Hydrocarbon Research, Inc.

John Shen

Michael C Chervenak

Clarence A Johnson

The gasification of coal to produce a methane-rich product gas is accomplished through the controlled slow heating of particulate coal in a gasifier comprising two or more zones, whereby any significant decrease in the density of the coal particles is minimized and particle swelling and friability are significantly reduced, while the carryover of fines and deposition of tars in the product gas conduit are thereby minimized. The particulate coal heating rate in the gasifier zones is usually between about 10.degree. and 200.degree. F per minute. When the particulate coal is to be fed to the gasifier at elevated temperature, further improvements are achieved with swelling type caking coals through their pretreatment by preheating the coal at a slow rate between 10.degree. and 100.degree. F per minute up to about 800.degree. F in multiple fluidized beds. Any carryover of fines in the product gas stream from the uppermost zone of the gasifier is further reduced by utilizing either a solids separation step or a scrubbing step in the gas stream. The coal particles and/or tars thus recovered are returned to a high temperature zone of the gasifier.

Process for the multiple zone gasification of coal

The removal of particulate solids containing iron sulfides from hydrogenated coal liquids by magnetic separation is improved by pretreatment of the liquid with a gas mixture containing hydrogen and hydrogen sulfide. The coal-derived liquid is contacted with the gas mixture containing at least about 2 vol. % hydrogen sulfide, with the remainder of the gas mixture comprising principally hydrogen. Residue time for the liquid-gas contact should be at least about two minutes and temperature should be less than about 650.degree.F. The treated liquid is then passed through a magnetic field having strength of at least about 3000 gauss to achieve substantial removal of sulfur-containing solids from the liquid. The magnetic solids are then removed from the separator unit, e.g., by flushing using a light solvent oil, and the remaining liquid fraction carrying less-magnetic solids is passed on to further processing.

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Yardley, PA, United States of America

John Shen