Panasonic Solar CO2 to Methane

United States Patent: 8597488

It should by now, from our many previous reports documenting the fact, be accepted incontrovertibly, that, Carbon Dioxide, as it arises in only a small way, relative to some all-natural and un-taxable sources of emission, such as the Earth's inexorable processes of planetary volcanism, from our essential use of Coal in the generation of truly abundant and truly affordable electric power, is a valuable, maybe even a precious, raw material resource.

We can reclaim Carbon Dioxide from industrial exhaust gases and, perhaps more advantageously, from the atmosphere itself, and, then, in processes which can be - - and in some places are already being - - driven by various forms of environmental energy, we can convert that CO2, in combination with Hydrogen extracted from Water, even, as demonstrated by the United States Navy in, for just two examples, our reports of:

West Virginia Coal Association | US Navy Announces $3/Gallon Jet Fuel from CO2 | Research & Development; concerning the official US Naval Research Laboratory news release, which presumably went out on the wires: "'Fueling the Fleet, Navy Looks to the Seas'; September 24, 2012; Refueling U.S. Navy vessels, at sea and underway, is a costly endeavor in terms of logistics, time, fiscal constraints and threats to national security and sailors at sea. The U.S. Naval Research Laboratory (NRL) is developing the chemistry for producing jet fuel from renewable resources in theater. The process envisioned would catalytically convert CO2 and H2 directly to liquid hydrocarbon fuel ... . Scientists at the U.S. Naval Research Laboratory (NRL) are developing a process to extract carbon dioxide (CO2) and produce hydrogen gas (H2) from seawater, subsequently catalytically converting the CO2 and H2 into jet fuel"; and:

West Virginia Coal Association | US Navy 2008 CO2 to Synfuel | Research & Development; 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";

from vastly abundant and continuously-renewing ocean water, into hydrocarbon fuels. And, as seen most recently in our report of:

West Virginia Coal Association | California Sunshine Converts CO2 into Methane for USDOD | Research & Development; concerning: "US Patent Application 20130118906 - Method and System for Enhancing Catalytic and Photocatalytic Processes; May 16, 2013; Inventors: Stephen Cronin, et. al., California; Assignee: University of Southern California, Los Angeles; Abstract: A system for solar energy conversion includes a photoelectric cell. The photoelectric cell includes a cathode and an anode comprising a nanostructure array. The nanostructure array includes a semiconductor photocatalyst; and a plasmon resonant metal nanostructure film arranged on the semiconductor photocatalyst. The system is used in a method to produce methane by placing a photocatalytic cell in an environment containing CO2; and exposing the photocatalytic cell to visible light thereby allowing the CO2 to be converted to methane";

simple sunlight, in a form of "artificial photosynthesis", is another of the environmental energies which can be used, to drive CO2-recycling processes, and substitute natural gas Methane is another of the hydrocarbons which can be synthesized from CO2.

We documented in other of our reports, such as, for just one example:

West Virginia Coal Association | Panasonic 2013 CO2 to Methane, Formic Acid and Carbon Monoxide | Research & Development; concerning: "United States Patent 8,414,758 - Method for Reducing Carbon Dioxide; Date: April 9, 2013; Inventors: Masahiro Deguchi (et. al.), Japan; Assignee: Panasonic Corporation, Osaka; Abstract: A device for reducing carbon dioxide includes a cathode chamber including a cathode electrolyte solution and a cathode electrode, an anode chamber including an anode electrolyte solution and an anode electrode, and a solid electrolyte membrane. The anode electrode includes a nitride semiconductor region on which a metal layer is formed. The metal layer includes at least one of nickel and titanium. A method for reducing carbon dioxide by using a device for reducing carbon dioxide includes steps of providing carbon dioxide into the cathode solution, and irradiating at least part of the nitride semiconductor region and the metal layer with a light having a wavelength of 250 nanometers to 400 nanometers, thereby reducing the carbon dioxide contained in the cathode electrolyte solution. The method ... wherein ... the device is left at a room temperature and under atmospheric pressure. The method ... wherein ... formic acid (and/or) carbon monoxide (and/or) methane is obtained";

that such artificial photosynthesis processes, for the conversion of Carbon Dioxide into Methane, are being developed in other nations of the world. And, as we saw in our report of:

