrographs of fresh (a, b) and used (c–f) Ca-Zr sorbent

582 Z. Skoufa et al.

Fig. 42.6 Carbonation profiles for the 1st (left) and 20th (right) cycle for Ca-Al synthetic sorbent

Fig. 42.7 SEM micrographs of fresh (a, b) and used (c–f) Ca-Al sorbent

As expected, Ca(OH)2-C900 and Ca(OH)2-MgO-GM natural sorbents presented

significantly lower sorption capacity compared to synthetic sorbents, and intense

deactivation in the first five cycles, as shown in Figs. 42.8 and 42.9. The carbonation

profiles for both natural sorbents in the 1st cycle are shown in Fig. 42.10. Unlike

Fig. 42.8 Sorption capacity versus number of cycle for Ca(OH)2-C900 (GHSV¼ 286.5 h�1) natural sorbent in fixed bed experiments

Fig. 42.9 Sorption capacity versus number of cycle for Ca(OH)2-MgO (GHSV¼ 427 h�1) natural sorbent in fixed bed experiments

584 Z. Skoufa et al.

synthetic sorbents, it can be observed that for the natural sorbents, the breakthrough

period lasts longer than the pre-breakthrough period. In other words, the amount of

CO2 that is captured in the diffusion controlled regime is greater than in the

kinetics-controlled regime, indicating different morphology between natural and

synthetic sorbents. Indeed, pore size distribution evidenced the occurrence of

smaller pores (mesopores) for natural sorbents compared to synthetic samples

that mainly present macroporosity. Consequently, in natural sorbents the easily

accessible surface sites are presumably less compared to synthetic sorbents. More-

over, unlike synthetic sorbents, for which the same activity results were obtained

both in TGA and bench scale testing, both natural sorbents presented higher activity

in the fixed bed reactor experiments compared to the preliminary results in TGA, in

terms of total sorption capacity. This increase of total sorption capacity results from

both surface reaction- and diffusion controlled steps; however the pre-breakthrough

period contributes the most to the observed total capture activity of the solids. In the

TGA setup, the 15% CO2/N2 feed is inserted in the oven in a “flow over” mode as

opposed to “flow-through” conditions in the fixed bed reactor. Moreover, in bench

scale testing the presence of steam might affect the carbonation reaction, as

previously suggested (Manovic and Anthony 2010; Kavosh et al. 2014). According

the results reported in the present study, it can be deduced that the presence of steam

enhances both steps of the carbonation reaction. Overall, based on the above,

enhanced CO2 diffusion to less easily accessible surface sites is probably the reason

for the higher CO2 capture efficiency recorded in the bench-scale experiments for

natural sorbents.

Since the natural sorbents were significantly deactivated during the first five

cycles, two different approaches were studied in an attempt to investigate the

possibility of sorbent regeneration. Concerning Ca(OH)2-C900 sorbent, after the

7th, 8th and 9th cycle, the sample was cooled down from 800 �C (desorption temperature) to 80 �C, under a 30%Η2Ο/Ν2 flow. According to the thermodynamic equilibrium curve for CaO hydration, calcium oxide is hydrated to calcium hydrox-

ide at temperatures lower than 400 �C. The reaction is accompanied by an increase in specific volume, from 16.9 cm3/mol for CaO 33.1 cm3/mol for Ca(OH)2,

Fig. 42.10 Carbonation profiles for the 1st cycle for (a) Ca(OH)2-C900 (GHSV¼ 286.5 h�1) and (b) Ca(OH)2-MgO-GM (B) (GHSV¼ 427 h�1) natural sorbents

42 CaO-Based Sorbents for Post Combustion CO2 Capture via Carbonate Looping 585

ultimately resulting to an increase in surface area and porosity (Li et al. 2014).

As shown in Fig. 42.8, the hydration procedure led not only to containment of

sorbent deactivation, but also to a significant increase (~180%) in sorption capacity

from cycle 7th to 10th. It should be noted here, that in case of process scale-up the

addition of such a regeneration procedure would not be economically efficient, in

terms of energy needs for cooling down and re-heating the regenerated sorbent.

Cycles 10–15 were conducted without a hydration step, and as shown in Fig. 42.8,

the sample was again deactivated following roughly the same trend as in the first six

cycles. In order to investigate the effect of steam presence in the flue gases, cycles

16, 17 and 18 were performed in the absence of steam in the feed, leading to a sharp

decrease of the sorption capacity from 8.85 mol CO2/kg in cycle 15–2.51 mol CO2/

kg in cycle 18. Overall, the above results indicate that the presence of steam in the

feed increases CO2 capture efficiency and promotes sorbent stability, most probably

by facilitating CO2 diffusion.

As shown in Fig. 42.9, Ca(OH)2-MgO-GM sorbent presents an initial sorption

capacity of 6.03 mol CO2/kg, and is deactivated by ~33% within the first five

cycles. The second approach to regenerate the sorbents was then investigated for Ca

(OH)2-MgO-GM sorbent. After calcination at 800 �C, the sample was cooled down

to 300 �C and left to react towards Ca(OH)2 under a 55% Η2Ο/Ν2 flow for 3 h. This hydration process resulted in an increase in sorption capacity, as shown in Fig. 42.9.

For the next cycles up until cycle 20 the carbonation/calcination procedure was

repeated without any intermediate regeneration step and the sorbent continued to

deactivate; an overall ~49% deactivation was finally recorded.

Table 42.4 summarizes the bench-scale results for CO2 capture. It is obvious that

the synthetic sorbents prepared by sol-gel auto-combustion synthesis presented

superior capture activity and stability compared to the natural sorbents derived

from industrial hydrated lime. In view of the important conclusions derived from

the comparison of TGA and fixed bed reactor testing and characterization of spent

solids, it can be deduced that the superiority of synthetic sorbents lies in their

porous structure. On one hand, this porous structure enhances CO2 capture by

maximizing the available CaO surface. On the other hand, the addition of Zr and

Al leads to the formation of thermally stable CaZrO2 and Ca3Al2O6 mixed phases

that provide stability. The final choice on whether synthetic or natural sorbents

should be used in a potential scale up will be determined by techno economic

factors, taking into account the cost of sorbent development versus the need for

sorbent make-up due to deactivation.

Table 42.4 Summary of CO2 capture results (pre-breakthrough time) obtained in the fixed bed reactor for the four selected sorbents

Ca(OH)2-C900 Ca(OH)2-MgO-GM Ca-Zr Ca-Al

Initial sorption capacity,

mol CO2/kgsorbent

7.80 6.03 9.02 9.49

Initial CaO conversion, % 43.7 51.2 76.6 80.6

Deactivation after 20 cycles, % 13a 48.7a 12.5 23 aAfter (several) hydration steps, see text for details

586 Z. Skoufa et al.

Conclusions

CO2 capture from flue gases via carbonation calcination cycles over CaO-based

sorbents is a promising technology. In the present study, several synthetic and

natural sorbents were developed and preliminary evaluated in TGA. Synthetic

sorbents prepared by sol-gel auto-combustion technique exhibited high sorption

capacity and stability. Natural sorbents derived from industrial hydrated lime

presented promising results; the preparation procedure seems not to significantly

affect activity and stability. The most promising synthetic, Ca-Zr and Ca-Al, and

natural, pure CaO derived from Ca(OH)2 direct calcination and MgO-doped Ca

(OH)2, were tested in a fixed bed reactor under realistic flue gas feed composition.

Zr and Al-doped CaO based sorbents exhibited very high sorption capacity and

stability over 20 consecutive carbonation/calcination cycles, owing to the porous

structure obtained by the auto-combustion technique and retained due to the

presence of thermally stable Ca-Zr and Ca-Al mixed phases. The natural sorbents

presented inferior results, however their regeneration via hydration seems possible,

although most likely not economically viable. The presence of steam in the flue

gases seems to enhance sorption capacity and stability. Ca-Al synthetic sorbent

exhibited the most promising performance and shows great potential for process

scale up.

Acknowledgement We acknowledge the financial support from European Union-European Regional Development Fund and Ministry of Development, ESPA 2007–2013/EPAN II

programme, Action Synergasia11’.

Nomenclature

f Total flow rate, cm3/s

MCO2 Moles of CO2 captured, mol CO2/s

MWCaO Molecular weight of CaO

MWCO2 Molecular weight of CO2 nCaO Initial moles of CaO in the sorbent sample

wCaO Weight fraction of free CaO present in the sorbent

winit Initial weight of the sorbent, kg

References

Abanades, J. C., Rubin, E. S., & Anthony, E. J. (2004). Sorbent cost and performance in CO2 capture systems. Industrial & Engineering Chemistry Research, 43, 3461–3466.

Alonso, M., Criado, Y. A., Abanades, J. C., & Grasa, G. (2014). Undesired effects in the

determination of CO2 carrying capacities of CaO during TG testing. Fuel, 127, 52–61.

42 CaO-Based Sorbents for Post Combustion CO2 Capture via Carbonate Looping 587

Angeli, S. D., Martavaltzi, C. S., & Lemonidou, A. A. (2014). Development of a novel-synthesized

Ca-based CO2 sorbent for multicycle operation: Parametric study of sorption. Fuel, 127, 62–69.

Antzara, A., Heracleous, E., Lemonidou, A. A., et al. (2015). Improving the stability of synthetic

CaO-based CO2 sorbents by structural promoters. Applied Energy, 156(2015), 331–343.

Blamey, J., Anthony, E. J., Wang, J., & Fennell, P. S. (2010). The calcium looping cycle for large-

scale CO2 capture. Progress in Energy and Combustion Science, 36, 260–279. Blockstein, D. E. & Shockley, M. A. (Eds.) (2006). National Council for Science and the

Environment. 2006. Energy for a Sustainable and Secure Future: A Report of the Sixth

National Conference on Science, Policy and the Environment. Washington, D.C.

Broda, M., Pacciani, R., & Muller, C. R. (2014). CO2 capture via cyclic calcination and carbon-

ation reactions. In A.-H. Lu & S. Dai (Eds.), Porous materials for carbon dioxide capture. Heidelberg, Berlin: Springer.

Coppola, A., Salatino, P., Montagnaro, F., & Scala, F. (2014). Hydration-induced reactivation of

spent sorbents for fluidized bed calcium looping (double looping). Fuel Processing Technol- ogy, 120, 71–78.

Diego, M. E., Arias, B., Grasa, G., Abanades, J. C., Dı́az, L., Lorenzo, M., et al. (2014). Calcium

looping with enhanced sorbent performance: Experimental testing in A large pilot plant.

Energy Procedia, 63, 2060–2069. Dieter, H., Bidwe, A. R., Varela-Duelli, G., Charitos, A., Hawthorne, C., & Scheffknecht,

G. (2014). Development of the calcium looping CO2 capture technology from lab to pilot

scale at IFK, University of Stuttgart. Fuel, 127, 23–37. Epple B. (2010). 2nd IEA Meeting on High Temperature Solid Looping Cycles, Netherlands 2010. EU Technology Platform for Zero Emission Fossil Fuel Power Plants. (2014). The EU technology

platform for zero emission fossil fuel power plants, recommendations for RTD, support actions

and international collaboration activities within FP7 energy workprogrammes in support of

deployment of CCS in Europe.

Fan, L.-S. (2010). Chemical looping systems for fossil energy conversions. Hoboken, NJ, USA: Wiley.

Grasa, G. S., & Abanades, J. C. (2006). CO2 capture capacity of CaO in long series of carbonation/

calcination cycles. Industrial and Engineering Chemistry Research, 45, 8846–8851. Harrison, D. P. (2005). The role of solids in CO2 capture: A mini review. In E. S. Wilson, D. W.

Rubin, C. F. Keith, M. Gilboy, T. Thambimuthu, J. Morris, & K. Gale (Eds.), Greenhouse gas control technologies. Oxford: Elsevier Science Ltd.

Kavosh, M., Patchigolla, K., Anthony, E. J., & Oakey, J. E. (2014). Carbonation performance of

lime for cyclic CO2 capture following limestone calcination in steam/CO2 atmosphere.

Applied Energy, 131, 499–507. Li, C.-C., Cheng, J.-Y., Liu, W.-H., Huang, C.-M., Hsu, H.-W., & Lin, H.-P. (2014). Enhancement

in cyclic stability of the CO2 adsorption capacity of CaO-based sorbents by hydration for the

calcium looping cycle. Journal of the Taiwan Institute of Chemical Engineers, 45, 227–232. Liu, W., An, H., Qin, C., Yin, J., Wang, G., Feng, B., et al. (2012). Performance enhancement of

calcium oxide sorbents for cyclic CO2 capture-a review. Energy and Fuels, 26, 2751–2767. Mandal, B. P., & Bandyopadhyay, S. S. (2006). Absorption of carbon dioxide into aqueous blends

of 2-amino-2-methyl-1-propanol and monoethanolamine. Chemical Engineering Science, 61, 5440–5447.

Manovic, V., & Anthony, E. J. (2010). Carbonation of CaO-based sorbents enhanced by steam

addition. Industrial & Engineering Chemistry Research, 49, 9105–9110. Martavaltzi, C. S., & Lemonidou, A. A. (2008). Development of new CaO based sorbent materials

for CO2 removal at high temperature.Microporous and Mesoporous Materials, 110, 119–127. Park, A.-H. A., Gupta, P., Li, F., Sridhar, D., & Fan, L.-S. (2010). Novel applications of chemical

looping technologies. In L.-S. Fan (Ed.), Chemical looping systems for fossil energy conversionsm. Hoboken, NJ, USA: John Wiley & Sons, Inc.

588 Z. Skoufa et al.

Reddy, G. K., Quillin, S., & Smirniotis, P. (2014). Influence of the synthesis method on the

structure and CO2 adsorption properties of Ca/Zr sorbents. Energy and Fuels, 28, 3292–3299. Ruff, O., Ebert, F., & Stephan, E. (1929). An article on highly fire resistant ceramic substances II

The ZrO2-CaO system. Zeitschrift fur anorganische und allgemeine Chemie, 180, 215–224. Str€ohle, J., Junk, M., Kremer, J., Galloy, A., & Epple, B. (2014). Carbonate looping experiments in

a 1MWth pilot plant and model validation. Fuel, 127, 13–22. Sun, P., Grace, J. R., Lim, C. J., & Anthony, E. J. (2008). Investigation of attempts to improve

cyclic CO2 capture by sorbent hydration and modification. Industrial & Engineering Chemistry Research, 47, 2024–2032.

United Nations, C. C. S. (2012). Summary of GHG emissions for Greece. url:unfccc.int/files/

ghg_emissions_data/application/pdf/grc_ghg_profile.pdf

Wang, J., Huang, L., Yang, R., Zhang, Z., Wu, J., Gao, Y., et al. (2014). Recent advances in solid

sorbents for CO2 capture and new development trends. Energy and Environmental Science, 7, 3478–3518.

White, C. M., Strazisar, B. R., Granite, E. J., Hoffman, J. S., & Pennline, H. W. (2003). Separation

and capture of CO2 from large stationary sources and sequestration in geological formations.

EM: Air and Waste Management Association’s Magazine for Environmental Managers 29–34.

42 CaO-Based Sorbents for Post Combustion CO2 Capture via Carbonate Looping 589

Chapter 43

Kinetics of CO2 Capture by Carbon Dioxide Binding Organic Liquids

Ozge Yuksel Orhan, Hakan Kayi, and Erdogan Alper

Introduction

CO2 emissions from human activities are consistently rising with the increase of

population growth and industrialization (Couchaux et al. 2013). Industries such as

chemical and petrochemical manufacturing, cement and steel production and nat-

ural gas processing are responsible for the largest sources of CO2 emissions (Liu

et al. 2014). Since CO2 is regarded as a major greenhouse gas that causes the global

warming and climate change problems, effective and economic CO2 capture tech-

nologies have gained importance. The most common and proven approach to

capture CO2 from gas streams is chemical absorption (Kumar et al. 2014). There-

fore, aqueous solutions of alkanolamines, such as monoethanolamine (MEA),

diethanolamine (DEA) and methyldiethanolamine (MDEA) are widely used sol-

vents for the removal of acid gas impurities such as CO2 and H2S (Alexia Finotello

et al. 2008; Kierzkowska-Pawlak et al. 2013; Garđarsd�ottir et al. 2015). Solvents for such absorption processes absorb CO2 from gas streams efficiently at low temper-

atures by an exothermic reaction resulting either carbamate or bicarbonate salts.

Regeneration of traditional amine solutions can be achieved by desorption at near

atmospheric pressures but high temperatures such as 120–130 �C (Finotello et al. 2008) are required. Therefore, the energy-intensive stripping requirement

(especially, the reboiler duty) is one of the disadvantages for using aqueous

alkanolamines arising from high specific and latent heats of water. In addition,

O. Yuksel Orhan (*) • E. Alper Department of Chemical Engineering, Hacettepe University, Beytepe, 06800 Ankara, Turkey

e-mail: [email protected]; [email protected]

H. Kayi

Chemical Engineering and Applied Chemistry Department, Atilim University, İncek, 06836

Ankara, Turkey

e-mail: [email protected]

591

mailto:[email protected]

thermal stripping of CO2 from aqueous alkanolamines at temperatures higher than

boiling point of the water leads to large evaporative losses of solvent. Further,

amines (especially MEA) at high concentrations have been reported to be respon-

sible for stress corrosion cracking. Accordingly, solvent loss, corrosive nature and

high energy intensive properties are major drawbacks of amine based technologies

(Guo et al. 2013).

Consequently, there are considerable on-going research and development to

design new solvents to reduce (or eliminate) the high latent heat requirement of

the aqueous systems. The key factors for solvent selection are high absorption

capacity, fast absorption rate, cost effectiveness, low corrosiveness, high solvent

stability and low energy requirement for regeneration (Liu et al. 2014). A new

approach to handle these conflicts is to employ a liquid absorbent medium of an

organic base in a non-aqueous, polar solvent. For instance, Jessop et al. (2005)

developed CO2-binding organic liquids (CO2BOLs).

CO2BOLs are smart solvents comprised of amidine/guanidine bases and organic

alcohols that capture CO2 and form amidinium or guanidinium alkyl carbonate

salts. It is presumed that the base of CO2BOL does not react directly with CO2, as

amines react to form carbamates. Conversely, the alcohol group in the CO2BOL

reacts firstly with CO2 to form an alkyl carbonic acid, and then protonates the base

to form a liquid alkylcarbonate (Mathias et al. 2013). Alkyl carbonate salts formed

are non-volatile ionic compounds and they do not contain as much hydrogen bond

as carbamate and bicarbonate salts do. Therefore, binding enthalpy of CO2 decreases and high stripping temperatures that amine systems need are no longer

required (Gordesli et al. 2013).

CO2BOLs can reversibly switch from non-ionic form to ionic form when

exposed to carbon dioxide and causes a notable increase in polarity (Jessop

et al. 2012). Then, CO2 is removed from CO2BOLs below the boiling point of

the mixture by simple heating or sweeping with an inert gas such as nitrogen.

They have tunable physicochemical properties; the solvent reverts back to its

less-polar non-ionic form and is ready for future CO2 uptake (Tao Yu et al. 2008).

The main advantages of these systems are high CO2 binding capacities, low heat

capacities and lower energy requirement for regeneration as compared to aqueous

alkanolamine solutions (Mathias et al. 2013). Wang et al. developed several

strategies to reduce volatility of superbase-derived absorbents by making them

such as alcohol-functionalized ionic liquids (Wang et al. 2010). Currently, several

CO2BOL systems are being investigated by us and one of these studies focuses on

reaction kinetics of CO2BOLs, composed of a mixture of 1,8-diazabicyclo [5.4.0]

undec-7-ene (DBU) amidine base in 1-hexanol or 1-propanol (Ozturk et al. 2012).

The others are focused on reaction performance and kinetics of CO2BOLs,

composed of a mixture of 1,1,3,3-Tetramethylguanidine (TMG) guanidine

base in 1-hexanol and 1-propanol, with carbon dioxide (Ozturk et al. 2014;

Yüksel Orhan et al. 2015). However, the observed rate constants reported in

these works are relatively low which can be enhanced by addition of

small amounts of activators such as piperazine and its derivatives (Moioli and

Pellegrini 2015).

592 O. Yuksel Orhan et al.

Analysis

Generally, the mechanism of the reaction between CO2 and amine systems can be

explained by two established mechanisms. These are the zwitterions mechanism,

originally proposed by Caplow in 1968, and then reintroduced by Danckwerts in

1979 and termolecular reaction mechanism proposed by Crooks and Donnellan

(1989) and modified by Ozturk et al. (2014).

The zwitterion mechanism, also known as a two-step mechanism, involves two

sequential reactions. In the first step, CO2 reacts with the amine (denoted here as

RNH2) and forms zwitterion intermediate product as in Eq. (43.1). In the next step,

this zwitterion reacts with a base (or bases) and a proton from zwitterion is

transferred to the base (B), resulting in a protonated base and carbamate ion. As

shown in Eq. (43.2), a water molecule, an additional amine, or any other basic

species can act also as the base.

CO2 þ RNH2 € k 2

k-1

RNþH2COO- ð43:1Þ

RNþH2COO- þ B ��! kB

RNHCOO- þ BHþ ð43:2Þ When the base is amine and the carbamate ion is stable, the resulting net reaction

is given in Eq. (43.3).

CO2 þ 2 RNH2 € RNHCOO- þ RNH3þ ð43:3Þ The termolecular reaction mechanism assumes that an amine reacts with both

one molecule of carbon dioxide and one molecule of a base in a single step as

illustrated in Fig. 43.1. It is also assumed that the reaction takes place via the

weakly-bound intermediate product as shown in Eq. (43.4).

CO2 þ RNH2� � �B € RNHCOO-� � �BHþ ð43:4Þ The modified termolecular reaction mechanism for CO2BOLs, containing

amidine/guanidine base and a linear alcohol, is shown in Eq. (43.5). While a

Fig. 43.1 Schematic drawing of a termolecular reaction mechanism (Crooks and Donnellan 1989)

43 Kinetics of CO2 Capture by Carbon Dioxide Binding Organic Liquids 593

fraction of this complex reacts with a second molecule of the amine or alcohol

molecule to form alkyl carbamate salt, a fraction of resulting intermediate breaks up

to form reactant molecules (CO2 and amine).

CO2 gð Þ þ B lð Þ þ ROH lð Þ € BHþ �

ROCOO-½ � lð Þ ð43:5Þ

Under pseudo-first order conditions where the solvent would be in excess, the

observed forward reaction rate can be expressed as in Eq. (43.6).

robs ¼ ko CO2½ � ð43:6Þ The observed reaction rate constant (ko) can be expressed by Eq. (43.7) in terms

of CO2BOL/alcohol system.

ko ¼ kB B½ � þ kROH ROH½ �f g B½ � ð43:7Þ Since, alcohol concentration is assumed to be in excess for the pseudo-first order

conditions, ROH can be considered constant and a new rate constant, k, can be

defined by Eq. (43.8).

k ¼ kROH ROH½ � ð43:8Þ

ko ¼ kB B½ � þ kf g B½ � ð43:9Þ

As seen in Eq. (43.9), if the amine and alcohol are comparably dominant bases,

degree of the reaction can change between 1 and 2. Also if the alcohol is the

dominant base, system exhibits a first-order reaction and Eq. (43.9) reduces to

Eq. (43.10).

ko ¼ k B½ � ð43:10Þ In summary, the rate constants of CO2BOLs were obtained by using Eqs. (43.9)

and (43.10).

Material and Method

Reagents

Reagent grade 1,5,7-Triazabicyclo[4.4.0]dec-5-ene (TBD) with purity of 99%

(CAS no. 5807-14-7) and 1,5-Diazabicyclo[4.3.0]non-5-ene with purity of 98%

(CAS no. 3001-72-7) were supplied by Sigma-Aldrich (St. Louis, MO, USA).

1-Hexanol with 98% purity (CAS no. 111-27-3) was also obtained by Sigma-

Aldrich. Carbon dioxide with a purity of 99.99%was obtained from Linde (Munich,

Germany). Reagent grade chemicals were used without further purification.

594 O. Yuksel Orhan et al.

Kinetic Measurement

The observed reaction rate constants of the amines with CO2 in 1-hexanol were

measured over a range of temperatures (278, 298 and 308 K) using a customised

stopped-flow instrument (Hi-Tech Scientific, UK, Model SF-61SX2). The

conductivity-detection system of the apparatus calculates directly the intrinsic

rate of a rapid homogeneous reaction by measuring the conductivity change during

the reaction. All parts of the flow circuit, with the exception of the stop/waste

syringe, are thermostated and the temperature control is better than �0.1 K. During an experimental run, amine (TBD or DBN)/1-hexanol solution and carbon dioxide

dissolved 1-hexanol solution were placed in the sealed drive syringes in the sample

unit. For each experimental run, equal volumes of the solutions were mixed

instantaneously in a stainless-steel cell for the reaction to occur and the flow was

stopped. The ion formation initiates a voltage change which is monitored as

function of time. Then, the equipment software calculates the pseudo-first order

reaction rate constants of the rapid homogeneous reaction based on least squares

regression. A typical experimental output from the standard stopped flow system is

shown in Fig. 43.2. To obtain consistent pseudo-first-order rate constants (ko), each

experimental set was repeated for an average ten times. The amine and alcohol

concentrations were always much in excess to that of CO2 (usually the molar ratio

was about 20:1) to satisfy the pseudo-first-order conditions. The main advantages of

the stopped-flow technique are easy operation, quick experiment run (~0.05 s),

small amount of solvent consumption for each experimental run (~ 0.1 mL) and

no effect of gas phase resistance (Liu et al. 2014). Further details of the equipment

and experimental procedure can be found elsewhere (Ume et al. 2012; Yüksel

Orhan et al. 2015).

Fig. 43.2 Combined avg. graphs of 5 wt% DBN/1-hexanol system at 298 K

43 Kinetics of CO2 Capture by Carbon Dioxide Binding Organic Liquids 595

Results and Discussion

In order to evaluate the potential integration of these switchable solvents to

industrial carbon dioxide capture applications, the reaction kinetics between

CO2BOLs and carbon dioxide were examined. In this work, as an amidine; DBN

(1,5-Diazabicyclo[4.3.0]non-5-ene) and as a guanidine; TBD (1,5,7-Triazabicyclo

[4.4.0]dec-5-ene) were used in 1-hexanol medium. Intrinsic reaction rates were

measured in “stopped flow” equipment for a temperature range of 298–308 K.

Experiments were carried out by varying organic base (amidine or guanidine)

percentage in a 1-hexanol medium from 5.0 wt% to 20.0 wt%.

Table 43.1 shows a summary of observed pseudo-first order reaction rate

constants for the CO2/TBD/1-hexanol system versus the weight-percent concentra-

tion of TBD at temperatures ranging from 288 K to 308 K. Table 43.1 shows clearly

that ko increases by increasing concentration or temperature.

In order to determine the reaction order of the CO2/TBD/1-hexanol system, the

natural logarithms of observed reaction rate constants versus TBD concentrations

were plotted as shown in Fig. 43.3. Empirical power law kinetics was fitted to lines

Table 43.1 Observed pseudo-first order rate

constants for the CO2/TBD/

1-hexanol system at different

temperatures

ko [s �1]

TBD [wt%] 5 10 15 20

288 K 253.1 420.6 526.4 690.7

298 K 463.5 645.4 912.8 1190.1

308 K 621.7 969.6 1190.1 1490.2

Fig. 43.3 Determination of the apparent reaction order for the CO2/TBD/1-hexanol system at various temperatures

596 O. Yuksel Orhan et al.

in Fig. 43.3 by using the least square method. Their slopes correspond to the

reaction orders of the CO2/TBD/1-hexanol system which are determined to be

approximately 0.6 with regression values of R2¼ 0.99 for the 5.0–20.0 weight percentages at a temperature range of 288–308 K. The experimentally observed

ko values were correlated using the termolecular mechanism to determine the

forward reaction rate constant k [m3 kmol�1 s�1]. The reaction rate constants vs. TBD concentration were plotted according to Eq. (43.6) in a very satisfactory

pseudo-first-order plot as seen in Fig. 43.4.

From the slopes of the fitted lines in Fig. 43.4, the first-order forward reaction

rate constants for CO2/TBD/1-hexanol systems were determined to be 451.21 m 3

kmol�1 s�1 at 288 K, 727.16 m3 kmol�1 s�1 at 298 K and 898.36 m3 kmol�1 s�1

at 308 K.

Similarly, observed pseudo-first order rate constants for the CO2/DBN/

1-hexanol system at 288, 298 and 308 K were determined. The summary of

obtained observed reaction rate constants versus the weight-percent concentration

of DBN at temperatures ranging from 288 K to 308 K are given in Table 43.2.

In Fig. 43.5, the natural logarithms of the observed rate constants (ko) are shown

as a function of versus DBN concentrations for the 5.0–20.0 weight percentages at a

temperature range of 288–308 K. By fitting empirical power law kinetics to lines in

Fig. 43.4 Pseudo-first order rate constant as a function of TBD concentration at various temperatures

Table 43.2 Observed pseudo-first order rate

constants for the CO2/DBN/

1-hexanol system at various

temperatures

ko [s �1]

DBN [wt.%] 5 10 15 20

288 K 79.8 211.5 271.9 360.5

298 K 145.4 409.3 521.9 699.4

308 K 216.1 548.5 689.1 891.2

43 Kinetics of CO2 Capture by Carbon Dioxide Binding Organic Liquids 597

Fig. 43.5, the reaction orders of CO2/DBN/1-hexanol system were found about 1.00

with high R-squared value. This result is in agreement with the pseudo-first-order

reaction suggestion of a single-step termolecular reaction mechanism for

CO2/DBN/1-hexanol system. In order to determine the forward reaction rate con-

stants k [m3 kmol�1 s�1], the experimentally observed ko values were correlated as seen in Fig. 43.6.

Fig. 43.5 Determination of the apparent reaction order for the CO2/DBN/1-hexanol system at various temperatures

Fig. 43.6 Pseudo-first order rate constant as a function of DBN concentration at various temperatures

598 O. Yuksel Orhan et al.

From the slopes of the fitted lines in Fig. 43.6, the first-order forward reaction

rate constants for CO2/DBN/1-hexanol systems were determined to be 271.75 m 3

kmol�1 s�1 at 288 K, 524.46 m3 kmol�1 s�1 at 298 K and 683.61 m3 kmol�1 s�1 at 308 K.

Activation Energies

In order to determine the activation energies, the Arrhenius diagrams were plotted

as shown in Figs. 43.7 and 43.8. Activation energies for both CO2/TBD/1-hexanol

system and CO2/DBN/1-hexanol were calculated by evaluating the Arrhenius

equation as in Eq. (43.11).

k ¼ A exp �Ea RT

� � ð43:11Þ

Figure 43.7 shows the Arrhenius diagram for CO2/TBD/1-hexanol system at 5.0,

10.0, 15.0 and 20 wt%, respectively. Using the slopes of these plots, activation

energies for the CO2/TBD/1-hexanol system were calculated as 33.25 kJ/mol at

5.0 wt%, 30.79 kJ/mol at 10.0 wt%, 30.46 kJ/mol at 15.0 wt% and 28.44 kJ/mol at

20.0 wt%. Figure 43.8 shows the Arrhenius diagram for CO2/DBN/1-hexanol

system at 5.0, 10.0, 15.0 and 20 wt%, respectively. Using the slopes of these

plots, activation energies for the CO2/DBN/1-hexanol system were calculated as

37.18 kJ/mol at 5.0 wt%, 35.37 kJ/mol at 10.0 wt%, 34.43 kJ/mol at 15.0 wt% and

33.54 kJ/mol at 20.0 wt%.

Fig. 43.7 Arrhenius diagram for the CO2/TBD/1-hexanol system

43 Kinetics of CO2 Capture by Carbon Dioxide Binding Organic Liquids 599

The stable lowest energy conformers of organic bases (TBD and DBN) obtained

from the B3LYP/6-31G(d) calculations are given in Figs. 43.9 and 43.10. As

expected, the activation energy of TBD is lower than the activation energy of

DBN since the amino group of TBD is not hindered (Figs. 43.9 and 43.10).

Finally, the obtained results of this work were compared with the published

papers of other CO2BOLs in 1-hexanol medium at 298 K are shown in Table 43.3.

However, the ko values are generally low in comparison with MEA or PZ

systems (Ume et al. 2012; Gordesli et al. 2013; Yuksel Orhan and Alper 2015),

they are comparable to DEA systems (Marta Siemieniec 2011).

Fig. 43.8 Arrhenius diagram for the CO2/DBN/1-hexanol system

Fig. 43.9 B3LYP/6-31G (d) optimized lowest energy

conformers of 1,5,7-

Triazabicyclo[4.4.0]dec-

5-ene (TBD) (atom types:

white¼H, gray¼C, blue¼N) (Color figure online)

600 O. Yuksel Orhan et al.

Conclusion

The reaction between organic bases (TBD or DBN) and CO2 was investigated and

modeled using a single termolecular reaction mechanism. Although, the observed

rate constants obtained in this work are lower than the other commercial carbon

dioxide capture agents, this can be enhanced by addition of small proportion of

activators such as piperazine and its derivatives as shown by Yuksel Orhan and

Alper (2015). CO2BOLs are potential candidates for industrial carbon dioxide

capture with beneficial properties, such as requiring a smaller reboiler duty in the

desorber. This work provided kinetic data for two of these novel CO2BOL systems

which are needed for rate-based modeling.

Acknowledgement This work was supported by a Turkish Scientific and Technological Research Council (TUBITAK) through a research project (Project No.: 213M390). Authors gratefully

acknowledge this financial support.

Nomenclature

CO2BOLs Carbon dioxide binding organic liquids

B Base (i.e., amine, water, or hydroxyl ion)

CO2 Carbon dioxide

DBN 1,5-Diazabicyclo[4.3.0]non-5-ene

Table 43.3 Comparison of kinetic properties of various CO2BOLs at 298 K

Amines

TBD/

1-hexanol

DBN/

1-hexanol

TMG/

1-hexanol

DBU/

1-hexanol

Reference This work This work Ozturk et al. (2014) Ozturk et al. (2012)

Reaction order 0.63 1.09 0.98 1.21

k (m3 kmol�1 s�1) 727.16 524.46 64.10 627.0 Ea (kJ mol�1) 30.74 35.13 9.76 13.7

Fig. 43.10 B3LYP/6-31G (d) optimized lowest energy

conformers of

1,5-Diazabicyclo[4.3.0]

non-5ene (DBN) (atom

types: white¼H, gray¼C, blue¼N) (Color figure online)

43 Kinetics of CO2 Capture by Carbon Dioxide Binding Organic Liquids 601

DBU 1,8-Diazabicyclo[5.4.0]undec-7-ene

DEA Diethanolamine

GHG Greenhouse gas

Ea Activation energy

kOH Rate constant for alcohol, m 3/kmol s

kB Rate constant for base according to Eq. (43.7), m 3/kmol s

ko Observed pseudo–first-order-rate constant, s �1

MDEA Methyldiethanolamine

MEA Monoethanolamine

SCC Stress corrosion cracking

TBD 1,5,7-Triazabicyclo[4.4.0]dec-5-ene

TMG 1,1,3,3-Tetramethylguanidine

References

Alexia Finotello, J. E. B., Camper, D., & Noble, R. D. (2008). Room-temperature ionic liquids:

Temperature dependence of gas solubility selectivity. Industrial & Engineering Chemistry Research, 47, 3453–3459.

Caplow, M. (1968). Kinetics of carbamate formation and breakdown. Journal of the American Chemical Society, 90, 6795–6803.

Couchaux, G., Barth, D., Jacquin, M., Faraj, A., & Grandjean, J. (2013). Kinetics of carbon dioxide

with amines. I. Stopped-flow studies in aqueous solutions. A review. Oil & Gas Science and Technology—Revue d’IFP Energies nouvelles, 69, 865–884.

Crooks, J. E., & Donnellan, J. P. (1989). Kinetics and mechanism of the reaction between carbon-

dioxide and amines in aqueous-solution. Journal of the Chemical Society-Perkin Transactions, 2, 331–333.

Danckwerts, P. V. (1979). Reaction of CO2 with ethanolamines. Chemical Engineering Science, 34, 443–446.

Garđarsd�ottir, S. Ó., Normann, F., Andersson, K., & Johnsson, F. (2015). Postcombustion CO2 capture using monoethanolamine and ammonia solvents: The influence of CO2 concentration

on technical performance. Industrial & Engineering Chemistry Research, 54, 681–690. Gordesli, F. P., Ume, C. S., & Alper, E. (2013). Mechanism and kinetics of carbon dioxide capture

using activated 2-amino-2-methyl-1,3-propanediol. International Journal of Chemical Kinet- ics, 45, 566–573.

Guo, D., Thee, H., Tan, C. Y., Chen, J., Fei, W., Kentish, S., et al. (2013). Amino acids as carbon

capture solvents: Chemical kinetics and mechanism of the glycine +CO2 reaction. Energy & Fuels, 27, 3898–3904.

Jessop, P. G., Mercer, S. M., & Heldebrant, D. J. (2012). CO2-triggered switchable solvents,

surfactants, and other materials. Energy & Environmental Science, 5, 7240. Kierzkowska-Pawlak, H., Siemieniec, M., & Chacuk, A. (2013). Investigation of CO2 and

ethylethanolamine reaction kinetics in aqueous solutions using the stopped-flow technique.

Chemical Papers, 67, 1123–1129. Kumar, S., Cho, J. H., & Moon, I. (2014). Ionic liquid-amine blends and CO2BOLs: Prospective

solvents for natural gas sweetening and CO2 capture technology—A review. International Journal of Greenhouse Gas Control, 20, 87–116.

602 O. Yuksel Orhan et al.

Liu, H., Sema, T., Liang, Z., Fu, K., Idem, R., Na, Y., et al. (2014). CO2 absorption kinetics of

4-diethylamine-2-butanol solvent using stopped-flow technique. Separation and Purification Technology, 136, 81–87.

Siemieniec, M., Kierzkowska-Pawlak, H., & Chacuk, A. (2011). Reaction kinetics of carbon

dioxide in aqueous diethanolamine solutions in the temperature range of 293–313 K using

the topped-flow technique. Ecological Chemistry and Engineering, 19(1), 55–56. Mathias, P. M., Afshar, K., Zheng, F., Bearden, M. D., Freeman, C. J., Andrea, T., et al. (2013).

Improving the regeneration of CO2-binding organic liquids with a polarity change. Energy & Environmental Science, 6, 2233.

