USDOE and US Navy Improve CO2 + H2O = Hydrocarbon Syngas

United States Patent: 8354011

We first remind you of the "syntrolysis" Carbon Dioxide utilization technology developed, primarily, at the USDOE's Idaho National Laboratory, by the USDOE and the company who appear to have been the DOE's primary contractors in the effort, Ceramatec, Incorporated, of Salt Lake City, Utah.

 

As explained, for just one example, in our report of:

More USDOE CO2 "Syntrolysis" | Research & Development | News; concerning: "Co-Electrolysis of Steam and Carbon Dioxide for Production of Syngas; Fifth International Fuel Cell Science, Engineering and Technology Conference; July, 2007; J.E. O'Brien, C.M. Stoots, et. al.; Idaho National Laboratory, USDOE; and Ceramatec, Inc., Utah; Abstract: An experimental study has been completed to assess the performance of single-oxide electrolysis cells ... simultaneously electrolyzing steam and carbon dioxide for the direct production of syngas. ... Syngas, a mixture of hydrogen and carbon monoxide, can be used for the production of synthetic liquid fuels via Fischer-Tropsch processes. ... Based on the results obtained to date, coelectrolysis of steam and carbon dioxide for direct production of syngas appears to be a promising technology that could provide a possible path to ... increased energy independence, without the infrastructure shift that would be required for a hydrogen-based transportation system";

Carbon Dioxide and Water, H2O, vapor can together be "co-electrolyzed", and be broken down into their constituent elements and compounds, Carbon Monoxide, Hydrogen and Oxygen.

The Carbon Monoxide and Hydrogen "Syngas" can then be, as noted, catalytically and chemically condensed into "synthetic" hydrocarbons, while, especially if the technology is employed in specific situations, like that disclosed in our report of:

USDOE Reforms Coal Syngas CO2 for Hydrocarbon Synthesis | Research & Development | News; concerning: "United States Patent 8,366,902 - Methods and Systems for Producing Syngas; 2013; Inventors: Grant Hawkes, et. al., Idaho; Assignee: Battelle Energy Alliance, LLC, Idaho Falls (USDOE Idaho National Laboratory); Abstract: Methods and systems are provided for producing syngas utilizing heat from thermochemical conversion of a carbonaceous fuel to support decomposition of at least one of water and carbon dioxide using one or more solid-oxide electrolysis cells. Simultaneous decomposition of carbon dioxide and water or steam by one or more solid-oxide electrolysis cells may be employed to produce hydrogen and carbon monoxide. A portion of oxygen produced from at least one of water and carbon dioxide using one or more solid-oxide electrolysis cells is fed at a controlled flow rate in a gasifier or combustor to oxidize the carbonaceous fuel to control the carbon dioxide to carbon monoxide ratio produced. Government Interests: This invention was made with government support under Contract Number DE-AC07-05ID14517 awarded by the United States Department of Energy. The government has certain rights in the invention. Claims: A method for forming syngas, comprising: producing heat and a mixed gas comprising carbon dioxide, carbon monoxide, water and hydrogen by gasifying a carbonaceous fuel; condensing the mixed gas to remove at least one impurity from the mixed gas and to generate a feed stream; after the condensing act, transferring the heat produced by gasifying the carbonaceous fuel to the feed stream to convert at least a portion of the water in the feed stream to steam; introducing the feed stream to at least one solid-oxide electrolysis cell; electrolyzing carbon dioxide and steam in the feed stream in at least one solid-oxide electrolysis cell to produce carbon monoxide, hydrogen and oxygen; and separating the carbon monoxide and hydrogen from the oxygen";

the byproduct Oxygen can be used to help support the generation of additional hydrocarbon synthesis gas by the partial combustion, or controlled oxidation, of a "carbonaceous fuel" such as, for example, Coal, in a process where the "syntrolysis" technology is employed to improve the quality of, to reform, the syngas made from the Coal.

