chemical paper topic of your choice, something in the Lectures in each module that you found interesting.
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LECTURE7604.docx
CHE 102: LECTURE 7 FOSSIL FUELS
An oil refinery or petroleum refinery is an industrial plant where crude oil is transformed and refined into more useful products such as gasoline, diesel fuel, jet fuel, naptha, asphalt, heating oil, kerosene, liquefied petroleum gas, and fuel oils.
Oil, coal, natural gas and other fossil fuels are called "fossil" because these fuels are the preserved carbon-hydrogen remnants of ancient life. Coal is formed from plants that decomposed and accumulated in ancient swamps.
EXAMPLES: Fossil Fuels:
Coal: Coal is the primary fuel for the production of electricity and is responsible for about 40% of the electric power supply in the United States.
Oil: Oil is the primary source for the world's transportation.
Natural Gas: About 27% of U.S. energy is fueled by natural gas. Natural gas is the cleanest burning fossil fuel.
CHEMISTRY: fossil fuel combustion.
One molecule of methane, combined with two oxygen molecules, react to form a carbon dioxide molecule, and two water molecules (usually given off as steam or water vapor) releasing energy. See Lecture 3 and figure below.
COAL
Coal is a combustible black or brownish-black sedimentary rock usually occurring in rock strata in layers or veins called coal beds or coal seams. The harder forms, such as anthracite coal, can be regarded as metamorphic rock because of later exposure to elevated temperature and pressure.
NOTE: Geologists classify rocks into three main rock types. Rocks are either a single mineral or a combinations of minerals.
Sedimentary rocks are a type of rock that formed by the accumulation or deposition of small particles (minerals or organic matter) at the Earth’s surface, subsequently followed by their cementation on the floor of oceans or other bodies of water. Examples: sandstone, limestone (see below).
Limestone is a carbonate sedimentary rock that is often composed of the skeletal fragments of marine organisms such as coral, foraminifera, and molluscs. Its major materials are the minerals calcite (CaCO3).
and aragonite,
which are different crystal forms of calcium carbonate (CaCO3).
Metamorphic rocks arise from the transformation of existing rock types, in a process called metamorphism, which means "change in form". The original rock is subjected to heat and pressure, causing profound physical or chemical changes. The precursor may be a sedimentary, igneous, or existing metamorphic rock. Examples: slate, marble.
Marble is a metamorphic rock composed of recrystallized carbonate minerals, most commonly calcite (see above) or dolomite. In Geology, the term marble refers to metamorphosed limestone. The Taj Mahal in the Indian city of Agra is entirely clad in marble. I was amazed to find that the limestone in the Taj Mahal structure is so transparent, the interior of this architectural masterpiece is “illuminated.”
Igneous rock is formed through the cooling and solidification of lava (or magma) from volcanic eruptions. The magma can be derived from partial melts of existing rocks in either a planet's mantle or crust. Example: obsidian, granite (see below).
The word "granite" comes from the Latin granum, a grain, in reference to the coarse-grained structure of such a rock. Strictly speaking, granite is an igneous rock with between 20% and 60% quartz (See Lecture 4) by volume, and at least 35% of the total, by feldspar [ Feldspar is an abundant rock-forming mineral typically occurring as colorless or pale-colored crystals and consisting of aluminum silicates of potassium, sodium, and calcium] . A crystal of one form of feldspar shown below.
Coal is composed primarily of carbon, along with variable quantities of other elements, chiefly hydrogen, sulfur, oxygen, and nitrogen. Coal is a fossil fuel that forms when dead plant matter is converted into peat, which in turn is converted into lignite, then sub-bituminous coal, after that bituminous coal, and lastly anthracite. Thus both biological and geological processes are involved in its formation. The geological processes take place over millions of years.
There are six main types of coal that are regularly used in power plants or by other sectors of society:
Peat. Peat is formed from decaying vegetation, and is considered to be the precursor of coal
Lignite. Lignite is formed from compressed peat, and is often referred to as brown coal
Bituminous/Sub Bituminous Coal
Steam Coal
Anthracite Graphite
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Coal |
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Element Composition of Various types of Coal: Mass % of each element. type of coal C H O N S lignite 71 4 23 1 1 subbituminous 77 5 16 1 1 bituminous 80 6 8 1 5 anthracite 92 3 3 1 1
NOTE: Anthracite is the “cleanest” coal, lignite the “dirtiest.” Sources of Energy: fossil fuels (2007). petroleum 36.0 % coal 27.4 % natural gas 23.0%
The following two account for 14.8%. nuclear 8.5 % hydroelectric 6.3 % All of the following account for 0.9%. geothermal solar tidal wood waste
Historical record of fossil fuel use: Wood Coal Petroleum/Natural Gas Hydro/Nuclear 1850 91% 9% 1900 21% 71% 5% 3% 1950 6% 36% 52% 6% 1975 3% 18% 73% 6% 2000 4% 23% 62% 11%
The separation of petroleum into “fractions” (by length of carbon chain) is what occurs in oil refineries. C5 – C10 gasoline C10 – C18 kerosene C15 – C25 diesel fuel, heating oil, lubricating oil > C25 asphalt
In the New York Times today (4/21/2020), the banner headline is: “Coronavirus Live Updates: Trump Says He Will Halt Immigration; Oil Prices Crater, and Stocks Fall” The oil market meltdown is continuing. Brent crude, the international benchmark, was down about 18 percent, to $20.90 a barrel.