Moioli, S., & Pellegrini, L. A. (2015). Improved rate-based modeling of the process of CO2 capture

with PZ solution. Chemical Engineering Research and Design, 93, 611–620. Ozturk, M. C., Yuksel Orhan, O., & Alper, E. (2014). Kinetics of carbon dioxide binding

by 1,1,3,3-tetramethylguanidine in 1-hexanol. International Journal of Greenhouse Gas Control, 26, 76–82.

Ozturk, M. C., Ume, C. S., & Alper, E. (2012). Reaction mechanism and kinetics of

1,8-diazabicyclo[5.4.0]undec-7-ene and carbon dioxide in alkanol solutions. Chemical Engi- neering & Technology, 35, 2093–2098.

Jessop, P. G., Heldebrant, D. J., Xiaowang Li, C. A. E., & Liotta, C. L. (2005). Green chemistry:

Reversible nonpolar-to-polar solvent. Nature, 436, 1102. Tao Yu, T. Y., Gaviola, G. C., & Weiss, R. G. (2008). Carbon dioxide and molecular nitrogen as

switches between ionic and uncharged room-temperature liquids comprised of amidines and

chiral amino alcohols. Chemistry of Materials, 20, 5337–5344. Ume, C. S., Ozturk, M. C., & Alper, E. (2012). Kinetics of CO2 absorption by a blended aqueous

amine solution. Chemical Engineering & Technology, 35, 464–468. Wang, C., Mahurin, S. M., Luo, H., Baker, G. A., Li, H., & Dai, S. (2010). Reversible and

robust CO2 capture by equimolar task-specific ionic liquid–superbase mixtures. Green Chem- istry, 12, 870.

Yuksel Orhan, O., & Alper, E. (2015). Kinetics of carbon dioxide binding by promoted organic

liquids. Chemical Engineering and Technology, 38(8), 1485–1489. Yüksel Orhan, Ö., Öztürk, M. Ç., Şeker, A., & Alper, E. (2015). Kinetics and performance studies

of a switchable solvent TMG (1,1,3,3-tetramethylguanidine)/1-propanol/carbon dioxide sys-

tem. Turkish Journal of Chemistry, 39, 13–24.

43 Kinetics of CO2 Capture by Carbon Dioxide Binding Organic Liquids 603

Chapter 44

Flue Gas CO2 Sequestration by Turkish Coal Fly Ashes and Anatolian Geothermal Hot Waters

Yıldırım _Ismail Tosun

Introduction

The increasing CO2 concentration in the Earth’s atmosphere, mainly caused by fossil fuel combustion, has led to concerns about global warming. A technology that

could possibly contribute to reducing carbon dioxide emissions is the in-situ

mineral sequestration (long term geological storage) or the ex-situ mineral seques-

tration (controlled industrial reactors) of CO2.

Carbonation of CO2 gas has many various advantages. Most distinct fact is that

carbonates have a lower energy state than CO2. Mineral carbonation is thermody-

namically occurs in nature (i.e., the weathering of rock over geologic time periods).

Further, the raw materials such as magnesium based minerals are abundant on earth.

The produced carbonates are basely stable and thus re-evolve of CO2 into the

atmosphere is not an issue. However, conventional carbonation reactions are slow

under ambient temperatures and pressures.

Forty percent of global electricity is generated in fossil fuel power plants per

annum, with emissions of about 33% (9.5 billion metric tons) of global energy

related CO2 emissions of approximately 28.8 Gt in 2010 (Minchener and McMullan

2007; IEA 2012). Over half of the electricity demand of the Turkey is supplied by

coal-fired power plants, with emissions of about 16 million metric tons of CO2 per annum, representing about 33% of Turkey energy-related CO2 emissions

(TKI 2009; TTK 2009).

Therefore, developing effective CO2 sequestration is one of the critical compo-

nents in addressing global climate change. Note that improving the efficiency of

energy production and utilization, and developing renewable energy sources will

certainly play a very important role in reducing CO2 emissions (5), however these

Y.İ. Tosun (*) Mining Engineering Department, Şırnak University, Şırnak, Turkey

e-mail: [email protected]; [email protected]

605

mailto:[email protected]

measures alone cannot address the greenhouse emissions issue mainly because

world energy consumption will increase significantly as the living standard

improves in many parts of the world.

Three boreholes, one injection well, and two observation wells will be drilled,

about 50–100 m (160–330 ft) apart, into the flank of an anticlinal structure. A total

of up to 1 t/day of CO2, in gaseous state at the well head, will be injected at about

700 m (2300 ft) depth into a saline mudstone aquifer. Injection is planned to start at

the end of 2013 and last for approximately 2 years, during which the distribution

and fate of the injected gas will be monitored by surface geophysical surveys and by

downhole instrumentation. Various processes and subprojects and work packages

address the science and operational aspects of CO2 (IPCC 2005; Stangeland 2007;

Solomon 2006; O’conner et al. 2000; Siegenthaler and Oeschger 1987; Keeling

et al. 1995; Plasynski et al. 1999). The proposed part of the project is restricted to

the baseline survey and the injection and basic monitoring of CO2. The supply of

CO2 will be provided by near Coal Power Station in Şırnak. Other choice will be the

purchase of a pure CO2 originating from flue gas of hydrocarbon production at an

oil refinery. The CO2 will be delivered by truck in liquid phase, temporarily stored

at the well site, and conditioned before injection. The project proposed plans to

inject the CO2 at the well head in gaseous phase at a slightly supercritical pressure

and slightly supercritical temperature. The anticline at Şirnak-Silopi was used for

gas storage in the past in a shallower depth interval in Şırnak-Silopi pit mine field,

which also is an mining industry partner in CO2 sequestration and will be respon-

sible for the CO2-injection operations.

This paper discussed progress on reactor achieved by tests and search for fast

reaction methods using exhaust gas containing waste sulfur and carbon gases at the

stack of Power Stations. This experimental study demonstrates that 1 ton of fly-ash

could sequester up to near 20 kg of CO2, i.e. 50 ton of fly ash per ton of CO2 sequestered. This confirms the possibility to use this alkaline residue for CO2 mitigation. Other alkaline sources containing calcium, magnesium and magnesium

salts, supercritical CO2, water slurry, and additives were searched for optimum

sequestration methods and also in order to enhance mineral reactivity; and in

analyzing the structural changes to identify reaction paths and potential barriers.

Carbonation liquid and gaseous products may change to near 20%–45% yield

performances by time increase from 1 to 6 h.

CO2 Sequestration and Carbonation

Options for storing CO2 in deep underground geological formations need adequate

porosity and thickness for storage capacity and permeability for gas injection are

critical. The storage formation should be capped by extensive confining units such

as shale, salt caves or anhydrite beds to ensure that CO2 does not escape into

overlying, shallower rock units and ultimately to the surface. Geological storage of

CO2 requires compression of CO2 to allow injection. This is done by compressing

606 Y.İ. Tosun

the CO2 to a dense fluid state known as ‘supercritical’. This supercritical state is achieved by exposing the CO2 to temperatures higher than 31.1

�C and pressure greater than 73.9 bars. The density of CO2 will increase with depth, until about

800 m or greater, where the injected CO2 will be in a dense supercritical state (DOE

1998; Simbeck 2004; Burruss 2004; Oldenburg et al., 2001).

The mineral carbonation, a process of converting CO2 into stable minerals—

mineralization has been studied extensively to capture and store CO2 (Stevens

et al. 2001). However, most of the mineral carbonation studies have been largely

investigated at lab scale. Preliminary and pilot scale studies for accelerated mineral

carbonation (AMC) were conducted at one of the largest coal-fired power plants

(2120 MW) in the USA by reacting flue gas with fly ash particles in a fluidized bed

reactor. In the preliminary experiments, flue gas CO2 and SO2 concentrations

decreased from 13.0% to 9.6% and from 107.8 to 15.1 ppm, respectively, during

the first 2 min of reaction (Stevens et al. 1999). The flue gas treated by fly ash

particles, even mineralization hold high mercury (Hg) concentration of 0.22 mg/kg

in flue gas (Myer 2003; Zweigel et al. 2001).

Geothermal brine waters utilization and using CO2 as feed material in mineral

carbonation produce various environmentally benign products. However, many

challenges to any solution include technical feasibility, economic viability, envi-

ronmental soundness and long term sustainability for mineralization of CO2 (Pacala

2003; Hepple and Benson 2003).

Method of Mineral Sequestration

Mineral sequestration involves the reaction of CO2 with minerals to form geolog-

ically stable carbonates. This mineralization of CO2 was searched by different

studies using various materials (Lindeberg 2003; Rubin and Rao 2003). General

and specific global mineral carbonation reaction pathway is shown in Fig. 44.1. The

goals of the current work were to design an ash–water suspension carbonation

process in a continuous mode laboratory-scale plant and to search for potential

means of intensifying the water neutralization process (Davis 2004; Seifritz 1990;

Kojima et al. 1997; Gunter et al. 1993; Lackner et al. 1995). The carbonation

process was optimized by cascading columns in which the pH progressed from

Fig. 44.1 General chemical

mineralization path

44 Flue Gas CO2 Sequestration by Turkish Coal Fly Ashes. . . 607

alkaline to almost neutral. The amount of CO2 captured from flue gases can reach

0,01–0,12 kg/l at the 500 �C temperature and 10 bar pressure level (O’Connor 1998). Laboratory-scale neutralization experiments were carried out to compare the

reactor designs. Sedimentation of carbonate particles was observed and their main

characteristics were determined.

Mineral carbonation reactions are known to geologists and occur spontaneously

on geological time scales. For example, the reaction of CO2 with common mineral

silicates to form carbonates like calcite and magnesite or calcite is exothermic

and thermodynamically favored (O’Connor 1998; Butt et al. 1997; Drägulescu et al. 1972).

The family of reactions represented by Reaction 44.1 has the potential to convert

naturally occurring silicate minerals to geologically stable carbonate minerals and

silica (Goldberg et al. 2000). This process follows natural chemical transformations

such as weathering of rocks to form carbonates over geologic time periods. Reac-

tion 44.2 illustrates the transformation of the common silicate mineral serpentine

(Goff et al. 1997), Mg3Si2O5(OH)4, and CO2 into magnesite, MgCO3, silica and

water. Using this ideal case, 1 ton of serpentine can dispose of approximately

one-half ton of CO2. Reaction 44.3 illustrates the transformation of forsterite,

which is the end member of the common silicate mineral olivine. One ton of olivine

can dispose of approximately two-thirds of a ton of CO2. Again, the reaction is

exothermic and releases 90 kJ/mole of CO2.

Mg;Cað ÞxSiyOx þ 2yþ zH2z þ xCO2 ! x Mg;Cað ÞCO3 þ ySiO2 þ zH2O ð44:1Þ

1=3 Mg3Si2O5 OHð Þ4 þ CO2 ! MgCO3 þ 2=3 SiO2 þ 2=3 H2O þ 64 kJ=mole:

ð44:2Þ

1=2 Mg2SiO4 þ CO2 ! MgCO3 þ 1=2 SiO2 þ 90 kJ=mole ð44:3Þ

A conceptual illustration of the projected Fly ash mineralization process is

presented in Fig. 44.2. As illustrated, CO2 from one or more power plants is

transported to a carbonation reactor, combined with fly ash slurry tank and held

at the appropriate reaction conditions until the desired degree of carbonation is

Fig. 44.2 Chemical reaction process of fly ashes for sequestration in the diagram

608 Y.İ. Tosun

reached. Careful control of solution chemistry yielded olivine conversions of 90%

in 24 h and 83% within 6 h. The most recent results show further modifications of

the same basic reaction can achieve 65% conversion in 1 h and 83% conversion in

3 h. A recent literature review indicated that weak carbonic acid treatments had also

been suggested for Mg extraction in the prior literature (O’Connor 1998). Carbon- ation tests performed at ARC employing heat pretreated serpentine have resulted in

up to 83% conversion in 30 min lower than 115 bars (O’Connor 1998). Indeed, by increasing sodium bicarbonate concentration the carbonation reaction of serpentine

can reach 62% completion under 50 bars. Waters contains various natural ele-

ments. Substantial fractions of these elements in springs could be lost during clay

rock pores leak. 50–60% of arsenic, lead, manganese, mercury and selenium could

be removed by salt transforming in cooling.

Then products of the reaction, which might be slurry of carbonated minerals and

residues and lean gas CO2 in aqueous, are separated. The residual CO2 is recycled.

Useful materials are collected for construction works or the carbonated materials

and residue are returned to the mine site. Almost calcium and magnesium oxide

(MgO) content in the magnesium silicate ore mineral of 40% and 60–70% chem-

ical efficiency of the carbonation reaction; mass balance of equation 44.1.

A 100 MW power plant in Sırnak-Silopi, generating approximately 200 tons/day

of CO2, would require just over 140 tons/day of calcium and magnesium containing

fly ash. Several fly ash types in Turkey containing sufficient calcium and magne-

sium oxide quantity in silicate mineral to provide raw materials for the mineral

carbonation.

Experimental Work

In this research, representative specimens the different types of Turkish geothermal

hot water sources Sirnak, were classified to calcium content and bicarbonate by

chemical analysis. Gas samples of 10–20 kg tubes from each different coal power

stations were used. Screen analysis of Turkish lignite samples were made by

standard Tyler Screens and particle size distributions and normal distributions of

Turkish fly ash samples are respectively illustrated from Fig. 44.3.

Number citations consecutively in alkali waters were reacted by waste gas in the

process reactor (Fig. 44.2) and solution distributions were investigated at each stage

of sequestration. Specific surface area of fly ash minerals was about 4.76–6.2 m2/g

determined by BET surface analyzer and highly sufficient in order to react with

gaseous CO2. 80% of weights of fly ash were reacted in 10 bar alkali solution. Main

reactive salt structure is widely distributed and pores structures are associated with

clay minerals. Coarse alkali oxides are also seen (Table 44.1).

From these results, we designed and developed laboratory scale process unit

consisting a three consecutive autoclave reactors (1 m Φ� 0.7 m) to capture and carbonize flue gas CO2. Flue gas was filtered and withdrawn from the gas tube and

was fed to the autoclave with fly ash slurry at about 7 l/s. The cyclone and decanter

44 Flue Gas CO2 Sequestration by Turkish Coal Fly Ashes. . . 609

Fig. 44.3 Particle size distribution and normal size distribution of the fly ash used in carbonation process

Table 44.1 Chemical analysis of Turkish fly ash used in the experiment

Chemical composition

Soma fly

ash F

Yatagan fly

ash F

Silopi fly

ash F

Afşin Elbistan

fly ash F

SiO2 (S) 42.14 52.05 40.4 20.4

Al2O3 (A) 17.12 23.69 4.1 7.1

Fe2O3(F) 4.34 5.94 15.96 4.96

CS+CAF 63.26 81.68 81 88

CaO 29.6 19.60 24.7 64.7

MgO 1.53 2.38 2.1 3.1

K2O 1.15 2.51 1.55 0.55

Na2O 1.29 2.56 1.25 0.250

Loss of ignition 0.34 0.90 5.22 4.22

SO3 3.43 1.45 2.2 2.4

Density (g/cm3) 2.22 2.12 1.9 2.0

Loose unit weight (g/cm3) 0.72 0.88 0.71 0.69

610 Y.İ. Tosun

unit separates ash and aqueous water. The salt particles were fluidized by flow of

slurry through a slurry tank and pump. The laboratory scale studies were conducted

at a controlled pressure (115.1 kPa) by controlling the flue gas content. The flue gas

was continuously monitored to measure flue gas CO2, SO2 and NOx concentrations

by an industrial grade gas analyzer, while the fresh and spent ash were analyzed for

calcium carbonate (CaCO3), sulfur (S), and mercury (Hg) content.

Results and Discussion

The major technical challenge now hindering the use of minerals to sequester CO2 is theirs low reaction rate. Weathering of rock is extremely slow. The highest

priority is given to identifying faster reaction pathways. The optimized process

has to be economical. Although many carbonation reactions are exothermic, it is

generally very difficult to recover the low-grade heat while the long reaction time

and demanding reaction conditions.

The environmental impact from mining, mineralization and carbonation pro-

cesses must be considered in sequestration. We succeeded in achieving shortened

carbonation reaction times employing fly ash containing lime and calcium magne-

sium silicates such as gehlenite, mehlenite. Reaction took 4 h to reach 40–50%

completion of carbonation. The reaction required temperatures of 450–550 �C, pressures of 10–20 bar, and mineral particles in the �100 μm size range. Because the high pressure requirement of the carbonation reaction will certainly lead to high

process costs, the team is modifying solution chemistry to allow reaction to proceed

at a lower pressure and temperature. The research showed that the concentration of

HCO3 � in the solution is critical to the reaction rate. The high CO2 pressure will lead

increased CO2 absorption in the solution and thus enhance the HCO3 � concentra-

tion. Adding bicarbonate such as sodium bicarbonate in the solution will signifi-

cantly increase the HCO3 � concentration even at a relatively lower CO2 pressure.

In experiments with 3 h reaction period at reactor temperature of 500 �C and fly ash slurries were kept under changing CO2 pressure ranged 5 bar to 40 bar. Products

were subjected to analysis for carbonate yield determination. Test results of yields

for different Turkish fly ash sources were seen in Fig. 44.4.

That quantity in the carbonation amounts were determined for different source

evaluation and reduce the effect of gas content of waste gas in order to optimize

carbonation rates. As given in Fig. 44.4 gas conversion yield for steam and ash

samples were greatly differed. Yata�gan and Elbistan Fly ash showed high carbon- ation yields reaching 32% and 30% respectively. Because of active lime amounts

were over 20% and even alkali Na and K contents were over totally over 5%, the

higher carbonation yields were sufficiently provided by three consecutive carbon-

ation columns at 20 bar.

In the carbonation experiments with addition alkali, reactor temperature changed

between 200 and 650 �C and ash slurries were mixed with active lime additionally by 10% rate. Products received from carbonation of ash specimens were subjected

44 Flue Gas CO2 Sequestration by Turkish Coal Fly Ashes. . . 611

to analysis for gas hold-up determination. Test results of carbonation by fly ash and

also alkali lime contained over active lime at 10% weight rate were investigated.

In experiments with 3 h reaction period of ash specimens, at reactor temperature

changed between 200 and 600 �C and all ash samples contained over active lime at 10% weight rate. Products were subjected to analysis for carbonate yield determi-

nation. Test results of carbonation yields of Turkish fly ash sources and additional

10% lime were seen in Fig. 44.5.

As given in Fig. 44.5 carbonation yield for steam and ash samples were linearly

changed between 200 and 650 �C. Yata�gan and Elbistan Fly ash showed high carbonation yields reaching 44% and 24% at 650oC, respectively. Because of

low reaction kinetics below 500 �C and even the effect 10% over dosage of active lime content in the reactors were ranged over 3% carbonate yield per hour, the

higher carbonation yields were sufficiently provided over 500 �C at 20 bar. In the carbonation experiments, the experimental conditions were controlled on

the basis of the gas composition in the ambient state. So neither the contained water

vapor nor the others, slurry was taken into account. In order to determine the effect

of reaction period on carbonation yield for Turkish fly ash samples, the tests were

carried out in three consecutive carbonation columns at 500 �C and 20 bar between1min to 6 h. Yata�gan and Elbistan Fly ash showed high carbonation yields reaching 33% and 26% at 500oC at 3 h reaction period, respectively. Because of

low reaction kinetics below 30 min reaction period in the reactors, yield rates were

ranged over 1% carbonate yield per hour, the higher carbonation yields were

sufficiently provided over 2 h reaction period at 20 bar. Carbonation of slurries

and yield products changed to 37% and 29% for Yata�gan and Elbistan Fly ash, respectively, by time increase from 1 to 6 h (Fig. 44.6).

Fig. 44.4 Effect of carbonation time over conversion yield rates in hot 500 �C steam used

612 Y.İ. Tosun

Fig. 44.5 Effect of time of carbonation over conversion yield rates in steam with 10% additional lime used at 20 bar

Fig. 44.6 Effect of time of carbonation over conversion yield rates in hot waters used at 500 �C and 20 bar

44 Flue Gas CO2 Sequestration by Turkish Coal Fly Ashes. . . 613

Conclusion

The qualitative comparison of the carbonation for three different Turkish fly ash

reactants and products revealed a complete MgO, CaO–MgO to MgCO3-CaCO3 conversion. The carbonation efficiency of CaO was dependent on the initial pres-

sure of CO2 of 20 bar. This was significantly affected by reaction temperature

500 �C and by the fly ash dose 100 g/l. The kinetic data demonstrated that the initial rate of CO2 transfer was enhanced by carbonation process for our experiments. The

precipitate calcium carbonate was characterized by isolated micron sized particles

and micron agglomerates of calcite.

This study reveals suitable large scale operating units in order to achieve the

carbonation method as a viable sequestration tool at industrially relevant scales by

using Turkish fly ashes in 500–600 �C waters. Carbonation liquid and gaseous products may change to near 20–40% yield performances by time increase from

1 to 6 h.

While there is a potential to utilize other types of flue ashes in mineralization,

lime or similar alkali can be evaluated to sequester CO2 allowing clearly significant

amounts. Even there are researches succeeded usage of serpentine and olivine.

Consequently, the flue gas should be continuously monitored to measure flue gas

flow at depleted gas outlet in order to reprocess it.

Carbonation of the ash slurries and carbonation yield products changed to 37%,

29%, 25% and 19% for Yata�gan, Elbistan, Silopi and Soma Fly ash, respectively, by time increase from 1 to 6 h.

Other harmful emissions caused by flue gas containing high sulfur (S), and

mercury (Hg) content can be eliminated by this method. In that study, results

suggested that an appreciable amount of flue gas CO2 and significant amounts of

SO2 and Hg can be directly captured and mineralized by the fly ash particles.

Even with progress made so far, to develop an economical method to

sequester CO2 with minerals is still a challenging task, because the process is still

relatively slow, and most reactions require high pressure and moderately elevated

temperature.

Acknowledgment The author would like to thank the Mining Engineering Department of Süleyman Demirel University, Isparta.

References

Burruss, R. (2004). Geologic sequestration of carbon dioxide in the next 10 to 50 years: An energy resource Perspective. Prepared for The 10-50 solution: Technologies and policies for a low-carbon future, Pew Center on Global Climate Change and the National Commission on

Energy Policy, March 25–26, Washington, DC.

Butt, D. P., Lackner, K. S., Wendt, C. H., Park, Y. S., Benjamin, A., Harradine, D. M., et al. (1997).

A method for permanent disposal of CO2 in solid form. World Resource Review, 9(3), 324–336.

614 Y.İ. Tosun

Davis. (2004). Gasification and carbon capture and storage: The path forward. Prepared for the 10-50 solution: Technologies and policies for a low-carbon future, Pew Center on

Global Climate Change and the National Commission on Energy Policy, March 25–26,

Washington, DC.

Drägulescu, C., Tribunescu, P., & Gogu, O. (1972). L€osungsgleichgewicht von MgO ausSerpentinen durch Einwirkung von CO2 und Wasser. Revue Roumaine de Chimie, 17(9), 1518–1524.

DOE. (1998, November). Vision 21, Clean energy for the 21st century. U.S. Department of

Energy, Office of Fossil Energy. DOE/FE-0381. www.fetc.doe.gov/publications/brochures/.

Goff, F., Guthrie, G., Counce, D., Kluk, E., Bergfeld, D., & Snow, M. (1997). Preliminary investigations on the carbon dioxide sequestering potential of ultramafic rocks. Los Alamos, NM: Los Alamos National Laboratory. LA-13328-MS.

Goldberg, P. M., Chen, Z.-Y., O’Connor, W., Walters, R., Lackner, K., & Ziock, H. (2000). CO2 mineral sequestration studies. Paper presented at GlobeEx 2000, August, Las Vegas, NV.

Gunter, W. D., Perkins, E. H., &McCann, T. J. (1993). Aquifer disposal of CO2 rich gases reaction

design for added capacity. Energy Conversion and Management, 34, 941–948. Hepple, R., & Benson, S. (2003). Implications of surface seepage on the effectiveness of geologic

storage of carbon dioxide as a climate change mitigation strategy. In J. Gale & Y. Kaya (Eds.),

Proceedings of greenhouse gas control technologies 6th international conference (GHGT-6) (Vol. 1, pp. 261–266). Amsterdam: Elsevier.

IEA. (2012). World energy outlook. IPCC. (2005). IPCC special report on carbon dioxide capture and storage. Prepared by working

group III of the intergovernmental panel on climate change [B. Metz, O. Davidson, H. C.

de Coninck, M. Loos, & L. A. Meyer (Eds.)]. Cambridge/New York: Cambridge University

Press, 442p.

Keeling, C. D., Whorf, T. P., Wahlen, M., & van der Plicht, J. (1995). Interannual extremes in the

rate of rise of atmospheric carbon dioxide since 1980. Nature, 375, 666–670. Kojima, T., Nagamine, A., Ueno, N., & Uemiya, S. (1997). Absorption and fixation of carbon

dioxide by rock weathering. In Proceedings of the third international conference on carbon dioxide removal, Cambridge, Massachusetts, September 9–11, 1996. Energy and Conservation Management, 38(Suppl.), S461–S466.

Lackner, K. S., Wendt, C. H., Butt, D. P., Sharp, D. H., & Joyce, E. L. (1995). Carbon dioxide

disposal in carbonate minerals. Energy (Oxford), 20(11), 1153–1170. Lindeberg, E. (2003). The quality of a CO2 repository: What is the sufficient retention time of CO2

stored underground. In J. Gale & Y. Kaya (Eds.), Proceedings of greenhouse gas control technologies 6th international conference (GHGT-6) (Vol. 1, pp. 255–260). Amsterdam: Elsevier.

Minchener, A. J., & McMullan, J. T. (2007). IEA Coal Research Ltd, Clean Coal Technology,

London.

Myer, L. (2003). Sensitivity and cost of monitoring geologic sequestration using geophysics. In

J. Gale & Y. Kaya (Eds.), Proceedings of greenhouse gas control technologies 6th interna- tional conference (GHGT-6) (Vol. 1, pp. 377–382). Amsterdam: Elsevier.

O’Connor, W. K. (1998). Investigations into carbon dioxide sequestration by direct mineral carbonation. Presentation at second meeting of mineral sequestration working group,

November 3. Albany, Oregon: Albany Research Center.

O’Connor, W. K., Dahlin, D. C., Nilsen, D. N., Walters, R. P., & Turner, P. C. (2000). Carbon dioxide sequestration by direct mineral carbonation with carbonic acid. Presentation at 25th

international technical conference on coal utilization & fuel systems, March 7, Clearwater, FL.

Oldenburg, C., et al. (2001). Process modeling of CO2 injection into natural gas reservoirs for

carbon sequestration and enhanced gas recovery. Energy & Fuels, 15(2), 293–298. Pacala, S. (2003). Global constraints on reservoir leakage. In J. Gale & Y. Kaya (Eds.), Pro-

ceedings of greenhouse gas control technologies 6th international conference (GHGT-6) (Vol. 1, pp. 267–272). Amsterdam: Elsevier.

44 Flue Gas CO2 Sequestration by Turkish Coal Fly Ashes. . . 615

http://www.fetc.doe.gov/publications/brochures/

Plasynski, S. I., Bose, C. B., Bergman, P. D., Dorchak, T. P., Hyman, D. M., Loh, H. P.,

et al. (1999). Carbon mitigation: A holistic approach to the issue. Paper presented at the 24th

intl. tech. conf. on coal utilization and fuel systems, March 8–11, Clearwater, FL.

Rubin, E., & Rao, A. (2003). Uncertainties in CO2 capture and sequestration costs. In J. Gale &

Y. Kaya (Eds.), Proceedings of greenhouse gas control technologies 6th international confer- ence (GHGT-6) (Vol. 1, pp. 1119–1124). Amsterdam: Elsevier.

Seifritz, W. (1990). CO2 disposal by means of silicates. Nature, 345, 486. Siegenthaler, U., & Oeschger, H. (1987). Biospheric CO2 emissions during the past 200 years

reconstructed by deconvolution of ice core data. Tellus, 39B, 140–154. Simbeck, D. (2004). CO2 capture economics. Prepared for the 10-50 solution: Technologies and

policies for a low-carbon future, Pew Center on Global Climate Change and the National

Commission on Energy Policy, March 25–26, Washington, DC.

Solomon, S. (2006). Carbon dioxide storage: Geological security and environmental issues—Case study on the Sleipner gas field in Norway. Oslo, Norway: The Bellona Foundation. http://www. bellona.no/artikler/notat_solomon.

Stangeland, A. (2007). A model for the CO2 capture potential. International Journal of Green- house Gas Control, 1, 418. http://www.bellona.no/artikler/notater_stangeland_solomon.

Stevens, S., Fox, C. E., & Melzer, L. S. (2001). Sequestration of CO in depleted oil and gas fields:

Global 2 capacity, costs, and barriers. In D. J. Williams, R. A. Durie, P. McMullan, C. A.

J. Paulson, & A. Y. Smith (Eds.), Proceedings of greenhouse gas control technologies 5th international conference (GHGT-5) (pp. 278–283).

Stevens, S., Rigg, A. J., Pearce J. M. (1999). CO2 sequestration in deep coal seams: Pilot results

and worldwide potential. In B. Eliasson, P. Riemer, & A. Wokaun (Eds.), Proceedings of greenhouse gas control technologies 4th international conference (GHGT-4) (pp. 175–180).

TKI. (2009). The Turkish Ministry of Energy, Energy, Dept., Lignite Coal Report.

TTK. (2009). The Turkish Ministry of Energy, Energy, Dept., Hard Coal Report.

Zweigel, P., Hamborg, M., Arts, R., Loethe, A., Sylta, F., & Tomeras, A. (2000). Prediction of

migration of CO2 injected into and underground depository: Reservoir geology and reservoir

modeling in the Sleipner Case (North Sea). In D. J. Williams, R. A. Durie, P. McMullan, C. A.

J. Paulson & A. Y. Smith (Eds.), Proceedings of greenhouse gas control technologies 5th international conference (GHGT-5) (pp. 360–365), Cairn, August 13–16, 2000.

616 Y.İ. Tosun

http://www.bellona.no/artikler/notater_stangeland_solomon

http://www.bellona.no/artikler/notat_solomon

Chapter 45

Geo.: Gas Production in Offshore Reservoirs in Brazil’s Pre-salt Region

Isabella Vaz Leal da Costa, Pedro Rochedo, Mariana Império,

Alexandre Salem Szklo, and Roberto Schaeffer

Introduction

The expectations regarding the oil sector in Brazil are very promising, both by the

extent of the sedimentary basins of interest for hydrocarbon exploration untapped

(about 7 million square kilometers), but also because of the recent discoveries in the

pre-salt region (BNDES 2010; Wood Mackenzie 2013). Petrobras estimates that

there are between four billion and eight billion recoverable barrels in Lula field and

four billion barrels in Iara field. Besides these, there are the Jubarte field (Campos

Basin) and (the ring-fence) Golfinho in the Espı́rito Santo Basin. The estimates of

the total reserves in the pre-salt region (between 70 billion and 100 billion barrels),

if confirmed, make Brazil a oil exporting country in the next few years (BNDES

2008; ANP 2014; Wood Mackenzie 2013).

However, we must also consider the difficulties linked to the pre-salt, mainly

because of its geographical location. The pre-salt reserves are located at a depth of

over 6000 m, with about 2000 m corresponding to a layer of salt. So there are a lot

of difficulties to extract the hydrocarbons deposited in the pre-salt layer, requiring

special materials and equipment, with technologies that aren’t fully developed yet (Petrobras 2014). Some of these difficulties are showed below:

• Going through a thick layer of salt in deep waters is not a trivial task;

• Plasticity and the solubility of the pre-salt layer will require new technologies to

maintain the well stability;

I.V.L. da Costa (*) • P. Rochedo • M. Império • A.S. Szklo • R. Schaeffer Energy Planning Program, Graduate School of Engineering, Centro de Tecnologia, Federal

University of Rio de Janeiro, Bloco C, sala 211, Cidade Universitária, Ilha do Fund~ao, Rio de Janeiro 21941-972, Brazil

e-mail: [email protected]; [email protected]; [email protected];

[email protected]; [email protected]

617

mailto:[email protected]

• Hydrocarbons are located in carbonate rocks, environment that is unknown by

Petrobras activities because their experience is concentrated in other types of

rocks such as sandstones;

And finally, the production occurs in a high temperature and pressure, at the

presence of large CO2 content between 10% and 45 mol% (Formigli 2008; Dino

2014; Credit Suisse 2014), which may be stored in the same underground field.

Petrobras believes that these difficulties can be overcome in the following years

(Petrobras 2011). In addition to the technological difficulties, there is the challenge

of producing hydrocarbons at an average distance of 170 km from the Brazilian

coast, distributing over a range of about 800 km of coastline extension of the states

of Espı́rito Santo and Santa Catarina (BNDES 2010).

According to estimates made by Petrobras (2014), Brazil will become self-

sufficient in oil products in the year 2020. In addition, the domestic supply of

natural gas will increase from 41 million cubic meters per day in 2013 to 86 million

m3/day, in 2020. Imports of Bolivia will remain at 30 million cubic meters/day

(contract expiring in 2019), plus the import via liquefied natural gas (LNG). By

2013, two LNG regasification plants were already in operation phase (27 million m3

/day) and the additional third plant started operation in 2014 (14 million cubic

meters/day) (Petrobras 2014).

The pre-salt oil fields contain large amounts of carbon dioxide (CO2), which

prevents the transportation of natural gas to the coast. CO2, when in contact with

water, forms acids such as carbonic acid, making it very corrosive that can cause

damages to the pipelines and equipment (Nascimento 2012). The presence of CO2 decreases the calorific value of natural gas, and helps the formation of hydrates at

low temperatures and high pressures, which are precisely the flow conditions of the

natural gas present in the pre-salt area (Nascimento 2012).

Thus, the need for separation of CO2 from natural gas produced in the pre-salt

becomes necessary to their production. The process of carbon capture and storage

(carbon capture and storage—CCS) has been used worldwide by large oil and

natural gas companies. In the oil extracting sector, this process is aimed precisely

to separate CO2 from the natural gas extracted. However, a high CO2 content in the

natural gas, reduces the amount of natural gas that can be produced. In the case of

the pre-salt region, the Brazilian natural gas production is related to the amount of

carbon dioxide present in the pre-salt fields.

So, this paper presents an estimate of the natural gas production in the pre-salt

fields, drawn from a model developed in HYSYS software, considering the amount

of CO2 estimated for this region.

618 I.V.L. da Costa et al.

Carbon Capture and Geological Storage Review

Carbon Capture and Geological Storage (CCGS)

CO2 Capture and Geological Storage systems (CCGS) are recognized worldwide

as alternatives to reduce carbon dioxide emissions from stationary sources

(IEA 2008; IPCC 2007; Rochedo 2011; Nogueira et al. 2014; Costa 2009, 2014).

These practices are used in the global oil industry to reduce emissions, for example,

in the offshore fields of exploitation in Norway (Sleipner Field) and onshore fields

in Algeria (Costa 2009, 2014; Roddy 2011; Statoil 2013a).

The first capture demonstration plant that is operating on an industrial scale is

the plant installed at Sleipner, Norway, located in the North Sea and operated by

Statoil since 1996 (Statoil 2014a). This plant is also the main CCGS offshore

project in the world. The Sleipner T platform was built especially for separating

CO2 from natural gas and has being able to separate one million tons of CO2 per

year. These platforms use chemical absorption technology with amine based sol-

vents for the separation of gases, used in post-combustion (Rochedo 2011). It is

worth mentioning that for the pre-salt fields, FPSOs (Floating Production, Storage,

and Offloading) are being used. In the pre-salt area the conditions are more severe

due to the distance from the coast and the depth, so it would be best not to use

chemical absorption technology that has large equipment that can generate insta-

bility on the floating platforms.

The In Salah project in Algeria is another CO2 capture project, conducted by

Statoil, which uses the same separation technology that was already applied in the

Sleipner field, based on the process of amines (Statoil 2014b). The project became

operational in 2004, and contains a storage industrial scale. Several fields with a

carbon dioxide content between 1 and 10 mol%, in order to adapt the natural gas to

the specifications of 0.3 mol% of CO2 present in the composition of the natural gas,

are injecting CO2 into deep saline formations, between 1850 and 1950 feet deep

(Mathieson et al. 2010). By 2010 were injected over three million tons of carbon

dioxide (Mathieson et al. 2010). However, the CO2 injection was discontinued in

2011 as a safety measure, mainly related to reservoir capacity. New data and

seismic results are being studied to create a more appropriate strategy for this

reservoir injection (Statoil 2014b).

CO2 Capture in the Pre-salt Fields

The CO2 capture can be performed before (pre-combustion), or after the use of

natural gas (post-combustion). This study is considering that the capture of CO2 is

directly made of associated gas extracted in the pre-salt fields (pre-combustion). It

is important to mention that the capture of CO2 from gas flaring and from gas

combustion for power generation did not occur. It is, also, worth mentioning that is

45 Geo.: Gas Production in Offshore Reservoirs in Brazil’s Pre-salt Region 619

not possible to capture the total amount of CO2 emitted by oil and gas production

platforms. Here comes to light the concept of "capturable" CO2. The “capturable”

CO2 is the portion of CO2 emitted mainly in the oil and natural gas extraction due to

generation of heat and/or burning fossil fuels, due to the industrial sector and due

to the use of fossil fuels in plants for generation of electricity. In these situations

it is feasible to separate CO2 using at least one of the technological routes

available. Technological routes includes pre-combustion, post-combustion and

oxy-combustion. In addition, it is only captured about 85% mol of “capturable”

CO2 due to technical limitations of existing methods of gas separation (Costa 2014;

Roddy 2011; Rochedo 2011; Kuramochi et al. 2012).

The capture method most suitable for the new pre-salt platforms (FPSOs) would

be the membranes (Dino 2014). Membranes are structures that act as selective

barriers for molecules that are able to cross from one side to another. In the gas

separation, membrane technology is based on chemical or physical interaction of

the gas with the membrane which allows certain gases to go through the membrane

at higher speeds than others.

Membrane performance was determined by the permeability and selectivity of

the materials, which the membranes are made of. The permeability is defined by the

ability to be penetrated with a certain driving force at once. Permeability is

generally indicated by units such as barrer or flux and, selectivity by the ratio of

the permeability of the gas components. The membrane separation takes place

through different mechanisms, which have important influence on the selectivity

and permeability.

