Biogastypically refers to a mixture of differentgasesproduced by the breakdown oforganic matterin the absence of oxygen. Biogas can be produced from raw materials such asagricultural waste,manure,municipal waste,plant material,sewage,green wasteorfood waste. Biogas is arenewable energysource.Biogas can be produced byanaerobic digestionwithmethanogenoranaerobic organisms, which digest material inside a closed system, orfermentationof biodegradable materials.This closed system is called ananaerobic digester,biodigesteror abioreactor.Biogas is primarilymethane(CH4) andcarbon dioxide(CO2) and may have small amounts ofhydrogen sulphide(H2S), moisture andsiloxanes. The gasesmethane,hydrogen, andcarbon monoxide(CO) can be combusted or oxidized with oxygen. This energy release allows biogas to be used as a fuel; it can be used for any heating purpose, such as cooking. It can also be used in a gas engine to convert the energy in the gas into electricity and heat