Patent US3645885
We've documented a number of times that primary Coal tars, or Coal oils, "long known in the art", as they are commonly described, can be utilized as agents of Coal liquefaction and hydrogenation.
And, we've documented from several sources that, in some processes of Coal liquefaction, as in some processes of Carbon Dioxide recycling through reforming with Methane, Carbon settlement and deposition on catalyst surfaces and in catalyst zones can slow and impair the hydrogenation reactions.
Esso, before they became Exxon, confirmed, as herein, in 1972, through the collaborative work of two of their scientists in facilities far removed from each other, that primary Coal oils can serve to hydrogenate and liquefy Coal; and, that systems to effect such Coal liquefaction can be designed so as to maximize the service life of the catalysts employed, and thereby improve the efficiency and economy of the overall process.
Comment follows very brief excerpts from:
"United States Patent 3,645,885 - Upflow Coal Liquefaction
Date: February, 1972
Inventors: G.W. Harris, MA, and Frank Sprow, TX
Assignee: Esso Research and Engineering Company
Abstract: Coal is liquefied ... in a turbulence-free upflow liquefaction zone, providing improved yield and selectivity of desireable liquid products ... .
Liquefaction of coal in a hydrogen donor solvent is accomplished ... in a continuous process which provides improved yields.
Background: The invention involves the production of liquid hydrocarbon products from solid coal, and more particularly, the step in such a process which utilizes a hydrogen donor solvent in the liquefaction zone. The basic feedstock ... is ... bituminous coal, sub-bituminous coal, lignite and brown coal, or a mixture thereof. (And) it has been found (that the treatment and dissolution of coal) will result in adequate conversion even if the particles are as large as one-fourth inch ... ."
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We close our excerpts here both because the full disclosure involves a lot of very detailed mechanics concerning how to keep Coal conversion catalysts clean and how to effectively separate residual solids from Coal liquids, which are beyond our scope. And, because we wanted to emphasize that the complete document specifies the use, for dissolving Coal, of, among other Coal-derived oils, such as hydrogenated Creosote and hydrogenated Anthracene, the Hydrogen-donor Coal solvent Tetralin, as does, we believe, WVU, in their "West Virginia Process" for direct Coal liquefaction.
In any case, as we see herein, and as we will continue to document, a giant among the petroleum industry, Exxon/Esso, recognized so much promise in Coal liquefaction that, over a period of decades, they assigned multiple scientists and multiple facilities to it's further development and improvement.
