Production of industrial gas mixture of hydrogen and carbon monoxide
We've lately been documenting the use of "Oxygen donors" in various Carbon conversion processes; such Oxygen donors being, typically, oxide compounds of various specific metals that are able to supply Oxygen, in a controlled and restricted way, to effect the partial oxidation of Coal, and other Carbon-containing substances.
The purpose of their use, again, is to restrict the supply of Oxygen so that, even though the oxidation reaction is able to proceed, it is incomplete and results in the production of relatively more of the desired Carbon Monoxide, as opposed to the less-desired Carbon Dioxide.
As a further, quite valuable, benefit, Oxygen donors prevent the formation of wasteful Nitrogen Oxide pollutants, as would be formed if plain air were used to supply the Oxygen for the partial oxidation.
And, where Coal is used as the Carbon source, the partial oxidation reaction, supported by the Oxygen donor, is still exothermic enough to power the co-reaction of Carbon with Steam, to form not only more Carbon Monoxide, but at least some of the Hydrogen needed to formulate hydrocarbon synthesis gas.
An early example of such technology can be seen in our report of:
Pittsburgh 1924 CO2-Free, Nitrogen-Free Coal Syngas | Research & Development; concerning: United States Patent 1,484,225 - Method of Producing Gas; 1924; Inventor: Carl Lundin, Pittsburgh, PA; The invention relates to a method for producing ... an artificial gas high in carbon monoxide and hydrogen (which) is substantially free from nitrogen and high in desirable combustible elements";
which describes a rather complicated procedure involving two Coal gasification chambers, wherein a conventional Coal gasification provides the heat needed to drive a second Coal gasification process in which an Iron compound supplies the Oxygen needed both to gasify the second amount of Coal and to promote the chemical reduction of Carbon Dioxide and Water vapor, produced in the initial gasification, through reaction with hot Carbon, into Carbon Monoxide and Hydrogen.
Such technology evolved over the following several decades and grew more sophisticated, as evidenced by:
Standard Oil 1952 Oxygen Donor Coal Gasification | Research & Development; concerning: "United States Patent 2,592,377 - Manufacture of ... Carbon Monoxide and Hydrogen; 1952; 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 (wherein) the gasification of solid carbonaceous materials with steam is carried out in the presence of metal oxides supplying the heat required";
in which process, not only do metal-based Oxygen donors provide the needed Oxygen in restricted amounts to produce Carbon Monoxide, but, the partial oxidation reaction between the Oxygen donors and Coal is exothermic enough to heat the metal particles sufficiently, so that they are then able to provide some of the thermal energy needed to drive the reaction between Carbon and Water, H2O, to generate Hydrogen, H2, and, as well, more Carbon Monoxide.
And, as we've also documented in many reports, not only can Coal, one way or another, be converted into a synthesis gas blend of Carbon Monoxide and Hydrogen, suitable for catalytic condensation into liquid hydrocarbons, but, through a variety of processes, so can Methane.
More intriguingly, one way to convert Methane into hydrocarbon synthesis gas is by reacting it with Carbon Dioxide, with or without the inclusion of Steam in the initial mix of reactants.
An early example of that technology can be seen in our report of:
1939 CO2 + CH4 = Hydrocarbons | Research & Development; concerning: "US Patent 2,180,672 - Process for Converting Gaseous Hydrocarbons; 1939; Phillips Petroleum; This invention relates to processes for the conversion of normally gaseous hydrocarbons into organic products of higher molecular weight and more specifically to the conversion of methane ... together with oxides of carbon into ... hydrocarbons suitable for motor fuel".
Such reactions, like the gasification of Coal with Steam and/or Carbon Dioxide, do require the input of thermal energy, and most earlier examples of Methane conversion technology, as with Coal gasification, make provision for some supply of Oxygen to the reaction, to support the partial oxidation of the Methane to provide that energy; or, they specify an external combustion process for the purpose of providing heat; both of which, of course, result in some co-production of Carbon Dioxide, and, thus, a consequent reduction in the total amount of Carbon Dioxide actually consumed by such processes.
Related technologies developed much later, as seen for one instance in:
USDOE 1990 Solar CO2-Methane Recycling-Reforming | Research & Development; concerning: "Solar Reforming of Methane in a Direct Absorption Catalytic Reactor on a Parabolic Dish; 1990; Sandia National Labs, NM; Abstract: Solar reforming of methane (CH4) with carbon dioxide (CO2)";
posit the use of environmental, Carbon Dioxide-free energy to drive such processes.