Membranes are industrially applied in the form of flat sheets or hollow fibers. In

the case of hollow fibers, the fibers are joined into a tubular beam. Membranes in

flat form are usually produced as a sheet of spiral modules, where two membrane

sheets are placed back-to-back, in the middle of a material which, ensures the

minimum space required to keep the gas flow.

These models have extremely high surface-volume ratios and offer advantages

related to costs and footprint (Schendel 1984).

Therefore, in the case of the platforms to be used in the exploitation of the

pre-salt fields, the use of membranes is justified mainly due to its footprint, which is

significantly smaller than the footprint of conventional absorption technology. A

membrane module has a smaller footprint than a capture plant using, for example,

the chemical absorption method. The space required to accommodate all the

equipment used to capture by chemical absorption is not usually available on a

FPSO. The layouts of the FPSO are well defined and restrict. Furthermore, this kind

of platform is not able to deal with the structure instability by installing equipment

for chemical absorption (Rochedo 2011; Dino 2014; Castelo Branco 2008).

After the capture method selection (membranes), the UOP Separex™ system, was chosen as a standard module for the separation of CO2 in the pre-salt

FPSOs (UOP 2013; Petrobras 2014; Echt and Meister 2009). According to UOP

(2013), these modules were bought by PETROBRAS to separate CO2 from seven

million m3 of natural gas per day in the pre-salt fields. In addition, eight modules

will be installed on production platforms (FPSO) in the Santos Basin. It is

620 I.V.L. da Costa et al.

estimated that a UOP Separex™ system (membraneþ skid) module occupies an area of approximately 347 m2 and weigh about 582 tons (Harness and Sharma

2012). This is a compact module suitable for oil and gas production platforms

because it can reduce the occupied area for gas separation equipment in a platform

(footprint) by 70% (Harness and Sharma 2012).

According to Petrobras (2014) and UOP (2013), will be used the same type of

membrane module in all FPSOs exploiting the pre-salt region. So, according to this

information, in this study, we made the assumption that all membrane modules

would be the same. Moreover, it is worth mentioning that the number of modules

should vary depending on the daily production capacity of each FPSO.

Methodology

Oil and natural gas exploration and production in Brazil occurs mostly offshore and

in deep waters. For the accomplishment of upstream sector analysis in Brazil, in this

study, information about typical marine installations of oil and natural gas produc-

tion located in Campos basin were used. These installations have electric power

system, using their own produced natural gas as an input. Using typical installations

was an assumption taken in this study due to the difficulty in the acquisition of

process data about all marine installations in all Brazilians basins. Campos Basin

represents more than 75% of Brazilian production.

The methodology used to estimate pre-salt natural gas production was divided in

three phases. Initially, it was adopted that pre-salt natural gas derives only from the

associated gas. Thereby, natural gas production is linked to pre-salt oil production.

Hence, the first phase was estimating oil production and number of platforms

required in pre-salt. For this, the oil curve developed by Saraiva (2013), where a

Multi-Hubbert modeling was made, was adopted. This modeling considers the total

volume of ultimately recoverable resources (URR), according to different proba-

bilities of adding reserves, to accomplish the oil production projection. Base year of

2010 has been updated with real oil production data (ANP et al. 2013a; Credit

Suisse 2014) and then an interpolation was made to reach oil production projection

made by Saraiva (2013) for 2015.

This Saraiva’s (2013) result, with a production of 3.8 million bpd, is clearly above numbers that will be achieved in 2015, which probably will be around 2.8

million bpd (Petrobras 2014). However, the aim of this study is building a long-term

scenario, where the current adversities undergone by Brazilian oil industry should,

by hypothesis, be overcome. This evaluation is even reported by Goldemberg

et al. (2014) projection, which clearly distinguishes the role of production arising

out the oil under the onerous assignment tax regime, for which Petrobras has

expended considerable resources.

In this sense, it’s worth noting that Petrobras has been focusing its investments for pre-salt region (Petrobras 2013). Therefore, even with large production

increases in pre-salt region, total production in 2012 and 2013 showed a decline,

45 Geo.: Gas Production in Offshore Reservoirs in Brazil’s Pre-salt Region 621

returning to 2010 levels (BDEP-ANP 2014; Reuters Brasil 2014). In 2012, for

example, Roncador field showed a 27% decrease in its production. In 2014,

Brazilian production increased again (BDEP-ANP 2014), but it was still far

below the post-salt region forecast developed by Saraiva (2013), which was used

in this work.

As a result of oil production, an estimate for pre-salt platforms was also made,

considering that new offshore facilities will be FPSO due to exploitation in deep

and ultra-deep waters. All platforms implemented in the same year will have the

same average capacity. This average capacity increases over time, due to increased

production resulting from pre-salt, which requires larger platforms to process the

estimated oil volumes for this region. Therefore, three different capacities platforms

had been used, with a daily production of 100, 150 and 200 thousand barrels of oil.

Based on pre-salt oil production, the second phase was accomplishing the

estimated natural gas gross production. According to IEA (2014), the extracted

gas amount from the processing of a pre-salt barrel of oil is around 40 m3. Total gas

extracted comes from the multiplication of 40 m3 of natural gas by the estimated

number of platforms, considering the average capacity of each platform. Bypass is

subtracted from extracted gas, resulting in natural gas gross production. Therefore,

each platform will have its respective gross gas production average capacity. Since

there is still much uncertainty about the precise amount of CO2 present in pre-salt

natural gas, a wide range was used, between 10%mol of CO2 and 45%mol of CO2,

as proposed by the available scientific literature (Echt and Meister 2009; IEA 2014;

Credit Suisse 2014). Thus, three classifications have been proposed for estimated

natural gas quantities associated with pre-salt resources: (1) total amount of

extracted gas; (2) natural gas gross production (extracted gas minus bypass); and

(3) natural gas net production (gross production minus platform auto-consumption

and energy penalty from membrane system used in CO2 capture). Equations (45.1)

and (45.2) refer to the amounts of natural gas represented by aforementioned

classifications.

NG GROSS PROD ¼ EXTRACTED GAS � BYPASS ð45:1Þ NG NET PROD ¼ GROSS NG PROD � AC þ EPð Þ ð45:2Þ

Note: NG Gross Prod¼Natural gas gross production (m3); NG Net Prod¼Natural gas net production (m3);

AC ¼ Auto� consumption on platforms m3� �; EP ¼ energy penalty m3� �: Regarding the gross natural gas produced and bypass, they were calculated from

a modeling made in HYSYS software, which took into account the membranes’ properties used in UOP Separex™ membrane module and CO2 content range considered in this study. Reinjection volumes and gas production for a single

module were also obtained through HYSYS model, as well as the composition of

each of these gases. These data are different for different CO2 contents considered.

622 I.V.L. da Costa et al.

According to platform capacity, a gross extracted gas volume from the field may

exceed membrane capacity. This volume does not pass by the membrane (bypass),

and it is directly injected into the reservoir along with the gas rich in CO2 captured

in the membrane, as shown schematically in Fig. 45.1.

The third phase consists in estimating natural gas net production, which is the

amount that actually can be transported to the coast and be available to natural gas

processing units (NGPU). Energy penalty considered by using membranes was the

electrical energy used by compressors for CO2 reinjection in reservoirs. This energy

was estimated based on compressor power, dimensioned by HYSYS® model, to process gross natural gas volumes on membranes for each platform capacity.

Compressors powers are shown in Table 45.1.

Then, considering compressors operating 24 h a day throughout the year, energy

that would be used by compressors is given in GWh and m3 of natural gas. These

values are calculated according to platforms estimates, their capacities and com-

pressors powers. They are presented in Table 45.2.

Platform auto-consumption, refers to energy consumption in platform, which

includes activities such as gas reinjection for oil recovery, transportation to pipe-

lines, power generation for operational activities and accommodations in offshore

platforms, heat and steam production, among others. Auto-consumption used in this

study was 3.2 m3/bbl, derived from oil and gas ratio and auto-consumption per-

centage (Maia 2007; ANP 2013b).

Fig. 45.1 Membrane functioning scheme

45 Geo.: Gas Production in Offshore Reservoirs in Brazil’s Pre-salt Region 623

Then, with natural gas gross production and number of platform for each average

capacity in operation, oil and gas ratio was calculated for each year, weighted by

number of platforms in operation. Therefore, annual natural gas production was

reached. To arrive at platform net production, energy auto-consumption and energy

penalty related to membrane system were discounted from gross production. Auto-

consumption was considered constant over time and equal for all average platform

capacities.

Thus, for each CO2 content and for each platform capacity considered, the

required modules number, volumes captured in membrane, reinjected volumes

(i.e., CO2 captured and bypass) and pre-salt natural gas volumes produced, were

possible to be calculated.

Results

Pre-salt Natural Gas Production

Natural gas gross production projections by typology of platform are presented in

Tables 45.2 and 45.3, separated by respective CO2 content in gross natural gas. CO2 Content: 10% mol of CO2 (Table 45.4).

Table 45.1 Estimated compressor’s powers on the membrane capture

Compressor power (MW)

CO2 content: 10% CO2 content: 45%

100 kbpd 150 kbpd 200 kbpd 100 kbpd 150 kbpd 200 kbpd

4.62 9.24 9.24 11.14 22.28 22.28

Table 45.2 Consumption/energy penalty of membranes (compressors)

Year

CO2 content: 10% CO2 content: 45%

Electric consumption (GWh)

Gas consumption (Mm3)

Electric consumption (GWh)

Gas consumption (Mm3)

2010 40.47 12.38 97.59 29.85

2015 323.77 99.02 780.69 238.77

2020 526.13 160.91 1268.62 388.00

2025 849.90 259.93 2049.31 626.76

2030 1254.61 383.71 3025.18 925.22

2035 1659.32 507.49 4001.04 1223.68

2040 1861.68 569.37 4488.97 1372.91

2045 1821.20 557.00 4391.39 1343.06

2050 1618.85 495.11 3903.46 1193.83

624 I.V.L. da Costa et al.

Thus, auto-consumption and energy penalty were deducted from natural

gas gross production, resulting in a new projection curve of natural gas net

production. A CO2 content range mentioned above—10% mol of CO2 and 45%

mol of CO2—for pre-salt was considered, so, a natural gas net production range was

estimated.

Membrane area calculated by HYSYS model was 32,000 m2. Below, Table 45.5

presents extracted gas estimates, gross and net natural gas production for pre-salt

contents of 10 and 45% mol of CO2. Figure 45.2 shows the same results.

Table 45.3 Production and reinjection volumes of natural gas with content of 10% mol of CO2

Average capacity platform (k bpd)

Extracted gas (M m3/ day)

Membrane modules

Bypass (M m3/ day)

Natural gas gross production (M m3/day)

100 4.0 1 1 2.73

150 6.0 2 0 5.46

200 8.0 2 2 5.46

Average capacity platform (k bpd)

Reinjection (M m3/day)

CO2 content in reinjected gas

CO2 capture on membrane (kt/day)

Capture tax

% (tCO2/ bbl)

100 1.37 26% 0.66 89% 0.0066

150 0.74 70% 0.95 86% 0.0064

200 2.74 26% 1.31 89% 0.0066

CO2 content: 45% mol of CO2

Table 45.4 Production and reinjection volumes of natural gas with content of 45% mol of CO2

Average capacity platform (k bpd)

Extracted gas (M m3/ day)

Membrane modules Bypass (Mm3/day)

Natural gas gross production (M m3/day)

100 4.0 1 1 1.82

150 6.0 2 0 3.64

200 8.0 2 2 3.64

Average capacity platform (k bpd)

Reinjection (M m3/day)

CO2 content on reinjected gas

CO2 Capture on membrane (kt/day)

Capture tax

% (tCO2/ bbl)

100 2.28 75% 3.15 96% 0.0315

150 2.56 95% 4.48 91% 0.0299

200 4.56 75% 6.30 96% 0.0315

45 Geo.: Gas Production in Offshore Reservoirs in Brazil’s Pre-salt Region 625

Concluding Remarks

CO2 content in reinjected gas is higher for 150 thousand bpd platforms. Its

production volume coincides with capacity from two membrane modules, so it

became possible to treat all extracted gas. In other words, there is no bypass, which

would dilute CO2 in reinjected gas and reduce hydrocarbon production. For 100 and

200 thousand bpd platforms there is a gas quantity, which is rich in natural gas that

cannot be treated by membranes. Therefore, it is reinjected back into the reservoir.

This wasted natural gas decreases the reinjected gas CO2 content. For 45% mol of

CO2 gas, 95% CO2 content in reinjected gas has been reached, which is configured

as a very pure gas, justifying the membrane area calculated.

Regarding the capture taxes, when they are compared, it can be seen that

150 thousand bpd platform has a lower tax than the 100 and 200 thousand bpd.

Table 45.5 Pre-salt natural gas production (10 and 45% mol of CO2)

Year

10% mol CO2 45% mol CO2

Extracted gas (Mm3)

Gross production (M m3)

Net production (M m3)

Extracted gas (Mm3)

Gross production (M m3)

Net production (M m3)

2010 1460 428 283 1460 286 123

2015 11,680 6994 4724 11,680 4663 2252

2020 18,250 11,569 7914 18,250 7713 3830

2025 27,010 19,117 13,481 27,010 12,744 6,742

2030 37,960 28,790 20,692 37,960 19,194 10,554

2035 48,910 38,534 27,992 48,910 25,689 14,431

2040 56,210 43,654 31,585 56,210 29,103 16,230

2045 54,750 44,409 32,441 54,750 29,606 16,852

2050 48,180 38,980 28,672 48,180 25,987 14,980

Fig. 45.2 Pre-salt natural gas production (10 and 45% mol of CO2)

626 I.V.L. da Costa et al.

This difference can be explained due to the passage through the membrane of all

extracted gas from the well. Once in gas separation process there is a small CO2 loss, capture tax of 150 thousand bpd platform is penalized. At the same time,

because the other platforms have a volume of bypass, they directly reinjected the

CO2 volume from bypass, without any loss, which increases the capture tax.

As regards the capture, it occurs more efficiently in 45% mol of CO2 gross

natural gas, naturally because of the increased presence of CO2 in extracted gas.

Therefore, there is both a greater CO2 capture in membrane system, as a larger

amount of carbon dioxide in gross natural gas that does not pass through the

membrane, but is directly reinjected. So, for an extracted gas from pre-salt with

higher CO2 content, natural gas production that would be available for the market

decreases, which can be seen from natural gas production curves estimates. Natural

gas gross production is 50% higher for gas with 10%mol of CO2 content, while net

production (discounting energy penalty and auto-consumption) is approximately

twice as large.

CCS implementation is a way to enable pre-salt exploration, as the associated

natural gas contains large CO2 amounts, estimated here between 10 and 45% mol

of CO2, but can reach higher values. When in contact with water, CO2 can produce

acids that may cause wear on pipes and equipment. It can also reduce natural gas

calorific value and it can favor the formation of hydrates at low temperatures and

high pressures. Thus, if there is no separation of CO2, it impedes natural gas

transportation, and therefore, their commercialization. From CCS implementation

and from separation of the largest portion of CO2 contained in natural gas, natural

gas production becomes technically feasible.

Analysis presented in this study is unprecedented and, therefore, in the absence

of public data, lack of relevant historical pre-salt oil and natural gas production and

complexity of the problem portrayed, many assumptions and hypotheses were

adopted to make the presented simulations. The high degree of uncertainty that

was considered here is clear and, thus, these simulations and their results could be

improved in the future, with new available data.

References

ANP. (2013b). Anuário estatı́stico brasileiro do petr�oleo, gás natural e biocombustı́veis. http:// www.anp.gov.br/?pg¼66833.

ANP, Agência Nacional do Petr�oleo, Gás Natural e Biocombustı́veis. (2013a). Dados Estatı́sticos Mensais. http://www.anp.gov.br/?pg¼56046&m¼&t1¼&t2¼&t3¼&t4¼&ar¼&ps¼& cachebust¼1311692440338.

BDEP-ANP. (2014). Base de dados. http://www.bdep.gov.br/?lng¼br. BNDES. (2008). Mercado de embarcações de apoio marı́timo �as plataformas de petr�oleo:

oportunidades e desafios.

BNDES. (2010). Perspectivas e desafios no setor de petr�oleo e gás. Castelo Branco, D. (2008). An�alise Técnica e Econômica da Aplicaç~ao da Tecnologia GTL de

pequena escala para monetizaç~ao do g�as natural associado remoto offshore no Brasil. Master Dissertation, Energy Planning Program—COPPE/UFRJ, Rio de Janeiro, RJ, Brasil.

45 Geo.: Gas Production in Offshore Reservoirs in Brazil’s Pre-salt Region 627

http://www.bdep.gov.br/?lng=br

http://www.anp.gov.br/?pg=56046&m=&t1=&t2=&t3=&t4=&ar=&ps=&cachebust=1311692440338

http://www.anp.gov.br/?pg=66833

Costa, I. V. L. (2009). An�alise do Potencial Técnico do Sequestro Geol�ogico de CO2 no Setor Petr�oleo no Brasil. Master Dissertation, Energy Planning Program—COPPE/UFRJ, Rio de Janeiro, RJ, Brazil.

Costa, I. V. L. (2014). Proposta de Estrutura Regulat�oria para Sequestro Geol�ogico de CO2 no Brasil e uma Aplicaç~ao para o Estado do Rio de Janeiro. PhD Thesis, Energy Planning Program—COPPE/UFRJ, Rio de Janeiro, RJ, Brazil.

Credit Suisse. (2014). Brazil Upstream Tracker. In: Connections Series. Dino, R., (2014). Personal communication. CENPES, PETROBRAS.

Echt, W., & Meister, P. (2009). Design, fabrication and startup of an offshore membrane CO2 removal system. 88th Annual Convention, Gas Processors Association, P-28, Texas, EUA,

Retrieved March 8–11, 2009.

Formigli, J. (2008). O p�olo Pré-sal da Bacia de Santos—Desafios Tecnol�ogicos para a área de Engenharia. Presented at Rio Oil and Gas, November/2008.

Goldemberg, J., Schaeffer, R., Szklo, A., & Lucchesi, R. (2014). Oil and natural gas prospects in

South America: Can the petroleum industry pave the way for renewables in Brazil? Energy Policy, 64, 58–70.

Harness, J., & Sharma, B. (2012). UOP Separex TM membrane systems. 2012 AIChE Spring Meeting, Houston, TX.

IEA. (2008). CO2 capture and storage—A key carbon abatement option. International Energy Agency.

IEA. (2014). Brazil Energy Outlook, in: World Energy Outlook 2013. International Energy Agency.

IPCC. (2007). Special Report on Carbon Dioxide Capture and Storage. Cambridge: Cambridge University Press, 2005. Preparado pelo Grupo de Trabalho III do IPCC.

Kuramochi, T., Ramirez, A., Tukenburg, W., & Faaji, A. (2012). Comparative assessment of CO2 capture technologies for carbon-intensive industrial processes”. Progress in Energy and Combustion Science, 38, 87–112.

Maia, J. L. P. (2007). Separaç~ao e captura do di�oxido de carbono em instalações marı́timas de produç~ao de petr�oleo. PhD Thesis. School of Engineering of the University of S~ao Paulo, S~ao Paulo, SP, Brazil.

Mathieson, A., Midgely, J., Wright, I., Saoula, N., & Ringrose, P. (2010). In Salah CO2 Storage

JIP: CO2 sequestration monitoring and verification technologies applied at Krechba, Algeria.

Energy Procedia, 4, 1063–1070. Nascimento, J. T. (2012). Avaliaç~ao técnico-econômica de ultracentrı́fugas a gás para remoç~ao de

CO2 em poços do pré-sal. Master Dissertation. Rio de Janeiro: School of Chemistry, Federal

University of Rio de Janeiro.

Nogueira, L., Lucena, A., Rathmann, R., Rochedo, P., Szklo, A., & Schaeffer, R. (2014). Will

thermal power plants with CCS play a role in Brazil’s future electric power generation?

International Journal of Greenhouse Gas Control., 24, 115–123. Petrobras. (2011). Energia e Tecnologia. http://www.petrobras.com.br/pt/energia-e-tecnologia/. Petrobras. (2013). Relat�orio de Sustentabilidade 2013. Disponı́vel em http://www.

investidorpetrobras.com.br/pt/plano-de-negocios-e-gestao/apresentacao-plano-estrategico-2030-

e-png-2014-2018.htm. Acessado em 22/07/2014.

Petrobras. (2014). Plano Estratégico Petrobras 2030. http://www.investidorpetrobras.com.br/pt/

plano-de-negocios-e-gestao/apresentacao-plano-estrategico-2030-e-png-2014-2018.htm.

Reuters Brasil. (2014). Petrobras perde participaç~ao na produç~ao brasileira de petr�oleo e gás. http://br.reuters.com/article/topNews/idBRKBN0EE22V20140603.

Rochedo, P. R. R. (2011). An�alise Econômica sob Incerteza da Captura de Carbono em Termoelé tricas a Carv~ao: Retrofitting e Capture-Ready. Dissertaç~ao de Mestrado, Programa de Planejamento Energético—COPPE/UFRJ, Rio de Janeiro, RJ, Brasil.

Roddy, D. (2011). Development of a CO2 network for industrial emissions. Applied Energy, 91(1), 459–465.

628 I.V.L. da Costa et al.

http://br.reuters.com/article/topNews/idBRKBN0EE22V20140603

http://www.investidorpetrobras.com.br/pt/plano-de-negocios-e-gestao/apresentacao-plano-estrategico-2030-e-png-2014-2018.htm

http://www.investidorpetrobras.com.br/pt/governanca/relatorio-de-sustentabilidade/relatorio-desustentabilidade-2013.htm

http://www.petrobras.com.br/pt/energia-e-tecnologia/

Saraiva, T. A. (2013). Uma Aplicaç~ao de um Modelo Multi-Hubbert Modificado para a Elaboraç~ao de Cen�arios de Produç~ao de Petr�oleo no Brasil, Dissertaç~ao de Mestrado, Programa de Planejamento Energético—COPPE/UFRJ, Rio de Janeiro, RJ, Brasil.

Schendel, R., (1984). Gas separation membranes and the gas industry. Apresentaç~ao em PCGA Transmission Conference. San Jose, CA.

Statoil. (2013a). http://engeprojnews.blogspot.com.br/2013/10/armazenamento-geologico-de-

co2-eor-no.html.

Statoil. (2014a). Sleipner Vest. http://www.statoil.com/en/EnvironmentSociety/Sustainability/

2007/Environment/Climate/CarbonCapture/Capture/Pages/SleipnerVest.aspx.

Statoil. (2014b). In Salah. http://www.statoil.com/en/technologyinnovation/newenergy/

co2capturestorage/pages/insalah.aspx.

UOP. (2013). http://www.uop.com/?press_release¼honeywells-uop-technology-selected-by- petrobras-for-natural-gas-processing-in-brazil.

Wood Mackenzie. (2013). Brazil Country Overview. Report on oil and gas production areas.

45 Geo.: Gas Production in Offshore Reservoirs in Brazil’s Pre-salt Region 629

http://www.uop.com/?press_release=honeywells-uop-technology-selected-by-petrobras-for-natural-gas-processing-in-brazil

http://www.statoil.com/en/technologyinnovation/newenergy/co2capturestorage/pages/insalah.aspx

http://www.statoil.com/en/EnvironmentSociety/Sustainability/2007/Environment/Climate/CarbonCapture/Capture/Pages/SleipnerVest.aspx

http://engeprojnews.blogspot.com.br/2013/10/armazenamento-geologico-de-co2-eor-no.html

Part XII

Environmental Technologies Related to Global Warming

Water Resources and Management Issues

Water management issues reflected on specific test cases

Chapter 46

Spatial and Temporal Patterns of the Water Quality in the Hammam Boughrara Reservoir in Algeria

Belkheir DJELITA, Souaad Bouzid-Lagha, and Kheira Camellia NEHAR

Introduction

Algeria is one of the countries where water availability is limited while the needs

are growing strongly. This growth is due to the population explosion, the industrial

and agricultural development as well as drought. To address this shortage, dam

construction seems to be the most suitable solution to meet different needs. If these

structures constitute a necessity to ensure, in any season, the water supply essential

for our country, it should control and protect the quality of water dams against

various sources of pollution, particularly those due to human activities, namely

agricultural practices, industrial and urban waste. Note that these discharges loaded

pollutants often lead to the natural environment without any treatment. Added to

this, the soil erosion natural processes are likely to bring different elements that

may be the cause of the deterioration of the water quality. One consequence of this

is the enrichment of water by nutrients, especially phosphorus and nitrogen, indi-

cators of an advanced eutrophication of water status (El-Ghachtoul et al. 2005).

Eutrophication is an increase in the fertilization of the lake water by a contribu-

tion of nutrients favoring their proliferation of phytoplankton and aquatic plants.

Gradually, this process accelerates sedimentation: the lake is shrinking, is closing

and finally disappears (Ramade 1982). This phenomenon was classified in 1997 by

B. DJELITA (*) • S. Bouzid-Lagha Laboratory of Environment, Water, of Geomechanics and Structures (LEEGO),

Faculty of Civil Engeniering (FCE), University of Science and Technology Houari

Boumediene (USTHB), BP 32 El-Allia, Bab-Ezzouar, Algiers 16111, Algeria

e-mail: [email protected]; [email protected]

K.C. NEHAR

University of Zian Achour, Djelfa BP 3117, Algeria

e-mail: [email protected]

635

mailto:[email protected]

the International Lake Environment Committee (ILEC), the fourth of the six major

risks that may affect the lakes and reservoirs of the planet.

The present study focuses on the dam Hammam Boughrara and aims to establish

a diagnosis of the current trophic state of the lake to contribute to the knowledge of

the evolution of this ecosystem. The first aim of this study is to assess the trophic

status of the dam, including eutrophication seems to be an evolutionary process,

natural, nutrient salts and therefore more and more rich in living organisms and

organic matter. Indeed, the lakes are pitfalls to nutritive substances they are

simultaneously victims. The Second is to determine the influence of water quality,

by its physico-chemical properties, chemical and biological aquatic populations. As

The third, it aims both to establish a better understanding of the quantitative

relationship between the intake of nutrient materials and trophic response of our

dam, the other to determine the impact of morphology, hydrology and physico-

chemical characteristics on the latter.

Materials and Methods

Presentation of the Study Site

Hammam Boughrara Dam, located in the extreme northwest of the Wilaya of

Tlemcen (West Algeria), belongs to the watershed area of river Mouillah, whose

area (largely shared with Morocco) is 2000 km2. This basin is bounded by a

perimeter of 241 km and composed in its majority by Angad Plains (located in

Oujda Moroccan territory) and that of Zrigua (located in Maghnia Algerian terri-

tory). The length of its main trough is 104.4 km (Fig. 46.1).

The study area is characterized by a semi-arid climate with mild winter, where

the average annual rainfall is 325 mm, the average annual temperature is 18.5 �C and potential evapotranspiration of 1167 mm. Monthly liquid intake is highly

variable with maximum averages in November (6.29 hm3) and lowest in June

(0.88 hm3). Solid contributions are also variable, the highest values are observed

in March with 0.15 MT and the lowest in July with 0.003 MT. From a geomorpho-

logical point of view, the catchment area of the river Mouillah is characterized by

an elongated shape (k¼ 1.5), an index of overall slope Ig¼ 7.5% and a concentra- tion time Tc¼ 12 h, which means speeds low, favoring the settling of solids in streams. Therefore, the runoff reaches the watershed outlet, low in suspended

solids.

On the geological basin, a terrain succession from Paleozoic to Quaternary has

been identified. The ancient land, dominated by carbonate formations (limestones

and dolomites very cracked and karstified) and sandstone are the reliefs. The

depressions are covered with soft terrain represented by clays, gypsum marl,

alluvium and silt.

636 B. DJELITA et al.

Built at the confluence of oueds Tafna and Mouillah the dam Hammam

Boughrara is intended mainly to meet the drinking water supply needs (AEP) of

cities of Oran (33 hm3) and Maghnia (17 hm3) ; 09 hm3 are provided for irrigation.

It is characterized by a total capacity of 177 hm3, volume 59 hm3 regularized and a

dead volume of 23.30 hm3. The area of the lake is 984 ha. Liquid intake of Wadi

Mouillah to the barrier Hammam Boughrara, as measured by the National Agency

for Water Resources (ANRH) during the 1999–2008 period an average of 79% of

the total intake. The rest is provided by its tributaries. As for the operation of the

dam, monitoring was conducted during the 1999–2008 period. The main results are

shown in the following table (Table 46.1).

They testify to a renewal rates (or dilution) Water (D¼Q/V) relatively small, rarely exceeding unity. Using the formula (D¼ 1/Ts) largely confirmed these results by order of values 0.39<D< 1.14 y�1. With Q: flow in m3/y; V: lake volume in m3. Ts values: mean residence time of the water in the dam (yr), are

shown in Table 46.2.

Fig. 46.1 Situation of the watershed of Oued Mouilah

46 Spatial and Temporal Patterns of the Water Quality in the Hammam Boughrara. . . 637

T a b le

4 6 .1

S it u at io n o f D am

H am

m am

B o u g h ra ra

in o p er at io n (1 9 9 9 – 2 0 0 8 )

Y ea rs

P lu v io m et ry

(m m )

T ri b u ta ry

(h m

3 )

C o n so m m at io n -A

E P (h m

3 )

Ir ri g at io n

(h m

3 )

L ac h er

V .F O N D

L ea k

(h m

3 )

E v ap o ra ti o n

(h m

3 )

D ef fl u en t

(h m

3 )

O ra n

M ag h n ia

O ra n

M ag h n ia

1 9 9 9 – 2 0 0 0

2 1 5 .0

1 1 .5 9 3

– –

8 .9 5 8

– 0 .0 1 0

3 .6 6 3

1 2 .6 1 2

2 0 0 0 – 2 0 0 1

2 3 8 .6

3 6 .6 5 1

8 .8 8 8

– 9 .6 2 6

– 0 .0 1 4

4 .6 8 1

2 3 .2 0 8

2 0 0 1 – 2 0 0 2

3 0 8 .6

4 3 .9 1 7

3 9 .7 5

– 9 .2 7 3

0 .3 2 4

0 .0 3 0

4 .5 6 9

5 3 .9 4 6

2 0 0 2 – 2 0 0 3

2 9 3 .6

3 8 .1 5

3 1 .9 8

– 1 .9 1 6

0 .0 2 7

0 .0 3 6

4 .1 7 3

3 8 .1 3 2

2 0 0 3 – 2 0 0 4

3 4 6 .6

4 8 .3 7 1

3 9 .3 7 8

– 4 .4 0 9

0 .3 6 0

0 .0 3 6

3 .8 6 3

4 8 .0 1 1

2 0 0 4 – 2 0 0 5

2 2 9 .3

1 5 .2 0 2

6 .0 4 4

0 .3 4 2

– 1 .0 2 3

0 .0 3 6

3 .4 4 1

1 2 .1 9 6

2 0 0 5 – 2 0 0 6

1 8 9 .6

3 8 .4 4 9

6 .9 0 9

7 .0 0 8

– 0 .5 4 0

0 .0 3 6

5 .0 9 3

1 9 .6 4 3

2 0 0 6 – 2 0 0 7

2 5 3 .0

3 2 .3 2 5

1 .9 9 2

6 .4 9 0

– 0 .3 4 3

0 .0 4 5

6 .2 5 2

1 5 .1 2 2

2 0 0 7 – 2 0 0 8

2 0 3 .0

3 0 .1 2

4 .4 6 5

3 .2 1 0

– 0 .0 8 7

0 .0 2 6

3 .8 3 4

1 6 .4 2 2

S o u rc e:

N at io n al

A g en cy

fo r D am

s an d T ra n sf er s (A

N B T )

638 B. DJELITA et al.

Sources of Pollution

Domestic pollution

Generally, this pollution is from discharges domestic waste water of all cities and

towns, located in the algerian part of the basin, namely the communes of Maghnia,

Bougherara Hammam, Sidi Medjahed and Bouhlou. A wastewater treatment plant,

with a total capacity of 150,000 population equivalents, was performed to treat

wastewater from the city of Maghnia. after several tests conducted from June 1999

to January 2000, the station has gradually achieved acceptable results.

Industrial pollution

Industrial effluents comes from four companies:

The ENOF: Company nonferrous minerals and useful substances. It produces

bleaching earth and bentonite foundry and used as raw materials: clay, and calcium

carbonate (CaCO3), and as secondary material: 98% sulfuric acid (H2SO4) and

sodium carbonate (Na2CO3). It rejects 500 m 3/day of water containing suspended

particles of clay, metal and heavy metals. All of these releases are in the wadi

Ouerdifou.

The ENCG: fatty substances Complex. It produces oil, soap and glycerin. It uses

as raw material: crude oil, animal and vegetable fats, and as secondary materials:

sodium hydroxide (NaOH), phosphoric acid (H3PO4), sodium chloride (NaCl) and

ferric chloride (FeCl3). The ENCG rejects 528 m 3/day of water containing crude

oils, tallow and glycerin. Releases are in the wadi Abbes (tributary of the wadi

Ouerdifou).

The ERIAD: Company food and derivatives industries. The unit produces

products derived from corn. It uses as raw materials corn, and secondary materials

Table 46.2 Results of the application of Eqs. (46.1) and (46.2) of dam Hammam Boughrara

N� (1) (2) (3) (4) (5) (6) Years Z (m) A0 (m

2) TS (yr) Lt(P) (t yr �1) Ld(P) (t yr�1) L. entré (t yr�1)

1999 10.6 2,538,983 2.32 0.37 0.49 6.34

2000 14.0 3,803,621 1.45 0.75 1.11 33.05

2001 15.3 4,097,382 1.52 0.82 1.23 14.21

2002 13.5 3,645,454 2.48 0.56 0.76 6.85

2003 12.6 3,397,891 1.18 0.70 1.06 21.73

2004 12.0 3,137,695 0.87 0.75 1.18 32.62

2005 11.0 2,813,500 1.19 0.54 0.80 35.89

2006 14.5 3,893,022 1.52 0.76 1.13 43.94

2007 18.8 4,790,995 2.57 0.83 1.18 31.42

Source of parameters Z, A0, Ts: ANRH & ANBT

46 Spatial and Temporal Patterns of the Water Quality in the Hammam Boughrara. . . 639

such as: sulfur water at 0.2% (SO2), hydrochloric acid (HCl), sodium carbonate and

sodium bisulfite. It rejects 600 m3/day of water containing gluten in Wadi Abbes.

TheECVO: ceramic tableware company. It uses as rawmaterials: clay, kaolin, sand,

water, calcite, dolomite, gypsum, mineral dyes and feldspars. It rejects 130 m3/day

of highly contaminated water with minerals in the wadi Abbes.

Agricultural pollution

Agricultural activities in the studied watershed are located mainly in the irrigated

area of Maghnia and especially in the plain of Angad.

The major sources of pollution from these activities are: fertilizer application,

soil treatment and plant well as livestock, especially poultry. Added to this, a

potential source of pollution that can cause serious damage to health and the

environment, in this case, storage of obsolete pesticides and maintenance of

agricultural machinery (drain) well as fuel and lubricants

Pollution from the Moroccan side

This pollution is caused by urban and industrial wastewater from the Moroccan

town of Oujda, discharged directly into the Oued Bounaim, the main tributary of the

Oued Mouillah, without any treatment.

Data and Methods

Faced with the problem of eutrophication, assessment of water quality requires

knowledge, as complete as possible, physicochemical and biological water. To this

end, nineteen (19) parameters (temperature, pH, conductivity, Ca, Mg, Na, K, Cl,

SO4, HCO3, NO2, NO3, PO4, Ptot, O2dissous, NH4, TSS, BOD5, COD) and biotic

parameters (chlorophyll a, phytoplankton) were selected.

Monthly samples were taken at the surface, at a station located in the tower

measures water intake dam over a period from 1999 to 2008. The samples used for

assays of chemical parameters and chlorophyll (a) have been achieved through a

bottle of overturning 2 L capacity. Various methods of analysis were used (Rodier

et al. 2005). Thus, the temperature, the salinity and the pH were measured by a

standard field probe WTW Multiline P3 PH/LF-SET. Dissolved oxygen was mea-

sured by the chemical method of Winkler. Chemical parameters, Ca, Mg, Na, K, Cl,

HCO3, NO3, NO2, NH4, PO4, and Ptot were analyzed by colorimetric methods using

a spectrophotometer. The gravimetric method was used for the determination of

SO4. Chlorophyll (a) was measured by the fluorimetric method described by

Neveux (1976). The analyzes were performed in the laboratories of the ANRH.

The results were the fundamental database for this study.

640 B. DJELITA et al.

Results and Interpretations

Study of Physicochemical and Biotic Parameters

The graphical representation of different results and reading of changes in physical

and chemical parameters (temperature, conductivity, Ph, Ca, Mg, Na, K, Cl, SO4,

HCO3, NO2, NO3, NH4, PO4, Ptot, O2dissous, TSS, BOD5, COD) imposes the

following comments:

– the monthly temperatures range between 10 and 12.5 �C in winter and between 25 and 31 �C in summer. The annual average is around 18.5 �C.

– the electrical conductivity fluctuates between 977 and 2750 μs/cm and indicates a highly mineralized water. This high mineralization would be due, firstly, to

leaching of the crossed fields and, secondly, to the pollution of waters from

industrial, domestic and agricultural.

– the pH measured varying between 7.5 and 9.1, indicating low to moderately

alkaline water. the value of 9.1 recorded in September 2004 coincided with high

photosynthetic activity.

Graphical representations and interpretations of concentrations of dissolved

oxygen (O2), suspended solids (TSS) and biochemical and chemical oxygen

demand (BOD5, COD), are as follows (Fig. 46.2):

– The Summer dissolved oxygen levels, ranging from 1.3 to 23 mg/L and is

abnormally proportional to temperature. This could be due, firstly, to the intense

photosynthetic activity, on the other hand, to the exchange of oxygen between

air and water, as our sampling station is located on the surface.

– The values of TSS, below 75 mg/L, show that the dam water is of acceptable

quality, with the exception of those of June 2002 and April 2004 (200 and

175 mg/L) due to major floods.

