We've documented quite a number of times that various technologies for gasifying Coal, and then catalytically transforming the synthesis gas thus produced into a high-Methane content synthetic, or substitute, "natural" gas, quite suitable for introduction into, and compatible with, existing natural gas pipelines, had at one time become almost commonplace.
One of our previously-reported examples of such technology can be accessed via:
Pennsylvania Coal to Methane | Research & Development; concerning: "US Patent 3,779,725 - Coal Gasification; 1973; Air Products and Chemicals, Inc., Allentown, PA; Abstract: A method for producing a synthetic pipeline gas by reacting a carbonaceous fuel in a gasifier to form a gas and thereafter subjecting the gas to additional process steps including a final cryogenic separation of high methane content gas for use as the pipeline gas."
Perhaps surprisingly, one of the corporations that devoted considerable effort into the development of such Coal conversion technology was the Royal Dutch Shell Company, originally founded in the Netherlands.
Some examples of our reportage concerning their achievements can be accessed via:
Shell Oil Maximizes Carbon Use in Coal Gasification | Research & Development; concerning: "United States Patent 4,969,931 - Process for the Preparation of Synthesis Gas; 1990; H.L. Wu, et. al., Amsterdam; Assignee: Shell Oil Company, Texas; Abstract: A process for the preparation of synthesis gas by the partial combustion of an ash-containing fuel with an oxygen-containing gas is described, the synthesis gas formed being removed from the top of the reactor through a gas discharge pipe, and slag formed through a slag discharge at the bottom of the reactor, the process being characterized by the counter-current contact of the synthesis gas in the reactor with cold fly-slag agglomerates";
wherein gasification slag is re-circulated within the Coal gasifier to maximize extraction of Carbon; and:
Shell Oil Coal + CO2 + H2O = Hydrocarbon Syngas | Research & Development; concerning: "United States Patent 7,829,601 - Partial Oxidation Process of a Solid Carbonaceous Feed; 2010; Johannes Ploeg, et. al., Netherlands; Assignee: Shell Oil Company, Texas; Abstract: The invention is directed to a process for preparing a mixture comprising CO and H2 by operating a partial oxidation process of a solid carbonaceous feed, which process comprises the steps of: (Supplying) the solid carbonaceous feed and an oxygen-containing stream to a burner, wherein a CO2 containing transport gas is used to transport the solid carbonaceous feed to the burner";
wherein the Coal gasification reaction had been made so efficient that Carbon Dioxide, recovered and supplied from whatever source, could be used as one of the agents of gasification for the Coal, with most of the CO2 being transformed via the gasifiction process into the more-desired Carbon Monoxide.
However, no matter how efficient the Coal gasification process could be made, it seems, even to the point where, as in the above process of "United States Patent 7,829,601", Carbon Dioxide could be added to the mix of gasification reactants, there was still some "slippage", as it were, of CO2 into the product syngas.
Given that fact, Shell it seems, as a corollary effort, devoted attention as well to the improvement of syngas catalysis, in the development of what we are compelled to view as an advancement of the Sabatier process, which won the Nobel Prize in 1912, as we reported, for one example, in:
CO2 Solution Wins Nobel Prize - in 1912 | Research & Development; and, wherein it's said of the Sabatier process, that: "Carbon monoxide and carbon dioxide are both changed immediately into methane, which can therefore be synthesized with the greatest ease";
and, wherein it's seen that, with the proper catalysts, and a supply of Hydrogen, both Carbon Dioxide and Carbon Monoxide, as might be present in a synthesis gas generated from Coal, as perhaps via Shell's above process of "United States Patent 7,829,601", and wherein any Carbon Dioxide present in that synthesis gas would only be a remaining residual amount of the Carbon Dioxide originally used to initially gasify the Coal, can be converted into Methane.
As seen, with comment inserted and appended, in excerpts from the initial link in this dispatch to:
"United States Patent 3,996,256 - Methanation Catalyst
Date: December, 1976
Inventor: Lynn Slaugh, Texas
Assignee: Shell Oil Company, Houston
Abstract: The reaction of ... carbon monoxide and carbon dioxide ... to form methane at temperatures above 300C is promoted by carrying out the reaction in the presence of a catalyst containing molybdenum disilicide.
(Note, that, while it won't be reflected well in our excerpts, as we have previously documented, methanation reactions of Carbon oxides with Hydrogen are exothermic, and generate heat energy. Once the reaction is started, it will itself sustain the necessary "temperatures above 300C", and, won't require the supply of any extra energy to keep going. It might, in fact, have to be cooled a little.)