However, as seen in our report of:

Utah 2011 CO2 + H2O = Hydrocarbon Syngas | Research & Development | News; concerning: "United States Patent 8,075,746 - Electrochemical Cell for Production of Synthesis Gas Using Atmospheric Air and Water; 2011; Inventors: Joseph Hartvigsen, et. al., Utah; Assignee: Ceramatec, Inc., Salt Lake City; 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 USDOE's primary contractor, in their design of a method and device to effect the "coelectrolysis of carbon dioxide and steam", in order to form a "synthesis gas" blend of Carbon Monoxide and Hydrogen, seem to prefer, and specify the use of "carbon dioxide obtained" from the environment, "atmospheric air", as the raw material 

And, as seen for only one example in our report of:

Columbia University August 2012 Practical CO2 Air Capture | Research & Development | News; concerning: "United States Patent 8,246,731 - Systems and Methods for Extraction of Carbon Dioxide from Air; 2012;
Assignee: The Trustees of Columbia University; Abstract: The present invention describes methods and systems for extracting, capturing, reducing, storing, sequestering, or disposing of carbon dioxide (CO2), particularly from the air. The CO2 extraction methods and systems involve the use of chemical processes. Methods are also described for extracting and/or capturing CO2 via exposing air containing carbon dioxide to - - a basic solution which absorbs carbon dioxide and produces a carbonate solution. The solution is causticized and the temperature is increased to release carbon dioxide, followed by hydration of solid components to regenerate the base";

we are getting pretty good at extracting Carbon Dioxide from the air around us.

Since we've also documented, as in only one out of now many examples, in our report of:

US Navy May 7, 2013, CO2 to Liquid Hydrocarbon Fuels | Research & Development | News; concerning: "United States Patent 8,436,457 - Synthesis of Hydrocarbons Via Catalytic Reduction of CO2; 2013; Assignee: The United States of America, as represented by the Secretary of the Navy; Abstract: A method of: introducing hydrogen and a feed gas containing at least 50 vol % carbon dioxide into a reactor containing a Fischer-Tropsch catalyst; and heating the hydrogen and carbon dioxide to a temperature of at least about 190 C to produce hydrocarbons in the reactor. An apparatus having: a reaction vessel for containing a Fischer-Tropsch catalyst, capable of heating gases to at least about 190 C; a hydrogen delivery system feeding into the reaction vessel; a carbon dioxide delivery system for delivering a feed gas containing at least 50 vol % carbon dioxide feeding into the reaction vessel; and a trap for collecting hydrocarbons generated in the reaction vessel";

that, the United States Navy, in addition to the United States Department of Energy, has a committed interest in developing the technology to convert Carbon Dioxide into hydrocarbon fuels, it's not surprising to learn, herein, that the USN and the USDOE have collaborated in financing the further development of "syntrolysis"-type technology, for converting CO2 and H2O together into a hydrocarbon synthesis gas, by the USDOE's Idaho Lab contractor, Ceramatec, of Salt Lake City.

Comment follows excerpts from the initial link in this dispatch to:

"United States Patent 8,354,011 - Efficient Reversible Electrodes for Solid Oxide Electrolyzer Cells

Patent US8354011 - Efficient reversible electrodes for solid oxide electrolyzer cells - Google Patents

Efficient reversible electrodes for solid oxide electrolyzer cells - Ceramatec, Inc.

Date: January 15, 2013

Inventors: S. Elangovan, J. Hartvigsen, F. Zhao, Utah

Assignee: Ceramatec, Inc., Salt Lake City, UT

Abstract: An electrolyzer cell is disclosed which includes a cathode to reduce an oxygen-containing molecule, such as H2O, CO2, or a combination thereof, to produce an oxygen ion and a fuel molecule, such as H2 (Hydrogen), CO (Carbon Monoxide), or a combination thereof. An electrolyte is coupled to the cathode to transport the oxygen ion to an anode. The anode is coupled to the electrolyte to receive the oxygen ion and produce oxygen gas therewith. In one embodiment, the anode may be fabricated to include an electron-conducting phase having a perovskite crystalline structure or structure similar thereto. This perovskite may have a chemical formula (as specified). In another embodiment, the cathode includes an electron-conducting phase that contains nickel oxide intermixed with magnesium oxide.

(The above "perovskite" is a naturally occurring, calcium-titanium oxide mineral that generally exhibits a specific crystal structure. They're just emulating that structure in the construction specified so as to enhance performance of the electrolyzer. It's not overly-exotic and is sometimes specified in catalytic/electrolytic processes like the one herein. For more background, see:

Perovskite - Wikipedia, the free encyclopedia.)

Government Interests: This invention was made in part with government support under grant number DE-AC07-05ID14517 awarded by the United States Department of Energy and the Office of Naval Research under contract number N00014-09-C-0441. The Government has certain rights in the invention.

