We've submitted multiple reports concerning the Coal conversion processes developed by Chevron, formerly Standard Oil of California - who inherited a suite of Coal liquefaction technologies, as we've documented, in their 1985 acquisition of/merger with Pittsburgh, PA's former Gulf Oil Corporation; which included Gulf's P&M (Coal) Mining subsidiary.
We have also earlier cited the Chevron Coal scientist, Joel Rosenthal, named as the lead inventor in the two United States Patents, issued in quick succession, we include herein via the initial and following links.
In the technologies disclosed by Rosenthal, we see that, in confirmation of many of our earlier reports, a liquid solvent derived from a total Coal liquefaction process can be utilized in the initial step of raw Coal dissolution; and, that, such a conversion process can be accomplished thoroughly and cleanly.
An additional link, with excerpts, follows excerpts from the initial link in this dispatch to:
"United States Patent 4,350,582 - Two-Stage Coal Liquefaction Process with Process-Derived Solvent
Date: September, 1982
Inventor: Joel Rosenthal, et. al., CA
Assignee: Chevron Research Company, San Francisco
Abstract: Disclosed is a two-stage process for the production of clean liquid hydrocarbons from coal. In the process sub-divided coal is dissolved in a process-derived solvent. The dissolver effluent is passed through a catalytic reactor operating under hydrocracking conditions, to produce normally liquid products and recycle solvent. The solvent is further subjected to treatment with an antisolvent to precipitate unconverted asphaltenes prior to recycle to the dissolution stage.
Claims: A process for liquefying coal which comprises: forming a coal-solvent slurry by mixing subdivided coal with a solvent; passing said slurry with added hydrogen through a dissolving zone to substantially dissolve said coal; contacting at least a portion of the effluent from said dissolving zone in a reaction zone containing hydrocracking catalyst under hydrocracking conditions, to produce a second effluent containing heptane-insolubles; mixing an antisolvent with at least a portion of said second effluent containing heptane-insolubles to produce a substantially heptane-insoluble-free hydrocarbon liquid; and recycling said substantially heptane-insoluble-free hydrocarbon liquid for use as coal-solvent.
Background and Field: The present invention relates to an improved process for the liquefaction of raw coal. More particularly, the invention relates to a process wherein subdivided coal is dissolved in a process derived solvent having a low heptane insolubles content and is subsequently hydrocracked under specified process conditions.
Coal is our most abundant indigenous fossil fuel resource, and as a result of dwindling petroleum reserves, concerted research efforts are being directed toward recovery of liquid hydrocarbons from coal on a commercial scale. A promising approach in this field is the direct liquefaction of coal accompanied with minimum gas production.
This approach has principally evolved from the early work of F. Bergius, who discovered that transportation fuels could be produced by the high pressure hydrogenation of a paste of coal, solvent and catalyst.
(We have previously documented for you the early-1900's evolution and application of the Coal liquefaction process invented and developed, in Germany, by the 1931 Nobel Prize Winner, Friedrich Bergius. Via separate dispatch today, we are sending more information concerning his process, including a pre-WWII United States Patent issued to him for his Coal conversion technology.)
Summary: The present invention provides a process for liquefying coal to produce normally liquid clean hydrocarbons, accompanied by minimum gas production with high-operating stability."
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As is often sadly the case, our personal insufficiencies don't allow us to do a truly adequate job of clarifying and summarizing Chevron's full technology. But, in confirmation of many of our earlier reports, note, that, the Coal liquefaction solvent needed for the initial Coal dissolution, is a "process derived solvent", generated as a by-product of the total Coal conversion process.
And, it represents an "improved process for the liquefaction of raw coal" that was followed, only months later, by additional improvements and refinements, as seen in the similarly-titled:
"United States Patent 4,358,359 - Two-Stage Coal Liquefaction Process
Date: November, 1982
Inventor: Joel Rosenthal, et. al., CA
Assignee: Chevron Research Company, San Francisco
Abstract: Disclosed is a two-stage process for the production of clean liquid hydrocarbons from coal. In the process subdivided coal is dissolved in a process derived solvent. The dissolver effluent is passed through a catalytic reactor operating under hydrocracking conditions, to produce normally liquid products and recycle solvent. The solvent is further cooled to precipitate unconverted heptane-insolubles prior to recycle to the dissolution stage.
Claims: A process for liquefying coal which comprises: forming a coal-solvent slurry by mixing subdivided coal with a solvent; ... (and) recycling at least a portion of the cooled, substantially heptane-insoluble-free, liquid portion for use as coal solvent.
Background and Field: The present invention relates to an improved process for the liquefaction of raw coal.
(An "improved process", we must presume, even with regards to the immediately-prior technology disclosed in United States Patent 4,350,582.)
Coal is our most abundant indigenous fossil fuel resource, and as a result of dwindling petroleum reserves, concerted research efforts are being directed toward recovery of liquid hydrocarbons from coal on a commercial scale. A promising approach in this field is the direct liquefaction of coal accompanied with minimum gas production.
Summary: The present invention provides a process for liquefying coal to produce normally liquid clean hydrocarbons, accompanied by a minimum gas production with high operating stability."
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Note again, that, in further confirmation of many of our earlier reports documenting related and similar technology, the needed Coal liquefaction solvent is derived by "recycling at least a portion of the" initial Coal liquids "for use as coal solvent".
We can, thus, without the need for any externally-supplied and expensive solvents, as confirmed herein by our own United States Government, liquefy our abundant "coal to produce ... liquid clean hydrocarbons".
And, we have known all of that to be true, as herein officially, for three decades.