Process for the manufacture of hydrocarbons from carbon monoxide and hydrogen
Over the long course of our reportage, we've many times made reference to the value of "synthesis gas", or, more simply, "syngas", a blend of Carbon Monoxide and Hydrogen which can be catalytically condensed through a variety of techniques, most often referred to generically, and, since there are wide variations on the art. somewhat inaccurately, as the "Fischer-Tropsch" technique, into liquid hydrocarbon fuels.
Which Fischer-Tropsch technique, we must note, as seen in:
Fischer & Tropsch Awarded 1930 US CoalTL Patent | Research & Development; wherein is reported the: "Patent US1746464 - Process for the Production of Paraffin-Hydrocarbons; 1930; Franz Fischer and Hans Tropsch; Germany; (Abstract): It is generally known that the oxides of carbon can be converted into methane by catalytic reduction ... . ... (we) now have found that, instead of methane, its homologues (and) higher homologues which are easily liquefiable (or) liquid ... are obtained";
has officially been known and acknowledged by our US Government for more than eight decades.
Fischer and Tropsch initially developed their hydrocarbon synthesis technology utilizing a synthesis gas blend of Carbon Monoxide and Hydrogen generated from Coal, a process that actually, later, but still more than half a century ago, was well-known and becoming highly-developed in the heart of US Coal Country, as seen in:
WV 1955 Hydrogen & Syngas from Coal | Research & Development; wherein is reported: "United States Patent 2,699,384 - Carbon Monoxide and Hydrogen from Carbonaceous Solids; 1955; Inventors: Luther Perry, et. al., Charleston, WV; Assignee: E.I. DuPont; Abstract: This invention ... is more particularly directed to the preparation of ... gaseous mixtures containing hydrogen and carbon monoxide (from) coal.
An object of this invention is to provide an improved process for the preparation of synthesis gas from coal (which will contain) principally carbon monoxide (and) hydrogen ... wherein the ratios of the constituents can be accurately controlled. We claim: ... a process for the preparation of carbon monoxide and hydrogen by the partial combustion of coal in the presence of steam".
Quite interestingly, even before West Virginia scientists demonstrated, as above, in 1955, that Coal could be converted into such a synthesis gas, other scientists, in Pittsburgh, Pennsylvania, had demonstrated that a hydrocarbon synthesis gas could, as well, be made from Carbon Dioxide, as seen in:
Pittsburgh 1941 CO2 + Methane = Hydrocarbon Syngas | Research & Development; concerning: "United States Patent 2,266,989 - Manufacture of a Gas from CO2 and Methane; 1941; Assignee: Koppers Company, Pittsburgh, PA; Abstract: The present invention relates to the manufacture of gases suitable for the synthesis of higher hydrocarbons or the like, said gases containing definite volumes of carbon monoxide and hydrogen in a certain proportion, by reacting on methane ... with carbon dioxide or a mixture of carbon dioxide and steam, so that the methane ... is decomposed into hydrogen and carbon monoxide".
And, the Koppers Company would, no doubt, have known that the Methane could, as Fischer and Tropsch actually explain in their referencing of prior art in the Disclosure of their 1930 US Patent 1,746,464, be made from Carbon Dioxide itself, via the 1912 Nobel-winning Sabatier process, as explained in:
Sabatier reaction - Wikipedia, the free encyclopedia; "The Sabatier process involves the reaction of hydrogen with carbon dioxide ... in the presence of a nickel catalyst to produce methane";
or, again as Fischer and Tropsch explain, and, as later confirmed in West Virginia via the disclosed process of the above-noted United States Patent 2,699,384, from Coal.
In any case, no matter what the source of the Carbon Monoxide and Hydrogen synthesis gas, we learn herein that, again in Pittsburgh, and again in 1941, the basic premise of Fischer and Tropsch was confirmed, via the development of an improved process for converting such synthesis gas into hydrocarbons.
Comment follows excerpts from the initial link in this dispatch to:
"United States Patent 2,244,710 - The Manufacture of Hydrocarbons from Carbon Monoxide and Hydrogen
Date: June, 1941
Inventor: Herbert Kolbel, Germany
Assignee: Koppers Company, Pittsburgh, PA
The present invention relates to the manufacture of hydrocarbon mixtures suitable for use as motor fuel or as lubricating means, by the reaction of a gas containing hydrogen and carbon monoxide ... .
In the following specifications and claims I use the word "synthesis gas" for specifying gases containing hydrogen and carbon monoxide as suitable for catalytic formation of said hydrocarbons.
The main object of my present invention is to provide such improvements which will render possible the immediate manufacture of valuable hydrocarbon mixtures by use of ordinary coke water gas or gases of similar composition without a previous conversion of such gases.
(The inventor, Kolbel, goes on the explain, in admirable, though tedious, detail how a Coal-, or Coke Oven-, derived synthesis gas is to be first passed over a specified Iron catalyst for an initial conversion. Remaining, un-reacted syngas, along with some products of that initial conversion, are then passed over a specified Nickel catalyst, which chemically condenses any un-reacted syngas and adjusts the final product mix into a more desirable blend of hydrocarbons.)