Claims: An electrolyzer cell comprising: a cathode to reduce an oxygen-containing molecule to produce an oxygen ion and a fuel molecule; an electrolyte coupled to the cathode to transport the oxygen ion; an anode coupled to the electrolyte to receive the oxygen ion to produce oxygen gas therewith, the anode comprising an electron-conducting phase comprising a perovskite having a chemical formula (as specified, comprising an) alkaline earth metal (and,) an oxide. 

The electrolyzer cell ...  wherein the oxide comprises zirconia doped with at least one of yttrium oxide, ytterbium oxide, calcium oxide, magnesium oxide, scandium oxide, and cerium oxide (and/or) wherein the oxide comprises ceria doped with at least one of yttrium oxide, ytterbium oxide, calcium oxide, magnesium oxide, scandium oxide, and zirconium oxide. 

The electrolyzer cell ... wherein the anode is porous, the porosity thereof being infiltrated with an electrocatalyst (and) wherein the electrocatalyst comprises at least one of praseodymium, cobalt, cerium, europium, and other rare earth elements. 

The electrolyzer cell ... wherein the alkaline earth metal comprises calcium (and) wherein the transition metal comprises at least one of manganese, cobalt, and iron.

The electrolyzer ... wherein the cathode comprises an electron-conducting phase comprising at least one of nickel oxide and magnesium oxide. 

(Although some "exotic" metals can be used, they might not be, strictly speaking, essential. Fairly mundane elements like "cobalt" and "calcium" seem capable of substituting, with perhaps some effect on overall performance. It looks like, with or without stuff like "praseodymium" or "europium", this can be done with materials available in the USA.)

The electrolyzer cell ... wherein the oxide comprises zirconia doped with at least one of yttrium oxide, ytterbium oxide, calcium oxide, magnesium oxide, scandium oxide, and cerium oxide (and) wherein the oxide comprises ceria doped with at least one of yttrium oxide, ytterbium oxide, calcium oxide, magnesium oxide, scandium oxide, and zirconium oxide. 

The electrolyzer cell ... wherein the anode is porous, the porosity thereof being infiltrated with an electrocatalyst (and) wherein the electrocatalyst comprises at least one of praseodymium, cobalt, cerium, europium, and other rare earth elements (and) wherein the cathode comprises an electron-conducting phase comprising at least one of nickel oxide and magnesium oxide (and) wherein the alkaline earth metal comprises at least one of calcium and strontium (and) wherein the transition metal comprises at least one of manganese, cobalt, and iron.

Background and Field: This invention relates to electrolyzer cells and more particularly to reversible electrodes for solid oxide electrolyzer cells. 

Fuel cells are expected to play an important role in ensuring our energy security and may be an important component to establishing a "hydrogen economy." Recent efforts have been dedicated to developing and implementing a commercially viable hydrogen fuel cell technology to power cars, trucks, homes, businesses, and the like, in order to reduce dependence on foreign sources of oil. Fuel cells also have the potential to reduce or eliminate harmful emissions generated by conventional power sources such as internal combustion engines (BUT) the present infrastructure for production, storage, and delivery of hydrogen is currently vastly inadequate to support a hydrogen economy. Transition to hydrogen use would require altering current industrial and transportation practices on an enormous scale. 

Currently, a "reversible" fuel cell offers one potential solution for generating both electricity and hydrogen (or synthesis gas) using a single device. A reversible fuel cell may be used to generate electricity, when operated in fuel cell mode, and hydrogen (or synthesis gas) when operated in electrolysis mode. A reversible fuel cell can be used to produce electricity as needed but may also utilize excess capacity of the electrical grid during off-peak hours to produce hydrogen fuel. This fuel may be used at a later time during periods of high electrical demand or to power a vehicle or other device. A reversible fuel cell also has the potential to reduce costs significantly by converting electricity to hydrogen and hydrogen to electricity using a single device. Nevertheless, to achieve commercial success, the reversible cell must produce hydrogen with enough efficiency to be competitive with other means of production. 

(What) is needed are electrodes that perform equally well in both fuel cell and electrolysis modes. Such electrodes may be used to provide a reversible fuel/electrolyzer cell which is efficient in either mode of operation. Ideally, the electrodes would exhibit similar polarization and other characteristics in both fuel cell and electrolysis modes of operation. 

Summary: (An) electrolyzer cell is disclosed in one embodiment of the invention as including a cathode to reduce an oxygen-containing molecule, such as H2O, CO2, or a combination thereof, to produce an oxygen ion and a fuel molecule, such as H2, CO, or a combination thereof. An electrolyte is coupled to the cathode to transport the oxygen ion to an anode. The anode is coupled to the electrolyte to receive the oxygen ion and produce oxygen gas therewith.

