We've many times made reference to WVU's "West Virginia Process" for the direct liquefaction of Coal, wherein the hydrogenated form of the primary Coal oil, Naphthalene, commonly referred to as "Tetralin", is utilized as the primary agent of Coal hydrogenation and liquefaction.
However, since inter net-accessible reports directly concerning WVU's technology are somewhat scanty, so have been our dissertations to you concerning it, specifically. But, one such report is accessible as:
WVU Hydrogenates Coal Tar | Research & Development; wherein is documented the thesis: "'Hydrogenation of Naphthalene and Coal Tar Distillate'; A. Bhagavatula; 2009; West Virginia University; The hydrogenation of naphthalene (to form) the hydrogenated product, tetralin (and) coal was hydrogenated ... using (tetralin) as the solvent (to effect) the conversion of coal to refinable crude hydrocarbons, from which liquid fuels such as gasoline, diesel, kerosene (can be derived)".
Herein, we learn of another, somewhat intriguing, use for "Tetralin", which could be seen as a preliminary treatment of Coal, prior to utilizing the then-treated Coal in any application.
According to scientists in Illinois, Tetralin can be utilized in a form of Coal "pre-treatment", before the Coal is then further utilized, whether, we submit, for combustion or liquefaction, to cleanse raw Coal of it's Sulfur.
And, the manner in which that's accomplished has implications we attempt to explain, following excerpts from the initial link to:
"United States Patent 4,888,029 - Desulfurization of Carbonaceous Materials
Date: December, 1989
Inventors: Richard Shirley, et. al., Illinois
Assignees: Southern Illinois University and the Illinois State Geologic Survey
Abstract: A process for desulfurizing carbonaceous material containing inorganic bound sulfur, organic bound sulfur, or combinations thereof. The process comprises reacting the carbonaceous material at desulfurization conditions with a hydrogen source material in the presence of a reaction accelerator to enhance production and reactivity of atomic hydrogen supplied by the hydrogen source. The reaction is prefereably carried out in the presence of a flowing reaction medium which carries away hydrogen sulfide products and other volatile desulfurization products separating them from the carbonaceous material.
Claims: A process for desulfurizing carbonaceous material containing inorganic bound sulfur, organic bound sulfur, or a combination thereof comprising reacting the carbonaceous material at desulfurization conditions with a hydrogen source material comprising an alcohol, a hydrocarbon, an alicyclic compound, hydrogen, or a combination thereof in the presence of a flowing gas medium comprising a reaction accelerator comprising oxygen, nitric oxide, or a combination thereof to enhance production and reactivity of atomic hydrogen supplied by said hydrogen source.
The process ... wherein the carbonaceous material comprises coal, cokes, coal products, liquid crudes, or combinations thereof.
The process ... further comprising adding an optional catalyst comprising a layered graphite or clay ... .
The process ... wherein the ... sulfur bound to iron as pyrite or marcasite reacts with ... hydrogen ... to yield iron and hydrogen sulfide.
The process ... wherein organic bound sulfur is hydrogenated to form hydrogen sulfide
The process ... wherein the hydrogen source material is ... tetralin ... .
Background and Field: The present invention relates to the removal of sulfur from carbonaceous materials. Specifically, the present invention relates to desulfurization of carbonaceous materials containing inorganic bound sulfur, organic bound sulfur, and combinations thereof.
The prior art contains many processes for desulfurizing carbonaceous materials such as coal, cokes, coal products, liquid crudes, and similar materials. These carbonaceous materials contain both inorganic bound and organic bound sulfur. One problem with many of these processes is that they are only capable of removing inorganic bound sulfur and are not very effective in removing organic bound sulfur.
It is therefore an object of the present invention to provide an economical and effective process for desulfurizing carbonaceous materials containing either inorganic bound sulfur, organic bound sulfur, or both. It is a further object of the present invention to provide a process for desulfurizing carbonaceous materials containing both inorganic bound sulfur and organic bound sulfur in a single step. It is still a further object of the present invention to provide a process for desulfurizing carbonaceous materials without substantially depleting the heating value of the original feedstock.
Accordingly, inorganic bound sulfur and/or organic bound sulfur present in the carbonaceous material respectively react with the atomic hydrogen to produce hydrogen sulfide which is preferably carried away from the carbonaceous material ... and efficiently separated from the carbonaceous material.
(Both) inorganic and organic bound sulfur can be removed in a single step. A single step desulfurization process decreases operation and maintenance cost."
