Last week, we sent you information, now posted on the WV Coal Association's R&D Blog, under the self-explanatory header of "Esso/Exxon 1973 Hydrogen from Coal and Steam".
The US Patent enclosed in this dispatch is for related technology.
Also today, as it relates, we will be sending you, under separate cover, yet another United States Patent, awarded to scientists in Europe, documenting the fact that Carbon Dioxide can be recycled, and transformed into valuable liquid hydrocarbons, such as Methanol, through catalyzed reactions with Methane.
Although Methane can be synthesized, via the Nobel-winning Sabatier reaction, from Carbon Dioxide, we wanted to again confirm that such valuable Methane can be synthesized in processes of Hydro-, or Steam-, gasification of Coal, in a way similar to that which Exxon used, as noted above, to make Hydrogen from Coal.
And, who better to tell us the truth of that than our good ole' Big Oil friends, Esso/Exxon; and, their US Government confessors in the Patent and Trademark Office?
Herein, we present further documentation, in addition to earlier of our reports, that Methane, if we want it, can indeed be synthesized via such Steam-, or Hydro-, gasification of Coal.
Following, with additional comment appended, are excerpts from yet another US Patent, as available through the above link and attached file, issued, nearly four decades ago, to Exxon, for a technology based on such Coal conversion techniques:
"United States Patent 3,847,567 - Catalytic Coal Hydrogasification Process
Date: November, 1974
Inventor; Theodore Kalina, NJ, et. al.
Assignee: Exxon Research and Engineering Company, NJ
Abstract: Methane is produced by the thermoneutral reaction of steam with coal or other carbonaceous material in a hydrogasification zone containing an alkali metal catalyst and sufficient hydrogen to suppress competing endothermic reactions. The gas taken overhead from the gasifier is subjected to steam reforming and then processed for the removal of acid constituents, hydrogen which is recycled to the hydrogasification zone, and carbon monoxide which is used as fuel for the steam reformer.
We claim:
1. A process for the manufacture of methane which comprises:
a. reacting finely divided carbonaceous solids with steam and hydrogen in the presence of an alkali metal catalyst in a hydrogasifier and withdrawing a methane rich gas overhead from said hydrogasifier;
b. reacting said methane-rich gas with steam in a catalytic steam reforming furnace and withdrawing a methane-rich gas of increased hydrogen content from said reforming furnace;
c. treating said gas of increased hydrogen content for the removal of acidic constituents;
d. separating the treated gas into a product methane stream, a hydrogen stream, and a carbon monoxide stream;
e. recycling at least a portion of said hydrogen stream to said hydrogasifier; and
f. burning at least a portion of said carbon monoxide stream as fuel in said steam reforming furnace.
8. A process as defined by claim 1 wherein said carbonaceous solids comprise a bituminous or lower rank coal.
In accordance with the invention, a high Btu gas suitable for pipeline purposes is produced by reacting finely divided coal or similar carbonaceous material with steam and hydrogen in the presence of an alkali metal catalyst, passing the resultant gas to a catalytic reforming unit where steam and methane react to form hydrogen and carbon monoxide, treating the reformer gas product for the removal of carbon dioxide and other acidic gases, and then separating the treated gas into a hydrogen stream which is recycled to the gasifier, a carbon monoxide stream which is used to fuel the reformer and provide heat for the process, and a product gas stream composed primarily of methane. The hydrogen and reactant steam concentrations in the gasifier are controlled so that the exothermic hydrogasification reactions provide sufficient heat for the endothermic steam reactions, reactant preheat and reactor heat losses. This results in a substantially thermoneutral process which has economic advantages over processes employed in the past."
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First, we are compelled to point out that a "treated gas" consisting of "methane ..., hydrogen ...., and carbon monoxide", as above, sounds like an hydrogenated synthesis gas ideally suited, without the separation specified herein, for further Fischer-Tropsch, or related, catalytic condensation into liquid hydrocarbons.
Note, though, that this is yet another "self-powered" or "auto-thermal" technique, as in "a substantially thermoneutral process", above, and is thus similar to other Coal conversion technologies we've documented for you, wherein some exothermic reactions provide heat to drive some needed endothermic reactions.
And, excess Carbon Monoxide is generated from the Coal, which can then be used as a fuel gas within the process, and thus serve as well to help drive the endothermic reactions.
Moreover, the needed Hydrogen, to hydrogenate the Coal and form Methane, is generated apparently in excess by the reactions between a fraction of the produced Methane and Steam. Such excess Hydrogen, we submit, could be used to hydrogenate, or "hydro-treat", carbonaceous Coal liquids derived from other Coal conversion processes; or, to re-hydrogenate direct Coal liquefaction Hydrogen donor solvents, some of which can be made from primary Coal oils or tars, such as Naphthalene.
In addition to it's use in tri-reforming processes for the recycling of Carbon Dioxide, Methane can, again as we've documented, also be directly converted into liquid hydrocarbon fuel; or, added to synthesis gas generated from Coal pyrolysis, to enhance the production of liquid hydrocarbons in some processes of indirect Coal liquefaction.