Any further debate about the dangers of Carbon Dioxide accumulating in our atmosphere as a result of our economically essential use of Coal in the generation of abundant, affordable and reliable electric power can now be considered, at best, a tiresome distraction.
Perhaps the best way to view such debate, such protest against Coal, is as an echo of history, the reverberation of an old tune that will eventually fade away as a new, and happier, choir begins to sing.
Carbon Dioxide can be seen and treated as a valuable raw material resource.
We can reclaim CO2 from whatever source most convenient to us and, then, in processes powered only by freely-available sunlight, we can convert that CO2, in combination with Hydrogen ions concurrently extracted from the abundant Water, H2O, molecule, into, among a significant number of other valuable products, substitute, fracking-free, natural gas Methane.
The implications of that fact for new Coal Country industries and Coal Country jobs, and for the quenching of various environmental concerns, should be obvious.
As we've seen, for just two examples, in our past reports of:
Korea Improves CO2 to Methane Artificial Photosynthesis | Research & Development | News; concerning: "United States Patent 8,716,171 - Method of Manufacturing a Porous Gallium (III) Oxide Photocatalyst for Preparation of Hydrocarbons; 2014; Assignee: Korea Advanced Instititute of Science and Technology, Daejon, Korea; Abstract: The present invention relates to preparation of porous gallium (III) oxide [Ga2O3] photocatalyst for production of hydrocarbons ... . The hydrocarbons described above may include hydrocarbons having 1 to 4 carbon atoms, preferably, aliphatic hydrocarbons having 1 to 4 carbon atoms, and more preferably, methane. Artificial photo-synthesis technologies that use a photocatalyst to produce useful fuel from carbon dioxide and/or conversion of carbon dioxide to the same are now a global issue. Such a method of preparing a useful fuel using carbon dioxide and/or converting carbon dioxide to the same substantially utilizes only water and solar light, therefore, may be the most eco-friendly and sustainable technique. The fuel produced by the foregoing method may include hydrocarbons having 1 to 4 carbon atoms, preferably, aliphatic hydrocarbons having 1 to 4 carbon atoms, and more preferably, methane. Methane ... is a main component of natural gas"; and:
USDOE Sunlight Converts CO2 into Methane | Research & Development | News; concerning: "US Patent Application 20130079577 - Synthesis of Photocatalysts for Solar Fuel Generation; 2013; Inventor: Brian Ingram, et. al., IL and TN; Assignee: UChicago Argonne, LLC, Chicago (USDOE Argonne National Laboratory); Abstract: In one preferred embodiment, a photocatalyst for conversion of carbon dioxide and water to a hydrocarbon and oxygen (as described). Government Interests: The United States Government has rights in this invention pursuant to Contract No. DE-AC02-06CH11357 between the United States Government and UChicago Argonne, LLC representing Argonne National Laboratory. A method of converting carbon dioxide and water into a hydrocarbon and oxygen comprising exposing a gaseous mixture of carbon dioxide and water to sun light in the presence of a photocatalyst of at a temperature sufficient to catalyze reduction of carbon dioxide to a hydrocarbon ... . This invention relates to the energy efficient photocatalytic conversion of carbon dioxide gas and water vapor to methane (as) promoted by sunlight (referred to herein as "solar-derived fuel" or "solar fuel"). The present invention provides wide band-gap photocatalytic materials useful for catalyzing the solar conversion of carbon dioxide and water to hydrocarbons (particularly methane) and oxygen";
technologies are proliferating quite literally around the world, including in the United States of America, wherein solar light - and in some cases solar thermal - energy is harnessed to drive the conversion of Carbon Dioxide, as recovered from whatever handy source, and Water into synthetic natural gas Methane.
As a nation, Japan is one of the primary innovators of "artificial photosynthesis" CO2-to-hydrocarbon technologies, as seen, for just one example, in our report of:
Panasonic Solar CO2 to Methane | Research & Development | News; concerning: "United States Patent 8,597,488 - Method for Reducing Carbon Dioxide; 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. 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. 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 ... 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 (Methane) ... from CO2 with less energy".