– The BOD5 is generally greater than 15 mg/L. These high values correspond to

high organic load mainly from the food industry. As to the DCO concentrations

vary between 19 and 110 mg/L. High values are associated with an increase in

Fig. 46.2 Monthly evolution of dissolved oxygen, TSS, BOD5 and COD (1999–2008)

46 Spatial and Temporal Patterns of the Water Quality in the Hammam Boughrara. . . 641

the amount of organic material and the oxidizable substances. The BOD5/COD

ratio of between 0.2 and 0.6 indicates the possibility of a biological treatment.

– Total phosphorus contents (Ptot), much higher than 0.5 mg/L (Standard ANRH)

indicate mediocre water quality at extremely polluted. They are due on the one

hand, for industrial discharges including those containing detergents, secondly,

to the phosphate fertilizers used in agriculture. It should be noted that the values

of phosphate (PO4) are consistent with those of total phosphorus and are always

less, with an average value of 2.37 mg/L. This confirms the excessive pollution

of water studied (Fig. 46.3).

– The concentrations of ammoniacal nitrogen (NH4) are the highest recorded in

January 2004, February 2005, April 2005, May 2005 and February 2006. They

are 12.2, respectively; 13.3; 14.8; 11.35 and 11.9 mg/L.

Concentrations of nitrite (NO2) vary between 0.01 and 4.5 mg/L.

These high values are due to industrial waste (ERIAD, corn mill and ENCG).

The values of nitrate (NO3) fluctuate between 1 and 15 mg/L (Fig. 46.4).

As to major cations and anions, we can see that:

– Values of chloride (Cl) showed a significant difference between the month and

vary between 213 and 510 mg/L. which ranks our water in Class 6 characterized

Fig. 46.3 Monthly variation in concentrations of total phosphorus and phosphates (1999–2008)

Fig. 46.4 Monthly variation in concentrations of ammonia Nitrogen, Nitrites and Nitrates (1999–2008)

642 B. DJELITA et al.

by specific water more or less polluted. Their presence is exclusively related to

discharges of ENCG (soap Workshop) dominated by sodium chloride (NaCl),

used to activate saponification.

– The average concentrations of sulphates (SO4) recorded is 155 mg/L and proves

that these waters are heavily polluted or very selenitic. This is due to the increase

in sulfur waste urban waste and especially industrial (ENOF unit with sulfuric

acid rejection of 98%).

– Bicarbonates range from 127 to 487 mg/L. They are due to the predominance of

limestone in the watershed.

– The calcium contents (Ca) sometimes exceed 100 mg/L, which may be related to

discharges of ENOF and the predominance of limestone in our site.

– Sodium values (Na) fluctuate between 113 and 416 mg/L. High levels recorded

in the summer, would be mainly due to the scarcity of precipitation combined

with increased evaporation.

– The potassium concentration (K) generally vary between 10 and 21 mg/L with

peaks of up to 32 mg/L. They result from the contributions of groundwater and

runoff. The concentration of magnesium (Mg) vary between 35 and 109 mg/L.

– The Values of chlorophyll “a” vary between 0.5 and 23.8 mg/L. The lowest

recorded concentrations may be due to the decrease of the water temperature and

the reduction of the light intensity. Those recorded in the summer would likely

due to high levels of suspended solids that increase the turbidity of the medium

and reduce, thus the photosynthetic activity. It should be noted, however, that

these values are unusually low for the season. The peak values recorded are due

to the elevation of the algal activity stimulated by environmental enrichment in

nutrients including phosphorus and nitrogen.

Modelisation of Water Plane

In studies of eutrophication, a multitude of models have been developed and

applied to various problems. We will concentrate on models of reservoir lakes.

This is justified by the fact that these models are used for two distinct purposes, but

closely related. They can, on one hand, help in the understanding of the processes

that further determine the overall behavior of the lake and on the other hand, used to

predict the response of the lake at a given change, such as a change in the burden of

nutrients or liquids contributions. Thus, they are a very useful tool for the evalua-

tion of eutrophication and planning and water resources management.

We considered the two main approaches to modeling (Riley 1946):

• The empirical approach: In empirical models (development of an equation from

statistical correlations of data), system variables are related to the input variables

without the detailed mechanisms that cause their relationships are known. The

relationship between trophic status, average depth of the lake and phosphorus

load, developed by Vollenweider (1968), is an example of this type of model.

46 Spatial and Temporal Patterns of the Water Quality in the Hammam Boughrara. . . 643

• Conceptual approach: conceptual models (development of an expression on

theoretical grounds and its subsequent combination with constants derived

data) attempt to explain the interactions between different components of the

system. As an example of simple models in this category include nutrient

balance models, such as phosphorus, also developed by Vollenweider (1975,

1976a, b). The model gives a differential equation for the average concentrations

of nutrients, based on a number of input parameters and the lake. In practice, the

two approaches, empirical and conceptual, are usually combined.

Based on these considerations and in order to proceed to the modeling of the

water dam Hammam Boughrara, we followed the following steps:

Estimate of Tolerable and Dangerous Loads of Phosphorus

Concentration in the Dam Hammam Boughrara According

Vollenweider

The equation of Vollenweider (1976b) permits to determine if phosphorus loading

constitutes a risk of eutrophication, since the charges “tolerable” and “dangerous” a

water body are set at 10 and 20 μg P/L, these loads are represented by the following equations:

Lt Pð Þ ¼ A0 100þ 10Z TS

� � ð46:1Þ

Ld Pð Þ ¼ A0 100þ 20Z TS

� � ð46:2Þ

Where: Lt(P)¼ tolerable loads; Ld(P)¼ dangerous loads; A0: the area of the tank (m2); TS: the mean residence time of the water in the tank (year); The entered. :

Estimated annual phosphorus load into our dam (t/year); Z: the average depth of the

container (m).

It should be noted that:

A0: was determined from the curve “height- capacity -surface” of the dam,

established by ANBT collaboration with the research department FUGRO GEOID

SAS-LEM (Laboratory for Maritime Studies), Algiers.

TS¼V/Q¼ lake volume (m3)/flow at the outlet (m3 an�1) The results of the application of these equations waters Boughrara dam are

shown in the following table (Table 46.2).

The values of tolerable and dangerous loads calculated using the equation

Vollenweider (1976b) (Table 2) show that the quantity of phosphorus in the dam

is 9–45 times greater than the load “dangerous” set by this equation when these

values were recorded in 2002 and 2005 respectively. The dam would therefore have

the characteristics of a hyper-eutrophic lake.

644 B. DJELITA et al.

It is emphasized that the application of these equations is not very reliable,

knowing they have been established according to water bodies located in temperate

zones at different trophic states; and that the dam studied (Hammam Boughrara) is

located in a Mediterranean climate zone and receives too loaded water nutrient

urban and industrial original features.

Simple Model of the Phosphorus Cycle (Vollenweider Model)

Vollenweider (1975, 1976a) has developed its models on the conceptual basis that

the concentration of phosphorus in lakes, although largely determined by the rate of

contributions is modified by losses to the sediments and in the flow of lake. Hence

the new formula Vollenweider (1976a):

P ¼ Lp qs

1þ ffiffiffiffiffiTspð Þ ð46:3Þ

Where Ts¼ l/Γw, is the average residence time of water (yr). Γw : annual frequency of renewal (yr�1).

The OCDE Model, 1982

This model represents the equation (3) after being perfected on the base of the

results of the international OCDE study (1982) and is expressed as follows:

P½ �λ ¼ 1:55 P½ �j

1þ ffiffiffiffiffiTspð Þ � �0:82

ð46:4Þ

Where: P½ �λ: average annual concentration of total phosphorus in the lake (μg/L); P½ �j ¼ Lpqs : average concentration of phosphorus in annual water intake (μg/L).

Application of Models in the Dam of Hammam Boughrara

The data are based on the results of analyzes made during the period from 1999 to

2007 by the services of the ANRH (Table 46.3).

The results of the application of Eqs. (46.3) and (46.4) obtained from the data of

Table 46.3 are summarized in Table 46.4.

The application of models, Vollenweider and OCDE, for the various annual

loads gave values close and near each other, but below the actual measured

concentrations.

46 Spatial and Temporal Patterns of the Water Quality in the Hammam Boughrara. . . 645

T a b le

4 6 .3

R ec ap it u la ti o n o f d at a (1 9 9 9 – 2 0 0 7 )

1 9 9 9

2 0 0 0

2 0 0 1

2 0 0 2

2 0 0 3

2 0 0 4

2 0 0 5

2 0 0 6

2 0 0 7

L : to ta l an n u al

in ta k e o f p h o sp h o ru s (t o n n es )

6 .3 4

3 3 .0 5

1 4 .2 1

6 .8 5

2 1 .7 3

3 2 .6 2

3 5 .8 9

4 3 .9 4

3 1 .4 2

A v er ag e v o lu m e o f th e re se rv e (h m

3 )

2 3 .3 3

4 0 .5 5

4 5 .3 2

3 8 .1 6

3 5 .1 2

3 1 .4 9

2 7 .2 4

4 2 .0 1

2 3 .3 3

S u rf ac e w at er

(1 0 6 m

2 )

2 .5 4

3 .8 0

4 .1 0

3 .6 5

3 .4 0

3 .1 4

2 .8 1

3 .8 9

2 .5 4

L iq u id

an n u al

in ta k e (h m

3 )

1 1 .5 9

3 6 .6 5

4 1 .2 5

1 9 .8 5

3 6 .1 4

4 3 .2 8

2 5 .9 7

3 7 .0 8

3 5 .1 1

Z : av er ag e d ep th

o f th e d am

(m )

1 0 .6 0

1 4 .0 0

1 5 .3 0

1 3 .5 0

1 2 .6 0

1 2 .0 0

1 1 .0 0

1 4 .5 0

1 8 .8 0

T s: R es id en ce

ti m e

2 .3 2

1 .4 5

1 .5 2

2 .4 8

1 .1 8

0 .8 7

1 .1 9

1 .5 2

2 .5 7

q s: A n n u al

w at er

lo ad

p er

u n it ar ea

4 .5 7

9 .6 4

1 0 .0 7

5 .4 4

1 0 .6 3

1 3 .7 9

9 .2 3

9 .5 3

7 .3 3

L p : an n u al

ch ar g e o f P p er

u n it ar ea

2 4 9 5 .7

8 6 8 8 .3

3 4 6 9 .2

1 8 7 9 .3

6 3 9 6 .4

1 0 3 ,9 6 .9

1 2 7 ,5 5 .4

1 1 2 ,8 5 .7

6 5 5 7 .1

C o as t in

m N G A

(N at io n al

G eo sp at ia l- In te ll ig en ce

A g en cy )

2 7 7 .7 5

2 8 3 .2 6

2 8 4 .4 7

2 8 2 .6 2

2 8 1 .7 6

2 8 0 .6 4

2 7 9 .2 1

2 8 3 .6 4

2 8 7 .9 5

S o u rc e:

A N R H &

A N B T

646 B. DJELITA et al.

The difference between the values calculated by these models and the measured

values could be several explanations for namely:

– the hypotheses of the models suggest that the lake is a homogeneous reactor,

there are no differences in concentrations in the water column. However,

differences exist of concentration in the same column of water especially at

the bottom. This is due to release of phosphorus at the sediment-water interface.

These hypotheses therefore become difficult to apply to the dam studied.

– One of the conditions for the application of the two models assume constant

inputs of phosphorus during the year. The observed irregular contributions do

not verify this hypothesis.

– The difference in high phosphorus concentration would be anthropogenic. Urban

and industrial waste undergoes primary treatment that degrades the organic

materials and leave the water containing phosphorus.

Adaptation of the OCDE Model for Estimating Phosphorus

Concentrations Dam Hammam Boughrara

The differences in phosphorus concentrations observed between the calculated and

measured values can’t be just a consequence of regional climate character (Medi- terranean), it is appropriate to add the effect of human activity. Thus has established

itself the adaptation of the model in question the reality of the waters of the dam

studied. For this purpose we used a non-linear estimation method Rosenbrock and

Quasi Newton, resolvable by “STATISTICA 6.1” software.

Remember that the OCDE equation is of the form:

Y ¼ a*Xb ð46:5Þ

knowing that: Y ¼ P½ �y; X ¼ P½ �J1þ ffiffiffiffiTSpð Þ � �

Table 46.4 Results of models application of Vollenweider (1976a) and of OCDE (1982)

Year Y ¼ P½ �y (μg/L) P ¼

Lp qsð Þ

1 þ√ T sð Þ (μg/L)

P½ �λ ¼ 1, 55 P½ �j

1 þ√ T sð Þ � �0,82

(μg/L) 1999 2186.3 216.59 127.51

2000 3606.6 408.85 214.69

2001 1378.3 154.33 96.57

2002 1380.8 134.08 86.05

2003 2405.8 287.99 161.07

2004 3015.0 389.97 206.53

2005 5528.3 660.70 318.22

2006 4739.1 530.40 265.77

2007 3579.1 343.93 186.31

46 Spatial and Temporal Patterns of the Water Quality in the Hammam Boughrara. . . 647

We will try to find again the coefficients a and b, based on the measured values.

The derived equation is of the form:

P½ �λ ¼ 1, 48*X1,28 ð46:6Þ

This equation permits to determine the values of concentration, average annual

total phosphorus in the dam, from the average total phosphorus loads.

The results obtained are shown in column (3) of the following table (Table 46.5).

The majority of the points are within the confidence interval of 95% with a

correlation coefficient R2¼ 0.87, which shows that the model fits correctly (Fig. 46.5).

Table 46.5 Results of the application of Eq. (46.6) Dam

Hammam Boughrara

N� (1) (2) (3)

Years

Y ¼ P½ �y (μg/L)

X ¼ P½ �J 1þ ffiffiffiffiTSpð Þ

� � P½ �λ ¼ 1, 48*X1,28

1999 2186.36 216.59 1489.75

2000 3606.67 408.85 3371.86

2001 1378.33 154.33 963.58

2002 1380.83 134.08 804.14

2003 2405.83 287.99 2148.84

2004 3015.00 389.97 3172.96

2005 5528.33 660.70 6249.58

2006 4739.17 530.40 4711.90

2007 3579.17 343.93 2699.69

Fig. 46.5 Relationship between the intake and the Phosphorus [from Eq. (46.6)] at the dam Hammam Boughrara

648 B. DJELITA et al.

The regression line, indicating the relationship of observed values based on

theoretical values calculated by the equation (7) shows good linear fit as most

points fall within the confidence interval of 95% (Fig. 46.6).

Qualitative Predictions

The management of dam requires the mastery of water quality forecasting system.

The open simple classification system is based on the probabilistic method, it

allows to define five categories namely: ultra-oligotrophic, oligotrophic, mesotro-

phic, eutrophic and hyper-eutrophic.

This classification was developed from a large database of more than a hundred

of water qualities and different trophic states (OCDE 1982). This system allows to

state a prediction closer to the reality that facilitates the evaluation and management

of eutrophication.

Figures 46.7, 46.8 and 46.9 illustrate the classification system and the recovery

of values to different thresholds obtained by projection, concentration values of the

different curves of trophic states then the probabilistic condition, in order to have

the percentage of each trophic state.

The parameters presented in the following table (Table 46.6) characterize the

probabilistic trophic status of the dam Hammam Boughrara. They are based on the

figures of distribution of trophic states.

Fig. 46.6 The regression line Eq. (46.6), indicating the relationship between the observed and predicted values of the mean concentration phosphorus water dam Hammam Boughrara

46 Spatial and Temporal Patterns of the Water Quality in the Hammam Boughrara. . . 649

From the open classification system based on the charts of the OECD (1982) and

according to the results of the models Vollenweider and OECD applied to our lake,

the probabilistic trophic status usually varies from eutrophic to hyper eutrophic.

Otherwise, the results of appropriate equations show a state 100% hyper eutrophic.

0,5

1,0

1 10 100 1000

Oligotrophie Méstrophie Eutrophie HypereutrophieUlta- oligotrophie

Phosphore total

[P] μg/l

Fig. 46.7 Trophic state distribution function of the total average concentration of phosphorus dam Hammam Boughrara (according Vollenweider 1976a)

0,5

1,0

1 10 100 1000

Oligotrophie Méstrophie Eutrophie Hypereutrophie Ulta- oligotrophie

Phosphore total

[P] μg/l

Fig. 46.8 Distribution of trophic states based on the total average concentration of phosphorus dam Hammam Boughrara (based on OCDE 1982)

650 B. DJELITA et al.

Conclusion

The study of physico-chemical and biological characteristics of water collected in

the dam Hammam Boughrara reveals high concentrations of certain parameters

such as Cl, SO4, NH4, NO2, Na, P, BOD5 and COD, which characterize water

highly mineralized and selenitic with conductivities ranging from 977 to 2750 μs/ cm. These waters are rich in nutrients, such as phosphorus, and with a slightly

alkaline pH (between 7.5 and 9.1) favor the proliferation of phytoplankton. This

proliferation causes a decrease in transparency and dissolved oxygen are also signs

of eutrophication. However, the BOD5/COD ratio, ranging between 0.2 and 0.6,

indicating the possibility of a biological treatment. The observed concentrations

of K, Mg, HCO3 result of a contribution by groundwater and leaching of carbonate

terrains. The knowledge of the trophic status of a dam is not enough. To protect it,

we must be able to predict the one hand, changing its state department overlooked

time changes in phosphorus concentrations and their impacts on the ecosystem, on

the other hand, better manage discards based on water use.

Thus, the application of models Vollenweider and OCDE annual loads to

different phosphorus, gave close but lower than actual concentrations estimates.

These models cannot be applied as such to our site, especially as climate and

anthropogenic conditions on which these models are not verified in our case.

Therefore, we adapted the parameters a and b of equation : Y ¼ a∗Xb (OCDE 1982) and in our case, by using the non-linear estimation method Rosenbrock and

Quasi Newton. The regression line obtained using the above mentioned equation,

equipped with the new parameters a and b, shows good fit all the points with

0,5

1,0

1 10 100 1000

Oligotrophie Méstrophie Eutrophie Hypereutrophie Ulta- oligotrophie

Phosphore total

[P] μg/l

Fig. 46.9 Distribution of trophic states based on the total average concentration of phosphorus dam Hammam Boughrara (from Eq. 46.6)

46 Spatial and Temporal Patterns of the Water Quality in the Hammam Boughrara. . . 651

T a b le

4 6 .6

P ro b ab il is ti c tr o p h ic

st at es

d am

H am

m am

B o u g h ra ra

w it h in

th e p ar am

et er s o f si m p le

cl as si fi ca ti o n sy st em

Y ea rs

1 9 9 9

2 0 0 0

2 0 0 1

2 0 0 2

2 0 0 3

2 0 0 4

2 0 0 5

2 0 0 6

2 0 0 7

P t (μ g /L ) (V

o ll en w ei d er

1 9 7 6 a)

E q . (4 6 .3 )

% 0 o li g o .

1 m és o .

3 0 eu

6 9 h y p er

0 o li g o

0 m és o

0 9 eu

9 1 h y p er

0 o li g o

4 m és o

5 0 eu

4 6

h y p er

0 o li g o

6 m és o

5 6 eu

3 8

h y p er

0 o li g o

0 m és o

1 8 eu

8 2 h y p er

0 o li g o

0 m és o

1 0 eu

9 0 h y p er

0 o li g o

0 m és o

3 eu

9 7 h y p er

0 o li g o

0 m és o

5 eu

9 5 h y p er

0 o li g o

0 m és o

2 5 eu

7 5 h y p er

P t (μ g /L ) (O

C D E 1 9 8 2 ) E q . (4 6 .4 )

% 0 o li g o

7 m és o

5 8 eu

3 5 h y p er

0 o li g o

1 m és o

3 1 eu

6 8 h y p er

0 o li g o

1 3 m és o

6 4 eu

2 3

h y p er

0 o li g o

1 6 m és o

6 5 eu

1 8

h y p er

0 o li g o

4 m és o

4 8 eu

4 8 h y p er

0 o li g o

1 m és o

3 2 eu

6 7 h y p er

0 o li g o

0 m és o

1 5 eu

8 5 h y p er

0 o li g o

0 m és o

2 2 eu

7 8 h y p er

0 o li g o

2 m és o

3 9 eu

5 9 h y p er

P t (μ g /L ) E q . (4 6 .6 )

% 0 o li g o

0 m és o

0 eu

1 0 0

h y p er

0 o li g o

0 m és o

0 eu

1 0 0

h y p er

0 o li g o

0 m és o

1 eu 9 9

h y p er

0 o li g o

0 m és o

2 eu 9 8

h y p er

0 o li g o

0 m és o

0 eu

1 0 0

h y p er

0 o li g o

0 m és o

0 eu

1 0 0

h y p er

0 o li g o

0 m és o

0 eu

1 0 0

h y p er

0 o li g o

0 m és o

0 eu

1 0 0

h y p er

0 o li g o

0 m és o

0 eu

1 0 0

h y p er

O li go

o li g o tr o p h ic , m és o m es o tr o p h ic , eu

eu tr o p h ic , hy pe r h y p er -e u tr o p h ic

652 B. DJELITA et al.

correlation coefficient R2 equal to 0.87. The model thus obtained gives concentra-

tions near the measured values. However, it would be interesting to test it on a

longer observation period. The trophic status of the studied waters varies from

eutrophic to hyper-eutrophic according to the models of Vollenweider and OECD.

While the classification according to the adapted models is 100% hyper eutrophic

for phosphorus.

The probabilistic model obtained will contribute to better management of water

quality in terms of trophic response. It allows to set specific goals for reducing

phosphorus inputs depending on the intended use of the waters. Thus, it can be used

in the context of sustainable development and decision support.

References

Agence Nationale des Ressources Hydriques (ANRH). (2008). Bulletins mensuels de la qualité des eaux superficielles. Algérie: Oran.

El Ghachtoul, Y., Alaoui Mhamidi, M., & Gabi, H. (2005) Eutrophisation des eaux des retenues

des barrages Smir et Sehla (Maroc): Causes, conséquences et consignes de gestion. Revue des sciences de l’eau/Journal of Water Science, 18, 75–89.

ILEC. (1997). Water issue and Global Warming, International Lake Environment Committee

Foundation. http://www.ilec.or.jp/database/Gl.html.

Neveux, J. (1976). Dosage de la chlorophylle a et de la phéophytine a par fluorimétrie. In Annales

Institut Océanographique 52, pp. 165–174. OCDE (Organization for Economic Cooperation and Development). (1982). Eutrophication of

Waters. Monitoring assessment and Control, Final Report. OCDE, Cooperative Programme on

Monitoring of Inland Waters (Eutrophication control), Environment Directorate, OCDE, Paris, France.

Ramade, F. (1982). Elément d’écologie: Ecologie Appliquée. Action de l’homme sur la biosphère. Paris, France: Macgraw-Hill.

Riley, G. A. (1946). Factor controlling phytoplankton populations on Georges Bank. Journal of Marine Research, 6, 54–73.

Rodier, J., et al. (2005). L’analyse de l’eau: eaux naturelles, eaux résiduaires et eau de mer (8th ed.). Paris, France: Dunod.

Vollenweider, R. A. (1968). Scientific fundamentals of the eutrophication of lakes and flowing

waters with particular reference to nitrogen and phosphorus as factors in eutrophication.OECD Technical Report DAS, CSI, 68, 27–54.

Vollenweider, R. A. (1975). Input-output models with special reference to the phosphorus loading

concept in limnology. Schweiz Journal of Hydrology, 3, 53–84. Vollenweider, R. A. (1976a). Advances in defining critical loading levels for phosphorus in

eutrophication. Memorie della Societa Entomologica Italiana, 33, 53–83. Vollenweider, R. A. (1976b). Rotsee, a source, not a sink for phosphorus? A comment to and a plea

for nutrient balance studies. Journal of Hydrology, 38, 29–34.

46 Spatial and Temporal Patterns of the Water Quality in the Hammam Boughrara. . . 653

http://www.ilec.or.jp/database/Gl.html

Chapter 47

Natural Tracers for Identifying Causes of the Quality Reduction in Groundwater Emerging Along the Aegean Volcanic Arc (Greece)

E. Dotsika and P. Chantzi

Introduction

The Santorini and Nisyros volcano in Greece located along the Aegean volcanic

arc, which developed during the Quaternary time as a result of a lithosphere

subduction process (Le Pichon and Angelier 1979). The Aegean volcanic arc

comprises, from west to east, Loutraki, Egina, Milos, Santorini, Kos and Nisyros.

In the Aegean Sea, this arc (Fig. 47.1) represents the youngest example of volca-

nism and the only one that can be related to the zone of subduction. The morpho-

logical situation of such a geodynamic setting is found in the south (200 km) of the

arc where the African and Eurasian plate’s collision is in progress (Mckenzie 1970; Lort et al. 1974). The collision takes place from the Pliocene along the south

Aegean island arc and is responsible of volcanism and seism city (Makris 1978).

All the volcanic centers of the south Aegean islands are situated across the Benioff

zone at depth from 130 to 150 km, suggesting that subduction controls magma

generation. Several studies (Papazachos et al. 1995; Jolivet et al. 2013; Chatzipetros

et al. 2013) have shown that tectonic activity is very vigorous in the Aegean region

and all these areas and islands were affected by numerous tectonic events that are

still active.

E. Dotsika (*) Institute of Geosciences and Earth Resources, Via G. Moruzzi 1, 56124 Pisa, Italy

Laboratories of Stable Isotopes and Radiocarbon, Institute of Nanoscience and

Nanotechnology, National Centre for Scientific Research “Demokritos”, 15310 Agia

Paraskevi, Attica, Greece

e-mail: [email protected]

P. Chantzi

Laboratories of Stable Isotopes and Radiocarbon, Institute of Nanoscience and

Nanotechnology, National Centre for Scientific Research “Demokritos”, 15310 Agia

Paraskevi, Attica, Greece

e-mail: [email protected]

655

mailto:[email protected]

A significant number of thermal water springs emerge in the areas and islands of

the Aegean arc. The temperature of these waters springs ranges from 30 to 53 �C. Also an important number of fresh water springs, with degrading quality, emerge in

the vicinity of hot waters of these islands. These fresh water resources frequently

suffer from severe salinisation problems that put in danger present and future

Fig. 47.1 Study areas of Egina, Milos, Santorini, Kos and Nisyros of the Aegean Volcanic arc

656 E. Dotsika and P. Chantzi

utilization as well economic and social development of the concerned islands. The

origin of this salinisation is very often attributed to the sea water intrusion. In the

islands, marine water might enter the aquifer systems through different pathways

e.g., atmospheric transport of marine aerosols, direct seawater ingression, particu-

larly near the coastal zones, by seawater and modified seawater. However the

vicinity of cold springs with the thermal fields suggests that part of the salinisation

is due to the deep thermal water, coming from geothermal aquifers that intrude in

the fresh aquifers.

The mobile constituent, chloride, is one of the most important geochemical tools

used in the hydro geochemical investigations. The high chloride concentration, in

most groundwater aquifers, in potable and irrigation waters is attributed to evapo-

rative concentration, intrusion of seawater, dissolution of evaporates and human

pollution. Although chloride can be added to deep aquifers by different sources the

mixing processes could be identifiable. Additionally the correlation δ18O-δ2H and mobile specie are particularly useful to investigate the mixing, because they

provide information about the water sources and the different mixing processes

that can operate between the sources. Especially, the δ18O-δ2H isotope composition of groundwater is mainly affected by recharge altitude, water-rock interaction and

mixing of different fluids. Additionally, the use of isotopes of sulphate δ34S, δ18O, consents to identify the origin of the dissolved sulphates and the mixing between

sulphates of different origin. The 13C values of bicarbonates ions in thermal and

fresh waters are used to identify modification processes of equilibration between

water and CO2. The combined use of δ34S, δ18O(SO4), δ18O, δ2H, 13C and Cl� serves as tracers for identifying mixing processes in groundwater system and is used as an

important tool for recognizing the causes of the quality reduction of coastal water

systems.

In this study we used Cl�, HCO3 � and SO4

2� with isotopes of water, carbonate and sulphate to identify the spatial distribution of pollution and its possible origin.

Sampling and Analysis

Seventy-six samples were collected for chemical (Cl�, HCO3 �, SO4

2�) and isoto- pic analyses of water (2H, 18O), carbonate (13C) and sulfate (34S, 18O). The isotopic

composition of water was determined in all collected waters samples while the

isotopic composition of carbonate and sulfate was determined in selected waters

samples. δ13C were also determined in two samples of carbonate rocks and 34S were also measured in three samples of native sulfur from Santorini. Seventy one

samples of water were collected for this study: 3 from Loutraki, 7 from Egina,

21 from Santorini, 19 from Kos, 15 from Milos, 7 from Nisyros and one from sea

water. Temperature and HCO3 � were measured directly in situ. Untreated samples

were collected for analyses of Cl� and SO4 2�. The temperatures of water samples

varied between 16 and 53 �C. Emissions of gases from these waters are abundant in Santorini, Nisyros, Kos and Milos. The major chemical constituents were analyzed

47 Natural Tracers for Identifying Causes of the Quality Reduction. . . 657

with standard methods described in Apha (1989). The anions of the water samples

were analyzed with ion chromatography. The δ18O compositions of water in the samples were determined from CO2 equilibrated with the water (Epstein and May-

eda 1953). The δ2H compositions of water were determined from the H2 generated by the Zn-reduction method (Coleman et al. 1982). The dissolved SO4

2� in the water samples was precipitated as BaSO4 for the analysis of S isotopic composi-

tions (Rafter 1957). The dissolved HCO3 � in the water, for the analysis of 13C, is

collected as BaCO3 precipitates. Determination of the different isotope ratios

carried out in Laboratories of Stable Isotopes and Radiocarbon of Nanoscience

and Nanotechnology Institute in N.C.S.R. in Demokritos with the following preci-

sion: δ2H� 1‰; δ18O� 0.2‰; δ34S� 1‰; δ18O(SO42�)� 0.3‰; δ13C� 0.5‰.

Results and Discussion

The Origin of the Waters and the Sources of the Quality Reduction in Ground Water

The stable isotope contents show quite large variations of δ18O ranging from –7.3‰ to 1.4‰ and δD from –47.4‰ to 6.5‰. The limits of maximum and minimum values were drawn by Nisyros and Loutraki respectively. In general, the water

samples from thermal springs show an isotopic enrichment in relation to the fresh

waters.

The stable isotopic composition (δ2H versus δ18O) of all sampled waters from areas and islands of the Aegean Volcanic arc is shown in Fig. 47.2. At the same

diagram, the global meteoric water line (GMWL) (Craig 1961) is also marked.

Generally, an isotope relationship between δ2H and δ18O with a slope of about 8 is normal for fresh precipitation of all types (Craig 1961), as well as for surface waters

not subjected to excessive evaporation relative to input. In Greece the correlation

function for rainwater (IAEA 1981) is: δD¼ 7.2 * δ18O + 9.3. A regression equation similar to the above and slightly greater (7 and 7.5 respectively) is reported for the

northern part of Eastern Macedonia and for the Eastern Peloponnesus (Leontiadis

et al. 1984). A slope inferior to 7 is reported for Central Macedonia (Christodoulou

et al. 1993), the southern part of Eastern Macedonia and Thrace (Leontiadis

et al. 1996), as well as the northern part of Epirus (Leontiadis and Nikolaou

1999). The local meteoric line that correspond to Greece (LMWL) has a correlation

equation δ2H¼ 8.7δ18O + 19.5 (Dotsika et al. 2009). In Fig. 47.2, two linear correlations appear, apart from the water of mainly

meteoric origin (Loutraki, Egina, Poros), between δ2H and δ18O suggesting a different origin for both elements. Line A, which expresses all the water samples

coming from the islands, is an ideal line mixing between seawater and fresh water,

suggesting that the isotopic data of waters are the result of a mixing at different

degree of meteoric and seawater. This is the case mainly of Santorini Island. The

658 E. Dotsika and P. Chantzi

second line (B) groundwater, from Milos Island, presents an enrichment of δ18O in relation to the δ18O of meteoric waters of the area, while the δ2H remains about stable. This change could suggest the intervention of modification processes. So, for

better identification of the causes of the quality reduction in ground water we study

separately the areas of Santorini, Kos and Nisyros islands, Loutraki-Egina and

Milos Island.

The Case of Santorini, Kos and Nisyros Islands

Figure 47.3 shows the relationship δ2H and δ18O of all the sampled waters from Santorini, Kos and Nisyros islands. The waters from Santorini are distributed along

a line joining local seawater with local fresh water, suggesting that the hot and cold

waters result from a mixing at different degree of meteoric and seawater. These

isotopic data confirm the sea intrusion in fresh aquifers of Santorini Island. In fact in

Santorini a significant number of water boreholes was found, which presented high

Cl� and SO4 2� values. Nevertheless, such brackish waters, with relatively high

temperature, Cl� and SO4 2� contents, are used, in summer for irrigation and

drinking purposes, and could therefore have an antagonistic effect on crop yield

and health.

In the δ18O versus Cl� content (Fig. 47.3) diagram the samples from Santorini located along a straight line, which intercepts the x-axis at the δ18O content of�5.2 ‰. This value corresponds to the mean content of the local meteoric waters as the

Fig. 47.2 The stable isotopic composition (δ2H‰ vs V-SMOW versus δ18O‰ vs V-SMOW) of all sampled waters from Egina, Milos, Santorini, Kos and Nisyros of the Aegean Volcanic arc.

Closed square: Loutraki; : Egina; open triangle: Santorini; open parallelogram: Kos; open diamond: Milos; open square: Nisiros; cross: sea water

47 Natural Tracers for Identifying Causes of the Quality Reduction. . . 659

rainwater samples collected from the area have been found to have similar value for

the δ18O. The position of sample N-Avlaki from Nisyros in the diagram δ2H versus δ18O

(Fig. 47.2) is very close to that of mean seawater, confirming its purely marine

origin. Other samples from Nisyros show very strong meteoric contributions.

Similar positions, in the diagram δ2H versus δ18O, to the one of the N-Avlaki sample show also the water from Kos (Aghios Fokas) suggesting its marine origin

as well. In reverse the δ18O and δ2H contents of the other samples from Kos Island show a meteoric origin for these waters. However the dispersion of some data

suggests intervention of modification processes. Figures 47.4 and 47.5 show the

relationship between δ18O versus SiO2 (Fig. 47.4) and δ2H versus SO42�

(Fig. 47.5). Despite the small number of samples the positive correlation between δ 18O and SiO2 (Fig. 47.4) is of major importance as concerns mainly the samples

which present the major dispersion of δ18O and δ2H. This correlation, δ18O-SiO2, could be explained from the equilibration between water-rock or/and water-CO2 of

deep origin. The augmentation of SiO2 (and probably of HCO3 �) could show the

“aggressiveness” of the water correlated to the partial pressure of CO2. In the

diagram δ2H versus SO42� (Fig. 47.5) the enrichment of δ2H content is accompa- nied by an increase of SO4

2� content. This correlation could be attributed to the equilibration between water and H2S of volcanic origin. Figure 47.2, which sum-

marizes these modification processes, indicates the isotopic change of the fresh

waters due to the modification processes of the equilibration between water and

gases—CO2 and H2S—of deep origin. The isotopic values of the Kos meteoric

water are �6.5‰ and �37‰ for the 18O and 2H respectively. So these two hypotheses, equilibration between H2O-CO2 and H2O-H2S could explain the δ18O and δ2H of all waters sampled in Kos Island (Fig. 47.2). In Fig. 47.2 the lines A and

Fig. 47.3 The relationship between δ18O ‰ vs V-SMOW and Cl� (mg/L) content of Egina, Milos, Santorini, Kos and Nisyros of the Aegean Volcanic arc. Symbols as Fig. 47.2

660 E. Dotsika and P. Chantzi

B show the exchange with H2S and CO2. The intermediate area illustrates the

exchange with both gases, H2S and CO2, of deep origin. The two-δ13C values from the bicarbonate ions in the waters from Kos are �8.4‰ (Aghios Fokas) and 11.9‰ (Fouskis). The very positive δ13C values of bicarbonates ions from Kos (Fouskis) confirm the equilibration between water and CO2 of deep origin.

The negative δ13C data, similarly as data from the Santorini samples (range from �13.7‰ to �8.6‰) probably suggest that the main part of dissolved CO2 is of biogenic origin; even a small contribution of deep CO2 cannot be excluded.

Fig. 47.4 Relationship between δ18O ‰ vs V-SMOW versus SiO2 (mg/L) of Santorini samples. Symbols as Fig. 47.2

Fig. 47.5 Relationship between δ18O ‰ vs V-SMOW versus SO42� (mg/L) of Egina, Milos, Santorini, Kos and Nisyros of the Aegean Volcanic arc. Symbols as Fig. 47.2

47 Natural Tracers for Identifying Causes of the Quality Reduction. . . 661

In Fig. 47.6 the 34S and 18O (SO4) contents of the samples, from Santorini,

Nisyros and Kos, are compared with those of marine sulphate, which are very

constant over the world [δ34S¼ 20‰ CD, δ18Ο¼ 9.5‰ SMOW (Longinelli 1989; Loyd 1968; Rafter and Mizutani 1967, Mizutani and Rafter 1969)]. In the same

diagram, it is also reported the S-bearing sublimate of the Santorini Volcano (Nea

Kameni). In total, ten water samples were analyzed from Santorini and three

samples of native sulfur (δ34S of native sulfur 7.9‰, 5.7‰ and 8.8‰) of the Santorini Volcano, three water samples from Kos, one from Nisyros and one

seawater sample. It appears, in general, that the isotope contents of the samples

are different from those of the marine sulphates. Only one sample from Kos and one

from Nisyros do not differ significantly from those of seawater, suggesting that the

dissolved sulphates of these waters are of purely marine origin. All the Santorini

samples contain sulphate that is depleted in heavy isotopes relative to marine

sulphate. The isotopic data suggest that these sulphates could come from the mixing

between sulphates of marine origin and sulphates, probably, contained in the

volcanic rocks of the island, which have been formed by the oxidation of the

primary sulfur of deep origin. Michaud et al. 2000 has reported the presence of

sulfur in various volcanic products of Santorini. In fact this δ34S depletion was attributed to a mixing of marine sulphate with ‘light’ sulphate (Michelot et al. 1993), deriving from the oxidation of sulphur minerals. This contribution of

sulphur oxidation is confirmed by the decrease of 34S concentration and the increase

of the sulphate contents in the water (Fig. 47.6). The very low δ34S content of the Kos waters is also attributed to oxidation of primary sulfur of deep origin and

defends the condition of existence of strong pressure of H2S of volcanic origin.

