Fuels and Combustion

A fuel, may be defined as a substance (containing mostly carbon and hydrogen) which on burning with oxygen in the atmospheric air, produces a large amount of heat. The amount of heat generated is known as calorific value of the fuel. Since the principal constituents of a fuel are carbon and hydrogen, therefore, it is also known as hydrocarbon fuel. Sometimes, a few traces of sulphur are also present in it.

The fuels may be classified into the following three general forms :

1. Solid fuels,

2. Liquid fuels,

3. Gaseous fuels.

Each of these fuels may be further subdivided into the following two types:

(a)    Natural fuels,

(b) Prepared fuels.