We regret if we sound weary. But, by now we have documented so many times that Carbon Dioxide, as harvested from whatever convenient source, can - - in processes which themselves can be powered by freely available but otherwise lower-grade, so-called "renewable", environmental energy, such as sunlight, and, which processes have been developed even by scientists employed by the United States Government - - be consumed in the synthesis of anything and everything, any hydrocarbon fuel or chemical, we now sell our nation out to continue buying from OPEC, that it beggars our belief that such facts aren't being publicly and openly acknowledged as a matter of course by our press and by our elected government representatives; and, that public plans to implement such CO2 utilization on a broad-scale industrial basis aren't moving forward at a brisk pace, while all the talk of Carbon Dioxide geologic sequestration nonsense and the carbon tax extortion of our economically essential Coal-fired generators of electric power and their customers is deep-sixed.
There are a number of technical routes now available for such CO2-to-Fuel conversion. One of them, as seen for just one example in our report of:
USDOE and US Navy Improve CO2 + H2O = Hydrocarbon Syngas | Research & Development | News; concerning: "United States Patent 8,354,011 - Efficient Reversible Electrodes for Solid Oxide Electrolyzer Cells; 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. 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";
in general terms, centers on the co-electrolysis of Carbon Dioxide, CO2, and water, H2O, in a special electrochemical device, an "electrolyzer cell", with the resultant products being Carbon Monoxide, CO, Hydrogen, H2, and byproduct Oxygen, O2. The blend of CO and H2 comprise an hydrocarbon synthesis gas, or syngas, which, as explained for example in our past report of:
Mobil Oil 1978 Coal Conversion with Zeolite Catalyst | Research & Development | News; concerning: "United States Patent 4,086,262 - Conversion of Synthesis Gas to Hydrocarbon Mixtures; 1978; Inventors: Clarence Chang, et. al., NJ and PA; Assignee: Mobil Oil Corporation, NY; Abstract: Contacting a mixture of carbon monoxide and hydrogen with an intimate mixture of a carbon monoxide reduction catalyst, such as a Fischer-Tropsch catalyst or a methanol synthesis catalyst, and an acidic crystalline aluminosilicate having a pore dimension greater than about 5 Angstroms to produce hydrocarbon mixtures useful in the manufacture of heating fuels, high octane gasoline, aromatic hydrocarbons, and chemicals intermediates";
and, again, in our most recent report of:
Utah Improves Fischer-Tropsch Hydrocarbon Synthesis | Research & Development | News; concerning: "United States Patent 9,011,788 - Advanced Fischer Tropsch System; 2015; Inventors: Joseph Hartvigsen, et. al., Utah and Idaho; Assignee: Ceramatec, Inc., Salt Lake City; A Fischer Tropsch ("FT") unit (as described and specified). Background and Field: The present disclosure relates to devices and methods for more efficiently performing Fischer Tropsch ("FT") processing of a syngas stream. More specifically, the present disclosure relates to a device and method for FT processing with improved catalyst and temperature control for more efficient results. The Fischer Tropsch ("FT") process, which is sometimes called FT synthesis, is a chemical reaction used routinely in oil and gas processing. This process involves the conversion of carbon monoxide and hydrogen gas into a hydrocarbon chain and water. Generally, a catalyst is used in this reaction. This FT process usually occurs at high temperatures and high pressures, such as, for example, at pressures of 150-300 psig and temperatures ranging from 200-300 C. (The input stream that is input into the FT reaction vessel is often called synthesis gas or "syngas"). The FT process will generally produce a mixture of liquid and gaseous hydrocarbons ... . In general, the liquid hydrocarbons (such as octane, hexane, and others hydrocarbons with carbon numbers greater than 5) tend to be more valuable than the gaseous products (such as methane, ethane, etc.) because these liquid products may be used in producing kerosene, diesel fuel and other desirable products";
can be used in long-known processes to directly manufacture anything and everything we now squander the inheritance rightfully belonging to the children of the USA to continue buying from the nations of OPEC, who have in turn for our largesse blessed us with things like the Iranian revolution, 9-11, Saddam Hussein, the Taliban, and ISIS - - gifts that keep on giving.
