What is biogas

Biogas is the mixture of gases produced by the breakdown of organic matter in the absence of oxygen, consisting of methane and carbon dioxide mostly. This anaerobic process of decomposition (or fermentation) of organic matter happens all around us in nature, and has been happening for a very long time. In fact, the bacteria that break down organic material into biogas are some of the oldest multi-celled organisms on the planet.
Biogas can be produced from raw materials such as agricultural waste, manure, municipal waste, plant material, sewage, green waste or food waste.
Biogas is produced by anaerobic digestion with methanogen or anaerobic organisms, which digest material inside a closed system, or fermentation of biodegradable materials.This closed system is called an anaerobic digester biodigester or a bioreactor

In this video Luwayo Biswick uses biogas examples at Permaculture Paradise