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So, whether the Coal is bound for straightforward combustion in a boiler, or, for further processing, perhaps with more Tetralin, as in the West Virginia Process, to be converted into liquid hydrocarbon fuels, any Sulfur in the Coal can be extracted beforehand, and converted into recoverable Hydrogen Sulfide.
And, note that, if appreciable amounts of "pyrite" are among the sources of the Sulfur in the raw Coal, then it might be feasible to produce "iron" as a by-product.
First of all, though, this is a type of "solvent-refined" Coal, or "SRC" process, which was studied and utilized at a number of government-funded "pilot" plants once scattered around the country, as we've previously reported, and, as seen, for a few examples, in:
Solvent Refined Coal | Research & Development; "The operating history of a Solvent Refined Coal (SRC) Pilot Plant (at Fort Lewis, Washington) through March 1978. The Solvent Refined Coal Process SRC I (solid fuel product) and SRC II (liquid fuel product) operating modes for converting high-sulfur, high-ash bituminous coals into low-sulfur, ash-free boiler fuels have been successfully demonstrated"; and, in:
USDOE Funds Pennsylvania Coal Liquefaction | Research & Development; concerning: "United States Patent 4,376,032 - Coal Liquefaction Desulfurization Process; 1983; Assignee: International Coal Refining Company, Allentown, PA; Abstract: In a solvent refined coal liquefaction process, more effective desulfurization of the high boiling point components is effected by first stripping the solvent-coal reacted slurry of lower boiling point components, particularly including hydrogen sulfide."
Aside from the fact that the "Solvent Refined Coal" produced by the Illinois process of USP 4,888,029 could then be reacted with even more Tetralin, as in the West Virginia Process, to make virtually Sulfur-free "liquid fuels such as gasoline, diesel (and) kerosene", note that one product of the USP 4,888,029 process, just as in the USDOE's Coal desulfurization at the Allentown SRC pilot plant, is "hydrogen sulfide", H2S.
And, even though H2S is, in and of itself, an unpleasant thing to have around, it does have, as we indicated above, some "intriguing" uses.
As seen, for one example, in our report:
Exxon Methane and Hydrogen from H2S and Carbon Monoxide | Research & Development; concerning: "United States Patent 4,517,171 - Synthesis of H2 and CH4 from H2S and CO; 1985; Assignee: Exxon Research and Engineering Company, NJ; Abstract: Hydrogen and methane are synthesized from a gaseous feed comprising a mixture of H2S and CO";
we can use that Hydrogen Sulfide, via reaction with Carbon Monoxide, to make both Methane and Hydrogen, with Sulfur as a commercial by-product.
As an additional aside, we are compelled to note that the Carbon Monoxide needed for Exxon's process can be made from Carbon Dioxide and, desulfurized(?), Coal, as seen for one instance in:
Carbon Dioxide Recycled in the Manufacture of Plastics | Research & Development; concerning: "United States Patent 4,564,513 - Process for the Production of Carbon Monoxide; 1986; Assignee: Bayer Aktiengesellschaft (AG), Germany; Abstract: Carbon monoxide is produced in an improved process in a carbon-filled, water-cooled generator in the configuration of a truncated cone in the longitudinal section, by the gasification of said carbon with a mixed gas of oxygen and carbon dioxide ...".
In any case, the Hydrogen produced by the process, above, of Exxon's USP 4,517,171, could then be utilized in the technology described by WVU, in "Hydrogenation of Naphthalene and Coal Tar Distillate", to make more Tetralin, for use in our subject US Patent 4,888,029, to make more Hydrogen Sulfide.
And, that additional Hydrogen Sulfide, again through Exxon's USP 4,517,171, could be used to make, as Exxon specifies, in addition to more Hydrogen, Methane.
Which Methane could then be employed, as seen, for just one example, in:
Standard Oil 1950 CO2 + CH4 + H2O = Syngas | Research & Development; concerning: "United States Patent 2,522, 468 - Production of Synthesis Gas; 1950; Assignee: Standard Oil Development Company;
Abstract: (The) production of a mixture of carbon monoxide and hydrogen suitably proportioned for use as a feed-gas in the synthesis of hydrocarbons ... boiling in the gasoline and gas oil range, by ... charging a mixture of methane, steam and carbon dioxide to a reforming zone";
to generate a hydrocarbon synthesis gas suitable for "the synthesis of hydrocarbons ... boiling in the gasoline and gas oil range" by reacting that Methane with Carbon Dioxide.