ABSTRACT
Methanation as a method of carbon monoxide removal was actually used as early as 1920 by George Claude, in France, and Casales, in Italy, who conducted the reaction at very high pressures. The methanation reactions are the reverse of those for methane steam reforming, and they are strongly exothermic. Methanation reactions are also used in the production of various substitute natural gases that contain large amounts of methane. Early experimental work on the methanation of carbon oxides mainly involved the used of nickel, although some work was done on other Group VIII metals. Commercial methanation catalysts are therefore mainly in the form of nickel metal dispersed on a support consisting of various oxide mixtures, such as alumina, silica, lime and magnesia, together with compounds such as calcium aluminate cements. In practice the formulation of a methanation catalyst is a compromise of opposing requirements to give optimum reducibility, activity and stability, together with appropriate physical properties.
