Anaerobic digestion

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.

The number of large-scale installations, with a capacity above 200 kWe, hovers around 80. In 2021 a total of 40 agro-industrial digesters are operational in Flanders: 26 agricultural and 14 industrial. There is also growing interest in pocket digesters.