PRODUCTION OF WATER GAS - FMC Corporation
We've previously reported on the development of Coal conversion technologies by the old FMC Corporation, including work at a New Jersey pilot plant that was funded by the US Government, as seen, for just a few examples, in:
FMC Liquefies Coal for USDOE in New Jersey | Research & Development; concerning: "Title: Char oil energy development. 1975; Research Organization: FMC Corporation, NY; DOE Contract Number: E(49-18)-1212; Abstract: Project COED has been under development by FMC Corporation since 1962. The COED process converts coal to synthetic crude oil, char and gas. The synthetic crude oil is low in sulfur and can be used as feedstock to a refinery or directly as a source of naphtha and fuel oil through simple distillation. The gas can be sold as fuel gas or converted by application of additional technology to pipeline gas or hydrogen"; and:
FMC CoalTL Patent | Research & Development; about the: "Pyrolysis of Coal - US Patent 3,375,175; 1978;
Assignee: FMC Corporation, NY; Abstract: Increased yields of oils and tars are obtained from the pyrolysis of coal. This invention resulted from work done under contract with the Office of Coal Research in the Department of the Interior. This invention is concerned with the pyrolysis of coal and it's principal aim is to ... insure the production of maximum amounts of liquid hydrocarbonaceous products from the coal."
What should be of even greater interest to all of us, however, is, that, at the same time FMC was converting Coal into liquid and gaseous hydrocarbons for our US Government in New Jersey, they were doing the same thing with Coal, on their own dime, at one of their own facilities, just outside the city limits of the state capital of West Virginia.
Comment, with additional links, is inserted within and follows excerpts from the initial link to:.
"United States Patent 3,787,193 - Production of Water Gas
Date: January, 1974
Inventors: Leonard Seglin, NYC, NY, and Charles Gray, Charleston, WV
Assignee: FMC Corporation, NY
Abstract: Water gas is produced by blowing steam through carbon suspended in a coal ash melt in a gasification section, the endothermic heat of reaction being supplied by the ash melt, which is continuously re-circulating through a separate superheating section where the ash is superheated by burning fuel separately introduced into that section; the superheated ash is then conveyed to the gasification section, substantially free of oxidative gas, preferably by means of a heated gas lift.
Claims: Method of producing synthesis gas from carbon and steam in a gasifier consisting of gasification and heating zones physically separated from each other which comprises (1) introducing carbon and steam into the gasification zone in the presence of a body of molten slag heated to a temperature sufficient to cause the carbon to react with the steam to produce carbon monoxide and hydrogen; (2) continuously withdrawing molten slag cooled by the reaction from the gasification zone to the heating zone; (3) introducing fuel into the molten slag after it leaves the gasification zone; (4) burning the fuel with oxygen in the heating zone to heat the slag to a temperature at least 225 F higher than its temperature when withdrawn from the gasification zone; and (5) continuously propelling the molten slag into the gasification section
The method ... in which the carbon is coal ... and the slag is ash derived from the coal.
Background and field: This invention is concerned with improvements in the process of making synthesis gas by the endothermic reaction of carbon and steam at elevated temperatures.
The gasification of carbonaceous solids with steam to produce a synthesis gas containing high concentrations of hydrogen and carbon monoxide has been practiced for many years; this "water gas" reaction is one of the classic processes of the fuel industry.
The principal difficulty with the process is that the reaction is endothermic, so that it is necessary to provide heat to the process. In older processes, a bed of carbon was arranged so that the lower portion of the bed was an oxidizing zone in which heat was developed; the water gas reaction was carried out in the upper portion of the bed. This meant that the CO2, in providing heat, was mixed with the steam, so that the synthesis gas produced contained substantially more carbon monoxide by volume than hydrogen, as distinguished from pure water gas, which contains one volume of hydrogen per volume of carbon monoxide.
(Note that the "synthesis gas produced contained substantially more carbon monoxide by volume than hydrogen" simply because "CO2 ... was mixed with the steam" with which the Coal was gasified, and, as we have many times documented, Carbon Dioxide is chemically reduced in reactions with hot Coal, and made thereby to form more of the reactive, and quite useful, Carbon Monoxide.)
