Process for the production of fuel values from coal

Claim 1

A process for the production of methane which comprises in combination the steps of: a. forming a slurry of particulate coal in a liquid hydrocarbon solvent comprising hydrocarbons boiling up to about 750° F and generated from the liquefaction of coal in the presence of hydrogen; b. combining the slurry and a hydrogen containing gas in a liquefaction zone maintained at a temperature from about 700° to about 1000° F and at a pressure up to about 2500 psi for a time sufficient to convert a substantial portion of coal to fluid hydrocarbons and a solid residue of liquefaction; c. combining the effluent, fluid hydrocarbons and the solid residue of liquefaction from the liquefaction zone with a synthesis gas in a stripping zone and forming a liquid-solids fraction comprising liquid hydrocarbons boiling above the boiling point of the liquid hydrocarbon solvent and the solid residue of liquefaction and a vapor fraction comprising hydrocarbons, carbon monoxide, carbon dioxide, hydrogen sulfide and hydrogen; d. combining, in a gasification zone, the liquid-solids fraction from the stripping zone with steam and oxygen in an amount sufficient to gasify substantially all of the carbon contained in the liquid-solids fraction to generate a synthesis gas comprising hydrogen and the oxides of carbon; e. passing a major portion of the synthesis gas to the stripping zone to form the vapor fraction; f. separating the vapor fraction by cooling and condensation into a liquid hydrocarbon solvent fraction, a light liquid hydrocarbon fraction and a residual vapor fraction comprising hydrocarbons containing up to about 5 carbon atoms, hydrogen sulfide, carbon dioxide, carbon monoxide and hydrogen; g. returning at least a portion of the liquid hydrocarbon solvent fraction to form additional slurry; h. converting a minor portion of the synthesis gas from the gasification zone into a hydrogen rich gas stream; i. hydrotreating the light liquid hydrocarbon fraction with at least a portion of the hydrogen rich gas stream to convert bound sulfur to hydrogen sulfide and separating the formed hydrogen sulfide from the hydrogen sulfide lean light liquid hydrocarbon; j. passing another portion of the hydrogen rich gas stream as at least part of the hydrogen containing gas to the liquefaction zone; k. separating at least a portion of the contained carbon dioxide and hydrogen sulfide from the residual vapor fraction to form a carbon dioxide-hydrogen sulfide lean vapor stream; l. methanating a portion of the carbon dioxide-hydrogen sulfide lean vapor stream in the presence of steam and a supported catalyst containing from about 5 to about 35% by weight of at least one metal of the third period of Group VII of the Periodic Table on a temperature stabilized, ceramic alumina support in a first methanation zone having an inlet temperature of at least about 900° F and exit temperature up to about 1500° F; m. combining, with steam, the effluent of the methanation zone, the balance of the carbon dioxide-hydrogen sulfide lean vapor stream and the hydrogen sulfide lean light liquid hydrocarbon in a catalytic reforming stage where, at a temperature from about 1200° to about 1500° F maintained by the effluent of the methanation stage, hydrocarbons are reformed to yield an effluent gas stream comprising steam, hydrogen, carbon monoxide, carbon dioxide and methane; and n. passing the effluent gas stream from the reforming stage to at least one additional methanation stage where the hydrogen and carbon monoxide react to form additional methane.