And, another Japanese company devoting some of it's quite considerable human and financial resources to the development of photosynthetic CO2-to-Methane technology, as seen in our report of:
Connecticu?t and Honda 2012 CO2 and H2O to Hydrocarbo?n Fuels | Research & Development | News; concerning: "United States Patent Application 20120241327 - Materials and Design for an Electrocatalytic Device and Method which Produces Carbon Nanotubes and Hydrocarbon Transportation Fuels; 2012; Inventors: Steven Suib, et. al.; Assignee: The University of Connecticut and Honda Motor Company, Tokyo; Abstract: The present teachings are directed toward an electrocatalytic cell (as described, and an)electrocatalytic method ... wherein the feedstock component comprises mixtures of CO2 and CO with mixtures of H2 and H2O. A method for producing hydrocarbons ... . The method ... wherein the hydrogen-containing feedstock component comprises mixtures of H2 and H2O. The present disclosure is directed to an electrocatalytic method of producing carbon nanotubes by providing an electrocatalytic reactor including a supported catalyst and a barrier comprising a material permeable to oxygen ions and impermeable to at least CO2, CO, H2, H.2O and hydrocarbons. There are working and counter electrodes contacted to the supported catalyst. The supported catalyst is then contacted with a carbon-containing feedstock component and a hydrogen-containing feedstock component under electrocatalytic conditions sufficient to reduce the carbon-containing feedstock component, a voltage is applied across the working and counter electrodes, and carbon nanotubes are produced at the surface of the supported catalyst. ... Also taught by the present disclosure is a method for producing hydrocarbons by providing a hydrogen-containing feedstock component and a carbon-containing feedstock component. It is further taught that at least one of the hydrogen-containing feedstock component and the carbon-containing feedstock component comprise oxygen-containing materials. ... Specifically, variably composed mixtures of CO2/CO with variable composed mixtures of H2/H2O can be used as feedstock materials for liquid hydrocarbon transportation fuels. With the presently disclosed method, liquid hydrocarbon fuels can be generated directly from feedstocks containing only carbon dioxide and water";
is the well-known Honda Motor Company, who have, as above, worked with the University of Connecticut to develop electro-catalytic techniques for splitting both the CO2 and H2O molecules, which techniques require so little power that it, too, can be supplied with the required electricity by photoelectric cells.
As most people, at least in the eastern United States of America, might know, Honda Motors began to establish a corporate presence in the USA, through manufacturing facilities and subsidiary business operations in and around the city of Marysville, Ohio, more than three decades ago. More can be learned via:
Welcome to Honda Manufacturing of Ohio - Honda of America Mfg. "It’s been more than 30 years since the first U.S.-made Honda Accord rolled off the line at our Marysville manufacturing plant in November 1982".
And, herein we see that a researcher employed by Honda in Ohio has furthered the development of their technology for using solar energy to power the transformation of Carbon Dioxide and Water into - - in a way similar to that disclosed by Panasonic, in their "United States Patent 8,597,488 - Method for Reducing Carbon Dioxide" - - among other valuable products, substitute natural gas Methane.
Comment follows excerpts from the initial link in this dispatch to the recent:
"United States Patent 8,840,772 - Solar Fuel Cell
Patent US8840772 - Solar fuel cell - Google Patents
Solar fuel cell - Honda Motor Co., Ltd.
Date: September 23, 2014
Inventor: Ting He, Dublin, Ohio
Assignee: Honda Motor Company, Ltd., Tokyo, Japan
Abstract: The present teachings are directed to a method of converting water and a carbon-containing compound, such as CO2, into a hydrocarbon through a process of absorbing sunlight on a light-absorbing component to photoelectrochemically oxidize water and reacting the products from that water oxidation reaction over a catalyst with the carbon-containing compound to produce the desired hydrocarbon compound.