Given that synthesis gas, which can be converted into such seemingly-desirable products like "heating fuels, high octane gasoline, aromatic hydrocarbons, and chemicals intermediates", etc., we note again, that, as seen for just one more example in:
West Virginia 2014 CO2 to Hydrocarbon Synthesis Gas | Research & Development | News; concerning: "United States Patent 8,658,311 - High Temperature Rechargeable Battery for Greenhouse Gas Decomposition and Oxygen Generation; 2014; Inventors: Bruce S. Kang and Huang Guo, Morgantown, West Virginia; Abstract: Instead of CCS (Carbon Capture and Storage) technique, a possible approach to mitigate the greenhouse gas (GHG) emission is to decompose it into useful products. This invention shows a high temperature rechargeable battery system for decomposition of oxygen-containing gases (e.g CO2/H2O, NOx, SOx, in particular GHG), oxygen generation, and energy storage by using ODF/La2NiO4-based materials in Li/Ti/Mg--CO2 battery architecture. ... During battery discharge, GHG can be decomposed into syngas (CO+H2) or solid carbon, while renewable energy (e.g. solar/wind power) could be used to charge the battery and generate oxygen. The energy consumption for GHG decomposition is self-sustainable and the byproducts (i.e. carbon/syngas and oxygen) have good market values. ... Claims: A high temperature rechargeable battery system for decomposition of oxygen-containing gases such as NOx, SO2, H2O, CO2, in particular greenhouse gas (GHG), oxygen generation and energy storage is invented by introducing an oxygen-deficient ferrites ... and/or La2NiO4 (Lanthanum Nickel Oxide)-based materials into rechargeable Lithium/Titanium/Magnesium--CO2 batteries, wherein during discharge of the battery, oxygen-containing gases like GHG can be decomposed into syngas (CO+H2) or solid carbon while renewable energy such as solar or wind energy can be used to charge the battery";
genuine American patriots have demonstrated that we can make such "syngas" from "H2O" and "CO2" in processes powered by "renewable energy".
Unfortunately, as seen for just one example in our report of:
Saudi July 10, 2014 Sunshine Converts CO2 into Hydrocarbon Fuel | Research & Development | News; concerning: "United States Patent Application 20140194539 - Carbon Dioxide Conversion to Hydrocarbon Fuel via Syngas Production Cell Harnessed from Solar Radiation; 2014; Inventors: Ahmad D. Hammad, et. al., Dhahran, Saudi Arabia; Assignee: Saudi Arabian Oil Company, Dhahran; Abstract: A process for converting carbon dioxide to hydrocarbon fuels using solar energy harnessed with a solar thermal power system to create thermal energy and electricity, using the thermal energy to heat a fuel feed stream, the heated fuel feed stream comprising carbon dioxide and water, the carbon dioxide captured from a flue gas stream, converting the carbon dioxide and water in a syngas production cell, the syngas production cell comprising a solid oxide electrolyte, to create carbon monoxide and hydrogen, and converting the carbon monoxide and hydrogen to hydrocarbon fuels in a catalytic reactor. In at least one embodiment, the syngas production cell is a solid oxide fuel cell. In at least one embodiment, the syngas production cell is a solid oxide electrolyzer cell";
some other folks, who have, let's face it, been living large thanks for the most part to America's thirsty need for liquid hydrocarbon fuels, have tripped onto the fact that they might be able to continue living in the style to which we have enabled them to become accustomed by using technology very much like that disclosed by American patriots in, among others, the above-cited "US Patent 8,354,011 - Efficient Reversible Electrodes for Solid Oxide Electrolyzer Cells" and "US Patent 8,658,311 - High Temperature Rechargeable Battery for Greenhouse Gas Decomposition and Oxygen Generation", to, once their reserves of natural petroleum are depleted, continue as a leading supplier of hydrocarbon fuels by synthesizing them, via an initial syngas manufacturing process, from, as harvested from whatever convenient source, Carbon Dioxide.
And, herein we see that another nation in that same part of the world, a nation for whom "keeping up with the Jones", their next-door neighbors, is very much a matter of just simple survival, have themselves applied their considerable intellectual capital to the development of closely-similar CO2-to-fuel, via syngas, Carbon Dioxide utilization technology.
Comment follows and is inserted within excerpts from the initial link in this dispatch to the recent:
"United States Patent 8,999,134 - Manufacturing Carbon-Based Combustibles by Electrochemical Decomposition of CO2
April 7, 2015
Inventors: Armand Bettelheim and Eli Korin, Beer Shiva, Israel
Assignee: Ben-Gurion University of the Negev Research & Development Authority, Israel
Abstract: Provided is a method for the electrochemical conversion of carbon dioxide to fuels. The method employs reducing CO2 in an electrochemical cell using an aerogel carbon electrode and an ionic liquid membrane, thereby providing a carbon-based combustible.
