• It is a comastable substance having carbon as the masor constituent which is the proper burning profiles a large quantity of heat. That can be used economically for domestic and industrial purposes.

• Example-coal, wood, .P.G gas

• Depending on origine fuels are two types.

• primary fuel or Natural fuel

• secondary fuel or Derived fuel.

• PRIMARY FUEL OR NATURAL FUEL• These are the fuels obtend from the nature• Example-Wood, Coal, Natural gas etc..• SECONDARY FUEL OR DERIVED FUEL

– These are the fuels obtend by the purification of natural fuels

• Example-Petrol, Diesel, L.P.G gas, Coke etc..•• Depending upon the fiscal states, fuels are three types.

– Solid fuel– Liquid fuel– Gaseous fuel

• PRIMARY FUEL OR NATURAL FUEL• These are the fuels obtend from the nature• Example-Wood, Coal, Natural gas etc..• SECONDARY FUEL OR DERIVED FUEL

– These are the fuels obtend by the purification of natural fuels

• Example-Petrol, Diesel, L.P.G gas, Coke etc..•• Depending upon the fiscal states, fuels are three types.

– Solid fuel– Liquid fuel– Gaseous fuel

• LOWER CALORIFIC VALUE OR NET CALORIFIC VALUE

– It is the amount of heat liberated during the combustion of the fuel only

• HIGHER CALORIFIC VALUE OR GROSS VALORIFIC VALUE

• It is the sum of the heat liberated during the combustion and pulling of the combustion products to room temp.

• Unit of calorific value.– Cal/gm---------------- kcal/kg– Cal/cc----------------- kcla/m3

• A fuel should have high carbon content.• A high calorific value.• Low volatice matter.• Low moisture contained.• It should be of low cust.• It should be easily transformable

• It should produce ash