We've many times documented that any carbonaceous residues, which might result from a primary process of converting Coal into liquid or gaseous hydrocarbons, can themselves be further processed to yield even more hydrocarbon values.
An example would be: Consol Hydrogasifies CoalTL Residues | Research & Development | News; wherein is disclosed: "United States Patent 4,248,605 - Gasification of Coal Liquefaction Residues".
Furthermore, we have also many times documented the development of extensive Coal, and other Carbon, conversion technologies by the former Texaco, Incorporated, prior to their assimilation into Chevron.
Texaco Improves Coal Liquefaction Solvent | Research & Development | News; is representative.
Herein, we see that Texaco scientists applied themselves, as did Consol in the process of USP 4,248,605, to the issue of recycling, and recovering additional hydrocarbon values from, any still-carbonaceous residues resulting from a primary process of converting Coal into other, more versatile, hydrocarbons.
Comment follows excerpts from the initial link in this dispatch to:
"United States Patent 2,980,521 - Carbon Separation Process
Date: April, 1961
Inventors: Roger Dille and Ronald Chapman, CA
Assignee: Texaco, Inc.
Abstract: This invention relates to a process for the production of synthesis gas from carbonaceous fuels. More especially, the invention is concerned with improvements in a method for the separation and recovery of free carbon particles from a carbon-water slurry formed in a synthesis gas generation process.
It is known that in the production of synthesis gas by the partial oxidation of a solid hydrocarbonaceous material (could they wriggle any harder to avoid saying "Coal"?) there is obtained as a by-product a certain amount of finely-divided carbon in the resulting product gases, carbon monoxide and hydrogen.
It is also known that the presence of these solid carbon by-products in the gaseous products obtained from the synthesis gas generator interfere with the main reactions in subsequent processes for the conversion of the synthesis gas products into hydrocarbons (for instance) Fischer-Tropsch ... or methanol ... synthesis.
Many methods have been proposed to effect separation of the free carbon particles from the synthesis gas products. These known carbon separation methods in general comprise treatment of the effluent products from the synthesis gas generator with water ... (to) form a carbon-water slurry.
In the process of the present invention, separation of the carbon particles from the carbon-water slurry can be accomplished by filtration or by use of a centrifugal separator.
The recovered carbon particles ... may be utilized as a fuel feed stock for a fuel-consuming operation ... .
Claims: (A) process for the generation of a synthesis gas mixture ... in which the generated gas mixture comprising carbon monoxide and hydrogen contains minor amounts of solid carbon particles ... the gas mixture is contacted in a scrubbing zone with an aqueous liquid to effect removal of said carbon particles from the mixture with the resulting formation of an aqueous slurry of said carbon particles ... ."
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First of all, the "fuel-consuming operation" in which the Carbon particles, recovered from a primary Coal conversion process, could be used, is in another Carbon hydro-gasification process, as in Consol's United States Patent 4,248,605, noted above; or, as described, for just one more out of many examples, in:
Texaco 1950 Coal + Steam = Hydrocarbon Syngas | Research & Development | News; which concerns:
"United States Patent 2,516,974 - Gasifying Carbonaceous Material; 1950; Assignee: Texaco Development Corporation, NY"; which discloses that a hydrocarbon synthesis gas composed of "predominantly hydrogen and carbon monoxide, is produced by the reaction of water vapor with carbon".
Furthermore, and perhaps importantly, the generation of the free Carbon particles, which can be so readily recycled, along with the Hydrogen and Carbon Monoxide hydrocarbon synthesis gas, in the initial Coal gasification, seems, to us, though not specifically stated as such, to be deliberately arranged, via the design of that initial gasification, so that free, elemental Carbon particles are generated as the primary Carbon-containing by-product, instead of, and as opposed to, Carbon Dioxide gas.
However, it is likely that at least some, even though minimal, Carbon Dioxide would be co-produced in such a Coal gasification process, and, we remind you, that, as in one earlier report:
Texaco Recycles More CO2 to Methanol and Methane | Research & Development | News;