(We've documented and explained it before, and won't include here any additional reference links, but, when they refer to "oxidizing" water, H2O, they mean, essentially, splitting it into Hydrogen and Oxygen, although, in water oxidation, it is typically Hydrogen ions, "H+", that are produced, or wanted, as opposed to molecular Hydrogen. The H+ ions, just "protons" as stipulated below, are more reactive, and can be made to react more readily, even spontaneously, with other compounds; in this case, as indicated and as will be seen, Carbon Dioxide. Further, at this point in United States patents, significant prior art contributing to the new development is cited by the inventors. Among the older technologies cited by Honda are a number about which we have previously reported, including several developed by the old Texaco Corporation, as in, for just one example:
Texaco Photosynthetic CO2 Recycling | Research & Development | News; concerning: "United States Patent 4,545,872 - Method for Reducing Carbon Dioxide to Provide a Product; 1985; Inventors: Anthony Sammells and Peter Ang, IL; Assignee: Texaco, Incorporated, NY; Abstract: A process and apparatus for reducing carbon dioxide to at least one useful product includes two redox couple electrolyte solutions separated by a first membrane having photosensitizers. The carbon dioxide to be reduced is provided to a second membrane which is contiguous to one of the redox couple electrolyte solutions. The second membrane has photosensitizers and a catalyst. Water provides hydrogen ions, which participate in the reduction of the carbon dioxide, via a separator. In operation both membranes are illuminated and produce excited photosensitizers which cause electron transfer from a first redox solution to a second redox solution and thence to the carbon dioxide in the second membrane thereby, in cooperation with the hydrogen ions, reducing at least some of the carbon dioxide at a surface of the second membrane to provide at least one product. Claims: A process for reducing carbon dioxide to at least one useful product comprising the steps of: (Providing two, specified) electrolyte solution(s) ... (and) ... separating the ... solution(s) with a first membrane having photosensitizers, (And) providing carbon dioxide to a second membrane contiguous to the (specified) solution and having photosensitizers and a catalyst, (And) providing water, (And) separating the water from the carbon dioxide in a manner so that hydrogen ions, but not oxygen, may pass from the water to participate in the reduction of the carbon dioxide, (And) illuminating both membranes so as to produce excited photosensitizers to cause electron transfer from (one) solution to the (other) thence to the carbon dioxide to ... provide at least one product. A process as described ... which ... includes exposing both membranes to solar radiation. A process ... in which the predominant product produced is formic acid (and/or) formaldehyde (and/or) methanol (and/or) methane".)
Claims: A method for converting a carbon-containing component and water to a hydrocarbon moiety-containing component comprising: exposing a light-harvesting, charge-separating and transporting component to sunlight to produce separated electron and hole pairs; contacting the water with the electron and hole pairs to produce oxygen gas, protons, and electrons; removing the oxygen gas; transporting the electrons through an electrical connection from the light-harvesting, charge-separating and transporting component directly to a catalyst component; conducting the protons across a proton-conducting membrane and the catalyst component prior to contacting the carbon-containing component; contacting a carbon-containing component with the catalyst component, the protons, and the electrons to produce a hydrocarbon moiety-containing component; and removing the hydrocarbon moiety-containing component, wherein the light-harvesting, charge-separating and transporting component comprises p-type semiconductor material selected from the group consisting of p-SliconCarbide, p-GalliumPhosphide, (etc.).
The method ... wherein the light-harvesting, charge-separating and transporting component comprises a semiconductor-based formulation (and) wherein the proton-conducting membrane comprises a ceramic-based membrane or a polymer-based membrane (and) wherein the catalyst component comprises a precious metal, base metal or chalcogenide containing formulation.
The method ... wherein the catalyst component comprises a hydrogenation catalyst formulation, a hydrogenolysis catalyst formulation, or a reduction catalyst formulation.
The method ... wherein the carbon-containing component comprises at least one (of) carbon monoxide and carbon dioxide.
The method ... wherein the hydrocarbon moiety-containing component (produced) comprises at least one member selected from the group consisting of an alcohol, an aldehyde, an alkane, an alkene and an alkyne.
(Note, that, although we headlined this report "CO2 to Methane", which is an "alkane", other hydrocarbons, some liquid, and "alcohol", can be produced via this solar-driven CO2 utilization process.)
Background and Field: The present teachings relate to a method of converting water and a carbon-containing compound into a hydrocarbon through a process of absorbing sunlight on a light-absorbing component to photoelectrochemically oxidize water and reacting the products from that water oxidation reaction over a catalyst with a carbon-containing compound, such as CO2, to produce a hydrocarbon compound.
Related Art: Photosynthesis is a kinetically slow process for the production of hydrocarbons from CO2 and water using solar radiation as an energy source to drive the conversion reaction.
The well-known Fischer-Tropsch synthesis process of producing hydrocarbons from CO and water requires high temperatures and pressures, even in the presence of a catalyst, to produce hydrocarbons.
(Fischer–Tropsch process - Wikipedia, the free encyclopedia; "The Fischer–Tropsch process (or Fischer–Tropsch synthesis) is a collection of chemical reactions that converts a mixture of carbon monoxide and hydrogen into liquid hydrocarbons (and, is a) component of ... technology (that) produces a synthetic lubrication oil and synthetic fuel, typically from coal".)
Several techniques are known to facilitate the oxidative decomposition of water into hydrogen and oxygen gases.
A process to produce hydrocarbons from water and a source of carbon-containing compounds at non-elevated temperatures and pressures with sunlight as the energy source in a kinetically fast manner is of great interest. Additionally, a device to carry out the process is desirable.