And, we're compelled to note at this point, that, as seen in:
Penn State Solar CO2 + H2O = Methane | Research & Development; concerning: "High-Rate Solar Photocatalytic Conversion of CO2 and Water Vapor to Hydrocarbon Fuels; The Pennsylvania State University; 2009; Efficient solar conversion of carbon dioxide and water vapor to methane".
the same sorts of environmental energy can be harnessed to drive an advanced corollary of the 1912 Nobel Prize-winning Sabatier process, which enables the conversion, in the first place, of CO2 into Methane.
Further, again quite recently, it has been posited to utilize the controlled and restricted oxidation enabled by Oxygen donors to provide the heat energy needed to drive the Methane-Carbon Dioxide reforming reactions, and, thus, as with Oxygen-donor Coal gasification technologies, as in the above-cited process of "United States Patent 2,592,377 - Manufacture of ... Carbon Monoxide and Hydrogen", restrict the amount of CO2 generated by the process itself, as seen in:
Oxygen Donor CO2 + CH4 + H2O = Syngas | Research & Development; concerning: "United States Patent 7,951,350 - Fuel Gas Reforming Systems and Methods; 2011; West Biofuels, LLC; Abstract: A process and system for producing an effluent gas containing carbon monoxide and hydrogen is presented (which) includes introducing a fuel gas including a hydrocarbon and a reformer gas into a reactor system. The reformer gas may include steam, CO2, or a mixture thereof (and) the gases are reacted in the presence of reactant solids (and) wherein the hydrocarbon comprises ... methane (and) wherein the reactant solids are finely divided metal or metal oxide reactants".
But, just as seems to be the case with all the technologies that have been developed lately for converting our abundant Coal into more versatile forms of gaseous and liquid hydrocarbons, none of this is news to Big Oil.
More than half a century before the innovative start-up, West Biofuels, LLC, as immediately above, proposed using metallic oxide Oxygen donors to promote and facilitate the reforming reactions between Carbon Dioxide and Methane, in order to generate a gas mixture of Carbon Monoxide and Hydrogen suitable for the catalytic synthesis of hydrocarbons, Big Oil had already beat 'em to the punch.
As seen, with comment inserted and appended, in excerpts from the initial link in this dispatch to:
"United States Patent 2,671,719 - Production of Mixtures of Hydrogen and Carbon Monoxide
Date: March, 1954
Inventors: Warren Lewis and Edwin Gilliland, MA
Assignee: Standard Oil Development Company, DE
Abstract: The present invention is directed to a method for producing industrial mixtures of carbon monoxide and hydrogen.
In many industrial processes, the raw material is composed of a mixture of carbon monoxide and hydrogen.
Chief among these are the so-called methanol synthesis, in which carbon monoxide and hydrogen are reacted in the presence of a suitable catalyst ... and the Fischer-Tropsch synthesis, in which carbon monoxide and hydrogen, in suitable proportions, are reacted in the presence of a suitable catalyst and under selected conditions to produce an product primarily composed of liquid hydrocarbons.
(One) way to obtain a mixture of carbon monoxide and hydrogen is to subject ... methane, and air to controlled combustion.
This procedure, however, results in a gas containing a large quantity of nitrogen.
One procedure which has been suggested is to use a metal as an oxygen carrier, said metal being first reacted with air to produce an oxide, which then is reacted with the hydrocarbon to produce a mixture of carbon monoxide and hydrogen.
Most of the metals useful for this purpose which do not introduce physical difficulties, of which iron is a typical example, are subject to the defect that reactions of their oxide with a hydrocarbon does not produce the desired mixture of carbon monoxide and hydrogen, but produces a conglomeration of gases of which carbon monoxide and hydrogen are only a minor part.
(Iron, having been deoxidized in the process of converting Methane and CO2 into a blend of Hydrogen and Carbon Monoxide, then actually catalyzes the subsequent formation of hydrocarbons from that Hydrogen and Carbon Monoxide generated by that partial oxidation. It promotes a Fischer-Tropsch-type reaction within the CH4-CO2 reforming process, which interferes with more desired subsequent processing steps.)
