We've documented the Carbon Dioxide recycling achievements of scientists working at the Gas Research Institute, in Chicago, many times previously.
One dispatch with direct pertinence to our report herein would include:
Chicago CO2 + H2O = Hydrocarbons | Research & Development; concerning: "United States Patent 4,756,806 - Synthesis of Gaseous Fuels from Water and Carbon Dioxide; 1988; Inventors: Francis Krist and Robert Serauskas; Assignee: Gas Research Institute, Chicago; Abstract: A hybrid thermoelectrochemical process cycle for production of gaseous fuels from cycle inputs of water and carbon dioxide combines thermochemical methane reforming and electrochemical carbon monoxide reduction providing a cycle which may be driven by energy from solar ... sources. Claims: A two step hybrid process cycle for production of gaseous fuels from inorganic compounds comprising: reforming methane ... by reacting (it) with an inorganic oxidizer selected from the group consisting of water, carbon dioxide, and mixtures thereof producing carbon monoxide and hydrogen";
wherein the "carbon monoxide and hydrogen", produced by "reforming methane ... water, carbon dioxide and mixtures thereof", comprise a synthesis gas suitable for catalytic chemical condensation, as via, for instance, the Fischer-Tropsch process into liquid hydrocarbon fuels. As explained in:
Fischer–Tropsch process - Wikipedia, the free encyclopedia; "The Fischer–Tropsch process ... is a set of chemical reactions that convert a mixture of carbon monoxide and hydrogen into liquid hydrocarbons".
The above reference to "solar sources" as being one energy source suitable for driving such Carbon Dioxide recycling reactions isn't fanciful, as you know if you've been following our reports, since the feasibility of its employment in driving Methane and Carbon Dioxide "reforming" processes has been verified by our own United States Department of Energy, as seen, for just one example, 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 (USDOE), NM; Abstract: The concept of solar driven chemical reactions in a commercial-scale volumetric receiver/reactor on a parabolic concentrator was successfully demonstrated in the CAtalytically Enhanced Solar Absorption Receiver (CAESAR) test. Solar reforming of methane (CH4) with carbon dioxide (CO2) was achieved".
And, we'll note that "solar power" is also useful for making the Methane, which is reacted with Carbon Dioxide, out of, in the first place, Carbon Dioxide; as seen for one example 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".
We further note that other Chicago-area scientists had also, in the same time frame as the above-cited "United States Patent 4,756,806 - Synthesis of Gaseous Fuels from Water and Carbon Dioxide; 1988", been at work on Carbon Dioxide recycling technologies of their own, as we reported, for one instance, in:
Texaco Recycles More CO2 to Methanol and Methane | Research & Development; concerning: "United States Patent 4,609,451 - Means for Reducing Carbon Dioxide to Provide a Product; 1986; Inventors: Anthony Sammells and Peter Ang, Illinois; Assignee: Texaco Incorporated; Abstract: A process and apparatus for reducing carbon dioxide to at least one useful product (including) formic acid ... formaldehyde, methanol and methane."
Herein, we learn that the above Texaco inventor, Anthony Sammells, later teamed up with another Gas Research Institute scientist, Kevin Krist, relation to the co-inventor of the earlier-cited "United States Patent 4,756,806 - Synthesis of Gaseous Fuels from Water and Carbon Dioxide", Francis Krist, unknown, to make even further refinements in a process for the "production of gaseous fuels from ... methane ... by reacting (it) with ... water, carbon dioxide, and mixtures thereof".
By way of forward, we must note that the full Disclosure of the technology we report herein might seem at first immensely complex.
And, in truth, the chemistry and physics of the thing, to a certain extent, are.
But, analysis of it will reveal that what is being described is a process design that uses a selection of available catalytic and reaction intermediaries that serve to "leverage" the chemical reactions needed to break Carbon Dioxide and Methane, and Water, down into their simpler elemental components, Carbon and Hydrogen, with by-product Oxygen, so that the Carbon and Hydrogen become available for contiguous reactions which then combine them into hydrocarbons.
As seen in excerpts from the initial link to:
"United States Patent 5,064,733 - Electrochemical Conversion of CO2 and CH4 to C2 Hydrocarbons
Date: November, 1991
Inventors: Kevin Krist and Anthony Sammells, IL
Assignee: Gas Research Institute, Chicago
Abstract: A solid electrolyte electrochemical cell and process for concurrent gas phase electrocatalytic oxidative dimerization of methane at one side of the solid electrolyte and reduction of carbon dioxide to gaseous hydrocarbon products at the opposite side of the solid electrolyte. The electrochemical cell may use a solid electrolyte of an oxygen vacancy conducting type or a proton transferring type capable of transferring any proton mediating ion.
