GB1111643A - Making methane-rich gas - Google Patents

Abstract

A methane-rich gas mixture is made by reacting with at least the minimum amount of hydrogen required for complete conversion to methane of the non-aromatic hydrocarbons present in the feedstock, in the presence of a fixed bed methanation catalyst, a hydrocarbon comprising liquefied propane and butane, or a petroleum distillate boiling up to 350 DEG C. The catalyst is preferably nickel or cobalt, optionally promoted by a precious metal of Group VIII and on a refractory support; e.g. the catalyst, before reduction, may comprise nickel chromite or cobalt chromite on a magnesia support, or nickel on alumina. The hydrogen may be provided by steam-reforming hydrocarbons, but the hydrogen-containing gas mixture should not contain more than 15% Co equivalent or more than 10% steam. Pressures of 0 to 750 p.s.i.g. are mentioned. Two specific examples are given. The product gas may be used to enrich a lean gas, e.g. water gas.ALSO:Three catalysts employed in a comparative example concerned with making a methane-rich gas by reacting hydrogen with a light petroleum distillate comprise:- nickel chromite comprising 52.6% NiO and 47.4% Cr2O3: nickel chromite on magnesia comprising 21.2% NiO, 17.8% Cr2O3, 0.4% Al2O3, 60.6% MgO; and coprecipitated nickel on alumina comprising 71.3% NiO, 28.7% Al2O3. Each catalyst was reduced with hydrogen at 450 DEG C.