70] 2. A sample of coal was found to contain the following: C=81%, H=4% 0=27., N=10%. the remaining being ash. Estimate the quantity of minimum air required for complete combustion of 1 kg of the sample. Find the combustion of dry flue gas by volume, if 40% excess air is supplied. (Ranchi B.Sc. Engg., 1965) [Ans. Air=10-7 kg, CO2=13.23%., Ny=80-77%, O2=6:0.]