In selected embodiments, the anode further includes an ion-conducting phase intermingled with the electron-conducting phase. The ion-conducting phase may include one or more oxides (and) the anode may be designed with a selected porosity to allow gas to pass therethrough. To further improve the electrochemical efficiency, the pores of the anode may be infiltrated with an electrocatalyst, such as praseodymium, cobalt, cerium, europium, other rare earth elements, and combinations thereof. 

In another aspect of the invention, an electrolyzer cell in accordance with the invention may include a cathode to reduce an oxygen-containing molecule, such as H2O, CO2, or combinations thereof, to produce an oxygen ion and a fuel molecule, such as H2, CO, or combinations thereof. The cathode may include an electron-conducting phase that contains nickel oxide intermixed with magnesium oxide. This nickel oxide may be reduced to nickel upon operating the electrolyzer cell. The magnesium oxide reduces coarsening of the nickel oxide to maintain the nickel's surface area and to maintain conductivity with adjacent particles. An electrolyte is coupled to the cathode to transport the oxygen ion from the cathode. An anode is coupled to the electrolyte to receive the oxygen ion and produce oxygen gas therewith.

The present invention has been developed in response to the present state of the art, and in particular, in response to the problems and needs in the art that have not yet been fully solved by currently available electrolyzer electrodes. 

Consistent with the foregoing and in accordance with the invention as embodied and broadly described herein, an electrolyzer cell is disclosed in one embodiment of the invention as including a cathode to reduce an oxygen-containing molecule, such as H2O, CO2, or a combination thereof, to produce an oxygen ion and a fuel molecule, such as H2, CO, or a combination thereof.

In selected embodiments, the anode further includes an ion-conducting phase intermingled with the electron-conducting phase. The ion-conducting phase may include one or more oxides. For example, in selected embodiments, the oxide may include zirconia doped with one or more of yttrium oxide, ytterbium oxide, calcium oxide, magnesium oxide, scandium oxide, cerium oxide, or the like. In other embodiments, the oxide may include ceria doped with one or more of yttrium oxide, ytterbium oxide, calcium oxide, magnesium oxide, scandium oxide, zirconium oxide, or the like. 

In certain embodiments, the anode may be designed with a selected porosity to allow gas to pass therethrough. To further improve the electrochemical efficiency, the pores of the anode may be infiltrated with an electrocatalyst, such as praseodymium, cobalt, cerium, europium, other rare earth elements, and combinations thereof. 

In another aspect of the invention, an electrolyzer cell in accordance with the invention may include a cathode to reduce an oxygen-containing molecule, such as H2O, CO2, or combinations thereof, to produce an oxygen ion and a fuel molecule, such as H2, CO, or combinations thereof.

Like the anode, the cathode may also be infiltrated with an electrocatalyst such as praseodymium, cobalt, cerium, europium, other rare earth elements, or combinations thereof. This electrocatalyst provides additional activation energy to break the bonds of H2O and CO2 molecules supplied to the cathode, further improving electrochemical performance. 

One notable characteristic of the anode and cathode materials described (herein) is that they exhibit significantly improved performance when electrolyzing CO2 to generate CO.

With many conventional electrode materials, it has been observed that the kinetics of the CO2 to CO electrolysis reaction are far worse than the kinetics of the H2O to H2 reaction. Stated otherwise, conventional electrodes exhibit far greater inherent resistance when converting CO2 to CO than they do when converting H2O to H2. Consequently, a good indicator of the overall performance of electrodes is how well they will convert CO2 to CO. It has been noted that the electrodes described herein exhibit significantly improved electrocatalytic performance for the CO2 to CO reaction when compared to historical electrode materials". 

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Regarding the immediately above, as seen for example in our report of:

Standard Oil Electrolyzes CO2 to Carbon Monoxide | Research & Development | News; concerning: "US Patent 4,668,349 - Electrocatalytic Reduction of CO2 by Square Planar Transition Metal Complexes; 1987; Assignee: The Standard Oil Company; Abstract: A process for the electrocatalytic reduction of carbon dioxide comprises immersing a transition metal complex with square planar geometry into an aqueous or nonaqueous solution which has been acidified to a (specified) hydrogen ion concentration ... , adding the carbon dioxide, applying an electrical potential of from about -0.8 volts to about -1.5 volts ... , and reducing the carbon dioxide to carbon monoxide";

we've known for quite a while how to electrolyze Carbon Dioxide, with "historical", but still innovative, "electrode materials", to form Carbon Monoxide, with a fair degree of efficiency. And, it's been known for a long time how to electrolyze Water, H2O, to form Hydrogen.