GREENHOUSE EFFECT: Overview 1. Solar radiation reaches the Earth's atmosphere - some of this is reflected back into space.
2. The rest of the sun's energy is absorbed by the land and the oceans, heating the Earth.
3. Heat radiates from Earth towards space.
4. Some of this heat is trapped by greenhouse gases in the atmosphere, keeping the Earth warm enough to sustain life. A greenhouse gas is a gas that absorbs and emits radiant energy within the (thermal) infrared range. Greenhouse gases cause the greenhouse effect on planets. Greenhouse gases include water vapor, carbon dioxide, methane, nitrous oxide, ozone and some artificial chemicals such as chlorofluorocarbons (CFCs). The molecular structures of ozone and nitrous oxide are shown below.
OZONE
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NOTE: The ozone layer or ozone shield is a region of Earth's stratosphere that absorbs most of the Sun's ultraviolet radiation. The ozone layer contains a high concentration of ozone in relation to other gases in the layer, although still small in relation to gases (e.g. oxygen O2 and nitrogen N2 ) in other regions of the stratosphere.
NITROUS OXIDE (“laughing gas”)
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NOTE: Nitrous oxide has significant medical uses, especially in surgery and dentistry, for its anaesthetic and pain reducing effects. Its colloquial name "laughing gas", coined by Humphry Davy (see Lecture 4 ), is due to the euphoric effects upon inhaling it, a property that has led to its recreational use as a dissociative anaesthetic ( A unique anesthesia characterized by analgesia and amnesia with minimal effect on respiratory function. The patient does not appear to be anesthetized and can swallow and open eyes but does not process information). It is also used as an oxidizer in rocket propellants and in motor
racing to increase the power output of engines.
5. Human activities such as burning fossil fuels, agriculture and land clearing are increasing the amount of greenhouse gases released into the atmosphere.
6. This results in trapping extra heat, and causing the Earth's temperature to rise.
The greenhouse effect is a natural process that warms the Earth’s surface.
Absorbed thermal energy warms the atmosphere and the surface of the Earth. This process maintains the Earth’s temperature at around 91.4 degrees Fahrenheit warmer than it would otherwise be, allowing life on Earth to exist.
The problem we now face is that human activities – particularly burning fossil fuels (coal, oil and natural gas), agriculture and land clearing – are increasing the concentrations of greenhouse gases. This is the enhanced greenhouse effect, which is contributing to global warming, an overall increase in the temperature of the Ear
Average global temperatures from 2010 to 2019 compared to a baseline average from 1951 to 1978. Source: NASA.
CARBON FOOTPRINT A carbon footprint is historically defined as the total greenhouse gas (GHG) emissions caused by an individual, event, organization, or product, expressed as carbon dioxide equivalent . Greenhouse gases, including the carbon-containing gases carbon dioxide and methane , can be emitted through the burning of fossil fuels, land clearance (e.g. in the Amazon basin) and the production and consumption of food, manufactured goods, materials, wood, roads, buildings, transportation and other services.
In most cases, the total carbon footprint cannot be calculated exactly because of inadequate knowledge of and data about the complex interactions between contributing processes, including the influence of natural processes that store or release carbon dioxide. For this reason, the following definition of a carbon footprint has been proposed:
Carbon Footprint: A measure of the total amount of carbon dioxide (CO2) and methane (CH4) emissions of a defined population, system or activity, considering all relevant sources, sinks and storage within the spatial and temporal boundary of the population, system or activity of interest. Most of the carbon footprint emissions for the average U.S. household come from "indirect" sources, e.g. fuel burned to produce goods far away from the final consumer. These are distinguished from emissions which come from burning fuel directly in one's car or stove, commonly referred to as "direct" sources of the consumer's carbon footprint. The 100-year global warming potential (GWP100) is calculated with reference to carbon dioxide.
Coal - Wikipedia
https://en.wikipedia.org/wiki/Coal GLOBAL WARMING
Global warming - Wikipedia
en.wikipedia.org › wiki › Global_warming
ECONOMIC IMPLICATIONS The Economic Impact of Greenhouse Gas Emissions | Clive Best
clivebest.com/?p=7139
