Exxon Research and Engineering Company

Theodore Kalina

James M Eakman

Harry A Marshall

Le Roy Clavenna

Roger E Moore

Denise Y Wolfs

In a coal gasification operation or similar conversion process carried out in the presence of an alkali metal-containing catalyst wherein solid particles containing alkali metal residues are produced, alkali metal constituents are recovered from the particles by treating them with a calcium or magnesium-containing compound in the presence of water at a temperature between about 250.degree. F. and about 700.degree. F. and in the presence of an added base to establish a pH during the treatment step that is higher than would otherwise be possible without the addition of the base. During the treating process the relatively high pH facilitates the conversion of water-insoluble alkali metal compounds in the alkali metal residues into water-soluble alkali metal constituents. The resultant aqueous solution containing water-soluble alkali metal constituents is then separated from the residue solids, which consist of the treated particles and any insoluble materials formed during the treatment step, and recycled to the gasification process where the alkali metal constituents serve as at least a portion of the alkali metal constituents which comprise the alkali metal-containing catalyst. Preferably, the base that is added during the treatment step is an alkali metal hydroxide obtained by water washing the residue solids produced during the treatment step.

Hydrothermal alkali metal recovery process

A high purity chemical synthesis gas is produced by reacting steam with a carbonaceous feed material in the presence of a carbon-alkali metal catalyst and substantially equilibrium quantities of added hydrogen and carbon monoxide at a temperature between about 1000.degree. F. and about 1500.degree. F. and a pressure in excess of about 100 psia to produce a raw product gas consisting essentially of equilibrium quantities, at reaction temperature and pressure, of methane, steam, carbon dioxide, carbon monoxide and hydrogen; withdrawing the raw product gas from the gasifier and treating it for the removal of steam and acid gases to produce a treated gas containing primarily carbon monoxide, hydrogen and methane; recovering carbon monoxide and hydrogen from the treated gas as a chemical synthesis product gas; mixing the remainder of the treated gas consisting essentially of methane with steam; passing the resultant mixture into a steam reforming furnace where the methane reacts with the steam to produce carbon monoxide and hydrogen; and passing the effluent from the reforming furnace into the gasifier.

Process for the production of a chemical synthesis gas from coal

Raw synthesis gas produced by the gasification of coal, heavy oil or similar carbonaceous material is contacted with a reforming catalyst at a temperature in the range between about 1000.degree. and about 1800.degree. F. and at a pressure between about 100 and about 2000 psig prior to adjustment of the carbon monoxide-to-hydrogen ratio and treatment of the gas to increase its B.t.u. content. This catalytic reforming step eliminates C.sub.2 + compounds in the gas which tend to form tarry downstream waste products requiring further treatment, obviates polymerization problems which may otherwise interfere with upgrading of the gas by means of the water gas shift and methanation reactions, and improves overall process thermal efficiency by making possible efficient low level heat recovery.

Synthesis gas production

Subdivided carbonaceous feed solids containing volatilizable hydrocarbons are hydrogasified by heating the solids to at least minimum hydrogasification temperature while in dilute phase suspension in a gas containing molecular hydrogen and in contact with subdivided hot solids having a temperature greater than minimum hydrogasification temperature. The feed and hot solids are passed with the hydrogen-containing gas through a transfer line hydrogasification zone having a length which, for the velocity of the solids passage therethrough, limits the residence of the solids therein to the time necessary for devolatilization of the carbonaceous feed solids and for conversion of a predetermined minor proportion of the carbon of the feed solids to methane. Suitably from about one to about 50 mol percent of the carbon in the carbonaceous feed solids is converted to methane. Preferably the hydrogen-containing gas is a synthesis gas produced in a fluidized bed steam gasification reaction zone into which carbonaceous solids from the transfer line hydrogasification zone are charged after the separation therefrom of product gases containing methane.

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Morris Plains, NJ, United States of America

Theodore Kalina