Anaerobic Digestion (AD) is a natural biological process where organic material is broken down by bacteria. It is similar to composting but differs in that it takes place in the absence of oxygen. The process occurs naturally in swamps and bogs and also takes place in landfill sites.
AD is a 4-stage process: hydrolysis, acidification, acetogenesis & methanogenesis. These are long words which describe why cows have four stomach compartments.
An Anaerobic Digester is a device for optimizing and controlling the digestion process to produce:
Biogas (made up of around 60% methane, 40% CO2 and small amounts of hydrogen, hydrogen sulphide, nitrogen, and water vapour).