Gasification of carbonaceous solid fuels
The United States Patent we enclose in this dispatch presents documentation of some facts concerning Coal gasification and conversion that represent only a slight variation on themes about which we've earlier reported.
Our more recent research, however, has uncovered some later and more sophisticated technologies for the indirect conversion of Coal into hydrocarbons, with little to no emissions of Carbon Dioxide or Sulfur, that seem to have evolved from the concepts established herein.
So, we feel it important that the foundation be fully laid.
As we have many times documented, our local Consolidation Coal Company, now Consol Energy, developed, over the course of many decades, a broad portfolio of Coal conversion technologies, including some, such as that seen in:
West Virginia Coal Association | Consol 14-cent Gasoline from Coal | Research & Development; concerning: "US Patent 3,188,179 - Producing High-Purity Hydrogen from Hydrocarbon Gas and Steam; 1965; Inventor: Everett Gorin, Pittsburgh; Assignee: Consolidation Coal Company, PA; Abstract: This invention relates to a process for the conversion of coal to ... hydrocarbonaceous liquids suitable for conversion to gasoline in a conventional gasoline refining plant";
which, despite the somewhat uninformative, inadvertently misleading titles in the United States Patents disclosing them, are directed to the straightforward manufacture, from Coal, of Gasoline.
As can be seen in many of our reports concerning Consol's Coal hydrogenation technologies, one of their leading researchers in that arena was award-winning scientist Everett Gorin, who, as we documented in:
Consol 1953 Coal to Hydrogen & Methane with No CO2 | Research & Development; concerning: "United States Patent 2,654,661 - Gasification of Carbonaceous Solid Fuels; 1953; Inventor: Everett Gorin, PA; 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. (An) object of this invention is ... making a high B.t.u. fuel gas which is rich in methane (and, a) further object of the present invention is ... converting solid fuels into a gas which is rich in hydrogen. Still another object of this invention is (to gasify) carbonaceous solid fuels in which the gaseous products are substantially free of carbon dioxide";
demonstrated that Coal could be used in gasification reactions with Steam, H2O, that resulted in the production of both Methane and elemental, molecular Hydrogen, with virtually no co-production of CO2.
Such technology should be seen as especially important, since, as seen in:
ConocoPhillips CO2 to Methanol | Research & Development; concerning: "United States Patent Application 20030060355 - Converting Carbon Dioxide to Oxygenates; 2003; A catalyst and process for converting carbon dioxide into oxygenates (such as) methanol and dimethyl ether ... said carbon dioxide-containing feed further comprising hydrogen"; and, in:
Exxon 2010 CO2 + Methane = Liquid Hydrocarbons | Research & Development; concerning: "United States Patent 7,772,447 - Production of Liquid Hydrocarbons from Methane; 2010; Assignee: ExxonMobil; A process for converting methane to higher hydrocarbons, the process comprising: (a) contacting a feed containing methane and ... H2O (and) CO2 with a (specified) catalyst under conditions effective to convert said methane to aromatic hydrocarbons";
both Methane and Hydrogen can be utilized in various processes that recycle and reuse Carbon Dioxide, as collected from whatever handy source, in the synthesis of valuable alcohols and liquid hydrocarbons.
As an aside, Conoco, as in "United States Patent Application 20030060355 - Converting Carbon Dioxide to Oxygenates" and Consol are, it seems, no longer corporately related. Although Continental Oil Company, now Conoco, acquired Consol in 1966, by reports, DuPont acquired Consol from Continental in 1981; then, in 1991, made them a part of CONSOL Energy, in partnership with the German utility company, RWE AG. DuPont began to withdraw from the partnership, and, as of 1991, although Consol was a publicly traded company, RWE AG owned more than 70% of it; but, with a publicly stated interest in divesting at least some of its shares. As of 2012, RWE, the second largest electricity producer in Germany, remained Consol's largest single shareholder.
That, at least, is as we understand the gist of multiple web-based information sources reporting on different facets and stages of the ownership changes.
