Coal liquefaction bottoms conversion by coking and gasification
AssigneeExxon Research & Engineering Co.
InventorRobert J. Lang
Life of this patent
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Abstract
Heavy bottoms produced by the liquefaction of coal or similar carbonaceous solids are converted into more valuable products by adding an alkaline earth metal compound to the bottoms in a concentration sufficient to give, following pyrolysis of the bottoms, an alkaline earth metal-to-carbon atomic ratio of from about 0.005:1 to about 0.1:1; pyrolyzing the bottoms at a temperature of from about 900.degree. to about 1600.degree. F. to produce gases, hydrocarbon liquids and coke or char containing added alkaline earth metal constituents; and thereafter gasifying the char with steam.
Claims19
A process for upgrading heavy bottoms produced by the liquefaction of coal or similar carbonaceous solids which comprises pyrolyzing said bottoms in the presence of an added alkaline earth metal compound to produce coke containing added alkaline earth metal constituents and thereafter gasifying said coke in the presence of steam.
An improved coal liquefaction process which comprises contacting feed coal with gaseous hydrogen and a hydrogen-donor solvent under coal liquefaction conditions in a coal liquefaction zone;
- withdrawing a liquefaction product including constituents boiling in excess of about 1000.degree. F. from said liquefaction zone;
- recovering a heavy liquefaction bottoms fraction containing said constituents boiling above about 1000.degree. F. from said liquefaction product;
- adding an alkaline earth metal compound to said bottoms fraction in a concentration sufficient to provide, following the pyrolysis of said bottoms fraction, an alkaline earth metal-to-carbon atomic ratio between about 0.005:1 and about 0.1:1, pyrolyzing said bottoms fraction and recovering coke;
- and thereafter gasifying said coke in the presence of steam.
Dependencies are inferred from the claim text.