Fig. 47.6 Relationship between δ34S ‰ vs CDD versus δ18O (SO4) vs SMOW of Egina, Milos, Santorini, Kos and Nisyros of the Aegean Volcanic arc. Symbols as Fig. 47.2

662 E. Dotsika and P. Chantzi

The Case of Loutraki and Egina Waters

Figure 47.2 shows the relationship between δ2H and δ18O contents of the water of Loutraki and Egina and the range of local meteoric water. The δ2H and δ18O values of Loutraki and Egina waters indicate a negligible contribution of seawater. The

position of these samples in the diagram δ2H versus δ18O confirms their mainly meteoric origin. However in Fig. 47.6 the 34S and 18O(SO4) contents of the Loutraki

samples are compared to those of marine sulphate. It appears that the isotope

contents of the samples do not differ significantly from those of seawater,

suggesting that the dissolved sulphates of these waters are of purely marine origin.

This marine participation is the cause for the augmentation of salinization.

The Case of Milos Waters

The δ2H and δ18O values of Milos’s waters (Fig. 47.2) are shifted to the right of the local meteoric water line.

The isotopic data of Milos’s water show an 18O enrichment with respect to those observed for the local fresh water. In opposite strong meteoric contributions appear

in the 2H contents. These changes could suggest that the stable isotope contents of

Milos’s water are controlled by geothermal exchange. However an exchange between water-rock increases the δ18O, conserving “firm” the Cl� contents. In Fig. 47.3 it is observed a modest enrichment in chloride, probably by mixing with a

solution rich in heavy isotope. So the position of the samples in Fig. 47.3 could be

attributed to the mixing between fresh water and deep thermal waters modified

jointly by water-rock interaction and evaporation. Regardless of the origin of deep

water the modification processes results the quality degradation of waters. The

temperature increase and the salinisation of waters contribute to the unacceptable

values of these waters according to the European standards.

In Fig. 47.6 the 34S and 18O(SO4) contents of Milos’s samples are compared to those of marine sulphate. It appears that the isotope contents of the samples,

especially the Milos samples, differ significantly to those of seawater, suggesting

that the dissolved sulphates of these waters come from oxidation of sulphur

minerals. In fact the contribution of sulphur oxidation is confirmed by the decrease

of 34S concentration and the increase of the sulphate contents in the water.

Conclusions

Interpretation of groundwater geochemical data, including isotopic data of water,

carbonate and sulphates, in terms of mixing and origin of solutes, and therefore

origin of pollution, is often complicated by the non-conservative nature of dissolved

47 Natural Tracers for Identifying Causes of the Quality Reduction. . . 663

components resulting from the mixing with gases, different type of fluid and from

interactions with the aquifer matrix. These fluids are of different origin and, in

particular, in groundwater emerging along the Aegean volcanic arc; result from

actual seawater and water that vary by interactions with the aquifer matrix, by the

exchange with the gases and the geothermal exchange. In the water emerging along

the Aegean volcanic arc, salinisation enrichment is a problem to the quality of the

intensely exploited groundwater, especially during the summer on account of

tourist increase. In general, this salinisation enrichment in coastal areas conjoins

with seawater intrusion. In fact the results of this study indicate that the waters

examined from Loutraki, Egina are essentially of meteoric origin, but some of them

are affected by a slight mixing with seawater. The seawater intrusion is the main

cause for the quality reduction of Nisyros and Santorini Island.

However, the enrichment in HCO3 � and SO4

2� concentrations in groundwater with the parallel increase of water isotopes indicates that the salinisation enrich-

ment in Kos Island is due to the intrusion of gases in the Island aquifers. Therefore

the salinisation enrichment in coastal areas in Kos Island is due to the modifications

processes of equilibration water- gases, CO2 and H2S, of deep origin.

The salinisation enrichment in groundwater in Milos, does not derive from a

contamination source, but is due to mixing between local fresh water and deep

water. In Milos Island the salinisation is controlled probably by mixing of fresh

water with a solution rich in heavy isotope and geothermal exchange. In both cases

the deuterium isotopes are applied in investigations on the origin of the salinisation

in groundwater and the use of δ2H is proved to be an effective approach for understanding the origin of quality reduction in geothermal areas.

In summary, for the water emerging along the Aegean volcanic arc, the

salinisation enrichment is due to sea intrusion, exchange with gas, geothermal

exchange and mixing of fresh water with a deep solution rich in heavy isotope.

References

Apha. (1989). Standard methods for the examination of water and wastewater (19th ed.). Washington, DC: American Public Health Association.

Christodoulou, T., Leontiadis, I. L., Morfis, A., Payne, B. R., & Tzimourtas, S. (1993). Isotope

hydrology study of Axios River plain in northern Greece. Journal of Hydrology, 146, 391–404. Chatzipetros, A., Kiratzi, A., Sboras, S., Zouros, N., & Pavlides, S. (2013). Active faulting in the

north-eastern Aegean Sea Islands. Tectonophysics, 597–598(19), 106–122. Coleman, M. L., Shepard, T. J., Durham, J. J., Rouse, J. E., & Moore, G. R. (1982). Reduction of

water with zinc for hydrogen analysis. Analytical Chemistry, 54, 993–995. Craig, H. (1961). Isotopic variations in meteoric waters. Science, 133, 1702–1703. Dotsika, E., Lykoudis, S., & Poutoukis, D. (2009). Spatial distribution of the isotopic composition

of precipitation and spring water in Greece. Global and Planetary Change, 71, 141–149. Epstein, S., & Mayeda, T. (1953). Variation of 18O content of waters from natural sources.

Geochimica et Cosmochimica Acta, 4(5), 213–224. International Atomic Energy Agency (IAEA). (1981). Statistical treatment of environmental

isotope data in precipitation. IAEA Tech. Rep. Ser. No. 206. Vienna: IAEA.

664 E. Dotsika and P. Chantzi

Jolivet, L., Faccenna, C., Huet, B., Labrousse, L., Pourhiet, L., Lacombe, O., et al. (2013). Aegean

tectonics: Strain localisation, slab tearing and trench retreat. Tectonophysics, 597–598(19), 1–33.

Leontiadis, I., Payne, B. R., Letsios, A., Papagianni, N., Kakarelis, D., & Chadjiagonakis,

D. (1984). Isotope hydrology study of Kato Nevrokopi of drama. In Proc. of the symposium on isotope hydrology 1983 (pp. 193–206). Vienna: International Atomic Energy Agency.

Leontiadis, I. L., Vergis, S., & Christodoulou, T. (1996). Isotope hydrology study of areas in

Eastern Macedonia and Trace, Northern Greece. Journal of Hydrology, 182, 1–17. Leontiadis, I. L., & Nikolaou, E. (1999). Environmental isotopes in determining groundwater flow

systems, northern part of Epirus, Greece. Hydrogeology Journal, 7, 219–226. Le Pichon, X., & Angelier, J. (1979). The hellenic arc and trench systems a key to the neotectonic

evolution of the eastern Mediterranean area. Tectonophysics, 60, 1–42. Longinelli, A. (1989). Oxygen-18 and Sulphur-34 in dissolved oceanic sulphate and phosphate. In

P. Fritz & J. C. Fontes (Eds.), Handbook of environmental isotope geochemistry (Vol. 3, pp. 219–255). Amsterdam: Elsevier. Chapter 7.

Loyd, R. M. (1968). Oxygen isotope behaviour in the sulfate-water system. Journal of Geophys- ical Research, 73, 6099–6110.

Lort, J. M., Limond, W. Q., & Gray, F. (1974). Preliminary seismic studies in the eastern

Mediterranean. Earth and Planetary Science Letters, 21(4), 355–366. Makris, J. (1978). The crust and upper mantle of the Aegean region from deep seismic soundings.

Tectonophysics, 46, 269–284. McKenzie, D. (1970). Plate tectonics of the Mediterranean region. Nature, 226, 269–284. Michaud, V., Clocchiatti, R., & Sbrana, S. (2000). The Minoan and post-Minoan eruptions,

Santorini (Greece), in the light of melt inclusions: Chlorine and sulphur behaviour. Journal of Volcanology and Geothermal Research, 99(1–4), 195–214.

Michelot, J. L., Dotsika, E., & Fytikas, M. (1993). A hydro chemical and isotopic study of thermal

waters on Lesbos Island (Greece). Geothermics, 22(2), 91–99. Mizutani, H., & Rafter, T. A. (1969). Oxygen isotopic composition of sulfates: 3. Oxygen isotopic

fractionation in the disulfate-water system. New Zealand Journal of Science, 12, 54–59. Papazachos, C., Hatzidimitriou, P., Panagiotopoulos, D., & Tsokas, G. (1995). Tomography of the

crust and upper mantle in southeast Europe. Journal of Geophysical Research, 100, 12405–12422.

Rafter, T. A. (1957). Sulphur isotopic variations in nature: Part 1. The preparation of sulphur

dioxide for mass spectrometer examination. The New Zealand Journal of Science and Tech- nology, B38, 849.

Rafter, T. A., & Mizutani, H. (1967). Oxygen isotopic composition of sulfates: 2. Preliminary

results on oxygen isotopic variation in sulphates and relationship of the environment and to

their δ34S values. New Zealand Journal of Science, 10, 816.

47 Natural Tracers for Identifying Causes of the Quality Reduction. . . 665

Chapter 48

Experimental Study of Longitudinal Dispersion on Trapezoidal Open Channel

Ali Mansour Lagoun and Salim Benziada

Introduction

Water demand does not cease to increase, especially with demography growth,

industry and agricultural development. Global warming and climate changing has

affected directly water resources, rains becomes rare and several areas

becomes arid.

Water, this vital source, that it becomes today very precious, is affected by

pollution, and providing water with quantity and quality is becoming very difficult

and expensive. Governments have to make all procedures to preserve this source

of life.

Pollution in shallow water resources and river is often punctual (Gerhard et al.

2005), when pollutants discharged in streams, is subjected to several processes of

mixing and transportation, a lot of scientists are interesting today to grow knowl-

edge of its mechanisms and to develop models for studying phenomenon of

pollutants transport and predicting its evolution in space and time, to develop

helpful decision tools.

A.M. Lagoun (*) Research Laboratory of Water Sciences, Polytechnic National School of Algiers, Algiers,

Algeria

Laboratory of Environment, Water, Geomechanics and Structures, Faculty of Civil

Engineering (FGC), University of Sciences & Technology Houari Boumediene (USTHB),

Bab Ezzouar, Algiers, Algeria

Scientific and Technical Research Center on Physical and Chemical Analyses, Bou-Ismail,

Tipaza, Algeria

e-mail: [email protected]

S. Benziada

Research Laboratory of Water Sciences, Polytechnic National School of Algiers, Algiers,

Algeria

667

mailto:[email protected]

Researches at this field are in situ (at rivers and streams), at reduced physical

models or mathematical and numerical developments, at this manuscript, we have

conceived an experimental device with trapezoidal open channel, that is the most

responded, usual and similar at rivers, a lot of experimentation was applied by

changing hydrodynamical parameters of flow to determine its effects and under-

standing the phenomenon of contaminations dispersion.

Phenomenon of Transport in Rivers

When any substance is injected in flow, a cloud with high concentration forms, this

cloud occupies a wide area at moving and concentrations become lower. Moving of

substance injected in flow and decreasing in concentration are effected by several

processes such as: diffusion, advection, dispersion (Fischer 1966; Shen et al. 1995;

Gharbi 1998; Hibbs et al. 1999; Czernuszenko et al. 2005; Steve et al. 2005).

Experimental Setup

Experimental setup consists essentially of feed tank, a trapezoidal channel, an

injection device and sampling and collecting systems.

Installation was conceived, and experiments were performed at Research Lab-

oratory of water Sciences (LRS eau) in Polytechnic National School of Algiers with

the aim to measure concentration profiles of contaminant (phenol) at downstream

stations resulting due different injections scenario of phenol in the upstream of

channel.

Figures 48.1 and 48.2 shows equipment of experimental setup, characteristics of

flume are presented in Table 48.1.

Measurement Tools

Discharge Measurement: Discharge measurement was made with V notch weir, after weir calibration, Discharge is given as function of head flow with:

Q ¼ 1, 35:hd5=2 ð48:1Þ

Concentration Measurement: Phenol concentration was measured by Spectropho- tometer, after calibration of phenol, concentration is given as function of optical

densities by:

C ¼ 80 D0 ð48:2Þ

668 A.M. Lagoun and S. Benziada

Feed tank

Support

V Notch Weir

Channel support

Injection system

Flow Stabilizer

Fig. 48.1 3D schema of experimental setup

Fig. 48.2 Photography of experimental setup (LRS. Eau, ENP)

Table 48.1 Summary of flume characteristics

Designation Parameters Values

Channel Form Trapezoidal

Bed slope [%] 5

Lench [m] 10,4

Bottom Width [m] 0,4

Side Slope [�] 60 Slope head [cm] 50

Weir Form Triangular (V notch)

Notch angle [�] 90 Crest elevation [cm] 10

48 Experimental Study of Longitudinal Dispersion on Trapezoidal Open Channel 669

Experimental Procedure

Discharge flow is regulated at upstream by valve and controlled and measured at

downstream by triangular weir.

The water was supplied to the flume through overhead tank with constant water

level in order to have a constant discharge of flow; Flume was market at every 1 m

length.

Once flow is stabilized by passing of water through a flow stabilizer at upstream,

injections of phenol for 30 s with three values of concentration (C0¼ 500, C0¼ 1000 and C0¼ 1500 mg/l) were applied at upstream.

Experimental measurements of water head was made, and samples from every

1 m length of flume was taken at surface of water for different scenario of injection

and a several flow values (Q¼ 0.52; Q¼ 0.78, Q¼ 1.6, Q¼ 1.75 and Q¼ 1.95 l/s). Samples were immediately analyzed at laboratory and concentrations were

determined.

Hydraulic Study of Fume Flow

Reynolds number: is given as: (Lencastre 2005).

Re ¼ UDh ν

ð48:3Þ

Flow regimes are classified according Reynolds number as follows: Re < 2000: laminar flow, 2000<Re< 4000: transient flow, Re > 4000 : turbulent flow (Lencastre 2005).

Froude Number: is given by:

Fr ¼ Uffiffiffiffiffiffiffiffiffiffiffi g� hp ð48:4Þ

Flow regimes are classified according Froude number as follows: Fr > 1 : super- critical flow, Fr < 1 : subcritical flow, Fr ¼ 1 : critical flow (Lencastre 2005) (Table 48.2).

Table 48.2 Flow regimes

Q [l/s] U [m/s] Re Fr Flow regimes

0.52 0.008 2848.03 0.006 Subcritical and transient

0.79 0.011 4220.03 0.009 Subcritical and turbulent

1.60 0.019 8144.88 0.015 Subcritical and turbulent

1.75 0.021 8830.58 0.016 Subcritical and turbulent

1.95 0.023 9754.51 0.017 Subcritical and turbulent

670 A.M. Lagoun and S. Benziada

Results and Discussion

Concentration Profiles of Longitudinal Dispersion

Concentration profiles of phenol for every 1 m of flume length at the surface of

water are shown at Figs. 48.3 and 48.4 (for Q¼ 0.79 l/s and Q¼ 1.75 l/s). (Instantaneous injection of phenol for 30 s):

Discussion

• Concentration peaks obtained (Figs. 48.3 and 48.4) are very smaller than initial

concentrations injected, this considerable decrease is mainly due to dilution phenomenon that occurs just after discharging pollutant at water flow.

16 14 12 10

8 6 4 2 0C

o n

ce n

tr at

io n

(m g

/l )

Time (s)

0 100 200 300 400 500

x=1m x=2m x=3m x=4m x=5m x=6m x=7m x=8m

Fig. 48.3 Concentration profiles of phenol for Q¼ 0.79 l/s and C0¼ 500 mg/l

16 14 12 10

8 6 4 2 0C

o n

ce n

tr at

io n

(m g

/l )

Time (s) 0 100 200 300 400

x=1m x=2m x=3m x=4m x=5m x=6m x=7m x=8m

Fig. 48.4 Concentration profiles of phenol for Q¼ 1.75 l/s et C0¼ 1000 mg/l

48 Experimental Study of Longitudinal Dispersion on Trapezoidal Open Channel 671

• In the Vicinity of injection area, concentrations profiles are pointed and sharp. At

the downstream direction, profiles bearing are becoming much more important

and profiles takes the Gaussian form with decrease in concentrations.

This is explained by the predominance of advection in the vicinity of the injection area, away from the pollutant discharge point, the transportation becomes diffusive.

Flow Discharge Influence

Figures 48.5 and 48.6 show a comparison of phenol concentration profiles for

different discharge flow. We note that for all initial phenol concentration injected

(C0):

• Concentrations obtained are much more important for low flow rates.

• Stays time of pollutant is more important for low flow rates.

Fig. 48.5 Concentration profiles of phenol for

different flow discharges at

x¼ 2 m C0¼ 1000 mg/l

Fig. 48.6 Concentration profiles of phenol for

different flow discharges at

x¼ 1 m, C0¼ 500 mg/l

672 A.M. Lagoun and S. Benziada

For determination of flow rates and stays times of pollutants on dispersion

longitudinal phenomenon, we analyze concentration peaks according discharge

flows and distances length at downstream.

Concentration Peaks According Discharge Flow

Concentration peaks as a function of discharge flow are presented in Figs. 48.7 and

48.8.

Peaks obtained are lower for important flow; this is due to the dilution rate that increases with flow discharge.

Longitudinal evolution of concentration peaks for different flow:

Discussion

By analyzing Figs. 48.9 and 48.10, we observe that decreasing of concentration peaks

is much more important for flow rate Q¼ 0.52 l/s, this is effect of stays time that it is

Fig. 48.7 Concentration peaks as function of

discharge flow for

C0¼ 500 mg/l for different distances x

Fig. 48.8 Concentration peaks as function of

discharge flow for

C0¼ 500 mg/l for different distances x

48 Experimental Study of Longitudinal Dispersion on Trapezoidal Open Channel 673

more important for this flow discharge, dispersion have had more time to

manifest, contrary to the case of flow with Q¼ 1.95 l/s when predominance was for advection.

Conclusion

Qualitative study of concentration profiles obtained experimentally, allowed to the

good understanding of dispersion longitudinal phenomenon, and to identify mech-

anisms that govern it.

For instantaneous injection of pollutant case, the analysis of the spatiotemporal

evolution of concentration of phenol at flume has identified two areas:

• An advection area, near the injection where profiles obtained are pointed; the pollutant transport is convective.

• A diffusive area, in the far field, where the concentration profiles bearing become important and the pollutant transport begin to be increasingly diffusive.

Fig. 48.9 Evolution of concentration peaks at

flume for different flows.

C0¼ 1500 mg/l

Fig. 48.10 Evolution of concentration peaks at

flume for different flows.

C0¼ 500 mg/l

674 A.M. Lagoun and S. Benziada

The quantitative study and the comparison between the results for different

injection scenarios shows that the transport phenomenon is related to the flow

rate, since its influence on the properties of the flow that transports the pollutant:

• The average velocity of flow, therefore the advection processes. Increased

discharge results in higher velocity and pollutant transport becomes more

convective.

• The residence (stays) time is more important for low flows (low velocity), so the

decreasing rate of longitudinal dispersion concentration will be higher.

• Dilution rate, which it is function as flow rate.

Nomenclature

C Pollutant Concentration, mg/l

Dh Hydraulic diameter, m Do Optical density

g Gravity, m/s2

h Hydraulic depth, m

hd Head, m

Q Flow discharge (m3/s)

U Flow velocity (m/s)

Dimensionless Numbers

Fr Froude number

Re Reynolds number

Greek Letters

ν Cinematic viscosity of water, m2/s

References

Czernuszenko, W., & Alexey, R. (2005). Three-dimensional model of flow and mixing processes

in open channels . InWater quality hazards and dispersion of pollutants (pp. 35–54). Library of Congress Cataloging-in-Publication Data. New York: Springer.

Fischer, H. B. (1966) . Longitudinal dispersion in laboratory and natural streams. Report

No. KH-R-12. Journal of Water Resources Division, 250p. Gerhard, H. J., & Volker, W. (2005). Mixing models for water quality management in rivers. In

Water quality hazards and dispersion of pollutants (pp 1–34). Library of Congress Cataloging- in-Publication Data. New York: Springer.

48 Experimental Study of Longitudinal Dispersion on Trapezoidal Open Channel 675

Gharbi, S. (1999). Évaluation des coefficients de mélange longitudinal et transversal des polluants

dans les cours d’eau: proposition de nouvelles formules. PhD thesis, University Laval Québec,

197p.

Hibbs, D., Gulliver, J., Voller, V., & Chen, Y. F. (1999). An aqueous concentration model for

riverine spills. Journal of Hazardous Materials, A64, 37–53. Lencastre, A. (2005). Hydraulique Général . Eyrolles Edition. 633.

Shen, H. T., Yapa, P. D., & Zhang, B. Z. (1995). A simulation model for chemical spills in the

upper St Lawrence River. Journal of Great Lakes Research, 21(10), 652–664. Steve, W., & Russell, M. (2005). On the theoretical prediction of longitudinal dispersion coeffi-

cients in a compound channel. In Water quality hazards and dispersion of pollutants (pp. 69–84). Library of Congress Cataloging-in-Publication Data. New York: Springer.

676 A.M. Lagoun and S. Benziada

Chapter 49

Mygdonia Basin (N. Greece) in the View of Isotope Geochemistry

P. Chantzi and E. Dotsika

Introduction

Mygdonia basin located 10 km N-E to Thessaloniki in northern Greece and it is

consisted by two sub-basins: Koroneia and Volvi lakes. Both lakes constitute an

important wetland which is being protected by International Ramsar Convention.

Mygdonia basin constitutes an elongated EW tectonic depression which combined

with adjusted minor basins (Zagliveri, Marathousa, Doubia) are the remains of an

initial basin called Promygdonia (Koufos et al. 1993). The initial basin was formed

by tectonic activity probably in the late Paleogene to early Neogene. In late

Neogene and early Pleistocene a set of river and lake surface sediments deposited

in this basin. A new tectonic activity at the end of the period “early-Pleistocene”

resulted to many faults of Promygdonia basin were several smaller basins formed

(Mygdonia, Zagliveri, Marathousa, Doubia). Among them the largest was

Mygdonia basin forming the Mygdonia Lake which gradually drained during the

medium-Pleistocene. Sedimentation continued in this basin mainly by lacustrine

deposits (Psilovikos 1977; Sotiriadis et al. 1983). Koronia and Volvi lakes are the remnants of the initial Mygdonia Lake.

P. Chantzi (*) Laboratories of Stable Isotopes and Radiocarbon, Institute of Nanoscience and

Nanotechnology, National Centre for Scientific Research “Demokritos”, 15310 Agia

Paraskevi, Attica, Greece

e-mail: [email protected]

E. Dotsika

Laboratories of Stable Isotopes and Radiocarbon, Institute of Nanoscience and

Nanotechnology, National Centre for Scientific Research “Demokritos”, 15310 Agia

Paraskevi, Attica, Greece

Institute of Geosciences and Earth Resources, Via G. Moruzzi 1, 56124 Pisa, Italy

e-mail: [email protected]

677

mailto:[email protected]

Mygdonia basin is bended in metamorphic layers from Serbomacedonian massif

(paleozoic gneisses, amphibolites, schists, marbles and granitic intrusions) with

groundwater circulating in metamorphic rocks and discharging in loose formations

in basin. Moreover it covers a basin about 2026 km2 where the terrestrial part covers

about 656 km2 and particularly extends west of Koronia Lake. The basin is defined

by the mountains of Volvi (627 m) and the lower vertices of Vertiskos mountain

(1103 m) in the north, in the east by the mountains of Psili Rachi (341 m) and

Soulgianodiou (746 m) which are interposed between the mountains Kerdylion and

Stratoniko and through the Strait of Rendina communicates with Strymoniko Bay

and in the south side by Chortiatis mountain (1206 m) the lower vertices of

Cholomontas (1165 m) and Stratoniko (918 m) with S-E direction. West boundaries

of basin are not well defined as there are a set of low hills and depressions except

Camila Mountain (569 m). The annual precipitation in the basin ranges

283–721 mm in the last 30 years. The climate varies from Mediterranean and

continental. For the entire basin the average annual temperature is estimated

about 13.55 �C and an average annual precipitation about 584.9 mm (Vatseris 1992).

Both Koroneia and Volvi subcatchments have been undergone sever environ-

mental and human impacts resulting their ecological death (Nimfopulos, M. K.

et al., 2002). An attempt was made in order to fingerprint the isotopic signature of

groundwater in order to strengthen the knowledge on the hydrology regime of

Mygdonia basin. Cold water samples from boreholes were collected from

Mygdonia basin for stable isotope analyses of δ18O, δ2H, δ13C which was performed in Laboratories of Stable Isotopes and Radiocarbon at NCSR

“Demokritos”. The network of boreholes that were sampled corresponded to

shallow (30–60 m) and moderate deep water circulation (60–100 m). The sampling

took place in June 2014 where the boreholes were operated for at least one month

resulting in the water sample to correspond to the actual groundwater body.

Moreover two water samples from lakes Koroneia and Volvi were taken however

that wasn’t possible for fresh spring water as no such springs were detected (Fig. 49.1).

Results and Discussion

Oxygen δ18O and δ2H Isotopes

The values of stable isotopes ranging from �10.3‰ to �7.3‰ and �70.4‰ to �45.7‰ for δ18O and δD. In more detail on the sub-basin of Lake Koronia the isotope values of water molecules vary from �9.0‰ to �7.5‰ (range 1.5‰) and from �59.2‰ to �45.7‰ (range 13.5‰) for δ18O and δD respectively, while on the sub-basin of Lake Volvi values vary from �10.3‰ to �7.3‰ (range 3‰) and from �70.4‰ to �47.2‰ (range 23.2‰) for δ18O and δD respectively. These

678 P. Chantzi and E. Dotsika

values are shown in diagram δ2H‰V-SMOW versus δ18O‰V-SMOW (Fig. 49.2) where global meteoric water line (GMWL, Craig 1961) and local meteoric water

line (LMWL) for Greece as proposed by Dotsika et al. (2010) are pictured as well.

The correlation equation of groundwater for Mygdonia basin is:

δD ¼ 7:8∗δ18Oþ 10:30 ð49:1Þ

Groundwater in Mygdonia basin presents an excellent correlation. Moreover

Koronia is grouped with groundwater in the south part of Volvi sub-basin, sites

where the network of boreholes is strong, supporting the hydraulic communication

(Fig. 49.3).

The correlation equation of groundwater for Koronia and Volvi sub-basins are:

δD ¼ 7:1∗δ18Oþ 4:11 ð49:2Þ δD ¼ 7:8∗δ18Oþ 10:95 ð49:3Þ

The correlation equations of Mygdonia, Koronia and Volvi basins present slopes

«7.8», «7.8» and «7.1» respectively. For Central Macedonia a slope inferior to 7 is

reported (Christodoulou et al., 1993) while for East Macedonia is reported slightly

greater «7.5» (Leontiadis et al., 1984). Generally fresh precipitation of all types and

surface water that have not undergone evaporation exhibit slopes between 7–8

(Craig 1961), while waters that have undergone secondary evaporation exhibit

Fig. 49.1 Study area of Mygdonia basin with Koronia and Volvi sub-basins (Google earth modified picture)

49 Mygdonia Basin (N. Greece) in the View of Isotope Geochemistry 679

Fig. 49.3 δ2H‰ V-SMOW versus δ18O‰ V-SMOW of cold groundwater in Koronia and Volvi sub-basins

Fig. 49.2 δ2H‰ V-SMOW versus δ18O‰ V-SMOW of cold groundwater in Mygdonia basin

680 P. Chantzi and E. Dotsika

lower slopes about «6» (Gat 1980). Therefore it is concluded that groundwater of

Mygdonia basin doesn’t present any evaporation or mixing episodes with different isotopic water.

Both oxygen and deuterium isotopic values are characterized by homogeneity

without significant fluctuations implying that no isotopic exchange with the geo-

logical environment takes place. This conclusion is in agreement with geological

regime of the basin where groundwaters circulate in metamorphic rocks and

discharge in loose formations in basin without presenting long retention time in

groundwater aquifers.

The correlation between sub-basins and surface water of the corresponding lake

is pictured in Fig. 49.4 with the following equations:

δD ¼ 5:9∗δ18O� 5:2 ð49:4Þ δD ¼ 6:3∗δ18O� 3:9 ð49:5Þ

The slopes of lines (49.4) and (49.5) with values «5.9» and «6.3» for the Koronia

and Volvi respectively reflect evaporation processes occurring in surface reservoirs

with Koronia exhibiting a higher rate. In both sub-basins groundwater and surface

lake water correlates excellent however the linking trend is evident in Volvi

catchment implying their direct hydraulic communication but in Koronia catchment

surface lake water placed slightly away from the corresponding trend-line. Isotopic

Fig. 49.4 δ2H‰ V-SMOW versus δ18O‰ V-SMOW of cold groundwater and surface water in Koronia and Volvi sub-basins

49 Mygdonia Basin (N. Greece) in the View of Isotope Geochemistry 681

values are strongly influenced by temperature and the evaporation processes but

also by the humidity (Fritz and Fontes 1980). Therefore this slightly deviation could

be attributed to the humidity above lake water layers. These observations possible

imply the communication of surface water with groundwater in Koronia basin

through lateral shallow formations as the lacustrine bottom is covered by a clay

layer that makes it impermeable

Carbon Isotopes δ13C

The values of carbon isotopes δ13C can detect the different origins of organic or inorganic carbon. The value of carbon in marine carbonate rocks is around 0‰, the soil CO2 around �25‰ (similar to that of plants) and about �7‰ for atmospheric CO2. However, carbonates evaporation may exhibits higher values about þ10‰. The carbon isotopic ratio of fresh water is strongly affected by carbonate mineral

dissolution in the case of carbonate bicarbonate aquifers: CaCO3þH2CO3!Ca2þ þ 2HCO3� (Dotsika 2015). In temperate climate the contribution of dissolved carbonates (δ13C¼�2‰ to þ1‰, Clark and Fritz, 1997) resulting groundwater δ 13C values about �11‰ (Jin et al. 2009) however in shallow aquifers soil CO2 and atmospheric CO2 (water-rock interaction product) contribute to the values forma-

tion resulting aquifers with δ13C values between �11‰ and �22‰ (Jin et al. 2009). Carbon isotope values δ13C range between �13.6‰ and �10.2‰ for Mygdonia basin. In greater detail range from �13.6‰ to �10.2‰ and from �13.2‰ to �10.4‰ for Koronia and Volvi groundwater respectively, reflecting both the dissolution of carbonate rocks and the participation of organic carbon from

soils.

Conclusions

Stable isotope values of cold water samples ranged from �10.3‰ to �7.3‰, from �70.4‰ to �45.7‰ and from �13.6‰ to �10.2‰ for δ18O, δD and δ13C respectively reflecting the isotopic signature of local precipitation water. In the

entirely basin subsurface water circulation exhibits short retention time influenced

by the strong network of irrigation wells without taking place any isotopic exchange

with the geological environment. Mechanism of neither evaporation nor mixing

with waters of different isotopic origin was detected. Dissolution of carbonate rocks

and the participation of CO2 from soils taking place through the circulation of

groundwater to the shallow and middle shallow aquifers.

682 P. Chantzi and E. Dotsika

References

Christodoulou, Th., Leontiadis, I.L., Morfis, A., Payne, B.R., Tzimourtas, S., 1993: Isotope

hydrology study of Axios River plain in northern Greece. J. Hydrol. 146, 391–404.

Clark, I. D., & Fritz, P. (1997). Environmental isotopes in hydrogeology. Boca Raton, FL: Lewis Publishers.

Craig, H. (1961). Isotopic variations in meteoric waters. Science, 133, 1702–1703. Dotsika, E., Lykoudis, S., & Poutoukis, D. (2010). Spatial distribution of the isotopic composition

of precipitation and spring water in Greece. Global and Planetary Change, 71, 141–149. Dotsika, E. (2015, March). H–O–C–S isotope and geochemical assessment of the geothermal area

of Central Greece. Journal of Geochemical Exploration, 150, 1–15. Fritz, P., & Fontes, J. (1980). Handbook of environmentai lsotope geochemistry. New York:

Elsevier.

Gat, J. R. (1980). Isotope hydrology of very saline lakes. In A. Nissenbaum (Ed.), Developments in sedimentology (Vol. 28, pp. 1–7). New York: Elsevier. Chapter 1.

Jin, L., Ogrinc, N., Hamilton, S., Szramek, K., Kanduc, T., & Walter, L. (2009, June). Inorganic

carbon isotope systematics in soil profiles undergoing silicate and carbonate weathering

(Southern Michigan, USA). Chemical Geology, 264(1–4), 139–153. ISSN: 0009-2541. Koufos, G., Syridis, G., Kostopoulos, D., & Koliadimou, K. (1993). Preliminary results about the

stratigraphy and the palaeoenvironment of Mygdonia Basin, Macedonia, Greece. In Proceed- ings of the 1st congress of paleontological association, Geobios.

Leontiadis, I., Payne, B.R., Letsios, A., Papagianni, N., Kakarelis, D., Chadjiagonakis, D., 1984:

Isotope Hydrology study of Kato Nevrokopi of Drama. Proc. Of the Symposium on Isotope

Hydrology 1983. International Atomic Energy Agency, Vienna, pp. 193–206.

Nimfopulos, M. K., Mylopoulos, N., & Katirtzoglou, K. G. (2002). A qualitative-quantitative

study of water and environmental pollution at the broader area of the Mygdonia Basin,

Thessaloniki, Northern Greece. In Proceedings of the 6th Pan-Hellenical geographical con- ference of the Hellenic geographical society, Thessaloniki, 3–6 October 2002 (Vol. II, pp. 436–444).

Psilovikos, A. (1977). Paleogeographic development of the basin and lake of Mygdonia (Lagada—

Volvi area, Greece). Ph.D. thesis, Department of Geology, Aristotle University of Thessaloniki

(in Greek).

Sotiriadis, L., Psilovikos, A., Vavliakis, E., & Syrides, G. (1983). Some tertiary and quaternary

basins of Macedonia/Greece. Formation and evolution, Clausthaler Geologische Abhandlungen (p. 21).

Vatseris, C. (1992). Hydrogeologie des Mygdonias-Beckens (Nord-Griechenland) under

Berucksichtigung der hydrochemischen und isotopen physikalischen komposition der

thermalwasse. Ph.D. thesis, University of Munster, 171p.

49 Mygdonia Basin (N. Greece) in the View of Isotope Geochemistry 683

Chapter 50

Sustainable Management of Sewage Sludge Conditioning and Valorization

S. Igoud, F. Souahi, and C.-E. Chitour

Introduction

Between 1999 and 2010, the Algerian wastewater treatment data showed that the

wastewater volume has doubled. It increased from 600 million m3 to 1.2 billion m3

corresponding to a ratio of 32.34 m3/inhabitant. This has required the building of

105 new wastewater treatment plant (WWTP) and the increase of the wastewater

collection which passed from 79% to 86% (Hammouche 2011). But, in the same

manner, this performance has increased the electricity consumption, the public

spending and the greenhouse gas emission.

The increase of the electricity consumption has been also recorded because the

wastewater treatment uses mainly the activated sewage sludge and the aerated

lagoon processes applied at 67.7% even if they allowed significant remediation

efficiency (Igoud et al. 2014).

This situation has been maintained particularly between 2010 and 2013 with

increases estimated at 35.2% of wastewater volume, 45.8% of electricity con-

sumption and 58% of electricity budget. During 2013, the volume of wastewater

treated by the most important treatment operator: the National Office of Sanitation

(ONA) was estimated at 161 million m3. Its remediation has consumed 21.68 GWh

of electricity for pumping and 60.28 GWh for treatment. Financially, the electricity

cost has been estimated at 2.6 million €. Also, the electricity consumption has emitted 185.61 tons of CO2-eq (Igoud et al. 2014). At 2015, ONA estimated that the

S. Igoud (*) Unité de Développement des Equipements Solaires, UDES/Centre de Développement des

Energies Renouvelables, CDER, 42415 Bou Ismail, W. Tipasa, Algerie

e-mail: [email protected]

F. Souahi • C.-E. Chitour

Ecole Nationale Polytechniques (ENP), Hacène Badi, 16200 El-Harrach, W. Alger, Algerie

e-mail: [email protected]; [email protected]

685

mailto:[email protected]

total volume of treated wastewater reached 197 millions m3 and its treatment

consumed 97.73 GWh of electricity (ONA 2015).

The development of the wastewater treatment sector which occurred this last

decade will continuous to increase. That because it is planned the systematic

treatment of all collected wastewater and its reuse to irrigate 1 million hectares.

This trend is also projected at the international level. The International Energy

Agency expects that between 2006 and 2030 the energy needs for the wastewater

treatment will increase by 44% (International Energy Agency 2006). This rate will

reach 60% in developing countries (UNESCO-WWAP 2012).

Contributing to reduce the electricity consumption, the aim of the study is to

suggest a sustainable wastewater treatment approach as it is planned by ONA. This

wastewater management was recommended since 2002 in the Johannesburg world

summit (United Nations 2002) to anticipate the significant energy consumption and

GHG emission.

Currently, in order to reduce the electricity consumption, two trends are

prospected: the generation of renewable energy inside the wastewater treatment

plants (WWTP). This requires the use of renewable resources available at the plants

level especially sewage sludge and solar energy. Also, the use of sustainable

treatment processes.

In the study, three proposal of a sustainable sewage sludge treatment are

investigated: the sludge methanization for the cogeneration of electricity and

thermal energy, the solar sludge dryness and the agricultural valorization by land

application in forest areas.

Also, in order to evaluate the electricity and cost saving the sequestration of the

greenhouse gas (GHG) emission, the yearly electricity consumption has been

conducted in an activated sludge wastewater treatment plant.

Methodology

Sewage Sludge Methanization

The energetic bioconversion of sewage sludge requires two steps: the sludge

methanization applied for the biogas production. Then the biogas cogeneration

used for both of electricity and thermal energy production.

The biogas production has been estimated using theoretical and experimental

approaches. The theoretical step consisted on use of Eq. (50.1) as follows:

BV ¼ SSQ:DM:RVM:CC ð50:1Þ

where:

BV: Biomethane volume

SSQ: Sewage Sludge Quantity¼ 3040 tons DM: Dry Matter¼ 65.1 kg/m3 RVM: Removed Volatile Matter¼ 41.23%

686 S. Igoud et al.

Removal biodegradable pollution rate¼ 30% CC: Conversion Coefficient¼ ranging from 0.5 to 0.7 m3 of biomethane/tons of

removed dry volatile matter (Record 2009; Lagrange 1979, 1995).