Background: Catalytic methanation is a well-known reaction which is widely employed in the chemical and energy industries. Probably it's most widespread current and potential application is in the treatment of the gaseous effluent from the gasification or partial oxidation of carbonaceous fuels with oxygen and/or water, (that, is) the steam-hydrocarbon reforming and partial combustion of ... solid carbonaceous fuels to produce a hydrogen-rich gas for chemical synthesis (such as) to form a methane-rich gas having high Btu value and low CO content for residential and industrial heating ... .
(The) gasification or partial oxidation effluent, which typically contains substantial quantities of H2, CO, CO2 and H2O as well as N2 when air is used as the oxidant source, is generally subject to a process known as the carbon monoxide shift-conversion reaction prior to catalytic methanation (which reaction) converts a substantial quantity of the CO present to H2 and CO2 by reaction with H2O in the presence of a catalyst.
(The) gasification or partial oxidation effluent gas is subject to (such) CO-shift to obtain the appropriate ratio of H2 to CO ... and the CO-shift product gas is then subject to catalytic methanation for conversion of carbon oxides and hydrogen contained therein to methane.
Because of the increasing demand for a high BTU, clean gas as an energy source in the United States and the acknowledged decreasing and finite nature of natural gas reserves in the United States as well as happenings on the world scene which make energy self-sufficiency desirable or even essential, there has been a dramatic increase in interest in the manufacture of a clean, high BTU gas energy source which will meet pipeline standards from alternative carbonaceous sources such as coal ... .
(With) conventional catalyst systems, methanations have been limited to the lowest temperatures consistent with acceptable catalyst activity, in part because of catalyst instability at high temperatures, the highly exothermic nature of the methanation reaction and the inability to effect an equilibrium shift towards methane at high temperatures under practical circumstances.
A novel methanation catalyst has now been found that not only is active in promoting the reaction of carbon oxides and hydrogen, but is also relatively sulfur resistant.
The present invention is a continuous process for the production of methane from a gaseous reactant mixture containing gases selected from the group comprising hydrogen, carbon monoxide, and carbon dioxide ....
(and) which process comprises contacting said gaseous reaction mixture in the reaction zone maintained at temperatures above about 300C with a catalyst containing molybdenum disilicide (MoSi2).
(Note: The "molybdenum disilicide" catalyst might sound dreadfully exotic and expensive, maybe even poisonous. It isn't. It is actually a ceramic-type material, that, as can be learned via:
I SQUARED R Element Co., Inc. - Moly-D®: Molybdenum Disilicide Heating Elements, and:
Molybdenum Disilicide Powder (MoSi2) from READE;
is widely used in certain, specific industrial and consumer applications, and is readily available in a variety of product forms, i.e., powder, granules, etc.)
In addition to being an active methanation catalyst, molybdenum disilicide is also relatively sulfur resistant.
Gaseous reactant feed mixtures which can be suitably methanated with catalyst compositions of the instant invention typically contain 10 to 99.9% H2, 0.1 to 50% CO, 0 to 20% CO2 (and) 0 to 70% H20 ... .
(That, we submit, is a pretty broad range; and, it allows and enables a number of options when it comes to actually generating the mix of feed gases, as we elaborate further on.)
One of the applications of the catalytic methanation process of the present invention is in the upgrading of methane-rich gas derived from the partial oxidation or gasification of coal. Several coal gasification processes employing non-catalytic gasifiers in which coal is converted into a crude product gas comprising principally CH4, H2, CO, H2O and CO2 by high temperature reaction with steam and oxygen are quite well known, e.g., the Lurgi process, the Koppers-Totzek process, etc., and need not be detailed herein.
(Note: Perhaps "the Lurgi process (and) the Koppers-Totzek process" do need to be "detailed" for some of our readers, however; and, if so, see, for example:
Pittsburgh 1942 Coal Gasification Utilizes CO2 | Research & Development; concerning: "United States Patent 2,302,156 - Process and Apparatus for the Production of Useful Fuel Gas; 1942; Inventor: Friedrich Totzek, Germany; Assignee: Koppers Company, Pittsburgh, PA; Abstract: This invention relates to the production of fuel gas or high heating power out of dusty of finely granular fuels, such as black or brown coal, or coke or semi-coke made therefrom, the fuel being converted at a high temperature with air (oxygen), steam and carbon dioxide whereby a gas is produced which is rich in hydrogen and carbon monoxide"; and:
Germany 98% Pure Carbon Monoxide from Coal, CO2 and O2 | Research & Development; concerning: "Carbon Monoxide from Coke, Carbon Dioxide and Oxygen; Hydrocarbon Process(US); 1986; Research Organization: Lurgi GmbH, Frankfurt (Germany); Abstract: Many valuable organic chemicals-both as intermediate or final products-can be made from high purity carbon monoxide (CO). Mainly, this includes: Diisocyanates; Polyurethane; Fatty acid derivatives; Acrylic glass. In order to provide a source of inexpensive CO for the above syntheses, a very attractive new scheme has been developed. This is very competitive indeed when compared to processes using natural gas or oil as feedstock. The scheme is well suited for (plants with low capacities) though much higher capacities can easily be accommodated. According to this concept merely two process steps are required to convert coke to high purity CO. The purpose of the first process step is to gasify coke using a mixture of CO2 and O2 as gasification agent";
making note in the above of the clearly stated further potentials for actually utilizing Carbon Dioxide as an agent of Coal gasification.)
