Anaerobic digestion is a biological process that produces a gas composed principally of methane (CH4) and carbon dioxide (CO2) otherwise known as biogas. These gases are produced from wastes such as livestock manure, food processing waste and other organic materials.
Anaerobic processes occur both in nature and in a controlled environment like a biogas industrial plant. Organic waste such as food wastes, brewer’s grain and manure are combined in an airtight container, called a digester, with methanophilic bacteria to catalyze the digestion process. Depending on the waste feedstock, operating temperature and system design, the resulting biogas could contain from 55 to 75 per cent pure methane. State-of-the-art systems can produce biogas that is more than 95 per cent pure methane.