The experimental study of the biogas production has also been conducted. It has

been experimented using a test bench (Fig. 50.1) composed of four 2 L flat-bottom

flasks.

During the experiments, each flask has been filled by 1 kg sewage sludge

recovered from Tipasa WWTP. The hermetic closure of the flasks allowed the

maintaining of the anaerobic conditions. To ensure the optimum methanization of

sludge, this last has been diluted at 100% of its weight. Then the flasks were tightly

closed and putted on controlled magnetic stirrer hotplates which allowed 37 �C sludge heat and 800 rpm sludge agitation.

The produced biogas has been quantitatively evaluated using gas meters then

stored in plastic bags for its analyze.

The second step evaluated the use of biogas for the cogeneration of electricity

and thermal energy. This estimation used technical characteristics of a 65-kW

biogas microturbine. Its electric efficiency (EE) is fixed at 29% and its thermal

efficiency (TE) at 50% (Product Catalogue 2010). The calculations were performed

as follows:

EG ¼ BV:LCV:EE ð50:2Þ TEG ¼ BV:LCV:TE ð50:3Þ

Fig. 50.1 Test bench of sewage sludge methanization (Igoud 2015)

50 Sustainable Management of Sewage Sludge Conditioning and Valorization 687

where:

EG: Electricity generation (kWh)

BV: Biogas volume (m3)

LCV: Lower calorific value (kWh/m3)

EE: Electric efficiency (%)

TEG: Thermal energy generation (kWh)

TE: Thermal efficiency (%)

Solar Drying of Sewage Sludge

The experiments were conducted in a test bench (Fig. 50.2) according to a protocol

that allowed a comparative study of a direct solar drying using a “drying bed”

prototype. This process is used in several WWTP in Algeria. The second prototype

used a solar greenhouse prototype; this type of sludge treatment is not applied in

Algeria.

The efficiency evaluation of these two drying processes was undertaken using

two types of sludge recovered from the studied WWTP: (1) biological sludge

recovered from the clarifier and containing 99.5% of humidity, (2) thickened

sludge containing 95.5% of humidity which was recovered from the thickener.

During the experiments, a sludge thickness of 2 cm has been maintained on the

drying bed and a volume of 15 L of sludge has been dried. The dryness kinetic has

been estimated through several daily samples. These last were weighed and then

dried at 105 �C for 24 h to be weighed again; this in order to determine their moisture content.

In the studied WWTP, the sludge conditioning consists firstly, on the gravity

thickening step secondary on the mechanical dehydration step using a belt press to

reach finally 24% of moisture.

Fig. 50.2 Test bench of the sewage sludge solar drying (Igoud 2015)

688 S. Igoud et al.

Sewage Sludge Agricultural Valorization

The essay (Ouanouki and Igoud 1993) has been conducted by the planting of forest

young seedlings: Pinus maritima and Acacia cyanophyla in an area of 3672 m2. This last was split into four plots. The first consisted on the witness. And the

remaining plots were planting after the digested sludge spreading as follows:

2 tons of digested sludge (21.76 tons/ha) in the first plot, 8 tons (87.14 tons/ha) in

the second and 15 tons (163.40 tons/ha) in the third.

For the experimentation, 576 young seedlings were planted with an equidistance

of 3 m� 3 m in a staggered rows distribution.

Results and Discussion

During 2010, the yearly electricity consumed in the activated sludge WWTP has

been estimated at 1.25 GWh. The electricity has been consumed at 89.63% by the

wastewater treatment process, 5.77% by the outdoor lighting and 4.6% by the

management department and laboratory (Fig. 50.3).

The electricity has cost 24,766 € and emitted 757.28 tons of CO2-eq with an average of 607.18 g of CO2-eq/kWh.

Renewable Electricity Generated from Sewage Sludge

The theoretical approach of the sewage sludge methanization estimates that

338,103 m3 of biogas could be produced. And its cogeneration could produce

392.78 MWh of electricity and 667.22 MWht of thermal energy recoverable for

the digesters heating.

Fig. 50.3 Yearly electricity consumption in Tipasa WWTP (Igoud et al. 2014)

50 Sustainable Management of Sewage Sludge Conditioning and Valorization 689

This amount of electricity would have to substitute 31.5% of conventional

electricity consumed by Tipasa WWTP. The experimental results have recorded a

lower biogas production (Fig. 50.4). The sludge methanization lasted 45 days and

cumulated a biogas volume of 20.12 L/kg of sludge. The biogas has been charac-

terized by an average methane content of 48%. This totalized a yearly production

of 61.16 103 m3 of biogas whose combustion could cogenerate 106.42 MWh of

electricity and 183.5 MWht of thermal energy.

The conventional electricity saving has been evaluated at 8.5% of the total

WWTP electricity consumption. This result is lower comparatively to the theoret-

ical. This could be induced by the experimental conditions of the sludge

methanization which require to be optimized. It could be also the result of the use

of mature sludge recovered from the storage area rather than fresh one when

available excess.

Sewage Sludge Dryness Induced by Solar Energy

During the trials, the dryness of the biological sludge characterized by 0.5% of

moisture reached 93%. The drying evolution has showed relatively similar kinetics

drying in the bed drying and under the solar greenhouse until 73 h (Fig. 50.5). This

duration is characterized by the evaporation of free water from sludge. From 73 h

which corresponded to the 3rd day of the experimentation, the speed of dehydration

has increased, especially in the drying bed. This is explained by the reduction of the

thickness of the sludge blade which increased their heating temperature. Indeed,

simulations studies performed for different sludge thicknesses showed that the

energy saving, about 20%, is obtained if the sludge thickness is reduced from

20 cm to 10 cm (Slim 2007).

Compared to the drying beds, the drying rate of the solar greenhouse was slower.

This is due to the low moisture wicking saturated air. The openings in the upper part

of the solar greenhouse were not sufficient for the natural wick moisture. For this,

Fig. 50.4 Total biogas production (Igoud 2015)

690 S. Igoud et al.

the optimization and control of the drying parameters would require the use of a

forced air circulation. Indeed, in industrial plants, the evacuation is carried out

through the air extractors to the ambient environment.

The solar drying of the thickened sludge (Fig. 50.6) containing 4.5% of moisture

also reached 93.6% of dryness. This result approaches that obtained after the

biological sludge treatment but this last was obtained during a longer drying time

(100 h against 72 h).

The solar drying of sludge could allow the substitution of the conventional

electricity estimated at 23,630 kWh (Hammouche 2011) required to achieve dry-

ness from 0.5% to 24%. This result corresponds to a saving of 2.1% of the

electricity consumption in the WWTP, 1.90% of the energy budget and 2.1% of

greenhouse gas emissions.

Fig. 50.5 Dryness kinetic of biologic sludge (Igoud 2015)

Fig. 50.6 Dryness kinetic of thickened sludge (Igoud 2015)

50 Sustainable Management of Sewage Sludge Conditioning and Valorization 691

Biomass Production Induced by Sewage Sludge Spreading

The sludge spreading in the plantation showed a positive correlation between the

height plants growth and the digested sludge spreading.

The best results have been obtained in the plot were the high quantity of sludge

was used. In this plot, the increase of the growth rate has been estimated at 71.87%

for pine, 73% for acacia and 68.38% for the mixed plantation using both pine and

acacia. The influence of acacia on pine growth has not shown a positive result. This

has been induced by the short duration of the experimentation which would not

allow the soil enrichment in nitrogen through the acacia nodules (i.e. root outgrowth

involved in the fixation of atmospheric nitrogen).

Conclusion

The obtained results showed the existence real opportunities for the sustainability

management of sewage sludge which benefit to the fossil energy saving and the

environment preservation.

The theoretical bioconversion of sewage sludge evaluated that 392.78 MWh of

electricity and 667.22 MWht of thermal energy could be generated. This amount of

renewable electricity would have to substitute 31.5% of conventional electricity

consumed in the WWTP. However, the experimental assessment allowed a lower

electricity generation which estimated a saving of 8.5%. This result has been

induced by the uncontrolled parameters of the experimentation which need to be

optimized.

Concerning the sewage sludge conditioning in the WWTP it is restricted at 24%

of dryness. This result has been improved by the use of solar drying process. The

obtained results showed the possibility to reach d up 93% dryness. A part this

improvement, the obtained results could allow saving a saving 2.1% of the elec-

tricity consumption in the WWTP, 1.90% of the energy budget and 2.1% of

greenhouse gas emissions. By the improving the dryness from 24% to 93%, the

savings will be most significant. Also, this sustainable treatment reduces the cost of

sludge storage and transport, increases their stabilization, sanitation and deodori-

zation sludge and facilitates energy recovery by burning.

The spreading of digested sewage sludge also has been beneficial for forest

plants growth. It has allowed an increase of the height plants growth which ranged

from 68.33% to 73%. A part this advantage, this kind of valorization should

particularly successes the reforestation undertaken in Algeria since the seventies’ to fight against desertification which threatening all the African countries. This

reforestation policy should be encouraged for the increase of the afforestation rate

which constitutes carbon sinks in fight against climate change.

692 S. Igoud et al.

Acknowledgement The authors would like to thank colleagues and all people who contributed to this studies especially Mrs. Ahmed and Toufik Medjiah from Tipasa’s wastewater treatment plant, Miss Amina Chalal from the Development Unit of Solar Equipment at Bou-Ismaıı̈l.

References

Hammouche, H. (2011, March). Algeria report country. Experts consultation on wastewater management in the Arab World. Dubai: The Arab Water Council.

Igoud, S. (2015). Integration of renewable energy and sustainable processes for the urban waste-

water treatment. Ph.D. thesis. National Polytechnic School ENP, Algeria.

Igoud, S., Souahi, F., Chitour, C. E., Adjrad, A., Habchi, M., & Chouikh, A. (2014). Diagnostic of

electricity consumption, its cost and greenhouse gas emission in the wastewater treatment

sector of Algeria. Desalination and Water Treatment, 55(7), 2015 1725-1735.55, 1725–1734. doi:10.1080/19443994.2014.928236.

International Energy Agency. (2006). World energy outlook 2009. Paris: IEA. Lafarge, B. (1995). Procédés de fermentation méthanique. Ed. Masson.

Lagrange, B. (1979). Biométhane 2. Principes-Techniques-Utilisations. Ed. Edisud.

ONA (2015). Tableau de bord mensuel, Direction de l’exploitation et de la maintenance. Office

National de l’Assainissement, Alger. ww.ona-dz.org.

Ouanouki, B., & Igoud, S. (1993). Contribution �a l’étude des boues résiduaires issues de stations d’épuration urbaine dans les plantations forestières. Revue Forestière Française, 45(2), 153–158.

Product Catalogue. (2010). Capstone Turbine Corporation. Documentation technique

microturbine �a biogaz. Capstone. Record. (2009). Record N�07-0226/1A. Techniques de production d’électricité �a partir de biogaz

et de gaz de synthèse.

Report of the world summit on sustainable development, Johannesburg, South Africa, 26 August–

4 September 2002. Ed. United Nations, New York, NY, 2002. Available from: www.

unmillenniumproject.org/projects/131302_wssd_report_reissued.pdf.

Slim, R. (2007). Etude et conception d’un procédé de séchage combiné de boues de stations d’épuration par énergie solaire et pompe �a chaleur. Thèse de Doctorat, Ecole des Mines de Paris, France.

UNESCO-WWAP. (2012). Managing water under uncertainty and risk. Facts and figures from the

United Nations world water development report 4 (WWDR4). United Nations World Water

Assessment Programme.

50 Sustainable Management of Sewage Sludge Conditioning and Valorization 693

http://www.unmillenniumproject.org/projects/131302_wssd_report_reissued.pdf

http://dx.doi.org/10.1080/19443994.2014.928236

Chapter 51

Photocatalytic Degradation of Tylosin and Spiramycin in Water by Using TiO2 and ZnO Catalysts Under UV Radiation

D. Tassalit, N. Chekir, O. Benhabiles, F. Bentahar, and N.A. Laoufi

Introduction

Some organic substances are either extremely stable or they have �a very slow rate of natural degradation. Pharmaceuticals for example are widely used by humans and

for food production and may react differently and persist in the environment (Sung-

Suh et al. 2004). During their life cycle, they create a new and emerging problem

and significant effects on the human health and ecological risks. For this reason, it’s important to develop a new efficient processes which can deteriorate these recalci-

trant pollutants (Neelavannan and Ahmed Basha 2010; Assabane et al. 2000). The

use of UV or visible light as a source of energy, especially sunlight, to promote

photocatalytic reactions is of great importance (Campion et al. 1999; Turchi and

Ollis 1989). The intensity of solar radiation reaching earth can be an alternative

source used especially in developing countries. Indeed, this renewable energy is

free and inexhaustible; it is the most abundant energy on Earth, especially in

Algeria (Herrmann et al. 2002; Simon and Dauby 2008).

D. Tassalit (*) • N. Chekir Unité de Développement des Equipements Solaires, UDES/Centre de Développement des

Energies Renouvelables, CDER, 42415 Bou Ismail, W. Tipaza, Algeria

Laboratoire des Phénomènes de Transfert, Faculté de Génie Mécanique et de Génie des

Procédes, Université des Sciences et de la Technologie Houari Boumediene (USTHB), Bab-

Ezzouar, 16111 Algiers, Algeria

e-mail: [email protected]

O. Benhabiles

Unité de Développement des Equipements Solaires, UDES/Centre de Développement des

Energies Renouvelables, CDER, 42415 Bou Ismail, W. Tipaza, Algeria

F. Bentahar • N.A. Laoufi

Laboratoire des Phénomènes de Transfert, Faculté de Génie Mécanique et de Génie des

Procédes, Université des Sciences et de la Technologie Houari Boumediene (USTHB), Bab-

Ezzouar, 16111 Algiers, Algeria

695

mailto:[email protected]

In the environment, pharmaceuticals have been detected in hospital wastewaters

(Jose-Gomez et al. 2006), in surface water such as rivers and lakes (Ternes and Joss

2006), in marine waters as well as in soil matrices (Benner et al. 2009; Santos

et al. 2009). Recent investigations have shown that a number of pharmaceutical

compounds, such as Naproxen, Ibuprofen, Tylosin, spiramycin, Diclofenac,

Naproxen, Amoxicillin and Ibuprofen (Yu et al. 2006; Kemper et al. 2008), are

not completely eliminated in wastewater treatment, they are often toxic and

non-biodegradable, becoming extremely dangerous for the ecosystems (Vıctor

et al. 2011; Westergaardn et al. 2001).

New waste water purification technology leading to the complete mineralization

of organic pollutants is now considered as being the most suitable solution

concerning the decrease of the contamination level in water and wastewater

(Lanao et al. 2012; Magalhaes and Lago 2009). Semiconductor-assisted

photocatalysis has attracted considerable attention because it uses advanced oxida-

tion process as a tool for implementing large-scale purification of waste waters at

low cost. Most studies have focused on large bandgap semiconductors oxides, such

as TiO2 and ZnO, whose photo-excitation by UV light provides electron-hole pairs

capable of initiating the production of hydroxyl radicals in water (Radjenovic

et al. 2009; Gumy et al. 2006; Oyama et al. 2004; Mathews et al. 2009). Although

TiO2 is universally recognized as being the most photoactive catalyst (Farooq

et al. 2009; Shifu and Gengyu 2005), many reports have highlighted the effective-

ness of ZnO in removing organic compounds in water matrices (Bahnemann 2004).

ZnO photocatalysts in most studies are generally applied in the form of aqueous

suspensions (Carlos et al. 2000).

The aim of this work was to investigate the kinetic and efficiency parameters of

the photo-oxidation of mixture of two antibiotics models (tylosine and spiramycin)

in an aqueous solution under UV illumination. The bibliographic research indicated

that assisted photocatalysis degradation of the tylosin and the spiramycin in the

same solution has never been reported. On the other hand, biological methods were

used for the elimination of this pollutant but the elimination ratio is not important.

Biodegradation and biosorption of tetracycline and tylosin were conducted by

Amrane. Tetracycline presented a good adsorbability while tylosin remained

mostly present in the soluble phase. The Langmuir maximum adsorption capacity

was found to be 72 and 7.7 mg g�1 for tetracycline and tylosin respectively (Amrane et al. 2009). Ching-Hua et al. estimated the tylosin concentrations in

animal’s liquid waste to be 496 mg/day-animal. The detection limit of tylosin in waste water is 0.01 mg L�1 (Ching-Hua et al. 2001).

Materials and Methods

All the experiments were carried out under an artificial UV light radiation using

Pyrex glass helical reactor with an illuminated volume of 800 mL. A peristaltic

pump permitted the circulation of water from a glass reservoir to the reactor with a

696 D. Tassalit et al.

flow rate of 3.787 mL s�1. The volume of the solution in the system (1000 mL) is divided into two parts: the 800 mL irradiated volume and the dead volume present

in connecting tubing and in the reservoir. The reactor was illuminated from the axe

with a UV lamp. This lamp has a spectral light that distributes the emitted photons

at wavelengths less than 365 nm.

Chemical and Reagents

Tylosin and spiramycin were obtained from Sinochem Corporation. The semicon-

ductors employed as photocatalysts are TiO2 Dugussa P25 obtained from Merck,

with a BET surface area of 50 m2 g�1 and an average particle size equal to 2 μm and Zinc oxide was purchased from Aldrich Chemical Company of 99% purity, with a

BET surface area of 9 m2 g�1 and an average particle size equal to 1.5 μm. This kind of particles is small enough to be transported by water suspension. Solutions

were prepared by dissolving requisite quantity of Tylosin and/or Spiramycin in

distilled water before each experiment. The pH of the solutions was not adjusted

(free pH of the solution) and the catalyst was introduced in solution of Tylosin or

spiramycin.

The solution was stirred for at least 20 min in the dark to allow the equilibration

of the system, so that the problem of the loss of compound caused by the adsorption

can be solved. The zero time reading was obtained from a blank solution kept in the

dark but otherwise treated similarly to the irradiated solution. Irradiations were

obtained out using a Phillips ATLD 24 W lamp (λmax¼ 365 nm). 2 mL of samples were collected before and after at regular intervals during irradiation from the

reservoir by a plastic syringe then filtered in a Millipore disk. The tylosin concen-

tration was determined by measuring the absorption of pollutants, on a UV–vis

spectroscopy (UV-Visible Lambda 25, commercialized by Perkin Elmer Com-

pany). A correlation curve between tylosin, spiramycin concentrations and the

absorption was set-out.

Results and Discussion

The organic pollutants are never found alone in the environment; wastewater is a

complex mixture of several chemical compounds. To get closer to reality, we

conducted a study of a mixture of two pollutants (spiramycin and tylosin) to

improve the influence of the coexistence of pollutants on the photocatalytic kinetics

degradation.

The presence of a second pollutant may inhibit the conversion of the first one,

which can be explained by a competition and a greater affinity of the second

pollutant for the catalyst than the first one (Jose-Gomez et al. 2006). The study of

the photodegradation of tylosin and spiramycin mixture was carried out with

51 Photocatalytic Degradation of Tylosin and Spiramycin in Water. . . 697

reports of mass concentrations from 0.25 to 2. To achieve this study, the

solutions were prepared with different weight ratios of tylosin/spiramycin

(Table 51.1) keeping the operating conditions of TiO2 and ZnO concentrations of

0.05 mg L�1, flow rate Q equal to 3.787 mL s�1 and a free pH of the solution.

Effect of TiO2 on the Co-degradation

The photocatalytic degradation of an initial concentration of 10 mg L�1 of tylosin with different amounts of spiramycin was performed using the titanium dioxide

suspension as catalyst. The study showed that the adsorption of these two pollutants

on the surface of catalyst was negligible. The kinetics of the two degradation curves

of pollutants during photocatalytic treatment are shown in Figs. 51.1 and 51.2 for

tylosin and spiramycin respectively. The concentration of pollutants decreases

exponentially involving first-order kinetics. Mineralization of spiramycin and

tylosin is complete after 100 and 120 min of the treatment respectively.

In the presence of spiramycin, tylosin degradation is slowed. The idea of a

competition for adsorption sites between tylosin and spiramycin is required. The

results of the degradation kinetics of tylosin are shown in Table 51.2. We observed

that the apparent rate constant of degradation increases with increasing concentra-

tion of spiramycin to a ratio equal to 1, then it remains practically constant for ratios

greater than 1. This can be explained by the competitiveness of the pollutants

adsorption which minimizes the amount of tylosin adsorbed on the catalyst surface.

The results revealed in Fig. 51.2 and in Table 51.2 shows that the presence of an

amount of tylosin affects the degradation kinetics of the spiramycin. The degrada-

tion of tylosin and spiramycin mixture was compared with the photodegradation of

the spiramycin alone in the solution; the results show that the total mineralization

time of the spiramycin alone (40 min) is shorter than in the tylosin/spiramycin

mixture which presents 120 min of radiation. The degradation of spiramycin is

slowed with increasing the concentration of this pollutant but the difference is

insignificant for the various studied reports except for the 0.25, where the reaction

kinetic follow a pseudo Zero order. The degradation kinetic of spiramycin for other

reports follows a pseudo first order (Table 51.3).

To compare between the different calculated rate constants, we plotted in

Fig. 51.3, the k/k0 report based on the concentrations of spiramycin and tylosin

(CSpi/CTyl) with k0, the apparent speed constants of tylosin and spiramycin alone.

Table 51.1 Different solutions considered during

the codegradation

C0Spi (mg L �1) C0tyl (mg L

�1) CSpir/Ctyl 2.5 10 0.25

5 10 0.50

10 10 1.00

15 10 1.50

20 10 2.00

698 D. Tassalit et al.

1.20

1.00

0.80

0.60

0.40

0.20

0.00 0 20 40 60 80 100 120

time (min)

0,25 tylosin alone

Cspi/Ctyl

C/C0

0,5 1 1,5 2

140

Fig. 51.1 Photodegradation of tylosin in the presence of spiramycin with different ratio CSpi/Ctyl,, CTiO2¼ 0.05 g L�1, Q¼ 3.787 mL s�1, free pH

1.2

1.0

0.8

0.6

0.4

0.2

0.0 0 20 40 60 80 100 120 140

time (min)

0,25 Spiram ycin alone

Cspi/Ctyl

0,5 1 1,5 2

C/C0

Fig. 51.2 Photodegradation of the spiramycin for different ratio CSpi/Ctyl, CTiO2¼ 0.05 g L�1, Q¼ 3.787 mL s�1, free pH

Table 51.2 Rate constant, initial rate and the half time of the degradation the tylosin on the presence of TiO2

Cspi/Ctyl (mg/mg) kapp (min �1) r0.10

3 (mmol L�1 min�1) t1/2 (min)

0 0.068� 0.002 0.739� 0.004 10 0.25 0.021� 0.001 0.229� 0.005 33 0.5 0.024� 0.003 0.262� 0.002 29 1 0.035� 0.002 0.382� 0.008 20 1.5 0.031� 0.003 0.338� 0.011 22 2 0.032� 0.001 0.349� 0.010 22

51 Photocatalytic Degradation of Tylosin and Spiramycin in Water. . . 699

When using the 0.25 report, we found that there is degeneration of the order of the

reaction, the rate constant relative to the apparent reaction order equal to the unit

was estimated by dividing it by the initial concentration of the pollutant. The plot

k/k0 based CSpi/CTyl shows that from a concentration ratio equal to 1, the two curves

are superimposed indicating that the degradation kinetics of the two pollutants is

practically the same.

Effect of ZnO on Co-degradation

It is interesting to study the behavior of a solution containing a mixture of tylosin

and spiramycin in competition in the reaction medium in the presence of zinc oxide

(ZnO). Thus, we studied the mineralization of a solution composed of a mixture

of spiramycin and tylosin in optimal conditions previously defined

(CTiO2¼ 0.05 g L�1, Q¼ 3.787 mL s�1, pH and free Cpolluant¼ 10 mg L�1). Concentrations measured during the photodegradation are plotted in Figs. 51.4

and 51.5.

Table 51.3 Rate constant, initial rate and the half time of the degradation of the spiramycin on the presence of TiO2

CSpi/Ctyl kapp (min �1) r0.10

3 (mmol L�1 min�1) t1/2 (min)

Spi. alone 0.078 0.003 min�1 0.908� 0.005 9 0.25 0.254.10�4� 0.001 mol L�1 min�1 0.025� 0.002 57 0.5 0.030� 0.003 min�1 0.175� 0.001 23 1 0.031� 0.001 min�1 0.361� 0.001 22 1.5 0.032� 0.002 min�1 0.559� 0.003 22 2 0.038� 0.005 min�1 0.885� 0.007 18

1.2

0.8

0.6

0.4

0.2

0 0 0.5 1 1.5 2

spiramy cin

Tylosin

2.5

k/k0

Cspi/Ctyl

Fig. 51.3 Evolution of the constant rate for different ratios CSpi/Ctyl, Q¼ 3.787mL s�1, CTiO2¼ 0.05 g L�1

700 D. Tassalit et al.

The photodegradation of tylosin is delayed by the coexistence of spiramycin.

Mineralization of tylosin is complete after 120 min for the different ratios studied

except for the 1.5 and tylosin alone. It’s concluded that the photo-oxidation constant rate of tylosin alone is higher than kapp obtained in the case of tylosine mixed with

the spiramycin. However, the decomposition of spiramycin is strong when it is

alone or mixed with equal ratios at 1.5 and 2 where the kinetic curves codégradation

appear very close together and the pseudo-first order. The apparent rate constants

for degradation of tylosin increase with increase in the amount of 1.5 relative to the

spiramycin, and then decreases to a ratio equal to 2 (Table 51.4).

1.20

1.00

0.80

0.60

0.40

0.20

0.00 0 20 40 60 80 100 120

time (min)

0.25 Tylosin alone Cspi/Ctyl

C/C0

0.5 1 1.5 2

140

Fig. 51.4 Degradation of tylosin for different ratios Ctyl/CSpi. CZnO¼ 0.05 g L�1, Q¼ 3.787 mL s�1

1.20

1.00

0.80

0.60

0.40

0.20

0.00 0 20 40 60 80 100 120

time (min)

0.25 Spiram ycin alone

CTyl/CSpi

C/C0

0.5 1 1.5 2

140

Fig. 51.5 Degradation of the spiramycin for different ratios Ctyl/CSpi, CZnO¼ 0.05 g L�1, Q¼ 3.787 mL s�1

51 Photocatalytic Degradation of Tylosin and Spiramycin in Water. . . 701

The curves in Fig. 51.5 correspond to the temporal evolution of the reduced

spiramycin concentration for different ratios of tylosin/spiramycin. From these

curves, the time of degradation of the pollutant is the lowest for the mixtures of

spiramycin and tylosin ratios equal to 1.5 and 2 in the case of the spiramycin. The

curves are almost super-imposable for these other values, while the highest degra-

dation time recorded is when using the tylosin/spiramycin ratio equal to 0.25. The

co-degradation of the spiramycin follows a pseudo zero order for a ratio of 0.25 and

becomes a pseudo-first order kinetics for higher values of CTyl/CSpi ratios

(Table 51.5).

Figure 51.6 present the values of k/k0 versus the ratio of concentrations of

spiramycin and tylosin (CSpi/CTyl) in the case of two pollutants photodegradation

in the presence of zinc oxide as catalyst, k0 is the apparent rate constant for tylosin

and spiramycin alone in the solution. When 0.25 ratio is used, it’s found that there is a degeneration of the reaction order. It’s concluded that the reduced constant k/k0 speed increases with increasing the ratio of these two pollutants in the case of

spiramycin but decreases in the case of tylosin. Furthermore, it’s noted that the values of rate constants for the degradation of tylosin are located below that of

spiramycin.

Table 51.4 Values of the rate constants, initial speed and half-degradation reaction time of tylosin by using ZnO as catalyst

Ctyl/CSpi kapp (min �1) r0.10

3 (mmol L�1 min�1) t1/2 (min)

Tyl. alone 0.056� 0.001 0.611� 0.002 12 0.25 0.017� 0.001 0.185� 0.002 41 0.5 0.022� 0.001 0.240� 0.003 32 1 0.023� 0.001 0.251� 0.001 30 1.5 0.044� 0.002 0.480� 0.004 16 2 0.026� 0.001 0.393� 0.001 19

Table 51.5 Values of the rate constant, initial rate and the half time of the degradation of the spiramycin on the presence of ZnO

Ctyl/CSpi kapp (min �1) r010

�3 (mmol L�1 min�1) t1/2 (min)

Spi alone 0.028� 0.004 0.356� 0.003 25 0.25 0.025� 0.003.10�3 mmol L�1 min�1 0.025� 0.002 57 0.5 0.038� 0.003 min�1 0.064� 0.008 45 1 0.049� 0.004 min�1 0.128� 0.011 45 1.5 0.069� 0.002 min�1 1.204� 0.031 10 2 0.074� 0.005 min�1 1.373� 0.025 12

702 D. Tassalit et al.

Comparison Between ZnO and TiO2 Efficiency on the Photodegradation Process

The tylosin and Spiramycin degradation have been studied by heterogeneous

photocatalysis process with Titanium dioxide (TiO2), Degussa P-25, and zinc

oxide (ZnO). The comparison Between TiO2 and ZnO Photocatalysis rate is reported in Figs. 51.7 and 51.8. In the case of the tylosin, the results show that

the degradation with TiO2 presents a better photocatalytic behavior than the ZnO

for ratios lower than 0.25 and 1.2, for highest ratios the photodegradation rate is

more important when using Zinc oxide.

The titanium dioxide and Zinc oxide are also reported as good photocatalysts for

the degradation of the Spiramycin. The degradation rates obtained by using TiO2 are also important than ZnO values for ratios less than 1.25 and decrease for the

highest ratios. In other hand, two picks are obtained for rates equal to 0.48 and

0.38 10�3 mmol L�1 min�1 when using TiO2 and ZnO respectively.

Conclusion

In this study, ZnO and TiO2 are used as photocatalysts to degrade two pharmaceu-

tical pollutants. It has been shown in the literature review that many of contami-

nants are present in the water to be treated. It would then be appropriate to assess the

effectiveness of the catalysts in the case of mixtures of target molecules. To

investigate this situation, the photodegradation of a mixture of tylosin and

spiramycin was conducted with different mass ratios. The obtained results show a

Fig. 51.6 Evolution of the constant rate of the spiramycin and tylosin for different ratios CSpi/Ctyl, Q¼ 3.787 mL s�1, CZnO¼ 0.05 g L�1

51 Photocatalytic Degradation of Tylosin and Spiramycin in Water. . . 703

decrease of the removal rate when other pollutant is present in the same solution.

The presence of TiO2 photocatalysis is effective for the complete degradation of the

tylosin and the spiramycin pollutants. Photocatalytic degradation by a suspension of

ZnO also showed a good performance for the removal of these pollutants. Degra-

dation ratio of both pollutants in the presence of ZnO is substantially important than

TiO2 for ratios less than 1.25, this ratio increases for the highest ratios of pollutants.

The effectiveness of the reactor is considerable giving the advantage of being used

in real cases upstream or downstream of the biological treatment to a complete

water treatment of urban and industrial waste by using TiO2 and ZnO as catalysts.

1.6

1.4

1.2

0.8

0.6

0.4

0.2

0 0 0.5 1 1.5 2

TiO2 ZnO

2.5 3

Fig. 51.7 Tylosin photodegradation rate in the presence of TiO2 and ZnO catalysts

Fig. 51.8 Spiramycin photodegradation rate in the presence of TiO2 and ZnO catalysts

704 D. Tassalit et al.

Nomenclature

C0 Initial concentration of the pollutant, mg/L

C Concentration of the pollutant, mg/L

kapp Kinetic rate constant, min �1

r0 Rate of the degradation of pollutant, mmol/L min

T1/2 Half time of the reaction, min

Q Flowrate of the water solution, mL s�1

UV Ultraviolet light

Tyl. Tylosin

Spi. Spiramycin

References

Amrane, A., Prado, N., & Ochoa, J. (2009). Biodegradation and biosorption of tetracycline and

tylosin antibiotics in activated sludge system. Process Biochemistry, 44, 1302–1306. Assabane, A., Ichou, Y., Tahiri, H., Guillard, C., & Hermann, J. M. (2000). Photocatalytic

degradation of polycarboxylic benzoic acids in UV-irradiated aqueous suspensions of titania.

Identification of intermediates and reaction pathway of the photo-mineralization of trimellitic

acid (1,2,4-benzene tricarboxylic acid). Applied Catalysis B: Environmental, 24(2), 71–87. Bahnemann, D. (2004). Photocatalytic water treatment: Solar energy applications. Solar Energy,

77, 445–459. Benner, J., Ternes, T. A., & Scholz, J. (2009). Ozonation of beta-blockers: kinetic studies,

identification of oxidation products and pathways. Environmental Science & Technology, 42, 10–18.

Campion, L., Giannotti, C., & Ouazzani, J. (1999). Photocatalytic degradation of 5-nitro-1,2,4-

triazol-3-one (NTO) in aqueous suspension of TiO2 comparison with Fenton oxidation.

Chemosphere, 38(7), 1561–1570. Carlos, S., Gouvêa, A. K., Wypych, F., Moraes, S. G., Durán, N., Nagata, N., et al. (2000).

Semiconductor-assisted photocatalytic degradation of reactive dyes in aqueous solution.

Chemosphere, 40, 433–440. Ching-Hua, H., Karen, E. R. J. P., & David, L. S. (2001). Occurrence and fate of antibiotic

compounds in municipal wastewater and animal’s waste. Proceedings of the Water Environ- ment Federation, 60, 686–697.

Farooq, M., Raja, I. A., & Pervez, A. (2009). Photocatalytic degradation of TCE in water using

TiO2 catalyst. Solar Energy, 83, 1527–1533. Gumy, D., Rincon, A. G., Hajdu, R., & Pulgarin, C. (2006). Solar photocatalysis for detoxification

and disinfection of water: Different types of suspended and fixed TiO2 catalysts study. Solar Energy, 80, 1376–1381.

Herrmann, J. M., Guillard, C., Disdier, J., Lehaut, C., Malato, S., & Blanco, J. (2002). New

industrial titania photocatalysts for the solar detoxification of water containing various pollut-

ants. Applied Catalysis B: Environmental, 35(4), 281–294. Jose-Gomez, M., Petrovic, M., Fernandez-Alba, A. R., & Barcelo, D. (2006). Determination of

pharmaceuticals of various therapeutic classes by solid-phase extraction and liquid chroma-

tography tandem mass spectrometry analysis in hospital effluent wastewaters. Journal of Chromatography A, 1114, 224–233.

51 Photocatalytic Degradation of Tylosin and Spiramycin in Water. . . 705

Kemper, N., Färber, H., Skutlarek, D., & Krieter, J. (2008). Analysis of antibiotic residues in liquid

manure and leachate of dairy farms in Northern Germany. Agricultural Water Management, 95, 1288–1292.

Lanao, M., Ormad, M. P., Mosteo, R., & Ovelleiro, J. L. (2012). Inactivation of Enterococcus

sp. By photolysis and TiO2 photocatalysis with H2O2 in natural water. Solar Energy, 86, 619–625.

Magalhaes, F., & Lago, M. R. (2009). Floating photocatalysts based on TiO2 grafted on expanded

polystyrene beads for the solar degradation of dyes. Solar Energy, 83, 1521–1526. Mathews, N. R., Morales, E. R., Cortes-Jacome, M. A., & Toledo Antonio, J. A. (2009). TiO2 thin

films-Influence of annealing temperature on, optical and photocatalytic properties. Solar Energy, 83, 1499–1508.

Neelavannan, M. G., & Ahmed Basha, C. (2010). Ag–TiO2 doped photo catalytic degradation of

Procion blue H-B dye in textile washwater. Toxicological & Environmental Chemistry, 92(8), 1423–1434.

Oyama, T., Aoshima, A., Horikoshi, S., Hidaka, H., & Zhao, J. (2004). Solar photocatalysis,

photodegradation of a commercial detergent in aqueous TiO2 dispersions under sunlight

irradiation. Solar Energy, 77, 525–532. Radjenovic, J., Petrovic, M., & Barcel, D. J. (2009). Fate and distribution of pharmaceuticals in

wastewater and sewage sludge of the conventional activated sludge (CAS) and advanced

membrane bioreactor (MBR) treatment. Water Research, 43, 8–31. Santos, J. L., Aparicio, I., Callejon, M., & Alonso, E. (2009). Occurrence of pharmaceutically

active compounds during 1-year period in wastewaters from four wastewater treatment plants

in Seville (Spain). Journal of Hazardous Materials, 164, 1509–1519. Shifu, C., & Gengyu, C. (2005). Photocatalytic degradation of organophosphorus pesticides using

floating photocatalyst TiO2.SiO2/beads by sunlight. Solar Energy, 79, 1–9. Simon, J. C., & Dauby, I. R. (2008). Evaluation de l’efficacité de l’oxydation avenacée par

photocatalyse hétérogène. U.V./TiO2 sur un effluent industriel contamine par des composes

organiques non biodégradables (colorants). Revue scientifique des ISILF, 22, 18–20. Sung-Suh, H. M., Choi, J. R., Hah, H. J., Koo, S. M., & Bae, Y. C. (2004). Comparison of Ag

deposition effects on the photocatalytic activity of nanoparticulate TiO2 under visible and UV

light irradiation. Journal of Photochemistry and Photobiology A: Chemistry, 163(1–2), 37–44. Ternes, A., & Joss, A. (2006). Human pharmaceuticals, hormones and fragrances: The challenge

of micropollutants in urban water management (1st ed., p. 453). London: IWA Publishing. Turchi, C. S., & Ollis, D. F. (1989). Mixed reactant photocatalysis: Intermediates and mutual rate

inhibition. Journal of Catalysis, 119(2), 483–496. Vıctor, J. P., Lıvia-Pinho, X., & Ariana, M. A. (2011). Treatment of textile wastewaters by solar-

driven advanced oxidation processes. Solar Energy, 85, 1927–1934. Westergaardn, K., Muller, A. K., Christensen, S., Bloem, J., & Sorensen, S. J. (2001). Effects of

tylosin as a disturbance on the soil microbial community. Soil Biochemistry, 33, 2061–2071. Yu, J. T., Bouwer, E. J., & Coelhan, M. (2006). Occurrence and biodegradability studies of

selected pharmaceuticals and personal care products in sewage effluent. Agricultural Water Management, 16, 72–80.

