1) Any chemical or heat process used to convert a substance to a gas.
2) The production of gaseous fuels by reacting hot carbonaceous materials with air, steam or oxygen. The process takes place at high temperature. The gasification product is a mixture of combustible gases and tar compounds, together with particles and water vapour. Depending on the gasification method, the proportion of components varies, but common to all the processes is that the gas has to be purified before it can be used directly in a gas engine or a gas turbine.