Exxon Research and Engineering Company

Charles J Vadovic

Nicholas Charles Nahas

Robert D Wesselhoft

Peter S Maa

Lavanga R Veluswamy

Coal or similar liquefiable carbonaceous solids are converted into hydrocarbon liquids by contacting the feed solids with molecular hydrogen in the absence of an added hydrocarbon solvent and in the presence of an added alkali metal compound under liquefaction conditions in one or more liquefaction zones.

Coal conversion in the presence of added alkali metal compounds

A process for the production of synthetic natural gas from a carbon-alkali metal catalyst or alkali-metal impregnated carbonaceous feed, particularly coal, by reaction of said feed with water (steam) in the presence of a mixture of hydrogen and carbon monoxide, in a series of staged fluidized bed gasification reactors (or gasification zones). The first reactor, or main reactor, of the series is operated as an entrainment reactor and entrained solids are carried over to the second reactor, or reactors, of the series. A carbonaceous feed, or coal, is thus partially gasified in a fluidized bed in the main reactor to form a product gas and a char, and char is entrained within the effluent gases, separated therefrom and then fed into the secondary gasification reactor, or reactors, of the series, the entrained char constituting feed to a secondary reactor, or reactors. Some char is also passed via dense phase transfer from the main reactor to the secondary reactor to maintain catalyst balance. More effective ultilization of the feed carbon is possible by use of the reactor system operated in such a manner than is possible by the sole use of the main reactor, even when the latter is operated at the same or at more optimum conversion conditions.

Process for the catalytic gasification of coal

In a coal gasification operation or similar process carried out in the presence of an alkali metal-containing catalyst wherein spent solids containing ash and alkali metal catalyst residues are produced, alkali metal constituents are recovered from the spent solids by first removing magnetic constituents from the solids, contacting the solid particles from which magnetic constituents have been separated with an acid solution to extract alkali metal constituents from the solids and produce a spent acid solution enriched in alkali metal salts, raising the pH of the enriched solution sufficiently to precipitate aluminum from the solution as aluminum hydroxide, heating the remaining solution to precipitate silicon compounds, and recovering an enriched alkali metal solution from which aluminum and silicon compounds have been removed. This process permits the effective recovery of alkali metal catalyst constituents, eliminates iron compounds and other inactive constituents which may otherwise tend to build up in the catalyst system, and makes possible the recovery of aluminum as a valuable by-product of the process.

Alkali metal catalyst recovery system

A water-soluble alkali metal compound or other soluble constituent is recovered from a mixture of solid particles of different densities and the solid particles are simultaneously separated into two fractions, one having a greater density than the other by countercurrently contacting the solids with a leaching agent in which said constituent is soluble in a countercurrent multistage leaching system, maintaining the density of the enriched leaching agent in the final stage of the system at a value intermediate the densities of the particles in the mixture, and separately recovering enriched leaching solution, particles having a density greater than that of the enriched leaching solution, and particles with a density less than that of the enriched solution from the system. The process is particularly useful for the recovery of alkali metal constituents used to catalyze the gasification of coal and other carbonaceous solids.

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LaPorte, TX, United States of America

Charles J Vadovic