706 D. Tassalit et al.

Chapter 52

Comparison Between the Photocatalytic Degradation of a Textile Dye Under Sun Light and Artificial Irradiation

N. Sahraoui, N. Chekir, and D. Tassalit

Introduction

Dyes occupy an important place in synthetic organic compounds. They are used

extensively in industries including textiles, ink, plastics, cosmetics, tannery, and are

therefore, automatically found in water as an industrial pollutants (Schwarzenbach

et al. 2006). Their rejection into aquatic systems is causing damage to the environ-

ment due to their toxicity, which requires treatment (Liu et al. 2009).

Some of these pollutants are very stable and therefore difficult to be degraded

naturally or by using classic processes. Others are able to be degraded partially but

producing highly stable intermediate compounds which can have more toxicity than

the first pollutant.

The complexity of these pollutants and their color greatly affect the efficiency of

the classical treatments application, hence the need to develop more efficient

processes than conventional methods which can degrade recalcitrant pollutants.

Among the most recent progress, based on advanced oxidation techniques,

heterogeneous photocatalysis is nowadays, an emerging solution to the problems

of pollution by organic pollutants (Gaya and Abdullah 2008).

The Advanced Oxidation Processes are defined by (McGuigan et al. 1999) as the

very interesting alternative for the degradation of non-biodegradable organic pol-

lutants by biological treatment processes. These POAs are based on the generation

and use of the hydroxyl radical (OH�).

N. Sahraoui (*) Département de Génie des Procédés, Laboratoire des phénomènes de transfert,

USTHB, BP32, El Alia, Bab Ezzouar, 16111 Alger, Algeria

e-mail: [email protected]

N. Chekir • D. Tassalit

Unité de Développement des Equipements Solaires (UDES)/Centre de Développement des

Energies Renouvelables CDER, Bou-Ismail 42415, W. Tipaza, Algeria

707

mailto:[email protected]

Any process requires, in addition to the products for the treatment, a source of

energy. Solar energy available throughout the year with varying intensities can be a

useful alternative source, especially in developing countries. Indeed, this renewable

energy source is free and inexhaustible; it is the most abundant energy on Earth.

Photocatalytic treatment is thus presented as a technology of choice for the

pollution control and the integration of wastewater reuse, because it is an efficient,

simple and economical method. These attractive factors generate a great interest

from researchers for understanding, optimizing the industrial application of this

process (Helali 2012).

The objective of our study is to demonstrate the effectiveness of the

photocatalytic process for treating contaminated water with a Sandocryl Red

(BR46) textile dye. For this purpose, optimization of the operating conditions was

carried out. Photocatalytic degradation experiments were carried out at room

temperature by irradiating Zinc oxide ZnO semiconductor using a batch

photoreactor under ultraviolet (UV) radiation via sunlight or artificially by using

a UV lamp. The temporal evolution of the initial concentration of the contaminant

was studied with different concentrations of catalyst. The light intensity is mea-

sured with a digital UV pyranometre.

Materials and Measurement Method

Chemical Reagents

The used pollutant in this study is the Sandocryl Red (BR46), a pollutant that

belongs to the family of azo dyes. It is a synthetic red dye powder which is very

soluble in water (Table 52.1).

The used photocatalyst in this study is the commercial dioxide Zinc (ZnO), it is a

white powder supplied by Sigma Aldrich. It has a 100% zincite structure with a

specific surface area of 9 m2 g�1 and a particle diameter of 1.5 μm.

Experimental Facility

The photocatalysis treatment of polluted water is conducted by using used batch

photoreactor of 1 L volume capacity. The installation consists essentially of a batch

reactor exposed to either direct sunlight or the Ultraviolet radiation. This last is

UVC radiation of a lamp with a power of 15 W. The experimental setup is shown in

Fig. 52.1.

708 N. Sahraoui et al.

Measurement of the Pollutant Concentration

The temporal evolution of the pollutant concentration of Sandocryl Red is given by

the measurement of absorbance by a UV-visible spectrometer with dual beam of

type Shimadzu UV1800m, coupled to acquisition results software (UV PROB). The

contaminant has a maximum absorbance at a wavelength λ¼ 530 nm. The solar flux is measured at 5-min intervals of time between 9 h am and 15 h, using a

pyranometer coupled to software (Kipp & ZONZN, CMP11) with inclination of

36�. The aim of this work is to perform the parametric study on the photocatalytic

degradation of BR46 in the presence of zinc oxide. The reaction mixture was stirred

to homogenize the solution. Three milliliters of samples are taken every 15 min of

reaction. Before analysis by UV spectrophotometer, the mixture is filtered using a

cellulose acetate filter to remove any traces of ZnO before analysis. At the end of

each experiment, the system is immediately rinsed with distilled water.

Table 52.1 Physical and chemical properties of the BR46

CH3

CH3 CH3OSO3 −

H3C

N N

Chemical structure of the BR46 dye

Physical properties

Physical State Solid

Appearance Powder

Chemical properties

Molar mass 432 g mol�1

Fig. 52.1 Experimental setup

52 Comparison Between the Photocatalytic Degradation of a Textile Dye Under Sun. . . 709

Results and Discussion

Determination of the Wavelength of the BR46

The absorbance of BR46 is committed to their maximum adsorption. The absorp-

tion spectrum was obtained by scanning the solution of BR46 with concentration of

10 mg L�1 between 300 and 600 nm. Figure 52.2 shows the absorption spectrum of the pollutant for different times of the photodegradation reaction. It is clearly

observed that the BR46 maximum absorption coincide with a wavelength

λ¼ 530 nm.

Direct Photolysis and Photocatalysis

Photolysis of BR46

We conducted a preliminary study to see the degradation of the BR46 under UV

radiation in the absence of ZnO. To study the degradation of the pollutant by direct

photolysis, a solution of this pollutant with a concentration of 10 mg L�1 was exposed to UV irradiation in the photoreactor. The obtained results show that the

dye concentration decreases insignificantly, demonstrating that the irradiation with

1.090

1.000

0.500

0.000

−0.190 400.00 500.00

1 1

600.00 nm.

A b

700.00 800.00

Fig. 52.2 Absorption spectra for different concentrations of BR46

710 N. Sahraoui et al.

UV in the absence of catalyst have no effect on the degradation of the dye. The ratio

of degradation is about 2% after 300 min of irradiation as shown in Fig. 52.3.

Photocatalytic Degradation of BR46 by Sun Radiation and UV

The photodegradation study of BR46 was performed using zinc oxide as catalyst

under solar and UV radiation. In order to optimize the operating conditions of the

photodegradation of BR46, several experiments were conducted by varying the

following parameters:

• Initial concentration of the pollutant;

• Catalyst concentration.

For the better understanding of the phenomenon of photocatalytic degradation of

BR46, knowledge of the degradation reaction order of is essential. For this reason,

we took inspiration from the results found in the literature explaining that the

kinetics of the phenomenon of photodegradation of many organic pollutants fol-

lows a first order reaction whose speed is described by the following equation:

r ¼ dC dt

¼ kapp C ð52:1Þ

with:

r: Photocatalytic degradation rate (mg L�1 min�1) kapp: Apparent degradation constant (min

�1) C: Dye concentration (mg L�1) t: Irradiation time (min)

The solution concentration of the dye when t¼ 0, generates another equation which gives the linearization:

1.20 C/C0

1.00

0.80

0.60

0.40

0.20

0.00 0 100 200 300

time(min)

Fig. 52.3 Photolysis of BR46, CBR46¼ 10 mg L�1, free pH

52 Comparison Between the Photocatalytic Degradation of a Textile Dye Under Sun. . . 711

�ln C C0

¼ kapp t ð52:2Þ

Photocatalytic tests were then carried out in the presence of ZnO assuming that

the reactions are pseudo-first order.

Influence of the Initial Concentration of the Pollutant Under Sunlight

The concentrations of Sandocryl Red (BR46) was varied between 5 and 40 ppm at a

free pH of the solution (between 6, 5 and 7) while maintaining the amount of used

catalyst constant and equal to 1 g L�1. Figure 52.4 shows the temporal evolution of the reduced concentrations of Sandocryl Red (BR46). The results confirm that the

degradation of BR46 is important when the initial concentration of this pollutant

decreases.

The plot of �ln C/C0 versus time in Fig. 52.5 and the values of Kapp reported in Table 52.2 shows that the rate constant (Kapp) decreases as the substrate concen-

tration increases. This is explained by a lower participation of photons when the

color of the solution becomes more intense and therefore a low activation of ZnO

(low production of OH� radicals). The obtained results show that the rate constant for the degradation (Table 52.2)

decreases with increasing of the concentration of BR46, the rate constants of the

values are between 0.143 min�1 for the lower concentration of pollutant (5 ppm) and 0.048 min�1 for the highest concentration (40 ppm).

Fig. 52.4 Evolution of the temporal different reduced pollutant concentrations with free pH and CZnO¼ 1 g L�1

712 N. Sahraoui et al.

Effect of the Initial Concentration of the Pollutant Under UV Radiation

The same experiments with sun light were repeated in the presence of UV radiation

in order to compare the two modes of radiation maintaining the same operating

conditions:

• Free pH of the solution (between 6.5 and 7);

• Initial concentrations of dye range are from 5 to 40 ppm;

• Amount of catalyst used constant are equal to 1 g L�1.

Figure 52.6 shows the evolution of reduced concentrations of Sandocryl Red

(BR46) versus time.

From the curves of Fig. 52.6, the photodegradation is strongly influenced by the

initial concentration of the substrate. The degradation of the BR46 is even more

important when the initial concentration of this pollutant decreases. By using a

concentration of 5 ppm, the degradation is very fast and it reaches an elimination

ratio of 97%.

Fig. 52.5 Temporal evolution of ln (C/C0) for different pollutant concentrations with free pH and CZnO¼ 1 g L�1

Table 52.2 Values of the rate constants for different values of the pollutant concentrations

BR 46 (ppm) Kapp (min �1) r0 (mg L

�1 min�1) t1/2 (min) R 2

5 0.143 0.715 5 0.99

10 0.092 0.920 7.5 0.99

20 0.065 1.300 10 0.99

40 0.048 1.921 14 0.99

52 Comparison Between the Photocatalytic Degradation of a Textile Dye Under Sun. . . 713

The plot of�ln(C/C0) versus time for various initial concentrations of Sandocryl Red (BR46) (Fig. 52.7) show that the kinetics is pseudo first-order, the concentra-

tion satisfactory follows the expression of the first order equation with a slope equal

to the apparent speed constant kapp. The values are shown in Table 52.3.

The obtained results (Fig. 52.7 and Table 52.3) shows that the rate constant of

degradation decreases with increasing the concentration of BR46, the rate constants

are situated between 0.059 min�1 for the lowest concentration of pollutant (5 ppm)

Fig. 52.6 Temporal evolution of different reduced pollutant concentrations with free pH and mass of catalyst¼ 1 g L�1

Fig. 52.7 Temporal evolution of �ln(C/C0) for different pollutant concentrations with free pH and catalyst mass¼ 1 g L�1

714 N. Sahraoui et al.

and 0.015 min�1 for the highest concentration (40 ppm). It can be observed that the rate constant (kapp) decreases as the substrate concentration increases. This is

explained by a lower participation of photons because of the screen effect.

Influence of the Catalyst Concentration Under Sun Radiation

The effect of catalyst concentration (ZnO) on the photo-oxidation of the BR46 was

studied using amounts ranging from 0.125 g L�1 to 1.5 g L�1 under the sun and UV radiation. The experiments were performed with a solution of 10 g L�1 of BR46 and free pH (pH of the solution without adjustment). The obtained results are illustrated

in Fig. 52.8.

The results presented in Fig. 52.9 show that the rate of deterioration of BR46

ZnO for different concentrations are very high and can reach a value of 100% of

removal, like in the case of high concentrations of catalyst (1,5 g L�1). The rate of degradation and the rate constants increase with increasing the amount of ZnO as

Table 52.3 Values of rate constants for the different values of pollutant concentrations

CBR46 (ppm) Kapp (min �1) r0 (mg L

�1 min�1) t ½ (min) R 2

5 0.059 0.295 11.748 0.95

10 0.041 0.410 16.906 0.90

20 0.24 0.480 28.881 0.98

40 0.015 0.600 46.210 0.98

Fig. 52.8 Evolution of the concentration of the pollutant over time with free pH, Cpollutant¼ 10 ppm

52 Comparison Between the Photocatalytic Degradation of a Textile Dye Under Sun. . . 715

shown by the results in Table 52.4 and Fig. 52.10 which present the temporal

evolution of �lnC/C0 at different concentrations in the catalysts.

Influence of the Catalyst Concentration Under UV

It is important to know the optimal catalyst load for the efficient removal of a

pollutant. The effect of catalyst concentration (ZnO) on the photo-oxidation of

BR46 under UV light was also conducted under the same operating conditions as

for the study of solar radiation using catalyst amounts ranging from 0.125 g L�1 to 1.5 g L�1. The experiments were performed with a solution of 10 g L�1 of BR46 and free pH (pH of the solution without adjustment). The results obtained are

illustrated in Fig. 52.11.

The results shown in Fig. 52.11 show that BR46 deterioration rate by ZnO with

different concentrations are very high and can reach a value of 100% removal, in

case of concentrations of catalyst (1.5 g L�1). It is also found that the rate of

Fig. 52.9 Temporal evolution of ln(C/C0) for different concentrations of ZnO, C0BR46¼ 10 mg L�1, free pH

Table 52.4 Values of rate constants, initial speed and time of half-reaction of BR46 degradation for different concentration ZnO

CZnO (g L �1) Kapp (min�1) r0 (mg L

� min�1) t1/2 (min) R 2

0.125 0.029 0.29 23 0.99

0.250 0.078 0.78 9 0.99

0.500 0.129 1.29 5 0.98

1.000 0.139 1.39 5 0.99

1.500 0.179 1.79 4 0.96

716 N. Sahraoui et al.

degradation and the rate constants increase with increasing the amount of ZnO as

shown by the results in Fig. 52.11 and the temporal evolution of �ln C/C0 for different catalysts concentrations and Table 52.5.

The increase in catalyst concentration generally favors the absorption of the

contaminant to the surface, which increases the degradation rate. However too

much affects the light scattering in the solution to treat involving a reduction of

the degradation kinetics

Fig. 52.10 Evolution of different reduced concentrations of the catalyst over time with free pH and Cpollutant¼ 10 ppm

Fig. 52.11 Temporal evolution of ln(C/C0) for different concentrations of ZnO, C0BR46¼ 10 mg L�1, free pH

52 Comparison Between the Photocatalytic Degradation of a Textile Dye Under Sun. . . 717

Conclusion

The carried studies in this work show that the advanced oxidation processes is

effective for the treatment of water polluted by textile dyes. Degradation of the

Sandocryl Red: BR46 is performed by the oxidizing action of the hydroxyl radicals

generated in the medium to be treated. These radicals are capable of degrading

almost all organic pollutants because of their high oxidizing power and their

reactivity and non selectivity against the organic substances. The study of the

influence of different parameters has shown that photodegradation of this pollutant

is favored for low pollutant concentrations and with increasing the concentration of

catalyst.

However, the results of treatment using sun radiation gave better results com-

pared to the treatment by using UV light radiation.

References

Gaya, U. I., & Abdullah, A. H. (2008). Heterogeneous photocatalytic degradation of organic

contaminants over titanium dioxide: A review of fundamentals progress and problems. Journal of Photochemistry and Photobiology C: Photochemistry Reviews, 9(1), 1–12.

Helali, S. (2012). Application de la photocatalyse pour la dégradation des polluants chimiques et bacteriologiques dans l’eau en utilisant des catalyseurs irradies par des photons de lumiere naturelle ou arti_cielle (UV-A/UV-B). France: Université Claude Bernard—Lyon I.

Liu, Z., Kanjo, Y., & Mitzutani, S. (2009). Removal mechanisms for endocrine disrupting

compounds (EDCs) in wastewater treatment—physical means, biodegradation, and chemical

advanced oxidation: A review. Science of the Total Environment, 407, 731–748. McGuigan, K. G., Joyce, T. M., & Conroy, R. M. (1999). Solar disinfection: Use of sunlight to

decontaminate drinking water in developing countries. Journal of Medical Microbiology, 48, 785–787.

Schwarzenbach, R. P., Escher, B. I., Fenner, K., Hofstetter, T. B., Johnson, C. A., Von Gunten, U.,

et al. (2006). The challenge of micropollutants in aquatic systems. Science, 313(5790), 1072–1077.

Table 52.5 Values of rate constants, initial speed and time BR46 degradation half-reaction for different concentration ZnO

CZnO (g L �1) Kapp (min

�1) r0 (mg L �1 min�1) t1/2 R

0.125 0.014 0.14 49.51 0.99

0.25 0.024 0.24 28.88 0.98

0.5 0.026 0.26 26.65 0.95

1 0.027 0.27 25.672 0.94

1.5 0.052 0.52 13.330 0.81

718 N. Sahraoui et al.

Chapter 53

Vulnerability and Impact of Climate Change Processes on Water Resource in Semi-Arid Areas: In Essaouira Basin (Morocco)

Salah Ouhamdouch, Mohammed Bahir, Abdellatif Souhel, and Carreira Paula

Introduction

Since the 1950s, the earth’s climate has undergone significant changes represented mainly by the warming due to greenhouse gas emissions, in close relation with

human activity (IPCC, 2013). These changes have a negative influence on the

environment and man. In most semi arid areas, seasonal and long-term climate

variability changes the dynamics of water cycle. Groundwater levels are also falling

at alarming rates. Nowadays, groundwater withdrawal and environmental trends

may bring about serious problems in some parts of the world. The availability of

sufficient fresh waters has become a limiting factor for development. Among the

consequences of these changes, include: (1) the increase of the temperature,

(2) decrease in precipitation as well as the mass of the ice sheets, (3) rise in sea

level and (4) the scarcity of water resources. In addition, the countries of the

Maghreb (Algeria, Morocco and Tunisia) have not been spared the impact of

these changes that negatively affect the most of their natural resources, including

water resources. Locally, the bay of Essaouira also has its share of these effects,

S. Ouhamdouch, Ph.D. (*) Department of Geology, Laboratory 3 GEOLAB, Faculty of Science Semlalia,

Marrakech, Morocco

e-mail: [email protected]

M. Bahir • A. Souhel

Department of Geology, E.N.S. Marrakech, Marrakech, Morocco

e-mail: [email protected]; [email protected]

C. Paula

Centro de Ciências e Tecnologias Nucleares, CTN/IST, Universidade Técnica of Lisboa,

Lisboa, Portugal

e-mail: [email protected]

719

mailto:[email protected]

which are represented mainly in the scarcity of water resources see also salinity

following the invasion of sea water and the increase in the salinity of the soil,

degradation of groundwater quality and the extermination of a number of water

sources.

Climate Change on a Global Scale

According to its report of September 2013, the Intergovernmental panel on Climate

change (IPCC) states that warming of the climate system of the earth is unequiv-

ocal, adding that the human influence is the primary cause of this warming. Among

the results of this global warming, we note that the three examples below:

– The warming of the atmosphere: The last three decades are successively warmer

at the earth’s surface than all preceding decades since 1850. The average temperature of the globe shows a warming of the order of 0.85 �C during the period 1880-2012 (Fig. 53.1). For precipitation, they have experienced an

Fig. 53.1 Observed Anomalies of average temperatures on the surface of the globe (IPCC, 2013)

720 S. Ouhamdouch et al.

increase since 1901 on the continental regions of the middle latitudes of the

northern hemisphere, as well as eastern South America, and a decrease in the

Sahel; in the Mediterranean; in southern Africa and in parts of south Asia

(Fig. 53.2) (IPCC, 2013).

– The reduction of the surface area of the ice caps and glaciers: everywhere in the

world, there is a reduction of the surface area of the ice caps, and ices. Over the

past three decades, the extent of annual average arctic sea ice has been decreas-

ing at a rate of 3.5–4.1% per decade (Fig. 53.3).

– Sea level: since the early 1970s, the decrease of the glacier masses and the

thermal expansion of the oceans contribute to them only about 75% of the rise

global mean sea level. Between 1901 and 2010, the average level of the sea

shows an increase of 0.19 cm (Fig. 53.4).

Fig. 53.2 Maps of the observed changes in precipitation between 1901 and 2010, and between 1951 and 2010 (IPCC, 2013)

4 1900 1920 1940 1960 1980 2000

Fig. 53.3 Arctic summer sea ice extent (in million km2) (IPCC, 2013)

53 Vulnerability and Impact of Climate Change Processes on Water Resource. . . 721

Climate Change in North African

As in most world countries, the three countries of the Maghreb (Algeria, Morocco

and Tunisia) have not been spared the impact of climate change, which has affected

and still affects negatively the most of their natural resources. Among these

resources, the resource water. For example, the north-west Algeria has experienced

a reduction of the order of 40% of annual precipitation from the first half of the

1970s (Nouaceur et al. 2013; UNESCO, 2010). This reduction is carried out in a

temperature increase, which corresponds to the signal of global climate change.

This change has affected the river flows of this region. According to the fourth

report of the IPCC (Bates et al., 2008), the blades of waters passed the annual

average of the period 1976–2002 are 28–36% lower than those of the period

1949–1976, and this reduction is due to climate change. According to the national

institute of meteorology Tunisia, the rainfall pattern in the Tunisia during the

twentieth century has been marked by relative stability. In contrast to the rest of

the century was marked by the alternation of dry periods (1940–1950) and wet

periods (1950–1960). However, the temperature tends to increase (1.1 �C) since the sixties. In addition to this increase, Tunisia has suffer amplification erosion pro-

cesses dry up the soil and consequently augment and increase the salinity of the

water tanks. In addition, the elevation of accelerated sea level due to global

warming will have serious impacts on the shoreline such that the contamination

of the aquifers in the coastal waters of freshwater by the marine waters of salt. In

Morocco, the water resources are limited and have a potential water that can be

mobilised estimated at 20 billion m3, giving an average of 700 m3/capita/year,

which is recognized as a relatively high water stress. The number of years of deficit

rainfall everywhere is more important than that of surplus years (Fig. 53.5). This

decline coincides with an increase in the frequency of droughts also visible from the

1980s (Driouech et al., 2013; Sebbar et al., 2011; Driouech, 2010; Sinan et al.,

2009). As found by various previous studies (including that of the minister of

public works, 2007), we distinguish two dry periods: 1980–1985 and 1990–1995.

200

150

100

−50 1900 1920 1940 1960 1980 2000

Fig. 53.4 Global average sea level evolution (in mm) (IPCC, 2013)

722 S. Ouhamdouch et al.

By contrast, the evolution of the temperature is constant, and tends to increase

(Fig. 53.6), which corresponds to the signal of global climate change, and makes

Morocco among the countries affected by climate change. Among the results of this

change, we quote: (1) Erosion of the soil under the effect of desertification, which

resulted in the silting up of dams. (2) Accentuation of soil salinization and water

resources. (3) Lowering of the piezometric levels of the groundwater on one side

Fig. 53.5 National averages (in %), of relative anomalies of annual rainfall, calculated over the 14 Moroccan meteorological stations. 1961–2008 period (Driouech, 2010)

Fig. 53.6 Trends in seasonal mean temperature calculated for the 1961–2008 period at the 14 meterological stations (in �C / decade). (Driouech, 2010) (Color figure online). Note bene: winter: red bars, spring: green bars, autumn yellow bars

53 Vulnerability and Impact of Climate Change Processes on Water Resource. . . 723

and the increase in the level of the sea on the other side, which creates in coastal

areas, a reversal of current, resulting in the invasion of seawater and the destruction

of the hydraulic potential.

Climate Change and Essaouira Basin

In Morocco, most studies of the impact of climate change on water resources

focused on coastal areas (Bouchaou et al., 2011; Bahir et al., 2003; Hsissou et al.,

2001). These regions that are densely populated and subjected tourism activities are

characterized by a growing demand for water.

Geographic Location

The Essaouira basin is located on the Atlantic coast of Morocco, specifically at the

western end of the high atlas chain, where it occupies an area of 1827 km2. This

basin includes several aquifer systems whose structures and resources are often

poorly known. The most important of these systems belong to two synclinal units:

the unit of Bouabout located in the eastern part of the basin and the unit of Essaouira

synclinal who represents the Western part of the basin. These two units are

separated by the Tidzi diaper (Fig. 53.7).

Fig. 53.7 Location of the study area

724 S. Ouhamdouch et al.

Geological Cadre

At the basin level of Essaouira, the Triassic and the Jurassic have outcrops very

reduced and localized to the anticlines core (jbel Hadid NW, jbel Amstétene to the

SW and Tidzi diaper). While the tertiary formations and the quaternary are found in

the basins syncline. The Triassic is made up of red clay salt, basalt diabase and

pelites sandstone. The Jurassic is represented by an alternation of carbonate

deposits (limestone’s and dolomites) and marls rich in evaporite (gypsum and anhydrites). While the cretaceous formations and quaternary rocks are grouped in

the stratigraphic log synthetic (Duffaud et al., 1966) (Fig. 53.8).

The Essaouira basin is a vast area synclinal open on the Atlantic Ocean, affected

by several folds and accident, which allow for the individualization of many

Fig. 53.8 Log synthetic stratigraphic Cretaceous and Tertiary of Essaouira basin

53 Vulnerability and Impact of Climate Change Processes on Water Resource. . . 725

synclinal basins: (1) the synclinal basin of Bouabout occupying the upstream part of

the basin, crossed by the river Igrounzar. (2) The bowl of Kourimat and (3) the

synclinal basin of Essaouira synclinal (downstream part of the basin), separate from

that of Bouabout by the diaper of Tidzi which shows the outcrop of the subterranean

triassic. These cups give birth to hydrogeological aquifer systems (Fig. 53.9) (Bahir

et al., 2013; Chamchati and Bahir, 2013; Bahir et al., 2008; Jalal et al., 2001).

Climate Cadre

According to the Martonne index (53.1) in which the equation stated below, the

Essaouira basin is located in a semi-arid zone, characterized by ocean, continental

and mountain influences. The aridity is marked in the basin, especially in the

summer; it is relatively increased in going from the Atlantic to the continent.

This aridity growth is the result of the remoteness of the ocean influence, where

the rain decreases and the thermal differences increase.

I ¼ P= Tþ 10ð Þ ð53:1Þ

With P: average annual rainfall in mm and T: average annual temperature in �C. At the level of the Igrounzar’s station, the temperatures show a very significant seasonal variation. In winter, minimum temperatures can reach up to�11 �C, while summer highs are in the order of 40–45 �C (Chamchati and Bahir, 2011). From the Ombrothermic diagram of Igrounzar’s station, the hot season runs fromMarch until

Fig. 53.9 Geological map (1:1,000,000) of study area

726 S. Ouhamdouch et al.

October or even November. While the wet period occurs from November to march

(Fig. 53.10). The rainfall varies from year to year around an average of 306 mm

(Fig. 53.11). For the series of years stripped (1977–1978 to 2010–2011), are found

in wet years, the height of which exceeds the average (1987–1989, 1995–1997,

2005–2006, 2008–2010), therefore, the rush and show an irregular interannual

striking.

Piezometry

To have an idea about the evolution of the piezometric level in the Essaouira basin,

we will treat in a first time the water cenomanian-turonian of Bouabout (upstream)

and in the second time the water plio-quaternary (downstream):

– Cenomanian-turonian water (Bouabout): The companions of measuring the level

piezometric carried out from 2006 to 2010 were used to establish the evolution

Fig. 53.10 Ombrothermic diagram of Igrounzar station

Igrounzar (1977-2010)

P moy(mm)

19 77

-7 8

19 78

-7 9

19 79

-8 0

19 80

-8 1

19 81

-8 2

19 82

-8 3

19 83

-8 4

19 84

-8 5

19 85

-8 6

19 86

-8 7

19 87

-8 8

19 88

-8 9

19 89

-9 0

19 90

-9 1

19 91

-9 2

19 92

-9 3

19 93

-9 4

19 94

-9 5

19 95

-9 6

19 96

-9 7

19 97

-9 8

19 98

-9 9

19 99

-0 0

20 00

-0 1

20 01

-0 2

20 02

-0 3

20 03

-0 4

20 04

-0 5

20 05

-0 6

20 06

-0 7

20 07

-0 8

20 08

-0 9

20 09

-1 0

20 10

-1 1

800.000 700.000 600.000 500.000 400.000 300.000 200.000 100.000

0.000

Fig. 53.11 Evolution of the annual rains in Igrounzar station from 1977 to 2010

53 Vulnerability and Impact of Climate Change Processes on Water Resource. . . 727

curves of the water level of a water points number such as 1126/52 and 1726/52

(Fig. 53.12). La représentation graphique de l’évolution du niveau piézométrique

dans la période 2006–2010 �a ces points, montre une diminution du niveau de l’eau de Juin 2006 �a Octobre 2008. Cette baisse se explique par la sécheresse qui affecte la région au cours des deux années 2007 et 2008 et aussi par la surexploitation de

l’aquifère pour l’irrigation afin de compenser l’impact de la sécheresse. Après

Octobre 2008, le niveau de l’eau commence �a monter pendant une période de huit mois, puis recommence �a baisser.

– Plio-quaternary water: the companions of measurement of the piezometric level

of the Plio-quaternary aquifer, during 1990,1995, 2000, 2004 and 2009 resulted

in the piezometric maps (Fig. 53.13). They show a sense of overall flow of the

South-East to North-West, conditioned by the recovery of its substratum to the Is

a result of the lifting of the Tidzi diaper. A comparison of these piezometric

maps reveals a decrease of the piezometric levels in 1995 (the driest year of the

century in Morocco) within a certain wells have experienced measures of level

30.00

02/2006

01 /2

00 6

03 /2

00 6

05 /2

00 6

07 /2

00 6

09 /2

00 6

11 /2

00 6

01 /2

00 7

03 /2

00 7

05 /2

00 7

07 /2

00 7

09 /2

00 7

11 /2

00 7

01 /2

00 8

03 /2

00 8

05 /2

00 8

07 /2

00 8

09 /2

00 8

11 /2

00 8

01 /2

00 9

03 /2

00 9

05 /2

00 9

07 /2

00 9

09 /2

00 9

11 /2

00 9

01 /2

01 0

06/2006

12/2006

02/2007

04/2007

06/2007

08/2007

10/2007

12/2007

02/2008

04/2008

06/2008

08/2008

10/2008

12/2008

02/2009

04/2009

06/2009

09/2009

22/12/09

35.00

40.00

1726/52

1126/52

45.00

P (M

) P

(M )

50.00

60.00

65.00

70.00

75.00

80.00

Fig. 53.12 Evolution of the piezometric level in the period 2006–2010 at the level of the water points 1126/52 and 1726/52 (2006–2010)

728 S. Ouhamdouch et al.

in the five periods (Table 53.1). After the dry year of 1995, a number of wet

years, the occurrence of 1996–1997, 2002, 2003, 2004, 2006 and 2009 can

restore and go back in the piezometric level in the aquifer. This variation of

the piezometric level can only be explained by the vagaries of the weather and

the over-exploitation for irrigation in order to disguise the impact of the drought.

Fig. 53.13 Maps piezometric groundwater Plio-Quaternary of the synclinal area of Essaouira in 1990, 1995, 2000, 2004 and 2009

53 Vulnerability and Impact of Climate Change Processes on Water Resource. . . 729

Hydrochemistry

The chemistry study of water allows the identification of chemical facies of waters,

their quality and potability, and their irrigation suitability. The Piper diagram shows

the water of plio-quaternary aquifer has a chloride-sodium facies (Fig. 53.14).

Based on electrical conductivity and chlorides of plio-quaternary groundwater,

we can have an idea on water quality and its evolution. In the temporary scale,

the groundwater quality is becoming more and more good by going to the driest

year that knows Morocco (1995) in 2009, through the years modestly dry and rainy.

Spatially, its takes a positive direction from the North to South of the groundwater

table (Fig. 53.15 and Table 53.2). The temporal and spatial evolution of this quality

have closely linked to climatic change.

Table 53.1 Variation in piezometric within the water Plio-Quaternary

N�

IRE X (m) Y (m)

(m)

Sep90

(m)

May95

(m)

Jul00

(m)

March04

(m)

Oct09

(m)

3/51 81400 93400 18 5.4 4.8 5.2 5.5 4

15/51 86000 97970 70 54.2 52.6 54 65 63

93/51 92370 101900 98 66.9 64.7 66.5 67.4 54

138 88275 92825 109 85 81.8 84.1 85.3 104

149/51 85100 105800 40 2 1 1.5 4 2

327/51 88800 88800 130 108.3 98.8 107.2 108.2 106

116/51 100650 96000 200 179 176 178.2 sec sec

117/51 100450 98500 180 137.4 134.5 136.7 sec sec

Fig. 53.14 Chemical facies of plio-quaternary

groundwater

730 S. Ouhamdouch et al.

Fig. 53.15 (a) Temporal and spatial distribution of the Electrical conductivity of the groundwater in the aquifer plio-quaternary (1995, 2004 and 2009). (b) Chlorides (1995 and 2009)

Table 53.2 Simplified grid for groundwater

Quality

parameter

C.E.

(μs/cm) Cl�

(mg/l)

NO3 �

(mg/l)

NH4 þ

(mgNH4 þ/l)

(mgO2/l)

Excellent <400 <200 <5 �0,1 <3 Good 400–1300 200–300 5–25 0,1–0,5 3–5

average 1300–2700 300–750 25–50 0,5–2 5–8

Bad 2700–3000 750–1000 50–100 2–8 >8

Very bad >3000 >1000 >100 >8

53 Vulnerability and Impact of Climate Change Processes on Water Resource. . . 731

Stable Isotopes

In the Essaouira basin, the hydrodynamic is influenced by the structure (folds and

faults) which determines the flow (Bahir, 2007). In the study area, the isotopes of

the water molecule, the oxygen-18 (18O), deuterium (2H), tritium (3H) and carbon-14

(14C), may provide part of the answer in the determination of the areas and

conditions aquifer recharge, as well as their relationship and their age. The isotopic

analyses were carried out in the institute of technology and nuclear Lisbon. The

isotopic content of the water plio-quaternary are between �3.72 and �4.56 δ‰ v-smow. Those of groundwater turonienne are between �4.17 and �4.55 δ‰ v-smow. The results of the analyses of 2H to allow to set on a diagram of

correlation 18O-2H the local meteoric right (LMW) equation 2H¼ 7.72� 18 Oþ 10.53 (r2¼ 0.82), close to the Global meteoric water (GMW) slope 8 with excess 2H close 10 (Craig, 1961). It characterizes the precipitation of oceanic

origin. The equation of this line was calculated without taking into account the

three points 390/51, 27251, and Ksob wadi, identified as evaporated, because they

fall below GMW. The other points are aligned on the LMR, which indicates that the

supply of water aquifers is completed quickly without significant evaporation. The 3

H is a radioactive element in the cycle of water through rainfall, its presence with

concentrations above 2 units tritium (TU) means a charging current (Olive et al.,

1996). By contrast, the water having concentrations of less than 2 UT are confed-

erated without active recharge (Olive, 1999). The results are compiled in Table 53.3.

The levels of 3H varied between a minimum value of 0.2 and a maximum of 4.2 UT.

The water points 272, 327, 65, 386, and 203/51 have a content 3H greater than 2 UT,

which means a charging current. While the other points are levels very low. This

uses the technique of dating by 14C to confirm or affirm the hypothesis. The 14C is

the radioelement the most used to date ancient waters at very low levels of 3H.the

results obtained are grouped in Table 53.3. The analysis makes it possible to

identify that: the waters of the two points 65 and 386/51 have significant assays in 3H and percentages in 14C higher than 85%, which makes them as current. The

drilling M98, which does not, 3H detectable but has a 14C content of 80% shows a

power supply prior to the nuclear tests from 1962 to 1963, and its radiocarbon age

does not exceed a 2000 years. The radiocarbon age of the drilling 390/51 is of the

order of 6500 years ago, and one of 380/51 is greater than 2000 year. These two

boreholes capturing the turonian aquifer, feed, respectively, the Essaouira city and

the village of Si Ahmed Ou Hmad (5000 inhabitants). This reflects that we are in the

presence of an ancient water and that it is in the process of exhausting a strategic

resource, which could be used in extreme cases (Fig. 53.16).

Conclusion

In addition to the demographic pressure, the cultural practices and pastoral, climate

change put the countries of the Maghreb (Algeria, Morocco and Tunisia) in

alarming water situation manifested by: (1) the drought, which accentuates the

732 S. Ouhamdouch et al.

T a b le

5 3 .3

P h y si ca l p ar am

et er s an d an al y si s o f ra d io ac ti v e is o to p es

o f g ro u n d w at er

in th e co as ta l ar ea

o f E ss ao u ir a

N � I R E

N at u re

O ri g in

A lt it u d e

P ro f (m

)

T (� C )

P H

A lc

M éq /l

3 H U T

1 4 C

p cm

1 3 C

� / ��

2 7 2 /5 1

W el l

P li o -Q

1 0 5 .5

3 8 .4

2 0 .6

7 .6 5

3 .3 0

3 .9

2 1 /5 1

W el l

P li o -Q

1 3 5

2 9

2 1 .7

7 .1 3

2 .8 0

2 .0

3 2 7 /5 1

W el l

P li o -Q

1 3 0

2 2 .2

7 .2 3

4 .0 3

3 .2

6 5 /5 1

W el l

T u ro n

1 5

2 0 .3

2 2 .5

7 .4 8

4 .6 4

2 .8

8 8 .9 � 0 .5

�9 .8

3 9 0 /5 1

b o re h o le

T u ro n

9 5

2 0 0

2 6 .7

7 .3 5

4 .9 4

2 3 2 .5 � 0 .4

�9 .4

3 8 6 /5 1

b o re h o le

T u ro n

1 0 5

1 0 0

2 3 .2

7 .5 6

4 .2 6

4 .2

8 4 .8 � 0 .6

�1 0 .3

3 8 0 /5 1

b o re h o le

T u ro n

1 3 5

1 9 4

2 6 .1

7 .5 4

4 .6 7

1 3 .0 � 0 .5

�9 .0

M 9 8

b o re h o le

B ar -A

p t

9 0

1 0 0

2 2 .0

7 .5 9

3 .5 5

1 .1

7 9 .6 � 0 .6

�9 .3

A . A g h b al o u

b o re h o le

B ar -A

p t

8 0

2 3 .1

7 .5 0

3 .5 8

1 7 2 .0 � 0 .4

�1 0 .0

2 1 6 /5 1

S o u rc e

P o r- B er

1 6 0

2 3 .1

7 .2 8

4 .5 3

2 1 8 /5 1

S o u rc e

P o r- B er

3 0 8

2 2 .5

7 .2 9

4 .2 4

1 6 8 .5 � 0 .6

�9 .9

3 6 1 /5 1

b o re h o le

L ia s

3 8 2

9 0

2 3 .5

7 .2 2

4 .4 5

2 0 3 /5 1

b o re h o le

C al lo w

1 4

5 0

2 2 .7

7 .1 1

4 .2 6

3 .8

3 4 6 /5 1

b o re h o le

T u ro n

1 0 5

1 .5

3 6 3 /5 1

b o re h o le

T u ro n

1 5 0

1 .2

1 4 9 /5 1

b o re h o le

T u ro n

4 0

0 .2

53 Vulnerability and Impact of Climate Change Processes on Water Resource. . . 733

phenomenon of desertification, (2) increased salinity of the soil and the lowering of

the piezometric levels of the groundwater. It encourages the countries of the

Maghreb to develop the strategy of the increased mobilization of

non-conventional, such as the desalination of seawater and brackish water. The

complementarity of the approaches hydrochemical, piezometric and isotopic may

lead to the diagnosis of the state of vulnerability of the aquifers in the basin of

Essaouira in the face of climate change. However, the development of a strategy for

the rational exploitation could thus enable the value of its waters, while preserving

its potential in the long term. As well as the use of non-conventional resources such

as desalinated seawater for the supply of drinking water or treated wastewater for

agriculture must be seen as a priority in order to avoid trigger situations of water

scarcity.