Claims: A process for the production of methane from a gaseous reactant mixture containing hydrogen, carbon monoxide and/or carbon dioxide (using a catalyst) comprising molybdenum disilicide."
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We'll close our excerpts there so that we can emphasize a few things.
First, obviously, we can convert Coal, via long-established, and perhaps somewhere "well known", initial gasification processes, efficiently into Methane.
Coal is the initial raw material specified herein by Shell Oil.
However, we submit, that, should we wish, instead, to conserve our precious Coal resources for other vital uses, such as the generation of electrical power, then, since this Shell Oil process, of "United States Patent 3,996,256 - Methanation Catalyst", as confirmed herein by our own US Government, will efficiently convert "hydrogen (and) carbon monoxide and/or carbon dioxide", with the emphasis on "or carbon dioxide", the "carbon monoxide" isn't really needed, into Methane, then, via the process disclosed in our report of:
USDOE Algae Make Hydrogen for Coal and CO2 Hydrogenation | Research & Development; concerning: "Photosynthetic Hydrogen and Oxygen Production by Green Algae; Oak Ridge National Laboratory; USDOE Contract Number: AC05-96OR22464; Abstract: Photosynthesis research at Oak Ridge National Laboratory is focused on hydrogen and oxygen production by green algae in the context of its potential as a renewable fuel and chemical feed stock";
we could have certain strains of Algae make the Hydrogen for us in specially-designed Algae cultivators, while those Algae go about their more routine business of photo-synthetically recycling Carbon Dioxide.
Or, as seen in:
NASA Hydrogen from Water and Sunlight | Research & Development; concerning: "United States Patent 4,045,315 - Solar Photolysis of Water; 1977; NASA; Abstract: Hydrogen is produced by the solar photolysis of water ... . (A) method ... in which the soluble photo-oxidizable reagent is a material which absorbs strongly in the solar range at ground level and is capable of photolyzing water to produce hydrogen";
we could let the Sun make the Hydrogen for us out of Water.
And, then, as seen in:
Efficient Power Plant CO2 Capture for CO2-to-Fuel Conversion | Research & Development; concerning: "Development of an Economic Post-Combustion Carbon Capture Process; Siemens AG and EON Energie AG, Germany; Siemens develops an improved CO2 capture process with minimized energy demand, optimized for integration in conventional coal-fired power plants"; and, in:
CO2 Recovered from Air for CO2-to-Gasoline Conversion | Research & Development; concerning: "United States Patent 4,047,894 - Removing Carbon Dioxide from the Air; 1977; Assignee: Siemens AG; Abstract: An improved method and apparatus for removing carbon dioxide from the air";
we could efficiently collect some Carbon Dioxide from whatever source we find most convenient.
And, then, we could combine that Hydrogen and that Carbon Dioxide, utilizing the process of our subject herein, "United States Patent 3,996,256 - Methanation Catalyst", and efficiently synthesize Methane.
Finally, CO2-based Methane in hand, we could collect some more Carbon Dioxide; and, via a process such as that disclosed in our report of:
More Standard Oil 1944 CO2 + CH4 = Hydrocarbons | Research & Development; concerning: "United States Patent 2.347.682 - Hydrocarbon Synthesis; 1944; Assignee: Standard Oil Company of Indiana; Abstract: This invention relates to an improved method and means for effecting the synthesis of hydrocarbons from carbon monoxide and hydrogen. In practicing my invention I ... prefer to employ... methane (which is) mixed with such proportion of carbon dioxide and steam as to give a gas mixture having an atomic hydrogen:carbon:oxygen ratio of about 4:1:1. (The specified) reforming operation converts the methane-carbon dioxide-steam mixture into a gas consisting chiefly of hydrogen and carbon monoxide ... hereinafter referred to as ... 'synthesis' gas (which) may be converted ... into high quality motor fuels";
and, by reacting that CO2-based Methane with that additional Carbon Dioxide, brew ourselves up some "high quality motor fuels".
Sounds a whole lot better than letting ourselves get taxed into impoverishment through Cap & Trade levies, or cementing our economic enslavement to OPEC and Big Oil, don't it?