WV Coal Member Meeting 2024 1240x200 1 1

Mobil Improves CoalTL Hydrogen Transfer

United States Patent: 4334977
 


We've cited former Mobil Oil scientist Frank Derbyshire multiple times previously; both in his capacity as a Mobil Oil Coal liquefaction researcher, and, from later in his career, as a faculty scientist at the University of Kentucky's Center for Applied Energy Research.
 
Herein, we see that, while still at Mobil, Derbyshire, and some of his colleagues, developed a technical improvement on Coal liquefaction processes; an improvement which we have already, from other sources, documented for you to be feasible; wherein primary Coal liquids, once produced, can be hydrogenated, and a portion of them then made to serve as hydrogen donor solvents for more raw Coal.
 


Comment follows highly-abbreviated excerpts from:
 
"United States Patent 4,334,977 - Generation of Recycle Solvents in Coal Liquefaction
 
Date: June, 1982
 
Inventor: Frank Derbyshire, et. al.; NJ
 
Assignee: Mobil Oil Corporation, NY
 
Abstract: A method is described to improve a coal liquefaction process by the use of a recycle solvent comprised of two fractions: the first, a lower boiling fraction, is obtained by an atmospheric distillation and is subsequently hydrotreated to enrich its hydrogen donor capacity; the second is a higher boiling fraction that is enriched in desirable hydrogen transfer agents by a solvent extraction process. The combined recycle solvent thus obtained is more efficient in transferring gas phase H2 to the coal and enables other significant process improvements.
 
Claims: ... In a process for the liquefaction of solid carbonaceous material ...  a hydrogen donor solvent component is provided by hydrotreating a fraction of ... digested mixture ... (and) a hydrogen transfer solvent component which ... is provided by extracting a heavy fraction of said digested mixture ... with a naphtha extraction solvent ... .
 
Background: This invention relates to the liquefaction of coal or similar liquefiable carbonaceous solids and is particularly concerned with H-donor solvent liquefaction processes in which recycle solvents are recovered from liquids produced by the treatment of carbonaceous solids with molecular H and a donor solvent. The principal object of such direct coal liquefaction processes, sometimes referred to as solvent refined coal processes, is to stabilize molecular fragments generated by thermal degradable coal.
 
The improved coal liquefaction process of the present invention is based on the discovery that mixtures of hydrogen transfer solvents and conventional hydrogen donor solvents have an unexpectedly high capacity for hydrogen transfer and are synergistic in coal conversion. More particularly, it has been discovered that when hydrogen transfer solvents such as the polynuclear aromatics pyrene, fluoranthene and coronene are used in the presence of hydrogenated lower boiling classical donor solvents such as tetralin,  ...etc., these hydrogen transfer agents are more efficient, allowing a greater fraction of the net hydrogen demand in liquefaction to be met by gas phase molecular hydrogen. This synergism is employed in the modified liquefaction process of the present invention to produce overall process improvement."
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The innovation herein is that, not only can hydrogenated primary Coal tars serve as agents of liquefaction and hydrogenation for more raw Coal, they do an even better job of it when combined with a  "classical" Hydrogen donor solvent, such as "Tetralin", which we believe to be specified in WVU's "West Virginia Process" for direct Coal liquefaction.
 
The hydrogenated Coal tars and the Hydrogen donor solvents, according to Derbyshire in this United States patent, do a better job of Coal liquefaction when combined together than either does alone.
 
And, all of it serves to emphasize how well-understood and how highly-developed the technology for converting our vast domestic reserves of Coal into the liquid hydrocarbon fuels we grow increasingly short of, and for which we are, by foreign powers, being extorted for the supply of, had, at one time, become.
 
Isn't it far, far past time we acknowledged the practical reality of Coal liquefaction technology, and began to implement it for the greater good of the United States of America, and for all of her citizens?