(The term "dimerization of methane" is just confusing organic chemistry jargon, we're told by one of our informal consultants, which means that they're forcing two molecules of Methane to stick together, either by jamming them up so tight they can't get away from each other, and are forced to adapt by changing their molecular structure slightly, or, by reacting them with another component, as in "oxidative dimerization", that glues them to each other. We reckon that's where the "reduction of carbon dioxide" comes in.)
Claims: A process for concurrent gas phase electrocatalytic oxidative dimerization of methane at the anode on one side of a solid electrolyte and reduction of carbon dioxide to gaseous hydrocarbons at a cathode on the other side of said solid electrolyte, said process comprising:
- passing methane containing gas in contact with a rare earth metallic oxide anode layer of an anode comprising a rare earth metallic oxide anode layer in contact with one side of an ionic and electronic conducting metallic oxide perovskite anode layer in contact with one side of a solid electrolyte on its opposite side, said anode catalytically oxidatively dimerizing said methane to C2 species;
- passing carbon dioxide containing gas in contact with one side of an ionic and electronic conducting metal cathode electrocatalyst capable of providing adsorption sites for carbon dioxide and chemisorbed and faradaically generated hydrogen species in proximity to said adsorbed carbon dioxide and capable of catalytic reduction of said carbon dioxide to predominantly C2 species; and
- withdrawing said C2 species from the region of said anode and said cathode.
A process for concurrent gas phase electrocatalytic oxidative dimerization of methane at the anode on one side of a solid electrolyte and reduction of carbon dioxide to gaseous hydrocarbons at a cathode on the other side of said solid electrolyte, said process comprising:
- passing carbon dioxide containing gas and water in contact with one side of a cathode selected from the group consisting of a rare earth metallic oxide cathode layer in contact on its inner side with an electronic and oxygen vacancy conducting perovskite cathode layer in contact with said solid electrolyte, copper, and copper alloy catalytically forming O2- and C2 species;
- passing formed O2- to and through an oxygen vacancy conducting solid electrolyte having high O2- conductivity at cell operating temperatures to an anode contacting the other side of said solid electrolyte;
- passing O2- from said solid electrolyte into an anode comprising a metallic oxide electronic and oxygen vacancy conducting perovskite anode layer in contact with said electrolyte on one side and in contact with a metallic oxide anode layer on the other side;
- passing methane containing gas in contact with said anode catalytically oxidatively dimerizing said methane to C2 species; and
- withdrawing said C2 species from the region of said cathode and said anode.
(Note: This is all about making "C2" hydrocarbons out of Carbon Dioxide and Methane. And, as we've been instructed, those compounds would include such things as ethylene, acetylene and ethane.
As can be learned via:
Ethylene - Wikipedia, the free encyclopedia; "Ethylene ... C2H4";
Acetylene - Wikipedia, the free encyclopedia; "Acetylene ... C2H2"; and:
Ethane - Wikipedia, the free encyclopedia; "Ethane ... C2H6";
they are all widely used commercially in the further synthesis of other hydrocarbon products, including fuels and plastics; and, they're well worth having some of, with most nowadays being produced from natural petroleum processes and sources.)
- A process ... wherein said cathode is selected from the group consisting of copper and copper alloy.
- A process ... wherein said cathode comprises a rare earth metallic oxide cathode layer and an electronic and oxygen vacancy conducting perovskite cathode layer, said rare earth metallic oxide selected from the group consisting of Sm2O3, Dy2O3, Ho2O3, Yb2O3, Nd2O3, Eu2O3, Er2O3, Lu2O3, Gd2O3, and Tm2O3, and said perovskite cathode layer selected from the group consisting of compounds having the general formula AMO3 where A is selected from the group consisting of La and Pr, M is selected from the group consisting of Co, Ni, and Mn, and O is oxygen; compounds having the general formula La1-x Max MbO3 where La is lanthanum, Ma is selected from the group consisting of Sr, Ca, K, and Pr, Mb is selected from the group consisting of Cr, Mn, Fe, Co, and Ba, x is a number about 0.01 to about 0.2, and O is oxygen; compounds having the general formula LaMcO3 where La is lanthanum, Mc is selected from the group consisting of Ni, Co, Mn, Fe, and V, and O is oxygen; and the above metallic oxide perovskite materials with copper introduced into a perovskite site.