It has already been proposed to improve the process ... by mixing the gas resulting from the reaction of the hydrocarbon with the metal oxide with additional hydrocarbon ... and to (then) contact the resulting mixture with a reforming catalyst at a temperature suitable for the reaction of the hydrocarbon (i.e., Methane) with steam and carbon dioxide.
This reaction is endothermic and requires a considerable heat supply.
(But, since) the oxidation stage of the overall process is highly exothermic, it is desirable to provide a method of this character in which the exothermic heat of reaction may be utilized to supply heat for the endothermic reforming step.
(They make it sound as complicated as possible; but, in essence, as we hope will become clear, what they propose is partially oxidizing Methane with an Oxygen donor, in an exothermic reaction that provides the heat needed to power a subsequent and integral endothermic reforming reaction between more Methane, Carbon Dioxide and Steam.)
The present invention contemplates a process in which the exothermic heat of reaction in the oxidation stage is carried directly into the reduction and reforming stages by a heat carrier traveling through such stages, which heat carrier may comprise the metal used in the process ... .
(In other words, after the metal oxide has donated it's Oxygen to the partial oxidation reaction, it will be both chemically reduced to the base metal, or a simpler oxide of the metal, and also be heated by the exothermic partial oxidation. It can thus serve to carry heat from that oxidation into the endothermic reforming reaction to help supply at least some of the energy that reaction requires.
Further, the full Disclosure goes on at some considerable length to describe how the process of the invention prevents deposition of free, particulate Carbon on the interior surfaces of the reactors, with the subsequent deactivation of the catalysts. We call your attention to some of our previous reports concerning similar Carbon Dioxide recycling technologies, as in:
More Exxon CO2 + CH4 + H2O = Hydrocarbon Syngas | Research & Development; concerning: "United States Patent 5,985,178 - Low Hydrogen Syngas using CO2 and a Nickel Catalyst; 1999; Assignee: Exxon Research and Engineering; Abstract: A process for making a synthesis gas comprising H2 and CO in the presence of a (specified) reforming catalyst ... from a feed including ... preferably methane ..., O2, H2O and CO2 without catalyst deactivation is achieved by partially oxidizing and steam reforming the feed in the presence of the catalyst";
and submit, that, we unfortunately seem to be solving and resolving the same problem in the same ways. All of the issues have long ago been dealt with, and it's far past time we just started doing it.)
It is important that the solid be predominantly free metal or reforming catalyst. A very suitable solid material for use in the process is alumina or magnesia carrying nickel and iron ... . The iron component serves as the oxygen carrier while the nickel and magnesia or alumina, as the case may be, serve as the primary reforming catalyst.
In order to realize satisfactory heat transfer from the oxidation chamber to the reduction and reforming chambers, it is advantageous to use an inert heat carrier (such as sand).
(That is, in addition to the heat-carrying Iron and Iron Oxide particles, it is a further economy to capture and utilize as much of the exothermic reaction heat as possible by including an additional, but inert, heat transfer agent in the mix.)
Claims: A method for producing an industrial mixture of carbon monoxide and hydrogen under pressure which comprises establishing a column of a fluidized solid, including a metal oxide capable of reacting with a hydrocarbon at temperatures between about 1600 and 2100 F. The metal of which is capable of catalyzing the reaction between a hydrocarbon and steam and carbon dioxide ... .
A method ... in which improved yields of CO and H2 are obtained by adding additional amounts of ... hydrocarbon, water vapor and carbon dioxide."
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And, again, the specified "hydrocarbon" is Methane, which, once more, as in:
Chicago Recycles CO2 to Methane | Research & Development; which makes report of: "United States Patent 4,609,440 - Electrochemical Synthesis of Methane; 1986; Assignee: Gas Research Institute, Chicago; A method is described for electrochemically reducing carbon dioxide to form methane"; and:
Exxon Converts 99% of Coal to Methane | Research & Development; concerning: "United States Patent 4,077,778 - Process for the Catalytic Gasification of Coal; 1978; Assignee: Exxon Research and Engineering Company, NJ; Abstract: A process for the production of synthetic natural gas from a carbon-alkali metal catalyst or alkali-metal impregnated carbonaceous feed, particularly coal";
we can synthesize either from Carbon Dioxide itself, or, from some of our abundant Coal.