In CNG, the major component is methane. Since the calorific value is more and the products formed as a result of combustion are less polluting agents When compared with petrol and diesehit is pre ferred. Petrol and diesel are mixtures of hydrocar- bons Where incomplete combustion takes place forming carbon monoxide which cases air pollution. Moreover in petrol and diesel sulphur and nitrogen are present which form corresponding oxides. These oxides cause air pollution. Further CNG undergo rapid combustion due to its low ignition temperature.
