GB1399452A - Production of gas - Google Patents

Abstract

1399452 Making combustible gas BRITISH GAS CORP 5 June 1972 [9 June 1971 10 June 1971] 19801/71 and 19944/71 Heading C5E The c.v. of a methane-containing primary gas which also contains minor quantities of H 2 , carbon oxides, non-methane paraffinic hydrocarbons and aromatic constituents, is increased by contacting the gas at elevated pressure, e.g. 10 to 100 atmos., and temperature, e.g. a gas exit temperature of 400‹ to 580‹ C., with a hydrogenation catalyst whereby H 2 in the gas reacts with the constituents, non-methane paraffinic hydrocarbons and carbon oxides, to increase the CH 4 content. The primary gas may be made by a non-catalytic hydrogenation process, e.g. in a fluidized bed as in Specification 1,154,321, or by gas recycle, as in Specification 1,031,717, and this gas is passed through a condenser to remove the aromatic constituents and cool the gas to, e.g. 200‹ to 375‹ C., and through a desulphurizer. Alternatively, the cooling may be limited to allow some aromatic constituents to pass a first purification stage for desulphurizing it and then be condensed out, the gas then being subjected to a second purification. Carbon oxides, steam and hydrocarbons may be added to the gas before it enters the catalytic (methanation) stage, e.g. CO 2 removed from the hydrogenating gas passed to the first stage, or benzene recovered from the primary gas. A catalytic hydrogenation stage may precede the methanation stage.