Summary: The present teachings are directed to a method for converting a carbon-containing component and water to a hydrocarbon component by providing a light-harvesting, charge-separating and transporting component, a proton-conducting membrane, and a catalyst component. There is an electrical connection between the light-harvesting, charge-separating and transporting component and the catalyst component. The light-harvesting, charge-separating and transporting component can be exposed to radiation of a sufficient wavelength to produce separated electron and hole pairs, and water can be contacted with the electron and hole pairs to produce oxygen gas, protons, and electrons. The oxygen gas is removed. The electrons are transported through the electrical connection from the light-harvesting, charge-separating and transporting component to the catalyst component, and the protons are conducted across the proton-conducting membrane to contact the catalyst component. The carbon-containing component is contacted with the catalyst component, the protons, and the electrons to produce the desired hydrocarbon component, which is then removed.
The present teachings also teach a device for using solar radiation to convert water and a carbon-containing component to a hydrocarbon component. The device includes a light-harvesting, charge-separating and transporting component having a first surface in contact with water and exposed to a radiation source, and a second surface in contact with a first surface of a proton-conducting membrane. The proton-conducting membrane has a first surface in contact with the second surface of the light-absorbing, charge-separating and transporting component and a second surface in contact with a first surface of a catalyst component. The catalyst component has a first surface in contact with the second surface of the proton-conducting membrane and a second surface in contact with a source of a carbon-containing component. There is an electrical connection between the light-harvesting, charge-separating and transporting component and the catalyst component.
The present disclosure is directed to a process for converting a carbon-containing component and water to a hydrocarbon component by first providing a light-harvesting, charge-separating and transporting component, a proton-conducting membrane, and a catalyst component. An electrical connection between the light-harvesting, charge-separating and transporting component and the catalyst component is also provided. The light-harvesting, charge-separating and transporting component is exposed to radiation of a sufficient wavelength to produce separated electron and hole pairs.
Water is contacted with the electron and hole pairs to produce, via oxidation, oxygen gas, protons, and electrons. The oxygen gas is removed from the process, while the electrons are transported through the electrical connection from the light-harvesting, charge-separating and transporting component to the catalyst component, and the protons are conducted across the proton-conducting membrane to contact the catalyst component.
At the catalyst component, the presently disclosed method continues, with a carbon-containing component contacting with the catalyst component, the protons, and the electrons to produce a hydrocarbon component. This newly produced hydrocarbon component is then removed from the process.
To function in the disclosed process, the light-harvesting, charge-separating and transporting component can be a semiconductor-based formulation (configured as specified) to drive the water oxidation reaction. The component generates the needed electron and hole pairs when irradiated with sunlight.
The light-harvesting, charge-separating and transporting component can be a p-type semiconductor material selected from the group consisting of (Silicon Carbide, and others specified), or in other embodiments it can be an n-type semiconductor material selected from the group consisting of (Titanium Dioxide, and others specified).
Also suitable for use in the present process as the light-harvesting, charge-separating and transporting component are organic materials that generate electron and hole pairs when irradiated with sunlight (with characteristics specified).
The proton-conducting membrane used in the present process can be a ceramic-based membrane or a polymer-based membrane, or in other embodiments, the proton-conducting membrane can be a membrane such as a Nafion-based or hydrocarbon-based membrane.
(http://en.wikipedia.org/wiki/Proton_exchange_membrane; "A proton exchange membrane or polymer electrolyte membrane (PEM) is a semipermeable membrane (which is) designed to conduct protons while being impermeable to gases such as oxygen or hydrogen. This is their essential function when incorporated into a membrane electrode assembly (MEA) of a proton exchange membrane fuel cell or of a proton exchange membrane electrolyser: separation of reactants and transport of protons. PEMs can be made from either pure polymer membranes or from composite membranes where other materials are embedded in a polymer matrix. One of the most common and commercially available PEM materials is the fluoropolymer (PFSA) Naflon, a DuPont product".)
Suitable catalyst components include formulations containing a precious metal, base metal or chalcogenide catalyst formulation. For instance, the catalyst component can include at least one metal selected from the group consisting of (Iron, Cobalt, Nickel, Copper, and others specified).
The carbon-containing component added as a reactant to the present process can be at least one member selected from the group consisting of carbon monoxide and carbon dioxide. According to various other embodiments of the present process, the carbon-containing component can include, in some instances, compounds that contain at least one carbon-oxygen bond.
The hydrocarbon component produced by the present process can include alcohols, aldehydes, alkanes, alkenes and alkynes. The exact composition of the produced hydrocarbon component will depend on reaction conditions, catalyst component, and the initial carbon-containing component. One of skill in the art will be able to select the parameters set forth above in order to produce their desired hydrocarbon component.
