Coal catalytic hydrogenation process using direct coal slurry feed to

Abstract

A process for improved catalytic hydrogenation of coal to produce increased yields of low boiling hydrocarbon liquids and gas products, in which a coal-oil slurry is fed directly with only limited preheating into an ebullated bed catalytic reaction zone to provide increased hydroconversion and improved yields of low boiling hydrocarbon liquids. In the process, a coal is slurried with a hydrogenated coal-derived liquid and heated to only a limited extent, as defined by a temperature-time severity unit index (STTU) less than about 0.1, so as to avoid depleting the hydrogen donor capacity of the solvent liquid, and the slurry is then fed directly into an ebullated bed catalytic reaction zone maintained at 650.degree.-900.degree. F. temperature and 1000-5000 psi hydrogen partial pressure. Supplemental heat is provided to the reaction zone as needed by heating recycled reactor liquid and recycled hydrogen streams to temperatures above the reaction zone temperature. If desired, effluent liquid from the reaction zone can be advantageously passed with hydrogen to a second ebullated bed catalytic reaction zone for further hydrogentation reaction at different severity selected to provide increased conversion of the coal and coal derived liquids and produce increased yields and/or improved selectivity of light hydrocarbon liquid products.