Gasification is the process of converting solid fuels to gaseous fuel. It is not simply pyrolysis; pyrolysis is only one of the steps in the conversion process. The other steps are combustion with air and reduction of the product of combustion, (water vapour and carbon dioxide) into combustible gases, (Carbon Monoxide, Hydrogen, Methane, some higher Hydrocarbons) and inerts, (Carbon Dioxide and Nitrogen). The process leads to a gas with some fine dust and condensible compounds termed tar, both of which must be restricted to less than about 100 ppm each, if the gas is to be used in internal combustion engines.

The producer gas obtained by the process of gasification can have end use for thermal application or for mechanical or electrical power generation. Like any other gaseous fuel, producer gas has the control for power when compared to that of solid fuel, in this solid biomass. This also paves way for more efficient and cleaner operation. The producer gas can be conveniently used in number of applications.

 Biomass has been a major energy source, prior to the discovery of fossil fuels like coal and petroleum. Even though its role is presently diminished in developed countries, its is still widely used in rural communities of the developing countries for their energy needs in terms of cooking and limited industrial use. Biomass, besides using in solide form, can be converted into gaseous form through gasification route.