Calorific Value of Fuels

The amount of heat produces by the complete combustion of a unit weight of fuel is known as its calorific value.
       
     Calorific value indicates the amount of heat available from a fuel.The greater the calorific value of fuel, the larger is its ability to produce heat. In case of solid and liquid fuels, the calorific value is expressed in cal/gm or kcal/kg. However , in case of gaseous fuels, it is generally stated in cal/litre or kcal/litre. Below is given a table of various types of fuels and calorific value along with composition.

S.No.	Particular	Calorific Value	Composition
1.	Solid Fuels
	(1)   Lignite	5,000 Kcal/kg	C=67%, H=5%, O=20%, ash=8%
	(2)   Bituminous coal	7,600 kcal/kg	C=83%, H=5.5%, O=5%, ash=6.5%
	(3)   Anthracite coal	8500 kcal/kg	C=90%, H=3%, O=2%, ash=5%
2.	Liquid Fuel
	(1)   Heavy oil	11,000 kcal/kg	C=86%, H=12%, S=2%
	(2)   Diesel oil	11,000 kcal/kg	C=86.3%, H=12.8%, S=0.9%
	(3)   Petrol	11,100 kcal/kg	C=86%, H=14%
3.	Gasoline Fuel
	(1)   Natural gas	530 kcal/m3	CH4=84%,C2H6=10% Other hydrocarbons=5%
	(2)   Coal  gas	7600 kcal/m3	CH4=35%, H=45%, CO=8%, N=6% CO2=2%, other hydrocarbons=4%