(Yeah, we know, it sounds complicated as all get out. But, we included the whole enchilada so that we could further explain, that:
The "perovskite" has been specified in other Carbon conversion processes we've reported to you; and, as can be learned via:
Perovskite - Wikipedia, the free encyclopedia;
it is a "calcium titanium oxide" mineral of which we have some domestic US deposits in Arkansas. Otherwise, we should be able to get plenty from Italy and Switzerland; and, since it's more of a catalyst, or catalyst substrate, it won't be getting used up to any appreciable extent; and, we thus shouldn't require large, new supplies of it.
The "Sm2O3, Dy2O3, Ho2O3", etc., are oxides of what are known as "rare earth" metals, or elements, including, for just a few examples:
Samarium: "Samarium oxide (samaria) is used as a catalyst for the dehydration and dehydrogenation of ethanol"; and:
Neodymium: "Neodymium is used ... to create powerful permanent magnets (which are) used in computers, cell phones, medical equipment, toys, motors, wind turbines and audio systems (and) is also used in a spark producing alloy ... for cigarette lighter flints"; and:
Lanthanum: "Lanthanum is used in large quantities in nickel metal hydride (NiMH) rechargeable batteries for hybrid automobiles. A Toyota Prius battery requires about 10 kg of lanthanum. Lanthanum is used as a petroleum cracking catalyst, catalyzing the splitting of long chain hydrocarbons".
Further, as can be learned from our United States Geologic Survey, via:
Rare Earth Elements—Critical Resources for High Technology | USGS Fact Sheet 087-02; and:
we have plenty of deposits of rare earth minerals in places as diverse as Alaska, New York and Florida, among many others, including a very large, currently-idle mine in California, from which we used to export them. None of the rare earths are currently being mined in the US because we now get all of them we need, and we do use them, cheap, from China.
The point of the foregoing being that these materials are known, available and being used industrially. We're not talking moon rocks here, so, if anyone ever does discuss the information we present in these dispatches with any of their acquaintances, don't be discouraged by the negativists among them. - JtM)
A process ... wherein said electrolyte is selected from the group consisting of binary ZrO2 based materials having (formulas as specified).
(We're not reproducing the formulas in this case, although two new catalytic materials are identified, Zirconium Oxide, as above, and Thorium Oxide, in sections of the Disclosure we're not reproducing, both in combination with the rare earth compounds discussed above.
The Zirconium is no problem, again as taught by the US Geologic Survey, via:
http://minerals.usgs.gov/
which informs that we currently obtain our needs from the mineral, zircon, which is produced primarily by two surface mines in Florida and Virginia. There are other significant reserves that could be obtained as a byproduct of Titanium mining; but, if we ever do run short, our good friend Australia has more than plenty.
Thorium is more problematic. Again as informed by the USGS, in:
http://minerals.usgs.gov/
USGS Circular 1336: Thorium Deposits of the United States—Energy Resources for the Future?;
we have plenty of it, with some that can be recovered in certain locations as a co-product with the rare earth minerals noted above. Other recoverable reserves exist in Idaho, Missouri, New York and New Jersey.
But, it is radioactive; and, that is bound to cause some controversy. However, as seen in:
Thorium | Radiation Protection | US EPA; and:
Thorium - Wikipedia, the free encyclopedia;
even though it can be used in reactors to breed uranium, Thorium itself emits only "alpha" radiation, and is thus basically harmless to humans; unless it's inhaled or ingested, in which case it can cause some real problems. It is, though, relatively speaking, safe; and, it is used in the manufacture of some consumer products, such as in the mantles for gas lanterns and in alloys for specialty welding rods.
The Claims go on to list other effective variations on the electrode compositions, which include alloys and mixtures of more mundane things, such as Iron, Barium and Molybdenum.
Although complex, it seems as if the mix of materials serves to effectively reduce the amount of electric current required to effect the needed electrochemical reactions that transform the Carbon Dioxide and the Methane into hydrocarbons, and thus makes the process an energy-efficient one.)
A process ... wherein said process is carried out at about 750 to about 800C.