In any case, with apologies for the digression, half a century ago, Consol, concurrently with the above-cited "United States Patent 2,654,661 - Gasification of Carbonaceous Solid Fuels"; further demonstrated that Coal could be converted, with little or no Carbon Dioxide being co-produced, into Methane and Hydrogen, via, as excerpted from the initial link herein, the closely similar and concurrently-developed process of the identically-titled:
"United States Patent 2,654,662 - Gasification of Carbonaceous Solid Fuels
Date: October, 1953
Inventor: Everett Gorin, PA
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.
In application Serial No. 99,562, filed June 16, 1949, a process for the gasification of carbonaceous solid fuels in the presence of barium oxide is described. In accordance with that process, barium oxide is mixed with carbonaceous solid fuels in certain critical proportions and under certain critical conditions of temperature and pressure and then subjected to gasification with steam.
A gaseous product is obtained which contains methane and hydrogen in varying relative proportions depending upon the particular temperature and pressure conditions. As a result of the reaction between the steam and the carbonaceous solid fuels, an inert solid residue or ash is formed in admixture with the barium oxide. In order to reuse the barium oxide which is converted to barium carbonate during the reaction, it is necessary to separate the barium carbonate from the ash and regenerate it at elevated temperatures.
(Note that, in the above, and as becomes more clear in the full Disclosure, regenerating the Barium Oxide from the Barium Carbonate involves the heat-driven emission of Carbon Dioxide. The Barium Oxide acts, in the gasification process, as a capture agent for extra molecules of Carbon and Oxygen that would otherwise combine into Carbon Dioxide. The Barium Oxide is too "weak" to wrest Oxygen from Carbon Monoxide; and, the net result is a reduction in Carbon Dioxide and a proportional increase in Carbon Monoxide in the product synthesis gas.
The Barium Oxide isn't acting as an Oxygen donor, as is the case, for one example, in our report of a process contemporary with Consol's US Patents "2,654,662" and "2,654,661", as accessible via:
Standard Oil 1952 Oxygen Donor Coal Gasification | Research & Development; concerning: "United States Patent 2,592,377 - Manufacture of ... Carbon Monoxide and Hydrogen; 1952; Assignee: Standard Oil Development Company; Abstract: The present invention relates to the manufacture of gas mixtures containing carbon monoxide and hydrogen from ... carbonaceous materials such as coal (and) cellulosic materials ... and more particularly to the manufacture of such gas mixture as are suitable for the catalytic synthesis of hydrocarbons. It has long been known that non-volatile carbonaceous materials such as coal ... may be converted into water gas by a high temperature reaction with steam. The process yields mixtures of CO and H2 in varying proportions depending mainly on the conversion temperatures and the feed ratio of steam. Furthermore, the process as such is extremely well suited ... for the production of feed gases for hydrogenation process and particularly for the catalytic synthesis of hydrocarbons ... . In accordance with the present invention the gasification of solid carbonaceous materials with steam is carried out in the presence of metal oxides supplying the heat required. (The) metal oxide is intimately contacted with, and gives off its oxygen to, the fluidized solid carbonaceous charge of the gas generator. In addition, the metal oxide is reduced so that it may be reoxidized in an exothermic reaction to produce heat required by the gasification reaction. Moreover, the metal oxide may act simultaneously as a cracking catalyst for organic sulfur compounds, thus simplifying the desulfurization of the product gas. The metal oxides which may be used in the present process are quite generally such oxides as have such an affinity for oxygen at the temperatures of our process (and, typical) of these are cupric oxide, ferric oxide and vanadium pentoxide";
wherein the metal oxides are actually a source of Oxygen for the partial oxidation reaction; restricting the supply of Oxygen in such a way that preferentially more Carbon Monoxide, relative to Carbon Dioxide, is formed during the Coal gasification process.
The Barium Oxide is, instead, acting more as a Carbon Dioxide receptor; or "acceptor", as more recent versions of similar and related technologies would have it. It participates in the gasification reaction by competing for some of the free Oxygen and Carbon atoms that are available, being transformed into Barium Carbonate in the process; which activity, thus, leads both to less Carbon Dioxide in the product synthesis gas and a more favorable Hydrogen to Carbon Monoxide ratio.)
