EXAMPLE 5.21 A producer gas contains CO2 = 10% C2H4=1% CO = 20% H2 = 15% CH4 = 2% and N2 = 52%. When it is burnt, the products of combustion contains CO2 = 12% CO = 1% 02 = 10% and rest N2 77%. Calculate: (i) The volume of air used in the combustion of 1 m³ of producer gas, both being at the same temperature and pressure. (ii) The percentage of excess air used in the combustion. (ii) The percentage of N2 in the product of combustion which comes from the producer gas.