What is "methanation"

n. (context organic chemistry English) The reaction of hydrogen and carbon monoxide to form methane

Methanation is a physical-chemical process to generate methane from a mixture of various gases out of biomass fermentation or thermo-chemical gasification. The main components are carbon monoxide and hydrogen. The main catalysts used for this reaction are ruthenium, cobalt, nickel and iron. The following main process describes the methanation:

$$\mathrm{\,CO + 3\, H_2 \rightarrow C H_{4} + \, H_2O}$$
This process is used for the generation of biogenous natural gas substitute, which can be fed into the gas grid.
Methanation is the reverse reaction of steam methane reforming, which converts methane into synthesis gas.
Important factors to consider in the design of a methanation unit are the water-gas shift reaction and the Boudouard Reaction.