Claims: The method of making gas from carbonaceous solid fuels which comprises maintaining two separate reaction zones, the first of which contains barium oxide in granular form and the second of which contains carbonaceous solids in granular form, said second zone being divided into a hydrogenation section and a preheating section which intercommunicate and which are arranged in heat exchange relation with each other, maintaining said first reaction zone at a temperature between 1700 and 2300 F, maintaining said second reaction zone at a temperature between 1400 and 1800 F, maintaining pressures in both reaction zones which are at least one atmosphere when the temperature of said first reaction zone is in the range of 1700 to 2050 F., and when the temperature is in the range of 2050 to 2300 F., (are maintained according to provided and specified formulae), circulating a methane-containing gas and preheated steam through said first reaction zone in the absence of methane-steam converting catalysts, the amount of barium oxide present in said zone being at least 800 parts by weight for each 100 parts of carbon contained in the methane-containing gas, circulating at least a portion of the product hydrogen from said barium oxide reaction zone through the hydrogenation section of the second reaction zone under fluidizing conditions, passing steam through the preheating section of the second reaction zone under fluidizing conditions, circulating solids in the fluidized condition between the said sections, recycling at least a portion of the
gaseous reaction product from the hydrogenation section of said first reaction zone as the aforementioned methane containing gas and preheated steam, respectively, and recovering at least a portion of the gas produced in one of said zones."
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Should you take the time to access and open the document itself, via the initial link in this dispatch, you'll note immediately that both Methane and Hydrogen are the ultimate products of this process. Although a portion of the Methane, as summarized immediately above, is recycled within the system, there is a net production of it.
As noted and documented in our opening comments, both the Methane and the Hydrogen could find great utility in the productive recycling of Carbon Dioxide, in processes leading to the synthesis of hydrocarbons.
And, as seen, for one example, in:
West Virginia Coal Association | Standard Oil Converts Coal with Methane and Hydrogen | Research & Development; concerning: "US Patent 4,326,944 - Rapid Hydropyrolysis of Carbonaceous Solids; 1982; Assignee: Standard Oil Company of Indiana; Abstract: A method is disclosed for recovering liquids and gases by a rapid hydropyrolysis of carbonaceous solids which comprises subjecting the carbonaceous material ... to a (sequence of specified reactions with) methane (and/or) hydrogen";
wherein the "carbonaceous solids" are specified to be "coal" and/or CO2-recycling "biomass", both the Hydrogen and the Methane can also be utilized in the production of hydrocarbons through other reactions with other raw materials that can be so structured as to entail additional elements of sustainability and, indirect, Carbon recycling.
Such potentials are further confirmed by our own USDOE, as seen in:
USDOE Liquefies Coal with Methane | Research & Development; concerning: "United States Patent 4,687,570 - Direct Use of Methane in Coal Liquefaction; 1987; Assignee: The United States of America; Abstract: This invention relates to a process for converting solid carbonaceous material, such as coal, to liquid and gaseous hydrocarbons utilizing methane ... 50-100% by volume in a mix of methane and hydrogen".
The Barium Oxide would be regenerated for reuse in the process of our subject, "United States Patent 2,654,662 - Gasification of Carbonaceous Solid Fuels", through thermal treatment of the product Barium Carbonate, with the resultant emission of nearly pure Carbon Dioxide in a controlled industrial setting.
That regenerated CO2 could then be utilized in any one of many processes developed by our own United States Departments of Energy and Defense, as seen, for just two examples, in:
USDOE 1976 Atmospheric CO2 to Methanol | Research & Development; concerning: "United States Patent 3,959,094 - Electrolytic Synthesis of Methanol from CO2; 1976; Assignee: The USA as represented by the USDOE; Abstract: A method and system for synthesizing methanol from the CO2 in air using electric power. The CO2 is absorbed by a solution of KOH to form K2CO3 which is electrolyzed to produce methanol, a liquid hydrocarbon fuel"; and:
US Navy 2008 CO2 to Synfuel | Research & Development; concerning: "US Patent 7,420,004 - Producing Synthetic Liquid Hydrocarbon Fuels; 2008; Assignee: The USA, as represented by the Secretary of the Navy; Abstract: A process for producing synthetic hydrocarbons that reacts carbon dioxide ... and hydrogen obtained from water, with a catalyst in a chemical process such as reverse water gas shift combined with Fischer Tropsch synthesis";
with the resultant production of even more liquid hydrocarbon fuels.