A natural gas has the following molar analysis. CH4: 81.62%; C2H6: 4.41%; C3H8: 1.85%; C4H10: 1.62%; N2:

Question:

A natural gas has the following molar analysis. CH4: 81.62%; C2H6: 4.41%; C3H8: 1.85%; C4H10: 1.62%; N2: 10.50%. The gas is burned with dry air, giving products having a molar analysis on a dry basis: CO2: 8.8%; CO: 0.2%; O2: 6%; N2: 85 %. Determine the air fuel ratio on a molar basis.