COAL HYDROGENATION PROCESS USING THERMAL COUNTERCURRENT FLOW REACTION ZONE

Thermal hydrogenation of coal to produce hydrocarbon liquid and gas products is performed in a thermal reaction zone, in which a coal/oil slurry flows generally downwardly countercurrent to upflowing hydrogen. An effluent stream containing light hydrocarbon liquid and gas is withdrawn from the thermal reaction zone upper end, and a heavy liquid stream containing unconverted coal and ash is withdrawn from the reaction zone bottom end. Both streams are passed to phase separation and distillation steps for recovery of hydrocarbon gas and liquid products. A portion of the light liquid effluent is preferably recycled to the reaction zone lower end for upflow therein to help increase coal residence time and for further hydrogenation reaction. If desired, the heavy liquid bottoms stream from the thermal reaction zone and containing unconverted coal and ash can be passed with additional hydrogen to a second catalytic reaction step for further hydrogenation reaction to increase the yield of lower-boiling hydrocarbon liquid products.