We have previously cited both of the Exxon scientists named as inventors herein; but, not, as far as we have yet been able to determine, in the context of the invention which is the subject of this report.
In the process they disclose via this United States Patent, they confirm several things we have - most often separately - already many times documented for you:
First, Coal can be gasified, and be made thereby to yield a blend of gases suitable for catalytic conversion into liquid and gaseous hydrocarbon fuels; with, during the gasification process itself, the direct formation of some liquids which can be expediently recovered prior to the catalytic conversion of the generated "syngas".
Second, in general, the still-carbonaceous residues produced by an initial, primary Coal conversion process, just like the high-Carbon "residua" that result from conventional oil refining, especially the refining of "heavy" crude natural petroleum, can be further processed and made to yield additional hydrocarbon products, to the point where virtually all of the Carbon in the initial Coal, or petroleum residua, feed is consumed and utilized.
Third, by extension, Carbon, obtained from any source, can be gasified, utilizing relatively inexpensive and innocuous catalysts, with Steam, and be converted by that Hydro-gasification into even more hydrocarbon synthesis gas.
More facts concerning Coal conversion are indirectly confirmed and indicated, as we emphasize, in comment suggesting even additional advantages which might be obtainable, following excerpts from the link to:
"United States Patent 5,055,181 - Hydropyrolysis-Gasification of Carbonaceous Material
Date: October, 1991
Inventors: Peter Maa, LA, and Martin Gorbaty, NJ
Assignee: Exxon Research and Engineering Company, NJ
Abstract: Disclosed is a process for obtaining liquids and gases from carbonaceous material, such as coal.
The carbonaceous material is first treated with a gasification catalyst, and optionally a hydrogenation catalyst, and hydropyrolyzed for an effective residence time, below the critical temperature at which methane begins to rapidly form, to make liquid products. The resulting char is gasified in the presence of steam at a temperature from about 500C to about 900C.
Claims: A hydropyrolysis-gasification process for obtaining liquids and gases from carbonaceous material, which process consists of:
- treating the carbonaceous material with an amount of one or more gasification catalysts selected from the alkali and alkaline-earth metals, and optionally (others, as specified);
- contacting the treated carbonaceous material, in the absence of liquid solvent or donor solvent, with an effective amount of hydrogen, for an effective time, below 500C, and obtaining a mixture of liquids, hydrocarbon gases and char;
(Note, that, no hydrogen "donor solvent", with it's attendant extra expense, is required.)
- recovering the liquids and hydrocarbon gases, wherein said gases contains less than 2% methane based on the weight of said carbonaceous material; and
- (then) gasifying the char in the presence of steam at a temperature from about 500C to about 900C.
The process ... wherein the gasification catalyst is calcium or potassium.
The process ... wherein the carbonaceous material is coal.
Background and Field: The present invention relates to a process for converting carbonaceous materials, such as coal and heavy petroleum residua, to useful liquids and gases. The process comprises treating the carbonaceous material in the absence of a liquid solvent with a gasification catalyst, subjecting the material to hydropyrolysis, then gasifying the resulting char.
Before carbonaceous material is gasified, it generally undergoes pyrolysis which yields liquids, gases, and a solid low Hydrogen/Carbon material referred to as char.
The char can be gasified in the presence of steam to produce CO and H2.
(Which "CO and H2" can then be passed through a Fischer-Tropsch, or related, catalyst, and be thereby condensed into liquid hydrocarbons.)
Summary: In accordance with the present invention, there is provided a process for obtaining useful liquids and gases from carbonaceous materials.
Carbonaceous materials which may be treated in accordance with the present invention include lignites, coals, and heavy petroleum residua. By heavy petroleum residua we mean that fraction of petroleum which is essentially not distillable at a nominal temperature of 500C. at atmospheric pressure. Coals which may be treated in accordance with the present invention include both subbituminous and bituminous coal. The instant process is particularly beneficial for carbonaceous materials which have a tendency to agglomerate when pyrolyzed, such as bituminous coals.
Relatively little hydrogen is consumed in the practice of the present invention when compared with more conventional hydropyrolysis processes. For example, ... even as little as 50% or less, of hydrogen is consumed when compared with such conventional hydropyrolysis processes.
(Note that there are, already in use, "conventional hydropyrolysis processes" which utilize free "hydrogen", in standard oil refineries, to help effect the hydrogenation of crude natural petroleum.)
The reason why such small amounts of hydrogen are consumed in the practice of the present invention is because little of it is used to make methane. In conventional hydropyrolysis processes, relatively large amounts of methane are produced, usually from about 10 wt. % to about 30 wt. %, based on the total weight of the carbonaceous feed. The production of methane during hydropyrolysis consumes hydrogen, consequently, it is desirable to keep the production of methane at a minimum so as to keep the consumption of hydrogen at a minimum.
Gasification catalysts suitable for use herein are the basic compounds of alkali and alkaline-earth metals, preferably potassium and calcium, more preferably potassium.
