| 摘要 |
Carbon monoxide-containing gas streams are passed over a catalyst capable of catalyzing the disproportionation of carbon monoxide so as to deposit a surface layer of active surface carbon on the catalyst substantially without formation of inactive coke thereon. The surface layer is contacted with steam and is thus converted to methane and CO2, from which a relatively pure methane produce may be obtained. Dilute carbon monoxide-containing streams, as from underground coal gasification with air or the effluent from blast furnace operations, can be used without pretreatment to concentrate the carbon monoxide and/or to separate inert gases therefrom. Conversion of the active surface carbon with high pressure steam enables a high pressure product methane stream to be generated without expensive compression equipment and high energy consumption. Nickel, cobalt, iron, ruthenium, rhenium and alloys thereof are preferred catalyst, with the surface area thereof being preferably at least about 10 m<2>/ gm. Conversion of the active surface carbon can also be accomplished by contact with hydrogen. Carbon monoxide-containing streams having hydrogen or water present therein can be used, with only the carbon monoxide available after reaction with said hydrogen or water being decomposed to form said active surface carbon. The hydrogen or water will be converted, partially or completely, to methane which can be utilized in a combustion zone to generate heat for steam production or other energy recovery purposes. |
