In anaerobic digestion, micro-organisms will break down complex organic components in the feedstock in the absence of oxygen. They will produce heat, new microbial biomass and biogas with it, which consists of methane (CH4) and CO2.
Biogas is a source of green energy. The semi-liquid stream that remains after fermentation is called digestate.
The majority of the large digesters are co-digesters: this means that they take a combination of manure, energy crops, vegetable or animal waste.
If only one type of biomass is taken in, this is calle mono-digestion.
The term 'vegetable digestate' is used for the end product of a digester that has not treated any animal by-products / manure.
In Flanders there are +- 35 biogas installations and some pocket digesters.