The final waste material produced in a petroleum refinery is a solid fuel like coal which has a very high carbon content. This waste is combusted in the power generation unit of a plant. The solid fuel has 3% S, 2% noncombustible material and the remainder C and H on a weight basis. The combustion process is conducted with 40% excess air. The fuel is burned completely but it is known that 5% of the total carbon is partially combusted to CO.

a) Draw a flowsheet stating all the unknowns and perform a DOF analysis for the combustor.

b) If you encounter any problems in part(a) please use also the measured air flowrate of 1270 m³(STP)/100 kg of the fuel for the determination of the fuel composition (C/H percentages) and the wet basis stack gas composition.

c)Do you think it is safe to vent the stack gases to the atmosphere? Name one solution as an engineer if you believe this may create a problem.