Integrated catalytic coal devolatilization and steam gasification process

An integrated catalytic devolatilization and steam gasification process for the simultaneous production of hydrocarbon liquids and a methane-containing gas from carbonaceous feed solids which comprises:

• (a) introducing said carbonaceous feed solids into a devolatilization zone;
• (b) introducing a mixture of gases containing carbon monoxide and hydrogen into said devolatilization zone;
• (c) contacting said carbonaceous feed solids in said devolatilization zone with said mixture of gases in the presence of a carbon-alkali metal catalyst at a temperature sufficiently high to devolatilize said carbonaceous feed solids but sufficiently low to prevent any substantial reaction of steam with said carbonaceous solids thereby producing char and a devolatilization effluent containing gaseous and vaporous constituents, wherein said carbon-alkali metal catalyst serves to catalyze the exothermic reaction of the carbon monoxide and hydrogen in said mixture of gases to form methane and wherein said temperature is sufficiently low that equilibrium in said devolatilization zone favors the formation of methane by said reaction of carbon monoxide and hydrogen and said reaction occurs to such an extent that substantially all of the heat required in said devolatilization zone is supplied by the heat given off by said reaction and by the sensible heat in the mixture of gases introduced into said devolatilization zone;
• (d) treating said devolatilization zone effluent to recover substantially tar free hydrocarbon liquids as product and a methane-rich gas;
• (e) contacting at least a portion of said methane-rich gas with steam in a steam reforming zone under conditions such that at least a portion of the methane in said methane-rich gas reacts with steam to produce hydrogen and carbon monoxide;
• (f) using the effluent from said steam reforming zone as the mixture of gases introduced into said devolatilization zone in step (b);
• (g) passing said char produced in said devolatilization zone into a steam gasification zone;
• (h) reacting said char with steam in said steam gasification zone under gasification conditions in the presence of a carbon-alkali metal catalyst and sufficient added hydrogen and carbon monoxide to provide substantially equilibrium quantities of hydrogen and carbon monoxide in said steam gasification zone at the gasification temperature and pressure;
• (i) withdrawing from said steam gasification zone a raw product gas containing substantially equilibrium quantities, at the gasification temperature and pressure, of methane, carbon dioxide, steam, hydrogen, and carbon monoxide, wherein substantially none of said raw product gas is passed into said devolatilization zone;
• and
• (j) recovering a methane-containing gas as product from said withdrawn raw product gas.