Chemistry Work

Q 1.

 A heater burns normal butane (n-C₄H₁₀) using 40.0 percent excess air.  Combustion is complete.  The flue gas leaves the stack at a pressure of 100 kPa and a temperature of 260⁰C.

a) Calculate the complete flue gas analysis.

b) What is the volume of the flue gas in cubic meter per kg mol of n-butane?

Q 2.

An incinerator produces a dry exit gas of the following Orsat composition measured at 60⁰F and 30 inches of Hg absolute: 4.0% CO₂, 26.0% CO, 2.0% CH₄, 16.0%H₂ and 52.0% N₂. 

A dry natural gas of the following (Orsat) composition: 80.5% CH₄, 17.8% C₂H₆, and 1.7%N₂ is used at the rate of 1200ft³/min at 60⁰F and 30 inches of Hg absolute to burn the incineration off gas with air.  The final products of combustion analyze on a dry basis: 12.2% CO₂, 0.7% CO, 2.4% O₂, and 84.7%N₂. 

Calculate (a) the rate of flow in ft³/min of the incinerator exit gas at 60⁰F and 30 inches of Hg absolute on a dry basis, and (b) the rate of air flow in ft³/min, dry, at 80⁰F and 29.6 inches of Hg absolute.

Q 3.

Compute the mass of wet air required (theoretically) to burn 1 lb. of coal having the following composition: 

                                    Carbon = 66.10%               Hydrogen = 6.03%             Oxygen = 11.91%

                                    Nitrogen = 1.04%               Sulfur = 2.40%    Ash = 12.52%

                  What would be the analysis of the dry flue gases produced?

                  If 20% excess air were supplied for combustion of this coal, and the coal was burned at a rate of 3 tons/hr., compute the required capacity of the fan (actual ft³) to supply the combustion air.  Assume the air to be at a pressure of 14.7 psi and temperature of 86°F. Assume that the air at 86 F contains 0.013lb of moisture per lb of dry air.