(Note: Although we titled this dispatch "Israeli Sunshine Converts CO2 into Hydrocarbon Syngas", solar energy isn't in fact mentioned by the inventors, Bettleheim and Korin. However, as we'll note in one or two comments inserted in these excerpts, the voltage needed to power the specified "electrochemical cell" and break CO2 and H2O down, into carbon monoxide and hydrogen, are low enough that it seems intuitive they could be supplied by the low-grade power solar cells are able to generate.)
Claims: A method for the preparation of a carbon-based combustible comprising reducing CO2 in an electrochemical cell which comprises an aerogel carbon electrode; an ionic liquid gel or membrane; an organic base comprising amine, added in the electrolyte or incorporated in the electrode, and a catalyst scavenging superoxide ion radical produced during the reduction of oxygen.
A method ... wherein said ionic liquid exhibits high ionic conductivity at ambient temperature and a wide electrochemical window (and) wherein said reducing CO2 occurs at ambient temperature.
(Note, especially, in the above claim, that, unlike many similar CO2 electrolysis technologies about which we've reported, high temperatures are not needed. This Israeli CO2-to-syngas process can proceed "at ambient temperature", thus reducing the energy needed to chemically reduce the Carbon Dioxide.)
A method ... wherein said gel comprises a synthetic or natural zeolite (and) wherein said zeolite is montmorillonite K10.
(We've explained "zeolite"s previously, and won't get into it again here. They are known and understood natural and synthetic minerals which have a wide variety of uses in chemical processing. If you're on well water and use a "water softener" to keep your underwear from turning orange in the washing machine, you've got some zeolites in a tank in your basement.)
A method ... wherein said ionic liquid comprises 1-butyl-3-methylimidazolium tetrafluroborate (and) wherein said membrane comprises RTV polysiloxane and ionic liquid (and) wherein said organic base is ethylenediamine.
A method ... wherein said electrochemical cell provides high current densities for CO2 reduction.
A method ... wherein the cathode comprises a material selected from porous copper or Ag (silver), copper or Ag on carbon powder pressed on carbon paper (Cu/C, or Ag/C), or porous carbon in which metallic Cu or Ag is deposited, said cathode comprising ethylenediamine.
A method ... wherein the anode is a gas diffusion electrode made of commercially available Pt/C or porous carbon in which metallic Pt is deposited.
A method ... comprising manufacturing CO (carbon monoxide) and H2 (hydrogen).
Background and Field: The present invention relates to the electrochemical conversion of carbon dioxide to useful products using a cell with a gel or solid electrolyte comprising an ionic liquid.
Electrochemical reduction of CO2 provides a potential renewable route to carbon-based fuels. Largely investigated has been the electrochemical reduction of CO2 in aqueous solutions, methanol and (etc.).
Numerous catalysts have been reported for the electrochemical reduction of CO2 and the products of the catalytic reduction include oxalate, CO, formate, carboxylic acids, formaldehyde, acetone, methanol, methane and ethylene.
Although water is an environmentally clean medium, its use is limited due to the low solubility of CO2, the variety of products obtained during the reduction and the difficulty of products recovery. Using a cobalt porphyrin attached to glassy carbon electrode as catalyst for CO2 reduction, the electrode was active for the electroreduction of CO2 to CO and H2 in aqueous medium with a current efficiency of CO production of 92% at -1.1 V.
(A little more than one volt - which should be relatively easy to achieve using solar cells.)
Another alternative is the use of organic solvents, however this is prohibitive due to their toxic and hazardous nature.
It has been reported that CO2 can also be reduced in molten eutectic mixture of Li2CO3+Na2CO3+K2CO3 at 700 C. This medium allowed high solubility of CO2. However, the current densities obtained for the reduction of CO2 were very low. This was explained as being due to a reaction occurring between CO2 and carbonate ions ... . The reduction of CO2 to O2 and CO in the 400-700 C temperature range with a ceramic electrolyte has also been reported.
