Numerous and common microorganisms within the domain Archaea convert the compounds hydrogen (H2) and carbon dioxide (CO2) into methane in a bio-catalytic way.
The therefore relevant metabolic processes run under strictly anaerobic conditions and in an aqueous environment.
[7] The Methanogens prefer lightly acidic to alkali living conditions and are found in a very wide temperature range from 4 to 110 °C.
[9] Biological methanation can take place as an in-situ process within a fermenter (see fig.
Biological methanation in a pressurized reactor vessel (in-situ process).
Since March 2015 the first power-to-gas plant globally is feeding synthetical bio methane, generated by means of biological methanation, into the public gas grid in Allendorf (Eder), Germany.