Acknowledgment This research was carried out within the Laboratory 3GEOLAB science faculty Semlalia of Marrakech Cadi Ayyad University, in collaboration with the ENS of Marra-

kech and the Institute of Technology Nuclear Lisbon, Portugal. Our acknowledgments will go to

the agents of the agency of the Basin Hydraulic Tensift that contributed to the realization of this

work. We also thank the research group of Professor Paul�a Carreira at the institute of technological and nuclear Lisbon, who has done isotope analyses.

−5 −30

−25

−20

−15

−10

−4,5

21/51 363/51

390/51

380/51

28/51 93/51

27/51

386/51 346/51

148/51 272/51

Oued Ksob

11/51

15/51

149/51

327/51

M98 M24

−3,5−4

d 18O‰ V-SMOW

LMW

GMW

d 2 H

‰ V

-S M

O W

−3

2H=7.7218O+10.53 R2=0.82

Fig. 53.16 Corrélation 18O-2H dans les eaux souterraines de la zone synclinale d’Essaouira (2006)

734 S. Ouhamdouch et al.

References

Bahir, M. (2007). Isotopes et ressources en eaux en zones-arides et semi-arides: exemple du bassin

d’Es saouira (p. 175). Bahir, M., Mennani, M., Olivreira Da Silva, M., & Blavoux, B. (2003). Impact de la sècheresse sur

la ressource en eau en zone semi-aride : cas de l’aquifère barremien-aptien de la zone côtière d’Essaouira (Maroc). Paı́ses Mediterráneos: Tecnologı́a De La Intrusi�on De Agua De Mar En Acuı́feros Costeros.

Bahir, M., Carreira, P., Oliveira da Silva, M., & Fernandes, P. (2008). Caractérisation

hydrodynamique, hydrochimique et isotopique du système aquifère de Kourimat (Bassin

d’Essaouira, Maroc). Estudios Geol�ogicos, 64(1) enero-junio 2008, 61–73. ISSN: 0367-0449. Bahir, M., & Chamchati, H. (2011). Caractérisation du système aquifère plio-quaternaire et

turonien (Bassin d’Essaouira, Maroc). geohydro (pp. 1–6). Bates, B. C., Kundzewicz, Z. W., Wu, S., & Palutikof, J. P. (2008). Le changement climatique et

l’eau. Document technique VI (p. 236). Genève: du GIEC. ISBN 978-92-9169-223-1. Bouchaou, L., Tagma, T., Boutaleb, S., Hssaisoune, M., & ElMorjani, Z. A. (2011). Climate

change and its impacts on groundwater resources in Morocco: The case of the Souss-Massa basin (pp. 129–144). Boca Raton, FL: CRC Press. H. Treidel, J. L. Martin-Bordes, & J. J. Gurdak (Eds.).

Chamchati, H. & Bahir, M. (2011). Contribution of climate change on water resources in semi-

aride areas: Example of the essaouita basin. Geographia Technica, 1, 1–8. Chamchati, H. & Bahir, M. (2013). Potential hydrogeological, environment and vulnerability to

pollution of the plio-quaternary aquifers of the coastal basin of Essaouira (Morocco). Journal of Environment and Earth Science, 3(10), 170–185.

Craig, H. (1961). Standarts for reporting concentration of deuterium and oxygen 18 in natural

waters. Science, 133, 1833–1834. Driouech, F. (2010). Distribution des précipitations hivernales sur le Maroc dans le cadre d’un

changement climatique: descente d’échelle et incertitudes. Thèse de doctorat de l’université de Toulouse, p. 163.

Driouech, F., Ben Rached, S., & ElHairech, T. (2013). Climate change and food security in West Asia and North Africa (pp. 161–171). Dordrecht: Springer. doi:10.1007/978-94-007-6751-5_9.

Hsissou, Y. Bouchaou, L., Krimissa, M., Mudry, J. (2001). Caractérisation de l’origine de la salinité des eaux de la nappe côtière d’Agadir (Maroc). First International Conference on Saltwater Intrusion and Coastal Aquifers—Monitoring, Modeling, and Management. Essa-

ouira, Morocco, 23–25 April, 2001.

IPCC. (2013). Climate Change 2013: The physical science basis (Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change, p. 1535).

Cambridge, UK and New York, NY: Cambridge University Press. T. F. Stocker, D. Qin, G.-K.

Plattner, M. Tignor, S.K. Allen, J. Boschung, A. Nauels, Y. Xia, V. Bex & P.M. Midgley

(Eds.).

Jalal, M., Bahir, M., & Mennani, A. (2001). Pollution nitratée des eaux souterraines du bassin

synclinal d’Essaouira (Maroc) (Nitrate in groundwater of the Essaouira Synclinal Basin, Morocco). Journal of Environmental Hydrology, 9, 1–10.

Nouaceur, Z., Laignel, B., & Turki, I. (2013). Changements climatiques au Maghreb: vers des

conditions plus humides et plus chaudes sur le littoral algérien. Physio-Geo, 7, 307–323. Olive, P., Hubert, P., & Ravailleau, S. (1996). Estimation pratique de l’age des eaux souterraines

en Europe par le tritium. Revue des Sciences de l’eau, 4, 523–533. Olive, P. (1999). Datation des eaux souterraines �a long de temps de résidences par le

radioacarbone. Mode d’emploi. Hydrogéologie. N�1, 1999. Sebbar, A., Badri, W., Fougrach, H., Hsaine, M., & Saloui, A. (2011). Etude de la variabilité du

régime pluviométrique au Maroc sep-tentrional (1935–2004). Sécheresse, 22(3), 139–148. doi:10.1684/sec.2011.0313.

53 Vulnerability and Impact of Climate Change Processes on Water Resource. . . 735

http://dx.doi.org/10.1684/sec.2011.0313

http://dx.doi.org/10.1007/978-94-007-6751-5_9

Sinan, M. Boussetta, M., El Rherari, A. (2009). Changements climatiques: causes et consequences

sur le climat et les ressources en eau. Revue HTE N�142. Mars–Juin 2009, PP. 21–30 UNESCO. (2010). Changement climatique enjeux et perspectives au Maghreb. GEB-Environ-

ment, pp. 258.

736 S. Ouhamdouch et al.

Part XIII

Environmental Technologies Related to Global Warming

Waste Management

Chapter 54

Experimental Study of Transverse Mixing of Pollutants in Trapezoidal Open Channel

Ali Mansour Lagoun and Salim Benziada

Introduction

Natural streams receive usually domestic, industrial and agricultural wastes. In

some cases, variously incidental discharges find way to rivers, which are generally

punctual and cause different problems for water quality. It is important to know the

capacity of rivers to mix those pollutants, and to determine the of mixing and

dispersing rates of rivers.

When miscible product is injected instantly into a river, it propagates and mixes

in three directions under the effect of several processes such as: diffusion, advection

and dispersion (Fischer 1966; Shen and Yapa 1995; Gharbi 1999; Hibbs et al. 1999;

Czernuszenko and Alexey 2005; Rutherford 1994; Steve and Russell 2005)

A.M. Lagoun (*) Research Laboratory of Water Sciences, Polytechnic National School of Algiers, Algiers,

Algeria

Laboratory of Environment, Water, Geomechanics and Structures, Faculty of Civil

Engineering (FGC), University of Sciences & Technology HouariBoumediene (USTHB), Bab

Ezzouar, Algiers, Algeria

Scientific and Technical Research Center on Physical and Chemical Analyses (CRAPC),

Bou-Ismail, Tipaza, Algeria

e-mail: [email protected]

S. Benziada

Research Laboratory of Water Sciences, Polytechnic National School of Algiers, Algiers,

Algeria

741

mailto:[email protected]

Transverse Mixing

The mixing term is reserved to express the global result of a miscible fluid transportation processes without accounting mechanism sources (Gharbi 1999).

Generally, the term of the transverse mixing refers to the lateral spread of

contaminants (horizontal) caused by turbulence (Fischer and John 1979; Rutherford

1994; Van Prooijen and Uijttewaal 2005) (Fig. 54.1).

Notion of Mixing Zones

Generally, Pollutants transport processes is consisted of three distinct areas (Fischer

1967; Yotsukura et al. 1976; Jobson 1997; Jabour 2006) which are:

Initial Mixing Zone: where the process is effected in the three dimensions of

space, this area is achieved relatively very quickly since the water depth is often less

than the width of the watercourse (Demetracopoulos and Stelan 1983a, b; Ruther-

ford 1994; Sanchez-Cabeza and Pujol 1999).

Complete Mixing Zone: The complete mixing zone begins at the limit of the

initial mixing zone. It ends when the rejected product becomes homogeneous

throughout the section of the river, in the vertical and lateral directions (Jabour

2006; Rutherford 1994).

The Far-Field Zone: It extends from the full mixing zone to the infinity.

Dispersion is one-dimensional in flow direction (Jabour 2006).

Fig. 54.1 Mixing processues in rivers (Chanson 2004)

742 A.M. Lagoun and S. Benziada

Experimental Setup and Procedures

Tests were performed in the Research Laboratory of Water Sciences (LRS water) at

the Polytechnic National School in Algiers, in a trapezoidal channel that was

designed specifically to study the problem of transport of pollutants in rivers,

especially transverse mixing, it consists essentially of:

Feeding System: allows adjusting the flow through block valve, and constant

level tank to maintain the flow invariable.

Trapezoidal Channel: 10 m of length, provided with:

– A triangular weir: to measure and control the flow. After calibration of the weir across flow measurement by the volumetric method according to water head at

weir, discharge is given by:

Q ¼ 1, 35:hd5=2 ð54:1Þ

– A flow stabilizer.

– An injection system of pollutant (phenol): consists of a double tanks with a

constant rate for 30 s. The injection is done at the channel center.

– A sampling system for each 1 m longitudinally and for each 10 cm laterally

(see Figs. 54.2 and 54.3) photography of the experimental setup is shown at Fig.

54.4.

Samples for different injection scenarios have been analyzed and the concentra-

tions were determined by spectrophotometer (Table 54.1).

Feed tank

Injection system

Flow StabilizerSupport

V Notch Weir

Channel support

Fig. 54.2 3D schema of experimental setup

54 Experimental Study of Transverse Mixing of Pollutants in Trapezoidal Open. . . 743

Injection point (0,0)

cross section of channel

y=−10cm

y=−20cm

y y=20cm

y=10cm y=0

Fig. 54.3 Injection system and sampling points

Fig. 54.4 Photography of experimental setup (LRS. Eau, ENP)

744 A.M. Lagoun and S. Benziada

Variables Studied

(a) Discharge flow:

The most hydrodynamic variables cited in the literature are the flow dis-

charge and mean flow velocity (Gharbi 1999; Chaudhry 2008). We selected

the first variable to study it; it is a general variable that covers several

hydrodynamic parameters (velocity and Reynolds number Re), and geometric

parameters (water depth, surface width . . .). This variable has a practical advantage, since its value is relatively easy to measure, with V-notch weir at

our case.

The selected flow rates studied are: 0.52, 0.79, 1.6, 1.75 and 1.95 l/s.

(b) Initial concentration of pollutant:

Three initial concentrations C0were studied: 500, 1000 and 1500 mg/l.

Results and Discussion

Flow Regimes

The different flow regimes are determined by the Reynolds number and Froude

number as follows:

Reynolds Number: Is defined as the ratio of inertial forces to viscous forces (Lencastre 2005; Gualtieri and Dragutin 2008):

Re ¼ UDh ν

ð54:2Þ

Flow regimes are classified according Reynolds number as follows: Re < 2000: laminar flow, 2000<Re< 4000: transient flow, Re > 4000: turbulent flow (Ernest and Horace 1996).

Table 54.1 Summary of flume characteristics

Designation Parameters Values

Channel Form Trapezoidal

Bed slope [%] 5

Length [m] 10,4

Bottom width [m] 0,4

Side slope [�] 60 Slope head [cm] 50

Weir Form Triangular (V notch)

Notch angle [�] 90 Crest elevation [cm] 10

54 Experimental Study of Transverse Mixing of Pollutants in Trapezoidal Open. . . 745

Froude Number: Is the ratio between the forces of inertia and forces of gravities:

Fr ¼ Uffiffiffiffiffiffiffiffiffiffiffi g� hp ð54:3Þ

Flow regimes are classified according Froude number as follows: Fr> 1: super- critical flow, Fr< 1: subcritical flow, Fr¼ 1: critical flow (Dingman 2009).

Flow regimes for the different flow rates examined are shown in Table 54.2.

Transverse Concentration Profiles

Lateral (horizontal) concentration evolution of phenol according time, at 2 m of

injection point of phenol with C0¼ 500 mg/l, for different flows, are given at Figs. 54.5 and 54.6.

Remarks and Interpretation

Transverse concentration profiles are identical for the two symmetrical point from

center of flow direction (y¼ 20 cm and y¼�20 cm/ y¼ 10 cm and y¼�10 cm), it shows that the pollutant injected at the center of channel is mixed to both lateral

sides of the channel (symmetric concentration profile); it is the effect of the

Table 54.2 Flow regimes according Reynolds number Re and Froude number Fr

Q [l/s] U [m/s] Re Fr Flow regimes

0.52 0.008 2848.03 0.006 Subcritical and transient

0.79 0.011 4220.03 0.009 Subcritical and turbulent

1.60 0.019 8144.88 0.015 Subcritical and turbulent

1.75 0.021 8830.58 0.016 Subcritical and turbulent

1.95 0.023 9754.51 0.017 Subcritical and turbulent

0 0 100 200 300

y=-20cm y=-10cm

y=10cm y=20cm

y=0

Time (s)

C o

n ce

n tr

at io

n (m

g /l

)

Fig. 54.5 Evolution of concentration profiles of

phenol in time for different

transverse distances at

x¼ 2 m—Q¼ 0,52 l/s, C0¼ 500 mg/l— Instantaneous injection

746 A.M. Lagoun and S. Benziada

horizontal velocity profile, which is not yet well defined (Chaudhry 2008; Gharbi

1999; Chanson 2004), but it is maximal at center (y¼ 0) and minimum at both banks of the canal.

Transverse Concentration Profiles Evolution at Downstream in Flow Direction

The concentration profiles obtained experimentally with deferent transverse dis-

tances (y¼�20 cm, y¼�10 cm, y¼ 0, y¼ 10 cm and y¼ 20 cm), at different distances from the injection point in downstream (x-direction) for a flow rate

Q¼ 0.52 l/s, with an injection of phenol with initial concentration C0¼ 500 mg/l, are shown in Figs. 54.7, 54.8, 54.9, and 54.10.

C o

n ce

n tr

at io

n (m

g /l

)

0 50 100 150 Time (s)

y=-20cm y=-10cm

y=10cm y=20cm

y=0

Fig. 54.6 Evolution of concentration profiles of

phenol in time for different

transverse distances at

x¼ 2 m—Q¼ 1,95 l/s, C0¼ 500 mg/l— Instantaneous injection

Fig. 54.7 Evolution of concentration profiles of

phenol in time for different

transverse distances at

x¼ 1 m—Q¼ 0,52 l/s, C0¼ 500 mg/l— Instantaneous injection

54 Experimental Study of Transverse Mixing of Pollutants in Trapezoidal Open. . . 747

Fig. 54.8 Evolution of concentration profiles of

phenol in time for different

transverse distances at

x¼ 2 m—Q¼ 0,52 l/s, C0¼ 500 mg/l— Instantaneous injection

Fig. 54.9 Evolution of concentration profiles of

phenol in time for different

transverse distances at

x¼ 5 m—Q¼ 0,52 l/s, C0¼ 500 mg/l— Instantaneous injection

Fig. 54.10 Evolution of concentration profiles of

phenol in time for different

transverse distances at

x¼ 6 m—Q¼ 0,52 l/s, C0¼ 500 mg/l— Instantaneous injection

748 A.M. Lagoun and S. Benziada

Remarks and Interpretation

From Figs. 54.7–54.10, we note that:

(a) There has a cloud movement of the pollutant (phenol) in the flow direction

(x direction) by the flow velocity effect; it is the process of advection. (b) There is a significant gradient of concentration profiles for different horizontal

points, concentrations are maximal at the center of the channel and becomes

less important for both boundaries of the channel (Figs. 54.7 and 54.8). Away

from the injection site at downstream, concentration profiles gradient becomes

less important (Figs. 54.9 and 54.10), and concentration started to be uniform

throughout the section of the channel at transverse direction (Fig. 54.10), this

is explained by the manifestation the transverse mixing of phenol.

Effect of Flow Discharge and Turbulence Phenomena:

Remarks and Interpretation

From Figs. 54.11–54.13 below, at different point in the downstream of injection

point, we note that concentration profiles for different horizontal distances (y) are

more homogeneous for flow with discharge Q¼ 1.95 l/s than for Q¼ 0.52 l/s. this means that the contaminant has been completely mixed at transverse direction,

concentration distribution becomes homogeneous and uniform in the cross section

of flow. This is can be explained by rate of turbulence that increase with flow

discharge, turbulent diffusion will be important that increase transverse mixing rate.

Fig. 54.11 Concentration Profiles for different transverse distances (y) at x¼ 3 m for Q¼ 0,52 l/s and Q¼ 1,95 l/s, C0¼ 500 mg/l

54 Experimental Study of Transverse Mixing of Pollutants in Trapezoidal Open. . . 749

Effect of Pollutant Quantity (Initial Phenol Concentration)

To determine the influence of the initial concentration on the transverse mixing,

making a comparative analysis between the concentration profiles obtained in

(x¼ 6 m, x¼ 7 m and x¼ 8 m) and at several transverse distances (y), for flow Discharge Q¼ 0.52 l/s for two initial concentrations C0¼ 500 mg/l and C0¼ 1500 mg/l:

Fig. 54.12 Concentration Profiles for different transverse distances (y) at x¼ 8 m for Q¼ 0,52 l/s and Q¼ 1,95 l/s, C0¼ 500 mg/l

Fig. 54.13 Concentrations profiles observed for different transverse distances (y) at x¼ 6 m for flow discharge Q¼ 0.52 l/s, for C0¼ 500 mg/l and C0¼ 1500 mg/l

750 A.M. Lagoun and S. Benziada

Remarks and Interpretation

From Figs. 54.14 and 54.15, we remark that the concentration profiles gradient for

different transverse distances is more important for an injection of phenol with

C0¼ 1500 mg/l that for C0¼ 500 mg/l, where the quantity of pollution has been well mixed, and the concentration distribution is more homogeneous and uniform

laterally for phenol injection C0¼ 500 mg/l then C0¼ 1500 mg/l. Mixing favors low amount.

Fig. 54.14 Concentrations Profiles observed for different transverse distances (y) at x¼ 7 m for flow discharge Q¼ 0.52 l/s, for C0¼ 500 mg/l and C0¼ 1500 mg/l

Fig. 54.15 Concentrations Profiles observed for different transverse distances (y) at x¼ 8m for flow discharge Q¼ 0.52 l/s, for C0¼ 500 mg/l and C0¼ 1500 mg/l

54 Experimental Study of Transverse Mixing of Pollutants in Trapezoidal Open. . . 751

Conclusion

Experimental model of flume designed at Research Laboratory of Water Sciences at

National Polytechnical School, and analyses of concentration profiles obtained

from several tests, have allowed to well study transverse mixing and to define the

mechanisms that govern it (advection with flow velocity and propagation with

velocity profile, turbulent diffusion).

Concentration profiles examination for different transverses sections at several

point in downstream allowed to understand the transverse mixing processes, to

distinguish the mixing zones and shows the effect of flow discharge in the

advection rate.

Flow discharge has a great effect on transverse mixing, turbulent diffusion that

becomes predominate away from injection area is accentuated with increasing flow

discharge, with growth the transverse mixing rate.

Pollutants and contamination rejected at flow will be easily mixed when their

amount and concentrations were low.

Nomenclature

C Pollutant Concentration, mg/l

Dh Hydraulic diameter, m

Do Optical density

g Gravity, m/s2

h Hydraulic depth, m

hd Head, m

Q Flow discharge (m3/s)

U Flow velocity (m/s)

Dimensionless Numbers

Fr Froude number

Re Reynolds number

Greek Letters

ν Cinematic viscosity of water, m2/s

752 A.M. Lagoun and S. Benziada

References

Chanson, H. (2004). Environmental hydraulics of open channel flow. Library of Congress Cataloguing in Publication Data, 423p.

Chaudhry, M. H. (2008). Open channel flow (2nd ed., 523p). Library of Congress, Control Number: 2007936602. New York: Springer.

Czernuszenko, W., & Alexey, R. (2005). Three-dimensional model of flow and mixing processes

in open channels. InWater quality hazards and dispersion of pollutants (pp. 35–54). Library of Congress Cataloging-in-Publication Data. New York: Springer.

Demetracopoulos, A. C., & Stelan, H. G. (1983a). Transverse mixing in wide and shallow rivers:

Case study. Journal of Environment Engineering, 109(3), 685–699. Demetracopoulos, A. C., & Stelan, H. G. (1983b). Model of Mississipi river pool: Mass transport.

Journal of Environment Engineering, 109(5), 1006–1019. Dingman, S. L. (2009). Fluvial hydraulics. Oxford: Oxford University Press. 559p. Ernest, F. B., & Horace, W. K. (1996). Handbook of hydraulics (7th ed.). New York: McGraw-

Hill. 611p.

Fischer, H. B. (1966). Longitudinal dispersion in laboratory and natural streams. Report N�. KH-R-12 . Journal of Water Resources Division, 250p.

Fischer, H. B. (1967). The mechanisms of dispersion in natural streams. Journal of Hydraulic Division. ASCE, 93(HY6), 187–215.

Fischer, H. B. & John, E. L. (1979).Mixing in inland and coastal waters. Academic Press. Library of Congress Cataloging in Publication Data, 458p.

Gharbi, S. (1999). Évaluation des coefficients de mélange longitudinal et transversal des polluants

dans les cours d’eau: proposition de nouvelles formules. Thèse Doctorat �a l’université Laval, Québec, 197p.

Gualtieri, C., & Dragutin, T. M. (2008). Fluid mechanics in environmental interfaces, Taylor & Francis e-Library, 332p.

Hibbs, D., Gulliver, J., Voller, V., & Chen, Y. F. (1999). An aqueous concentration model for

riverine spills. Journal of Hazardous Materials, A64, 37–53. Jabour, D. (2006). Etude expérimentale et modélisation de la dispersion en champ lointain suite �a

un rejet accidentel d’un polluant miscible dans un cours d’eau. Application �a la gestion de crise. Thèse Doctorat �a l’Université de Provence, 246p.

Jobson, H. E. (1997). Predicting travel time and dispersion in rivers and streams. Journal of Hydraulics Engineering. ASCE, 123(11), 971–978.

Lencastre, A. (2005). Hydraulique Général. Edition Eyrolles, 633p. Rutherford, J. C. (1994). River mixing. New York: Willey. 347p. Sanchez-Cabeza, J. A., & Pujol, L. (1999). Study on the hydrodynamic of the Ebro River lower

course using tritium as radiotracer. Water Research, 33(10), 2345–2356. Shen, H. T., & Yapa, P. D. (1995). A simulation model for chemical spills in the upper St

Lawarence River. Journal of Great Lakes Research, 21(10), 652–664. Steve, W., & Russell, M. (2005). On the theoretical prediction of longitudinal dispersion coeffi-

cients in a compound channel. In Water quality hazards and dispersion of pollutants (pp. 69–84). Library of Congress Cataloging-in-Publication Data. New York: Springer.

Van Prooijen, B. G., & Uijttewaal, W. S. J. (2005). Horizontal mixing in shallow flows; Physical

aspects and numerical modelling. In Water quality hazards and dispersion of pollutants (pp 55–68). Library of Congress Cataloging-in-Publication Data. New York: Springer.

54 Experimental Study of Transverse Mixing of Pollutants in Trapezoidal Open. . . 753

Chapter 55

Elimination of Micropollutent Lysine Acetylsalicylate by Adsorption on Natural and Synthetical Supports

Amel Djouadi and Fatiha Bentahar

Introduction

The existence of several micropollutents in wastewater has been long identified in

broad categories in persistent organic pollutants that remain active after conven-

tional wastewater treatment. This study conducts a biotechnological strategy, the

adsorption phenomena, using natural supports as algae, black tea, or synthetical

supports as the powered activated carbon or the titan oxide. Its main focus is to

produce water that may be reutilized after treatment (Gupta and Rastogi 2008).

Adsorption phenomena have been identified for its ability to degrade

micropollutents. The pollutant, a common painkiller, acetylsalicylic acid also

goes by the name aspirin. Lysine acetylsalicylate is a slightly different molecule

in structure to the original aspirin molecule, but scientists still use the name aspirin

to refer to it (Aronson 2006).

Aspirin Properties

Lysine acetylsalicylate is an analgesic substance. Its different properties are the

following:

• Formule: C9H8O4 • Poids moléculaire: 180.1574

• Structure Chimique

A. Djouadi (*) • F. Bentahar Laboratoire de phénomènes de transfert, Faculté de Génie des Procèdes et de Génie

Mécanique, USTHB, Bab Ezzouar, BP 32 El Alia, 16111 Alger, Algeria

e-mail: [email protected]; [email protected]; [email protected]

755

mailto:[email protected]

Method and Procedure

A UV-Vis Absorbance Spectroscopy is used in this experiment in order to deter-

mine the absorbance of the sample and, in turn, determine purity. This is done by

weighing out a carefully measured amount of product and fully dissolving it in a

certain amount of water. If some of this resulting solution is placed in a cuvette and

is analyzed by the UV-Vis machine, it is then possible to determine the concentra-

tion of the dissolved substance from the given absorbance values using Beer’s law. The IR analysis is established to determine the characterization of each utilized

adsorbent giving their own absorbance bands and to identify the experimental

adsorption protocol (Sarat Chandra et al. 2015; Salima et al. 2013). The parametric

study is based on varying the initial concentration of the adsorbate, Lysine acetyl-

salicylate, and the temperature of the aqueous solution, pH and the mass of

adsorbent. The obtained results are summarized giving the adsorption efficiencies

of these adsorbents for the degradation of this adsorbate: The activated carbon is

considered as the best one followed by titan oxide, algae and black tea (Fig. 55.1).

Fig. 55.1 Absorbance versus wavelength

756 A. Djouadi and F. Bentahar

Results and Discussion

The obtained results are summarized giving the adsorption efficiencies of these

adsorbents for the degradation of this adsorbate: The activated carbon is considered

as the best one followed by titan oxide, algae and black tea. The adsorption

isotherms of each couple (adsorbate-adsorbent) resulting from experimental data

show that they describe well the model of Langmuir with the coefficient of

correlation R2 equal to 0.996. The kinetic model pseudo-second order represents

faithfully the experimental results, coefficient of correlation R2¼ 0.996. The ther- modynamic study has revealed that the adsorption of Lysine acetylsalicylate on the

natural supports is an exothermic reaction characterized by an increase of molecular

disorder at interface solid/ adsorbate. Adsorption reaction is endergonic on natural

supports, algae and black tea but spontaneous reaction using synthetical supports,

activated carbon or titan oxide. At the end of this work, we can conclude that the

waste plant studied have an important adsorbing power of this pollutant, Aspirin.

The absorbance values of the three working standard solutions were measured,

the measured values are shown in Table 55.1.

Conclusions

The batch studies conducted in the present study provides significant information

regarding biosorption of the pollutent on green algae Spirogyra species in terms of

optimum pH and biomass dose from the aqueous solution. The studies indicate that

Spirogyra species is an effective biosorbent for Lysine acetylsalicylate removal.

The maximum biosorption capacity has been found of dry weight of biomass at an

algal dose of 0.5 g/L in 150 min of contact time with initial Lysine acetylsalicylate

concentration of 200 mg/L and optimum pH of 5.0. The Langmuir and Freundlich

adsorption model were used for the mathematical description of the biosorption of

Lysine acetylsalicylate onto algal biomass and it was found that the adsorption

equilibrium data fitted well to the Langmuir model. The biosorption of Lysine

acetylsalicylate on the algal biomass follows second-order biosorption kinetics.

With the advantage of high biosorption capacity, the biomass of Spirogyra has the

potential to be used as an efficient and economic biosorbent microorganism for the

removal of Lysine acetylsalicylate from aqueous solutions.

Table 55.1 Absorbance values of aspirin

Equivalent conc. (mg/ml) Absorbance

0.0125 0.232

0.0250 0.466

0.0501 0.942

55 Elimination of Micropollutent Lysine Acetylsalicylate by Adsorption. . . 757

References

Aronson, J. K. (2006). Lysine acetylsalicylate. In J. K. Aronson (Ed.), Meyler’s side effects of drugs: The international encyclopedia of adverse drug reactions and interactions (15 ed., p. 2179). Amsterdam: Elsevier.

Gupta, V. K., & Rastogi, A. (2008). Biosorption of lead from aqueous solutions by green algae

Spirogyra species: Kinetics and equilibrium studies. Journal of Hazardous Materials, 152(1), 407–414.

Salima, A., et al. (2013). Application of Ulva lactuca and Systoceira stricta algae-based activated

carbons to hazardous cationic dyes removal from industrial effluents.Water Research, 47(10), 3375–3388.

Sarat Chandra, T., et al. (2015). Defatted algal biomass as a non-conventional low-cost adsorbent:

Surface characterization and methylene blue adsorption characteristics. Bioresource Technol- ogy, 184, 395–404.

758 A. Djouadi and F. Bentahar

Chapter 56

Integrated System for Optimized Data Collection and processing of End of Life Tires: Case of Greece

Panagiotis Vounatsos, John Vournas, George Mavrias, and Panagiotis Grammelis

Introduction

The tires used from all types of vehicles, like private vehicles, trucks, motorbikes,

bikes, construction and agricultural machinery, turn into waste at the end of their

life cycle. According to European Tyre and Rubber Manufacturers Association

(ETRMA 2011), about 3.3 million tonnes of end of life tyres were gathered in

Europe, of which 2.5 million tonnes were recycled or recovered. In the international

scale, each year about 1 billion tyres reach the end of their life cycle. The treatment

schemes followed in order to utilize the amounts of collected End of Life Tyres

(ELT) vary (ETRA 2013). As presented in Fig. 56.1, the situation in EU is led to a

continuous increase of methods that are more environmental friendly than

landfilling which, as shown, represents less than 10% of the total treatment

methods in 2012. On the contrary, methods such as energy utilization and tyre

recycling grew the past decade to such a degree, that more than 70% of the

collected tyres are treated by one of these methods.

The material recovery applications include among others the recycling of ELTs

as rubber granulated and powder (83%), utilization in civil engineering works

(~12%), and other applications which cover the rest of the percentage. The energy

recovery options include the utilization in cement industry at a devastating per-

centage of 91% and the majority of the rest of the quantities are used for electricity

P. Vounatsos (*) • P. Grammelis Chemical Process and Energy Resources Institute (ISFTA Sector), Centre for Research and

Technology-Hellas, 6th Km, Charilaou-Thermi Road, 57001 Thermi-Thessaloniki, Greece

e-mail: [email protected]

J. Vournas

Motion Hellas Ltd., 8, Philippou Litsa Str., Halandri, 15234 Athens, Greece

G. Mavrias

Εcoelastika SA, 14 Sorou Str., Marousi, 15125 Athens, Greece

759

mailto:[email protected]

generation (ETRMA 2014). Likewise, as presented from the Rubber Manufacturers

Association (Rubber Manufacturers Association 2013) the percentage of end of life

tires that is led to landfill is reduced to around 12,6%, while the percentage of tyres

utilized in energy or recycling sector (as Tyre-Derived Fuel, Ground Rubber and

Civil Engineering) covers more than 70%. The available data are presented in

Table 56.1.

As far as the best treatment methods for ELT is concerned, it has been a case of

study from many different teams around the world in terms of financial and

environmental viability and sustainability. Xingfu et al. (2010) compared four tire

treatment methods in China, were it was found that the most eco-effective ELT

treatment technology is pyrolysis (with product recovery) followed by dynamic

devulcanization and ambient grinding. It is noted that in future, ambient grinding

for crumb rubber may be more advantageous with less energy consumption and less

emissions of pollutants. Moreover, regarding the pyrolysis process, the viability

depends on the variation of the prices that the products will be sold in the future.

The work elaborated from Corti and Lombardi (2004) supports the aforementioned

utilizing life cycle assessment (LCA) tools, they found that the use of ELT as fuel

substitute in cement kilns and in Waste to Energy (WTE) processes allow better

environmental behavior than other alternatives. More specifically cryogenic and

mechanical pulverization of ELT for reuse as filling materials presented the worst

results of environmental impact comparing to all other treatment methods. Pyrol-

ysis was studied and is proposed as an alternative method for waste tyres treatment

(Williams 2013), proving that high added value products can derive from this

treatment method. Sometimes the produced products may require upgrading in

order to fit in specific standards for commercial use.

Fig. 56.1 End of Life Tyres treatment schemes in EU

760 P. Vounatsos et al.

Samolada and Zabaniotou (2012) studied the application of pyrolysis in Greece

and found that it is environmentally and financial a more sound application from

combustion-incineration (which is a destructive one). Specifically, pyrolysis can be

considerably attractive if all of the final products are effectively used. It was also

studied from Zabaniotou et al. (Zabaniotou et al. 2014), the barriers and drivers for

ELT pyrolysis in industrial application, and it was noted that the current EU

legislation prevents the implementation of large scale pyrolysis plants. As another

means for waste ELT utilization, the production of acoustic material from tire fluff

was studied (Jimenez-Espadafor et al. 2011) and it was found that it is a technically

possible and sound approach.

Apart from the studying of the after use treatment methods, there have been

studies for the replacement of metal parts (alumimium) of tires with other rubber or

plastic parts, in order to improve the carbon footprint depending on the final

treatment method that will be used. Specifically, it was found that aluminum

wore is better for landfilling while plastic and rubber parts are far better for thermal

utilization (Simoes et al. 2013). However Arroyo et al. (2011) found that steel

corrosion is the main source of heat production in Tires that have been landfilled or

in tire derived aggregate that is actually ELT that have been reduced in size and

used as lightweight fill alternative solution. This leads to possibilities of occurring

uncontrolled fires in landfills. Shakya et al. (2008) studied the emissions of

uncontrolled open-air burning of waste vehicle tyres, as happens in landfills. It

was found that CO and SO2 emissions were significantly higher than controlled

thermal utilization of tyres. Moreover the emission of other pollutants such as NO2,

CO2, polyaromatic hydrocarbons and smoke were also higher than controlled

utilization in specially designed facilities.

As presented from all of the aforementioned studies, all of the technologies and

treatment schemes present advantages and disadvantages. It was clearly observed

that despite the wide technological study for environmental and financial viability,

Table 56.1 Market trends in U.S.

Product (thousand tons) 2005 2007 2009

Tire-derived fuel 2144.64 2484.36 2084.75

Ground rubber 552.51 789.09 1354.17

Land disposed 590.81 593.98 653.38

Used tires – – 371.25

Civil engineering 639.99 561.56 284.92

Reclamation projects – 132.58 130

Exported 111.99 102.08 102.1

Baled tires/market – – 27.79

Electric arc furnace 18.88 27.14 27.1

Baled/no market 42.22 9.31 15.57

Agricultural 47.59 7.13 7.1

Punched/stamped 10.51 1.85 1.9

Generated 4410.73 4595.72 5170.5

Land disposed/generated 13.39% 12.92% 12.64%

56 Integrated System for Optimized Data Collection and processing. . . 761

there is not a widely accepted scheme or combination of technologies in order to

achieve the optimum treatment of ELTs. There are some studies (Uruburu

et al. 2013; Ene and Ozturk 2015; Subulan et al. 2015) were the product recovery

operations network as well as the final treatment for environmental optimization

has been investigated. As presented in these studies the first step is data collection,

in order to acquire certain parameters for processing.

Scope of the present study is to present a model for optimized data collection and

processing of end of life tires produced in Greece. This will lead to an integrated

system for controlling the fate of ELT, leading the treatment to most environmental

friendly solutions and therefore reducing the emissions and pollution created from

ELT utilization.

Methodology

In Greece the products from ELT treatment can be utilized in new products and

replace in some cases other raw material with equal or better properties. In the

following table (Table 56.2) the tyres categories that are collected in Greece are

presented.

The monitoring of data from the collection, transportation and final utilization of

end of life tyres is organized from ECOELASTIKA S.A. which is the Greek body

responsible for tyres recovery. Afterwards, the data are registered in a designed

database. Each party that collaborates with Ecoelastika, fills in periodically (every

week) an electronic file in which the following parameters are detailed:

• Time of collection

• The collection point

• Tyre category and quantities of used tyres per collection point

• The tyre quantities carried forward to the final users

Table 56.2 Tyres Categories that are collected in Greece

Description

Mean weight of

each tyre