West Virginia Coal Association | Japan Solar Energy Converts More CO2 into Methane | Research & Development; concerning: "United States Patent Application 20120234691 - Method for Reducing Carbon Dioxide; Date: September 20, 2012; Inventor: Masahiro Deguchi, et. al., Japan; Assignee: Panasonic Corporation, Osaka; Abstract: The method for reducing carbon dioxide of the present disclosure includes a step (a) and a step (b) as follows. A step (a) of preparing an electrochemical cell. The electrochemical cell comprises a working electrode, a counter electrode and a vessel. The vessel stores an electrolytic solution. The working electrode contains at least one nitride selected from the group consisting of titanium nitride, zirconium nitride, hafnium nitride, tantalum nitride, molybdenum nitride and iron nitride. The electrolytic solution contains carbon dioxide. The working electrode and the counter electrode are in contact with the electrolytic solution. A step (b) of applying a negative voltage and a positive voltage to the working electrode and the counter electrode, respectively, to reduce the carbon dioxide. The method ... wherein in the step (b), at least one compound selected from the group consisting of methane, ethylene, ethane and formic acid is produced";

Japan's Panasonic Corporation has been refining and improving their CO2-recycling, Methane-synthesizing photosynthetic processes, to the point of specifying the "nitride semiconductor" materials of construction for photocatalytic electrodes to be used in the process.

And, herein we see that technical experts in the employ of our United States Government acknowledged the technical viability of Panasonic's claims of artificial CO2-to-Methane photosynthesis embodied in the above ""United States Patent Application 20120234691 - Method for Reducing Carbon Dioxide", via their recent issuance of:

"United States Patent 8,597,488 - Method for Reducing Carbon Dioxide

Patent US8597488 - Method for reducing carbon dioxide - Google Patents

Method for reducing carbon dioxide - Panasonic Corporation

 

Date: December 3, 2013

Inventors: Masahiro Deguchi, et. al., Japan

Assignee: Panasonic Corporation, Osaka

Abstract: The method for reducing carbon dioxide of the present disclosure includes a step (a) and a step (b) as follows. A step (a) of preparing an electrochemical cell. The electrochemical cell comprises a working electrode, a counter electrode and a vessel. The vessel stores an electrolytic solution. The working electrode contains at least one nitride selected from the group consisting of titanium nitride, zirconium nitride, hafnium nitride, tantalum nitride, molybdenum nitride and iron nitride. The electrolytic solution contains carbon dioxide. The working electrode and the counter electrode are in contact with the electrolytic solution. A step (b) of applying a negative voltage and a positive voltage to the working electrode and the counter electrode, respectively, to reduce the carbon dioxide.

(Note that this technology is closely related to similar Panasonic CO2-recycling processes, like that seen in our report of:

West Virginia Coal Association | Japan Converts CO2 into Lower-Cost Methane | Research & Development; concerning: "United States Patent Application 20120018311 - Carbon Dioxide Reduction Method; January 26, 2012; Inventors: Satoshi Yotsuhashi, et. al., Japan; Assignee: Panasonic Corporation, Osaka

Abstract: The carbon dioxide reduction method of the present invention is a method including steps of: bringing an electrode (working electrode) containing a carbide of at least one element selected from Group V elements (vanadium, niobium, and tantalum) into contact with an electrolytic solution; and introducing carbon dioxide into the electrolytic solution to reduce the introduced carbon dioxide by the electrode. The material contained in the electrode, that is, the material containing a carbide of at least one element selected from Group V elements (vanadium, niobium, and tantalum) is the carbon dioxide reduction catalyst of the present invention. (The) method and the device of the present invention achieve reduction of carbon dioxide to carbon monoxide, formic acid, methane, etc. and provide these substances with less energy and at lower cost. The present embodiment can also be applied to more environmentally-friendly methods and devices. For example, it can be applied to the use of a solar cell as an external power supply, and to a catalyst for solar energy reduction by combination with a photocatalyst";

wherein "carbide", as opposed to "nitride" metal catalysts are specified.)

Claims: A method for reducing carbon dioxide, the method comprising: a step (a) of preparing an electrochemical cell, wherein the electrochemical cell comprises a working electrode, a counter electrode and a vessel, the vessel stores an electrolytic solution, the working electrode contains, as a catalyst, only at least one nitride selected from the group consisting of titanium nitride, zirconium nitride, hafnium nitride, tantalum nitride, molybdenum nitride and iron nitride, the electrolytic solution contains carbon dioxide, the vessel comprises a solid electrolyte membrane, the solid electrolyte membrane is interposed between the working electrode and the counter electrode, the working electrode is in contact with the electrolytic solution, and the counter electrode is in contact with the electrolytic solution; and a step (b) of applying a negative voltage and a positive voltage to the working electrode and the counter electrode, respectively, to reduce the carbon dioxide. 

The method ... wherein in the step (b), at least one compound selected from the group consisting of methane, ethylene, ethane and formic acid is produced.

Summary: One non-limiting and exemplary embodiment provides a method for reducing carbon dioxide using a highly-durable catalyst that is capable of reducing CO2 at an overvoltage equal to or lower than overvoltages for conventional catalysts to produce highly useful substances (such as formic acid (HCOOH), methane (CH4), ethylene (C2H4) and ethane (C2H6)). 

