Lecture 3: Cont. on Numericals of Fuels and Combustion

In this video also, numericals on fuels and combustion are discussed. Q.1 A sample of dry anthracite has the following composition by mass: C = 90%, H = 3%, O = 2.5%, N = 1%, S = 0.5% Ash = 3%. Calculate: a) Stoichiometric Air fuel Ratio b) The actual air fuel ratio and dry and wet analysis of products of combustion by mass and volume when 20% excess air is supplied. Q.2 The gravimetric analysis of coal gives 80% of carbon, 8% of hydrogen, 4% of moisture and 8% of ash. Actual air supplied is 18kg per kg of coal. Calculate the theoretical amount of air required. If 80% of carbon is burned by CO2 and the remaining to CO. Also the volumetric composition of dry products of combustion. (Underline part is discussed) In the second question, amount of oxygen required is the sum of oxygen required for complete combustion of .64kg C (80% of 80% of Carbon) and .08kg of Hydrogen AND oxygen required for incomplete combustion of .16kg C (20% of 80% of Carbon) to CO. For incomplete combustion of CO , reaction involved is : 2C + O2 = 2CO Amount of Oxygen Required = [(8/3)C + 8H] + [(4/3)C]