Combustion of Solid Fuel. A fuel analyzes 74.0 wt % C and 12.0% ash (inert). Air is added to burn the fuel, producing a flue gas of 12.4% CO2, 1.2% CO, 5.7% O2, and 80.7% N2. Calculate the kg of fuel used for 100 kg mol of outlet flue gas and the kg mol of air used

Mass of fuel used=220.54 Kg

Mass of air added=2145.189 Kg

Explanation:

Basis 100 kg mol of flue gas

flue gas:

CO2 = 12.4 kg mol

CO = 1.2 kg mol

O2 = 5.7 kg mol

N2 = 80.7 kg mol

now N2 is provided by air

so moles of air added = 80.7/0.79 = 102.15 kg mol

so mass of air added = 102.15*21 = 2145.189 kg air

now total moles of carbon = 12.4 (from CO2) + 1.2 (from CO) = 13.6 kg mol

so mass of Carbon = 13.6*12 = 163.2 kg C

so mass of fuel = 163.2/0.74 = 220.54 kg