One suggestion for overcoming this difficulty is the use of fluidized beds of carbon, utilizing a recycle stream of carbon which is superheated by partial combustion and separated from the carbon dioxide produced before being returned to the gasification section.
An interesting scheme for gasifying coal with steam and CO2 is described in ... US Patent 2,647,045.
(We have in preparation a report on that technology, i.e.: Gasification of combustible materials.)
This invention aims to provide a circulating slag process for producing water gas which is efficient, becomes more efficient as it is scaled up, and overcomes the problem of dilution of the synthesis gas with combustion products.
In accordance with the present invention, synthesis gas is produced by reacting coal or coal char and steam in a gasification section in the presence of a body of molten coal ash or other slag containing sufficient heat to cause the reaction to take place, continuously withdrawing molten ash cooled by the reaction to an oxidizing section, introducing fuel into the molten ash after it leaves the gasification section, heating the molten ash in the oxidizing section by introducing an oxidizing gas to burn the fuel to a temperature at least about 225 F higher than the temperature of the gasification section, and continuously propelling the heated molten ash into the gasification section, the products of combustion produced while heating the molten slag being separated from the slag before it is introduced into the gasification section. Most preferably, the transfer device is a heated gas lift, the gas-transfer medium being hot products of combustion
(Such "hot products of combustion" in the "gas lift" would include, or course, some, but not all, of the Carbon Dioxide generated in the heat-generating "oxidizing section". Some of the CO2 generated in this process is converted into Carbon Monoxide through reactions with the heated Coal in the "gasification section", but an excess will remain. Comment concerning that excess CO2 follows.)
The carbon used may be coal or any rank from peat to anthracite, or any char prepared from coal. With coal or coal char, the molten coal ash becomes the heat-transfer medium (and, such) use of molten coal ash as the heat-transfer medium offers marked economic advantages over the use of other heat-transfer media, particularly when combined with the fact that very-low-cost coals may be used.
The process may be used in an over-all scheme to produce a synthetic pipeline gas to be used as a substitute for natural gas (and, co-product) tar is treated with hydrogen to form a synthetic crude oil."
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Did we forget to mention, in our introductory comments, that, in addition to a "synthesis gas" which can be catalytically condensed into, among other things, "a substitute for natural gas", this process also generates, from our abundant Coal, as a by-product, "a synthetic crude oil"?
That is how productive the Steam-, or, as labeled elsewhere, the "Hydro-", gasification of Coal can be.
First of all, the process disclosed herein by FMC, in their United States Patent 3,787,193, seems to us only a slightly earlier version of quite similar technology about which we've reported previously, as seen in one example via:
California Hydrogenates Coal, & CO2, with Steam | Research & Development; concerning: "United States Patent 4,162,959 - Production of Hydrogenated Hydrocarbons; 1979; Assignee: Occidental Petroleum Corporation, Los Angeles; Abstract: In a continuous process for recovery of values from a solid carbonaceous material, the carbonaceous material is pyrolyzed in the presence of a particulate source of heat to yield a particulate carbon containing residue of pyrolysis and volatilized hydrocarbons while simultaneously the volatilized hydrocarbons are hydrogenated. The particulate source of heat is formed by oxidizing carbon in the solid residue to heat the particles. Hydrogen for hydrogenation is obtained by reacting at least a portion of the hot particulate carbon containing residue of pyrolysis with steam prior to feeding the hot particulate residue to the pyrolysis reaction zone.
Steam and/or carbon dioxide can be introduced into the pyrolysis reaction zone to interact with carbon containing residue contained therein.
Claims: A continuous process for recovery of liquid hydrocarbon values from a solid carbonaceous material."
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Occidental Petroleum's above process is so efficient, in fact, that our take on it is that extra Carbon Dioxide, reclaimed from an outside source, can be added to the mix of Coal gasification agents.