A still further object of the present invention relates to improvements which will increase the life of the catalysts when used in connection with a synthesis gas containing sulphur and/or sulphur compounds in process in which hydrocarbon mixtures are produced directly from coke water gas or other gases of which the proportions of carbon monoxide to hydrogen do not correspond (to the specified, needed ratios).
The manufacture is effected in such a way that the raw water gas after elimination of the dangerous sulphur compounds is first of all brought into contact with an iron catalyst and then in a second stage of the process with a cobalt or nickel catalyst ... .
(Kolbel does go on to discuss ways in which the Sulfur can be removed; and, we remind you that, as in:
Georgia Tech By-Product Sulfur from Coal Syngas | Research & Development; concerning the: "Electrochemical Polishing of Hydrogen Sulfide from Coal Synthesis Gas; Advanced coal-fired power systems `95 review meeting, Morgantown, WV; June,1995; Georgia Tech Research Institute; Abstract: An advanced process has been developed for the separation of H2S from coal gasification product streams through an electrochemical membrane" and, in:
FMC Corporation Recovers Sulfur from Coal Syngas | Research & Development; which discusses: "United States Patent 4,302,218 - Process for Controlling Sulfur Oxides in Coal Gasification; 1981; Assignee: FMC Corporation; Abstract: In a fluidized coal gasification process in which heat for the gasifier is provided by recycle combustor residue from a slagging combustor, SO2 in the combustor's flue gas is removed by contacting the flue gas with the incoming coal feed whereby the SO2 is adsorbed on the coal and converted to H2S in the gasifier. Sulfur is recovered from the H2S in a Claus Plant";
with more, similar reports to follow, there are ways to remove Sulfur and Sulfur compounds from synthesis gas derived from Coal that are not only practical and effective, but also result in the generation of useful and profitable by-products.)
According to my invention the residual gas of the first stage of the process may also be mixed with an adjustable quantity of untreated synthesis gas if necessary in order to obtain for the second stage of the process a gas mixture of the desired composition.
When based upon a synthesis gas containing equal volumes of carbon monoxide and hydrogen, for instance an ordinary coke water gas, it is possible to attain the effect, by a suitable carrying out of the reactions in the two stages of the process according to the invention, of having the carbon monoxide and the hydrogen contained in the synthesis gas fully utilized for the formation of hydrocarbons ... without any preliminary treatment or conversion of the synthesis gas.
Claims: In a process for the manufacture of hydrocarbons from gases containing carbon monoxide and hydrogen by means of catalysts of the 8th group of the periodic system (i.e., Iron, Nickel and Cobalt) the improvement comprising the flow of the synthesis gas mixture first of all over an iron catalyst, then effecting the removal of the hydrocarbons produced ... then further treating the gas in the presence of another metal of the 8th group as a catalyst for the production of additional hydrocarbons."
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The process is, in sum, a two-step procedure to effect both the removal of Sulfur and the nearly complete conversion of the Coal-derived synthesis gas into hydrocarbons.
Kolbel posits in the full Disclosure that the more inexpensive and more easily-refined and recycled Iron catalyst of the first stage will, in fact, cleanse the syngas of any remaining Sulfur prior to the remaining, unreacted Syngas being passed to the second stage for further, final reactions over the more expensive Cobalt or Nickel.
Further, the technology, as becomes apparent on a full reading, is, in part, one which enables the adjustment of Carbon Monoxide and Hydrogen ratios in the Syngas, as it is processed from one stage to another, to enable complete usage of the Hydrogen and Carbon Monoxide with some control over final hydrocarbon product composition.
We submit that, if it is desirable to so adjust the gas ratios, then any needed extra amounts of either Hydrogen or Carbon Monoxide could be obtained from outside the process of our subject "United States Patent 2,244,710", via separate technologies, as described for just two examples in:
Chicago Hydrogen from H2O | Research & Development; wherein we make report of the: "United States Patent 4,793,910 - Photoelectrochemical Cell for Unassisted Photocatalysis; 1988;
More Oklahoma CO2 + Coal = Hydrocarbon Syngas | Research & Development | News; concerning: "United States Patent 4.040,976 - Process of Treating Carbonaceous Material with Carbon Dioxide; 1977; Assignee: Cities Service Company, OK; Abstract: A mixture of carbon dioxide and ... coal ... is rapidly heated in a reactor, giving a gaseous effluent comprising carbon monoxide".
Koppers themselves developed their own process of independently generating Carbon Monoxide from Carbon Dioxide and Coal, by the way. And, another Pittsburgh company developed a, perhaps more efficient, version of the Hydrogen-generating technology of ""United States Patent 4,793,910".
Both will ultimately be featured in coming reports.
In any case, as documented herein, it was known as far back as the early days of WWII, in one of the very hearts of United States Coal Country, that "a gas containing hydrogen and carbon monoxide", as could be derived from Coal, i.e., "coke water gas", could be efficiently and completely converted into "motor fuel".
When, if ever, do you suppose, such knowledge will finally reach the Coal-mining public up and down the valley of the Ohio River, at whose source such knowledge was, seven decades ago, as herein, established?