In one general aspect, the techniques disclosed here feature a method for reducing carbon dioxide, the method including: a step (a) of preparing an electrochemical cell, wherein the electrochemical cell comprises a working electrode, a counter electrode and a vessel, the vessel stores an electrolytic solution, the working electrode contains at least one nitride selected from the group consisting of titanium nitride, zirconium nitride, hafnium nitride, tantalum nitride, molybdenum nitride and iron nitride, the electrolytic solution contains carbon dioxide, the working electrode is in contact with the electrolytic solution, and the counter electrode is in contact with the electrolytic solution; and a step (b) of applying a negative voltage and a positive voltage to the working electrode and the counter electrode, respectively, to reduce the carbon dioxide. 

The electrochemical cell is used in the method for reducing carbon dioxide of the present disclosure. The electrochemical cell comprises the working electrode for reducing carbon dioxide. The working electrode contains at least one nitride selected from the group consisting of titanium nitride, zirconium nitride, hafnium nitride, tantalum nitride, molybdenum nitride and iron nitride. These nitrides are capable of reducing carbon dioxide at an overvoltage equal to or lower than overvoltages for conventional catalysts for reducing carbon dioxide. Therefore, the method of the present disclosure makes it possible to produce highly useful substances, such as HCOOH, CH4, C2H4 and C2H6, at an overvoltage equal to or lower than overvoltages in conventional methods. Furthermore, the high durability of the nitrides allows the working electrode to achieve high durability.

The (specified) nitrides used as catalysts in reducing CO2 allows CO2 to be reduced with an external energy from DC power supply at ordinary temperature.

Moreover, the method for reducing CO2 of the present disclosure can be applied to methods using a solar cell as an external power supply. The catalysts for reducing CO2 can be applied, by combination with a photocatalyst, to catalysts that can be used with solar energy."

The present disclosure demonstrates that nitrides of elements selected from Ti, Zr, Hf, Ta, Mo and Fe, which are highly durable compounds, are capable of reducing CO2 electrolytically at an overvoltage lower than overvoltages for conventional catalysts for reducing CO2.

These nitrides make it possible to produce CH4 ... from CO2 with less energy.

That is, the method for reducing CO2 of the present disclosure can provide these useful substances from CO2 at lower cost.

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There's a good bit more to the full Disclosure, but, our excerpts encapsulate the essence of it:

Using what we would perceive to be some pretty inexpensive, non-exotic catalysts, we can convert Carbon Dioxide, as entrained in an "electrolytic solution", "at ordinary temperature", into "at least ... methane", in a process that can, when a "photocatalyst" is included, be driven by "solar energy".

And, in passing, we do of course have to remind you, that, once we have the Methane, in addition to the other valuable products specified, as herein synthesized from Carbon Dioxide and Water in a process driven by "solar energy", we can then, as seen for only one example out of many in our report of:

West Virginia Coal Association | Saudia Arabia CO2 + Methane = Hydrocarbons + Syngas | Research & Development; concerning: "United States Patent 7,355,088 - Process for Producing Benzene, Ethylene and Synthesis Gas; 2008; Inventors: Agaddin Mamedov, et. al., Saudi Arabia; Assignee: Saudi Basic Industries Corporation, Riyadh; Abstract: Process for producing benzene, ethylene and synthesis gas, comprising the steps of: i) introducing a starting gas flow comprising methane and carbon dioxide into a reactor; ii) oxidizing the methane in the reactor at certain reactor conditions optionally using a first catalytic material and/or and additional oxidant; and: iii) removing a product gas flow comprising benzene, ethylene and synthesis gas from the reactor";

react that CO2-derived Methane with even more Carbon Dioxide, forming thereby valuable hydrocarbons, "benzene" and "ethylene", and, a hydrocarbon "synthesis gas", consisting of Carbon Monoxide and Hydrogen; which, as seen for one recent example in:

West Virginia Coal Association | Bayer Improves Fischer-Tropsch Hydrocarbon Synthesis | Research & Development; concerning: "US Patent 8,557,880 - Multi-stage Adiabatic Method for Performing the Fischer-Tropsch Synthesis; 2013; Inventors: Ralph Schellen, et. al., Germany and Texas; Assignee: Bayer Intellectual Property GmbH, Germany; Abstract: The present invention relates to a multistage adiabatic process for performing the Fischer-Tropsch synthesis at low temperatures, in which the synthesis is performed in 5 to 40 series-connected reaction zones under adiabatic conditions. Process for preparing liquid hydrocarbons from the process gases carbon monoxide and hydrogen"

can be catalytically reacted and condensed, in the long-known and continuously improved "Fischer-Tropsch synthesis", and made thereby to form "liquid hydrocarbons".