Water soluble hydrogenation catalysts suitable for use herein include compounds containing metals (as specified). Preferred are compounds containing ... nickel, cobalt, zinc, or iron. Non-limiting examples of such preferred compounds include ... nickel sulfate, cobalt sulfate, and iron acetate."
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We'll close our excerpts there so that we can summarize and emphasize a few things.
First, note that nothing too exotic, or too expensive, is needed to catalyze the Coal hydrogenation reactions.
Nickel isn't that hard to come by: Canada can dig up plenty of it for us; and, we should be able to scrounge together a little Sulfur in US Coal Country, so that we can make some "nickel sulfate".
The "iron acetate", our consultants tell us, and as seems confirmed by some web-based reference sources we double-checked with, could be made, essentially, from the scrap Iron content of that '65 Chevy Biscayne and '63 Falcon wagon you have stashed axle-deep in mud out behind the barn; and, from the results of your experiment in making hard apple cider that "went bad"; i.e., Vinegar, acetic acid, in other words.
And, since that, through the use of bad apples to make acetic acid, hints at a little bit of Carbon recycling, consider, as well, that, as in some references we've cited in earlier reports, there seems little reason that Organic wastes, including such things as sawdust and sewage treatment plant sludge, couldn't be tossed in at one stage or another, somewhere along the line, in Exxon's complete, multi-faceted gasification technology, along with the specified conventional oil refinery residues, i.e., "heavy petroleum residua", and, with the "bituminous coals" - the raw material for which this conversion process is "particularly beneficial".
Also, even though we weren't able to discern indication or explanation of it in Exxon's full Disclosure, we note that the initial Coal gasification specified seems to be a "partial oxidation" process.
If so, some appreciable heat will be generated by it; heat which could be recovered and utilized to generate at least some of the Steam needed for the Hydro-gasification of the still-carbonaceous residues resulting from that initial gasification process.
The resultant potential for further economy should, thus, we would think, be apparent.
Even further, note that the production herein of the specified "useful liquids and gases" is carefully conducted "below the critical temperature at which methane begins to rapidly form".
That confirms that we can, if we want, simply manufacture, primarily, Methane, CH4, by the gasification of Coal, and/or the Steam gasification of any Carbon-containing substance, such as the specified "petroleum residua", and, we again suggest, any and all available CO2-recycling Biomass, purpose-grown or waste, via this Exxon process.
We could then utilize that CH4, as explained, for just one example, out of now many, in our earlier report:
Australia CO2 + CH4 = Hydrocarbons | Research & Development | News; which concerns: "US Patent Application 20090205254 - Converting Methane Gas to a Liquid Fuel; 2009; Abstract: A method for converting a methane gas to liquid fuel forms a non-thermal plasma with radicals and directs the plasma over a catalyst to convert the radicals to higher hydrocarbons in liquid form ... (and) wherein the liquid fuel comprises methanol, gasoline ... or diesel ... (and) wherein the flow of the reactant gas (to be combined with the Methane) comprises CO2 ... and H2O";
to react with Carbon Dioxide, recovered from whatever conveniently-available source, perhaps the waste gases of a nearby brewery, or, the off-gases from a natural hot spring, and convert that Coal-derived Methane, produced by the Exxon process herein of United States Patent 5,055,181, and that Carbon Dioxide, reclaimed from whatever handy source, into "methanol, gasoline ... or diesel".
Further, just to settle one additional point, some, relatively small, amount of free Hydrogen seems to be required herein, at least for the initial pyrolysis of the Coal, prior to the Steam-gasification of the residual carbonaceous Char.
Such free, elemental Hydrogen can be produced, as again seen in one of our earlier reports:
Consol 1953 Coal to Hydrogen & Methane with No CO2 | Research & Development; concerning: "United States Patent 2,654,661 - Gasification of Carbonaceous Solid Fuels; 1953; Assignee: Consolidation Coal Company, Pittsburgh; Abstract: This invention relates to the gasification of carbonaceous solid fuels, and particularly to the production of hydrogen or high B.t.u. gas from such fuels";
as a co-product of Methane generated from a very-productive process for the hydro-gasification of Coal; or, as seen in:
Florida Hydrogen and Sulfur from H2S | Research & Development; which discloses: "United States Patent 6,572,829 - Photocatalytic Process for Decomposing Hydrogen Sulfide; 2003; Assignee: University of Central Florida; Abstract: System for separating hydrogen and sulfur from hydrogen sulfide (H2S) gas produced from oil and gas waste streams";
as a co-product of commercial Sulfur generated from H2S recovered, as UCF suggests, from a "sour natural gas well"; or, we can get Hydrogen, as seen in:
Solar-Powered Hydrogen Generation | Research & Development; a process wherein "solar energy" is "used to generate electricity that can be used to create hydrogen from water through electrolysis";
from plain old Water electrolyzed by solar-derived electricity, with the same being true of and applicable to, of course, electricity generated from the conversion of any environmental energy, such as the Wind and Hydro sources that are much more abundant in US Coal Country.
Finally:
This gift, of United States Patent 5,055,181, was officially handed to us, by Exxon, via our United States Government, fully two decades ago.