FMC's overall process of US Patent 3,787,193, though, on the other hand, might actually generate just a bit more CO2 than it utilizes; which, as another company that once had facilities in New Jersey, not far from FMC's COED pilot plant tells us, in:
New Jersey 1948 CO2 Recycling | Research & Development; concerning: "US Patent 2,448,279 - Synthesis of Organic Compounds; 1948; Assignee: The M. W. Kellogg Company, Jersey City; Abstract: This invention relates to an improved method for hydrogenating carbon oxides to produce hydrocarbons and oxygenated organic compounds (and, the) carbon oxides treated include ... carbon monoxide and carbon dioxide";
might not be a bad thing, since such excess CO2 can be recycled into "hydrocarbons".
But, back to West Virginia, it's interesting to note that FMC's process of our subject "United States Patent 3,787,193" was being developed there, in South Charleston and Institute, within eyeshot of another facility where even more Coal conversion science was being established, and in roughly the same time frame, by the old Union Carbide Corporation. As documented separately in:
RESEARCH: Chemicals from Coal - TIME; wherein we're told, on, "May 12, 1952", that: "Deep in the coal country, at Institute, W. Va., 30 newsmen gathered last week to see something new in the way of a chemical plant. From a distance, the $11-million factory looked like many another—a mass of storage tanks, pipes, warehouses, and above it all a thin wisp of smoke. But close up, it was like nothing else in the world. Amid the maze of gurgling pipes and steaming valves, scarcely a worker could be seen. Staffed by only 50 men—mostly chemical engineers—the plant runs continuously, 24 hours per day, with scarcely any need of human attention. It is different in another way. Built and operated by the huge Union Carbide & Carbon Corp., it is the only commercial plant in the world that uses coal as a direct raw material for producing chemicals. By means of hydrogenation, a method of pulverizing coal and combining it with hydrogen under extreme pressure, it produces cheap hydrocarbons."
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We'll presume the Coal conversion process Union Carbide developed in West Virginia to be one of the "classic processes" FMC refers to in their disclosure of our subject 1974 "United States Patent 3,787,193", even though, as seen in our report of:
Charleston, WV, Coal + Steam = Hydrocarbon Syngas | Research & Development; concerning: "United States Patent 3,988,237 - Integrated Coal Hydrocarbonization and Gasification of Char; 1976; Inventors: Hubert Davis, Charles Albright, et. al.; all of West Virginia; Assignee: Union Carbide Corporation, NY;
Abstract: An integrated continuous process for the production of liquid and gaseous fuels wherein coal particles are hydrocarbonized with a hydrogen-rich gas supplied by a gasification process employing two separate and interconnected zones for combustion and gasification and wherein char produced by the hydrocarbonization of the coal particles provides the feed for the gasification zone";
Union Carbide seems to have been only playing catch-up with very similar-sounding technology.
Oddly, not that long after both companies developed their respective Coal conversion processes, both more or less vanished from the Charleston-area landscape. Union Carbide was absorbed by Dow Chemical, and FMC sold, among others, their Charleston operations to Great Lakes Chemicals, which didn't have a good end. And, it's no wonder the technologies are similar, since, as can be seen in photos accessible via:
KANAWHA VALLEY; and, which photos are captioned with the labels: "Where once a sprawling Great Lakes Chemical plant once stood, now there are only these brownfield foundations. The offices of the Great Lakes Chemical Corporation are in ruins"; and: "Taverns in South Charleston, WV with the Dow / Union Carbide plant in the background"; wherein you can barely see the Dow plant because of the beer halls, the two facilities are seemingly within shouting distance of each other.
We were tempted by the poet among our little crew to dwell at some fancy length on the forlorn scenes of the now-abandoned FMC plant and the saloons around the old Union Carbide plant, where some obviously innovative and valuable work, centered on the conversion of Coal into more versatile hydrocarbons, was, long ago, accomplished.
But, we'll pass on the embellishment of regrets. It's just far, far past time we all picked up our shovels, or, where appropriate, our pens, and headed, literally and figuratively, into the mines.