Ionic liquids are salts which are in the molten state at low temperatures (less than 100 C); they are considered to be green solvents due to their very low vapor pressure and chemical inertness. High conductivity and wide electrochemical windows make them very useful electrolytes with wide potential applications. Ionic liquids were suggested for use as an electrolyte for the reduction of CO2. Although the solubility of this gas is high in these solvents, supercritical CO2 was supplied to the cathode, and when water was added the ionic liquid, CO and H2 were obtained at the cathode and O2 at the anode. A known method to overcome mass limitations of gases being reduced (such as O2 in fuel cells) is by the use of gas diffusion electrodes which interface the gas, electrocatalyst and electrolyte phases. However, when a liquid electrolyte is used, the pores of the electrode at which the gas is reduced are prone to flooding. This can be overcome by using a solid polymer electrolyte, such as the perfluorosulfonate membranes (such as Nafion) used in fuel cells. This membrane has also been used for the electrochemical reduction of CO2 to CH4 and C2H4. However, this membrane functions only in strong acidic media and very small faradaic efficiencies have been achieved for the reduction of CO2 at gas diffusion electrodes. It is therefore an object of this invention to provide a method for reducing CO2 at gas diffusion electrodes with a gel or solid electrolyte comprising an ionic liquid, while avoiding the drawbacks of the previous techniques.
It is further an object of the invention to provide a method for reducing CO2 at gas diffusion electrodes with an ionic liquid, trapped in a gel or membrane which serves as electrolyte. Besides the benefit of being environment friendly, these matrices will allow high CO2 solubility, and relatively high conductivity even at low water content.
It is another object of this invention to provide an electrochemical cell comprising an anode and a cathode, and an electrolyte in the form of gel or membrane comprising an ionic liquid, for use in manufacturing carbon-based combustibles.
Summary and Description: The present invention provides a method for the preparation of a carbon-based combustible comprising reducing CO2 in an electrochemical cell, which cell comprises an aerogel carbon electrode, an ionic liquid membrane as electrolyte, and an amino-containing organic base, such as ethylenediamine (EDA), present in the electrolyte or entrapped in the electrode.
In one embodiment, a gel or membrane serves in said cell as electrolyte (and) comprises ionic liquid. Although the present invention uses an ionic liquid, ..., the electrolyte in the present case is a solid matrix in which the ionic liquid is entrapped. Said ionic liquid preferably exhibits high ionic conductivity at ambient temperature and a wide electrochemical window. In the method according to the invention, said reducing CO2 occurs advantageously at ambient temperature.
In one aspect of the invention, the method for the preparation of a carbon-based combustible comprises reducing CO2 in an electrochemical cell, in which a membrane serves as electrolyte. Said membrane may comprise RTV polysiloxane and ionic liquid. Said electrochemical cell, in the method of the invention, provides high current densities for CO2 reduction. In a preferred embodiment, CO2 is supplied to the cathode of said electrochemical cell, and water supplied as liquid or vapor to the anode. Said cathode is preferably a gas diffusion electrode at which CO2 and H2O are reduced and the main products are CO and H2. The main product at the anode is usually O2.
In one embodiment of the invention, the cathode comprises a material selected from porous copper, copper on carbon powder pressed on carbon paper (Cu/C), or porous carbon in which metallic copper is deposited. Ag is another metal which can be considered as catalyst at the cathode. Said cathode preferably comprises ethylenediamine. Certain macrocyclic compounds, such as metalloporphyrins, can be used as alternative catalysts at the cathode. The present invention makes also use of ethylenediamine as an additive to the catalyst in the cathode (Cu, Ag, or metalloporphyrin) which improves CO2 reduction by increasing the current density. The anode may be a gas diffusion electrode made of commercially available Pt/C or porous carbon with deposited metallic Pt. Other water oxidation catalysts based on metal oxides, such as titanium oxide or tungsten oxide, can also be used at the anode. In a preferred embodiment, said cell is a planar cell, and the electrolyte is a gel. In a preferred embodiment of the method of the invention, the reduction current density depends linearly on the CO2 concentration. In other important embodiment, the reduction current density depends linearly on the CO2 concentration even in the presence of oxygen.
