Resulting primarily from organic waste, biogas is produced through anaerobic digestion. The fermentation of matter (food, wood, straw, crop waste…) in the absence of oxygen enables bacteria to break up the organic matter into methane (2/3), carbon dioxide and a few other gases (H2S, water, nitrogen). The reaction takes place in a closed tank called a digester.
anaerobic digestion produces 4.5 times more energy than it consumes.
Biogas can either be used as it is, or once it has been purified.
This gas can be recovered in the form of heat (heating, drying…) or electricity. Other uses of biogas are currently being studied. These include injection into existing natural gas networks (after standardisation) and the production of a fuel for vehicles (compressed natural gas for vehicles). Biogas can be also be used to power an industrial process implemented to transform gas into liquid fuels (Fisher-Tropsch process).
The “biogas” field is highly developed in Germany, Austria, Switzerland and Denmark.