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US 4,537,675 AGranted
Upgraded solvents in coal liquefaction processes
AssigneeIn-Situ, Inc.
InventorsHoward F. Silver, Ronald L. Miller
Life of this patent
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AssigneeIn-Situ, Inc.
InventorsHoward F. Silver, Ronald L. Miller
Estimating the term…
New solvent compositions and a new two-stage direct coal liquefaction process are provided which permit control of the liquid product state from one consisting primarily of low boiling distillate to one consisting primarily of high boiling fuel oil. The use of the new solvent composition in the process significantly increases distillable liquid yields from coal or lignites. The preferred solvent contains from about 0 to 100 weight percent of pyridine-soluble bottoms, i.e., mineral matter-free normally solid dissolved coal, in which the hydrogen content is maintained at an optimum level by adding from about 0.05 to about 2.0 weight percent hydrogen in a hydrotreating step and from about 0 to 100 weight percent of a coal-derived distillate boiling below about 800.degree. F. to about 1000.degree. F.
In a coal liquefaction process wherein a slurry of feed coal and a solvent are introduced into a coal liquefaction zone wherein coal dissolution and hydrogen transfer to the coal fragments formed in dissolution are accomplished by heating the slurry in the presence of molecular hydrogen, the improvement comprising using as a hydrogen donor material in the solvent, coal-derived, pyridine-soluble, bottoms consisting essentially of oils, asphaltenes and preasphaltenes boiling above about 800.degree. F. to about 1000.degree. F., containing no more than about 50 weight percent benzene-insoluble material, all of which bottoms have been hydrotreated in a hydrotreater under mild conditions sufficient to add to said bottoms a controlled amount of hydrogen in the range of from about 0.05 to about 2.0 weight percent.
Dependencies are inferred from the claim text.