(Yeah, that's hot. But, it ain't steel-furnace hot. It could easily be achieved by electric resistance heating, with, perhaps, the electricity being generated by a site-specific environmental source. See, for further exposition of such potentials:
http://hydropower.inl.gov/
Wind Powering America: Pennsylvania 50-Meter Wind Map; wherein we're told, that: "Pennsylvania has wind resources consistent with community-scale production. The good-to-excellent wind resource areas are concentrated on ridge crests in the southwestern part of Pennsylvania, located southwest of Altoona and southeast of Pittsburgh".
Further, in parts of our nation where it's reliably available, as can be inferred from our report of:
West Virginia Coal Association | USDOE Converts Coal to Gasoline with Solar Power | Research & Development; concerning:
"United States Patent 4,229,184 - Apparatus and Method for Solar Coal Gasification; 1980; Assignee: The USA; Apparatus for using focused solar radiation to gasify coal and other carbonaceous materials. Incident solar radiation is focused ... onto the surface of a vertically-moving bed of coal, or a fluidized bed of coal, contained within a gasification reactor. Steam introduced into the gasification reactor reacts with the heated coal to produce gas consisting mainly of carbon monoxide and hydrogen, commonly called "synthesis gas", which can be converted to methane, methanol, gasoline, and other useful products. Description: "Coal gasification" is the conversion of coal, coke, or char to gaseous products by reaction with air, oxygen, steam, carbon dioxide, or a mixture thereof. A chemical reaction basic to virtually all coal gasification methods is the reaction of char (carbon) with water (steam) to produce carbon monoxide and hydrogen.It is therefore an object of this invention to provide an improved apparatus for gasifying coal and other carbonaceous materials, and especially mixtures of coal and wastes";
solar heat can be used to drive reactions that convert "coal ... steam, carbon dioxide" and "carbonaceous wastes" into a "synthesis gas" blend of "carbon monoxide and hydrogen" suitable for further conversion into "methane, methanol, gasoline, and other useful products".
And, though not reflected in our excerpts in that report, the full Disclosure of "US Patent 4,229,184" reveals that, the "maximum calculated equilibrium temperature at the solar focus ranges from 2600 to 2900 K for existing solar facilities"; and, since, as calculated by:
Kelvin to Celsius converter; "2900 K = 2627 C",
Solar energy, too, can easily be harnessed to drive the process of our subject herein, "United States Patent 5,064,733 - Electrochemical Conversion of CO2 and CH4 to C2 Hydrocarbons", since the needed reactions are "carried out at about 750 to about 800C".)
A process for concurrent gas phase electrocatalytic oxidative dimerization of methane at the anode on one side of a solid electrolyte and reduction of carbon dioxide to gaseous hydrocarbons at a cathode on the other side of said solid electrolyte, said process comprising:
- passing methane containing gas in contact with one side of a rare earth metallic oxide anode layer in contact on its other side with one side of an electronic conducting and proton mediating metallic oxide perovskite anode layer in contact with one side of a solid electrolyte on its opposite side catalytically oxidatively dimerizing said methane to C2 species and forming proton mediating ions;
- transferring formed proton mediating ions to and through a proton mediating solid electrolyte to a cathode contacting the other side of said solid electrolyte;
- passing carbon dioxide containing gas in contact with one side of an electronic conducting and proton mediating metallic cathode selected from the group consisting of a rare earth metallic oxide cathode layer in contact on its inner side with an electronic and ionic conducting perovskite cathode layer in contact with said solid electrolyte, said perovskite having copper partially substituted into lattice sites, copper, and copper alloys catalytically reducing said carbon dioxide to C2 species; and
withdrawing said C2 species from the region of said cathode and said anode.
An electrochemical cell for concurrent gas phase electrocatalytic oxidative dimerization of methane at the anode on one side of a solid electrolyte and reduction of carbon dioxide to gaseous hydrocarbons at a cathode on the other side of said solid electrolyte, said electrochemical cell comprising:
- an anode (as specified, capable of) catalytically oxidatively dimerizing said methane to C2 species;
- a cathode (as specied) capable of catalytic reduction of said carbon dioxide to predominantly C2 species;
- means for withdrawing said C2 species from the region of both said anode and said cathode.
Background and Field: The solid electrolyte electrochemical cell of this invention provides concurrent gas phase electrocatalytic oxidative dimerization of methane at one side of the solid electrolyte and reduction of carbon dioxide to gaseous hydrocarbon products at the opposite side of the solid electrolyte. The electrochemical cell may use a solid electrolyte of an oxygen vacancy conducting type or a proton transferring type capable of transferring any proton mediating ion. The process of this invention uses a solid electrolyte electrochemical cell to produce C2 hydrocarbon species on each side of the electrolyte concurrently by gas phase reaction, using methane reactant on the anode side and carbon dioxide reactant on the cathode side.