Elemental Oxygen is a byproduct in both cases.

As seems to be explained by our subject herein, "United States Patent 8,354,011 - Efficient Reversible Electrodes for Solid Oxide Electrolyzer Cells", the trick, which is addressed by USP 8,354,011, is in balancing out the relative resistance of, individually, CO2 and H2O to electrolysis, so that they can both be electrolyzed together, to form Carbon Monoxide and Hydrogen in appropriate proportions to each other as a combined "syngas" product, which, as explained in disclosure of what seems to us closely-similar Carbon Dioxide utilization technology, as in our report of:

Columbia University CO2 + H2O to Hydrocarbon Syngas | Research & Development | News; concerning:

"United States Patent Application 20140130415 - Method and System for Production of Hydrogen and Carbon Monoxide; 2014; Inventor: Siu-wai Chan, NJ; Assignee: The Trustees of Columbia University in the City of New York; Abstract: A method for preparing a fuel using oxygen-storing compound nanoparticles is provided, in which the nanoparticles is heated at a first temperature to release an amount of oxygen, thereby producing a reduced oxide compound, and the reduced oxide compound is exposed to a gas at a second temperature to produce the fuel. The gas can include carbon dioxide and water vapor, and the fuel can include carbon monoxide and/or hydrogen.  Converting H2O and CO2 gases into syngas (H2 and CO) can be a useful strategy for carbon sequestration and as a source of renewable energy (since) liquid fuels such as gasoline and diesel oil can be prepared from CO and H2";

can be catalytically, chemically condensed via long-known processes, such as the Fischer-Tropsch synthesis, into synthetic petroleum and into the fuels derived from petroleum, such as "gasoline and diesel".

We acknowledge in summary that the Disclosure herein is also one which concerns the design of a device which can as well be operated as a fuel cell for the production of electricity by oxidation of products of the cell when it is operated in reverse, as disclosed herein, when a surplus of energy is available, to convert the products of combustion and oxidation, CO2 and H2O, back into fuel, i.e., Hydrogen and Carbon Monoxide, and/or the hydrocarbons synthesized from Hydrogen and Carbon Monoxide.

And, the process could be driven, as suggested by one of the co-sponsors herein, the US Navy, in:

US Navy 2008 CO2 to Synfuel | Research & Development | News; concerning: "United States 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, obtained from seawater or air, and hydrogen obtained from water, with a catalyst in a chemical process such as reverse water gas shift combined with Fischer Tropsch synthesis. The hydrogen is produced by ... ocean thermal energy conversion, or any other source that is fossil fuel-free, such as wind or wave energy" 

by one form or another, "wind or wave", of freely-available, and carbon-free, environmental "energy".

We'll note further that the process of our subject differs from, and is likely more efficient than, that disclosed by the Navy in USP 7,420,004, in that it forms Carbon Monoxide from Carbon Dioxide directly via electrolysis, while the Navy's process of USP 7,420,004 seems to convert CO2 into CO via the reverse water gas shift reaction with Hydrogen, which requires that an excess of Hydrogen be formed from H2O, with an attendant excess of energy required to generate the excess Hydrogen.  

In any case, if we sad sacks resident in United States Coal Country ever do decide to quit whining - - about the US EPA's carbon rules, and how they're going to affect our Coal-fired power generation industries, and, about OPEC, and how those foreign devils and their Big Oil cohorts are charging us so much for liquid hydrocarbon fuels that we have to feed our kids canned generic beans for breakfast - - and, to demand that something more positive be done for everyone in the United States of America, then, herein, is another tool with which to move forward.

As confirmed by the United States Government, through their allowance of our subject herein, "United States Patent 8,354,011 - Efficient Reversible Electrodes for Solid Oxide Electrolyzer Cells", the technology exists, and is being even further improved upon, which would enable us to begin converting Carbon Dioxide, in concert with Water, H2O, into a Carbon Monoxide and Hydrogen blend of synthesis gas, which syngas can, via known and established processes, such as the Fischer-Tropsch synthesis, be directly converted into any and all forms of hydrocarbon fuels.