A few of our previous reports briefly touched on the fact that the Sulfur contained in some Coals can not only be removed almost entirely, but even used to advantage in processes that convert Coal into liquid and gaseous hydrocarbons.
Herein, from Exxon, we have further exposition of how Sulfur can actually be used to advantage in a process designed to convert Coal into liquid hydrocarbons. The full Disclosure is both lengthy and complex, and we thus present only brief excerpts, trusting that the qualified among our readers will access the full document via the link, and then will understand the import and find the information useful.
Aside from the described utility of Sulfur, there are a few other points of interest in this Exxon technology for converting Coal into liquid hydrocarbons, as we emphasize following excerpts from:
"United States Patent 4,094,765 - Coal Liquefaction Process
Date: June, 1978
Inventor: Roby Bearden, et. al., Baton Rouge, LA
Assignee: Exxon Research and Engineering Company, NJ
Abstract: A coal liquefaction chargestock is first treated with a hydrogen sulfide-containing gas and thereafter subjected to coal liquefaction conditions.
Claims: A process for the liquefaction of coal, which comprises the steps of: treating a slurry comprising coal and a diluent with a hydrogen sulfide-containing gas ... .
The present invention relates to an improved coal liquefaction process. More particularly, the invention relates to a process comprising pretreatment of a coal liquefaction chargestock followed by coal liquefaction.
It has now been found that pretreatment of the coal liquefaction feed with a hydrogen sulfide-containing gas gives improved coal liquefaction results such as, coke suppression and an increase of liquid yield.
The process of the present invention is generally applicable to treating a slurry comprising coal and a diluent.
The term "coal" is used herein to designate a normally solid carbonaceous material including all ranks of coal, such as anthracite coal, bituminous coal, semibituminous coal, subbituminous coal, lignite, peat, and mixtures thereof.
The hydrogen donor diluent employed will typically be an intermediate stream ... derived from a coal liquefaction process. This stream comprises hydrogenated aromatics, naphthenic hydrocarbons, phenolic materials and similar compounds ... ."
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In other words, as we have from other sources documented, long-known primary Coal oils, such as Naphthene and Phenols, can serve as Hydrogen-donor solvents for liquefying Coal.
Moreover, virtually "all ranks of coal" can be efficiently converted into liquid hydrocarbons.
And, Hydrogen Sulfide, once thought of as only an obnoxious pollutant arising from Coal use, can be utilized in way that "gives improved coal liquefaction ... (with) ... an increase of liquid yield".
That is, of course, if, in US Coal Country, we had any Coal liquefaction operations to increase the yield of.