(It seems important to note that the C2 hydrocarbons are being produced from both electrodes; that is, the Methane and the Carbon Dioxide are interacting, under the influence of the catalysts and the electric current, on either side of a "solid electrolyte ... capable of transferring" the ions generated from the Methane and the Carbon Dioxide, one to the other. Thus, the C2 hydrocarbons are being produced at the anode, which is "dimerizing" the Methane; and, concurrently, at the cathode, which is "reducing" the Carbon Dioxide, with the results of both processes being the consumption of Methane and Carbon Dioxide, and the synthesis of Ethylene, Acetylene, etc.
Summary: In one embodiment, the process of this invention for concurrent gas phase electrocatalytic oxidative dimerization of methane at the anode and reduction of carbon dioxide to gaseous hydrocarbons at a cathode comprises:
passing carbon dioxide containing gas and water in contact with one side of a cathode selected from the group (specified above) in contact on its inner side with an electronic and oxygen vacancy conducting perovskite cathode layer in contact with the solid electrolyte, copper, and copper alloy catalytically forming O2- and C2 species. The formed O2- is passed to and through an oxygen vacancy conducting solid electrolyte having high O2- conductivity at cell operating temperatures to an anode contacting the other side of the solid electrolyte. The O2- is passed from the solid electrolyte into an anode comprising a metallic oxide electronic and oxygen vacancy conducting perovskite anode layer in contact with the electrolyte on one side and having a rare earth metallic oxide perovskite anode layer in contact with the metallic oxide anode layer on the other side. The methane containing gas is passed in contact with the anode catalytically oxidatively dimerizing the methane to C2 species and the C2 species is withdrawn from the region of both the cathode and the anode."
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The full Disclosure is much more involved and detailed, and is well-worth study for it's revelation of prior references affirming the economical potentials of co-converting Methane and Carbon Dioxide into more useful compounds and materials.
Note that our excerpts from the Disclosure describe the device as being one that utilizes a "solid electrolyte"; and, thus, we conjecture it to be similar to that described in our report of:
Utah 2011 CO2 + H2O = Hydrocarbon Syngas | Research & Development; concerning: "United States Patent 8,075,746 - Electrochemical Cell for Production of Synthesis Gas Using Atmospheric Air and Water; 2011; Ceramatec, Inc.; Abstract: A method is provided for synthesizing synthesis gas from carbon dioxide obtained from atmospheric air or other available carbon dioxide source and water using a sodium-conducting electrochemical cell. Synthesis gas is also produced by the coelectrolysis of carbon dioxide and steam in a solid oxide fuel cell or solid oxide electrolytic cell. The synthesis gas produced may then be further processed and eventually converted into a liquid fuel suitable for transportation or other applications".
The process of our subject, "United States Patent 5,064,733 - Electrochemical Conversion of CO2 and CH4 to C2 Hydrocarbons", unlike the above-cited "United States Patent 8,075,746" does, again, specify Methane as the co-reactant for Carbon Dioxide, rather than "water"; and, we remind you, yet again, especially since we dwell above on the wise utilization of Solar energy, that, as seen in:
West Virginia Coal Association | Pittsburgh USDOE Converts CO2 to Methane & Methanol | Research & Development; concerning: "Visible Light Photoreduction of CO2; 2009; National Energy Technology Laboratory, USDOE, Pittsburgh, PA; Abstract: A series of ... Titanium Dioxide (catalysts) have been synthesized, characterized, and tested for the photocatalytic reduction of CO2 in the presence of H2O. The ... analysis shows that the primary reaction product is CH4, with CH3OH, H2, and CO observed as secondary products";
our, we US taxpayers', own government employees in cloudy old Pittsburgh, PA, have demonstrated that Solar energy can be utilized to drive processes that will produce not only a blend of "H2 and CO" hydrocarbon synthesis gas and the nearly-precious alcohol, Methanol, ""CH3OH"; but, primarily, the Methane, "CH4", required by the process of our subject herein, "United States Patent 5,064,733", to make a selection of valuable "C2 Hydrocarbons" out of Carbon Dioxide, out of nothing but Water and, as recovered from whatever source, even more Carbon Dioxide.