Ideally, in the process disclosed herein, the radiation of a sufficient wavelength will be sunlight. In other embodiments of the present process, different sources of radiation, such as lasers, or concentrated sunlight, can be utilized. Radiation sources that do not use decrease the overall energy efficiency of the presently disclosed process are preferred.
A device for using solar radiation to convert water and a carbon-containing component to a hydrocarbon component is also taught by the present disclosure. One embodiment of the presently disclosed device can include a light-harvesting, charge-separating and transporting component having a first surface in contact with water and exposed to a radiation source, and a second surface in contact with a first surface of a proton-conducting membrane. The proton-conducting membrane can have a first surface in contact with the second surface of the light-absorbing, charge-separating and transporting component and a second surface in contact with a first surface of a catalyst component. The catalyst component can have a first surface in contact with the second surface of the proton-conducting membrane and a second surface in contact with a source of a carbon-containing component. The presently disclosed device can also have an electrical connection between the light-harvesting, charge-separating and transporting component and the catalyst component.
In the presently disclosed device, electron and hole pairs are produced by the absorption of radiation of a sufficient wavelength to cause the oxidation of water at the first surface of the light-absorbing, charge-separating and transporting component to produce oxygen, protons, and electrons.
An electrical connection is provided between the light-harvesting, charge-separating and transporting component and the catalyst component in embodiments of the presently disclosed device to permit transport of the electrons.
Additionally, the device provides for the protons to be conducted across the proton-conducting membrane from the light-harvesting, charge-separating and transporting component to the catalyst component. At the second surface of the catalyst component the carbon-containing component is contacted with the protons and the electrons to produce the hydrocarbon component.
The carbon-containing component can contain both carbon and oxygen and can be, for example, carbon monoxide and/or carbon dioxide. The hydrocarbon component produced by the present process can include alcohols, aldehydes, alkanes, alkenes and alkynes. The reaction conditions, catalyst component, and the initial carbon-containing component will influence the final structure of the hydrocarbon component".
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One step in Honda's overall process seems to be a version of the reverse water gas shift, RWGS, reaction, as explained more fully in our report of:
France Efficient CO2 to Carbon Monoxide Conversion | Research & Development | News; concerning: "United States Patent Application 20030113244 - Method for Producing Carbon Monoxide by Reverse Conversion with an Adapted Catalyst; 2003; Assignee: Air Liquide (France); Abstract: The invention concerns a method for producing carbon monoxide by reverse conversion, in gas phase, of carbonic acid gas and gaseous hydrogen ... . ... A process for the production of carbon monoxide by reverse conversion, in the gas phase, of gaseous carbon dioxide and gaseous hydrogen, while minimizing the production of methane".
Substitute natural gas Methane is one desirable product, of course, of sunlight-driven processes that consume Carbon Dioxide, but, by minimizing the production of Methane, more of the Carbon Monoxide product of CO2 reduction is then available to react with Hydrogen in further catalytic processes akin to and derived from the "well-known Fischer-Tropsch synthesis" that produce alcohols and liquid hydrocarbons.
Honda's technology herein seems much more sophisticated, and seems to enable a much greater control on the mix of products, than the now nearly-ancient RWGS and Fischer-Tropsch processes.
And, the mix of products which Honda can, as herein, generate, in a process powered only by sunlight, from nothing but Water and Carbon Dioxide, includes "alcohol", and various hydrocarbons, characterized as "an aldehyde, an alkane, an alkene and an alkyne", with an example of one "alkane" being substitute natural gas Methane.
Seriously: Doesn't anyone think that it's getting to be way past time - - since the Texaco artificial photosynthesis technologies upon which this recent Honda CO2-to-hydrocarbon innovation is founded were developed three decades ago, back in the 1980's - - that we, all United States citizens, were told, fully and openly, as confirmed again herein officially by our United States government, that: Carbon Dioxide, along with Water, in processes powered only by freely-available sunlight, can be consumed and utilized in the productive synthesis of virtually any type of liquid and gaseous hydrocarbon fuel?
The implications of the fact that our United States Government has, as herein, officially confirmed the truth implied by that question, in terms of putting an end to the squandering our national treasure by buying hydrocarbons from OPEC and by fighting foreign wars to defend that "privilege" of remaining economic servants so indentured to foreign powers; and, in terms of vastly increased employment opportunities all across the United States of America; and, in terms of removing the Carbon Dioxide yoke hung so unjustly around the neck of our economically essential Coal-fired power generation industries should, we here are led to think, be obvious.