Liquid petroleum gas (LPG) is used to fuel spark-ignition engines. A typical sample of the fuel consists of: 70% by volume propane C3H8
5% by volume butane C4H10
25% by volume propene C3H6
The higher heating values of the fuels are: propane, 50.38 MJ/kg; butane, 49.56 MJ/kg; propylene (propene), 48.95 MJ/kg.
(a) Work out the overall combustion reaction for stoichiometric combustion of 1 mole of LPG with air, and the stoichiometric F/A and A/F.
(b) What are the higher and lower heating values for combustion of this fuel with excess air, per unit mass of LPG?