(Note, in the above, more mention of special "gas diffusion electrode"s for electrolytic Carbon Dioxide conversion processes. As seen for one example in our report of:
New Jersey Improves CO2 Recycling Technology | Research & Development | News; concerning: "United States Patent Application 20130105304 - High Surface Area Electrodes for the Electrochemical Reduction of Carbon Dioxide; 2013; Inventors: Jerry Kaczur, et. al., FL, NY, NJ, and CA; Assignee: Liquid Light, Inc., NJ; Abstract: Methods and systems for electrochemical conversion of carbon dioxide to organic products including formate and formic acid are provided. A system may include an electrochemical cell including a cathode compartment containing a high surface area cathode and a bicarbonate-based catholyte saturated with carbon dioxide. The high surface area cathode may include an indium coating and having a void volume of between about 30% to 98. The system may also include an anode compartment containing an anode and an acidic anolyte. The electrochemical cell may be configured to produce a product stream upon application of an electrical potential between the anode and the cathode. Background and Field: The present disclosure generally relates to the field of electrochemical reactions, and more particularly to methods and/or systems for electrochemical reduction of carbon dioxide using high surface area electrodes";
and as we will further see in reports to follow, development work is underway in various places to design and improve special electrodes for specific use in such electrochemical Carbon Dioxide recycling and conversion processes. For some specific introduction to "gas diffusion electrodes", developed it seems for use in fuel cells, see:
Gas diffusion electrode - Wikipedia, the free encyclopedia.)
In one aspect, the method of the invention comprises manufacturing CO and H2.
The invention relates to an electrochemical cell comprising, beside anode and cathode, an electrolyte in the form of gel or membrane comprising an ionic liquid. Said gel preferably comprises a synthetic or natural zeolite. Said zeolite may be montmorillonite K10. Said ionic liquid may comprise 1-butyl-3-methylimidazolium tetrafluoroborate. Said membrane may comprise RTV polysiloxane and ionic liquid. The electrochemical cell according to the invention preferably exhibits a reduction current density which depends linearly on the CO2 concentration even in the presence of oxygen.
It has now been found that an electrochemical cell (as described) provides surprisingly efficient means for reducing CO2 and obtaining a variety of carbon-based combustibles ... .
In one arrangement, the electrochemical reduction of CO2 leads to massive conversion of CO2 to fuels such as CO and H2 at the cathode, and to O2 at the anode. ... All experiments were carried out at ambient temperature (around 25 C).
It has now been found that the presence of EDA (ethylenediamine) as additive to an electrolytic solution, such as NaHCO3 (aka baking soda - sodium bicarbonate), is efficient in increasing the current density of CO2 reduction.
The new technology, thus, relates to electrochemical reduction of carbon dioxide (CO2).
In a preferred aspect of the invention, the technology relates to an electrochemical cell comprising i) an aerogel carbon electrode; ii) an ionic liquid gel or membrane; and iii) organic base comprising amine added in the electrolyte or incorporated in the electrode. In one preferred embodiment, said ionic liquid gel comprises 1-butyl-3-methylimidazolium tetrafluoroborate in a synthetic or natural zeolite. In another preferred embodiment, said membrane comprises RTV polysiloxane membrane and an ionic liquid.
If CO2 is supplied to the cathode and water to the anode, the products are carbon based fuels (such as CO) and hydrogen at the cathode and oxygen at the anode".
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And, again, the "CO", carbon monoxide, and the hydrogen, as can efficiently be made as herein by Israel's Ben Gurion University from water and Carbon Dioxide, comprise an hydrocarbon synthesis gas that can, via long-known technologies that are being continually improved, as well as being actually used, in various nations around the world, as in our introductory citation of our earlier report concerning Mobil Oil Corporation's "US Patent 4,086,262 - Conversion of Synthesis Gas to Hydrocarbon Mixtures", be chemically and catalytically condensed into any and every type of both liquid and gaseous hydrocarbon fuel and chemicals.
As noted by Ben Gurion University, the carbon monoxide and hydrogen can, as well, serve, as is, as a fuel, although that doesn't seem to us the best and highest use of such a product.
In any case, we have further confirmation herein that Carbon Dioxide could, we insist should, be seen and treated as a valuable raw material resource.
In the process of our subject, "United States Patent 8,999,134 - Manufacturing Carbon-Based Combustibles by Electrochemical Decomposition of CO2", it is seen that Carbon Dioxide, in combination with Water, H2O, can be efficiently converted into an hydrocarbon synthesis gas mixture of Carbon Monoxide and Hydrogen from which, using known and established technologies, any and all types of liquid and gaseous hydrocarbon fuels and industrial raw materials, most of which we now import from OPEC, can be directly synthesized.