We have so far presented many reports documenting the development, by Princeton University scientists Andrew Bocarsly and Emily Barton Cole, of technology wherein Carbon Dioxide, as harvested from whatever convenient source, can be efficiently and productively used and consumed in the synthesis of valuable organic chemicals; as in, for just one example:
Princeton University March, 2014, CO2 to Methanol | Research & Development | News; concerning: "United States Patent 8,663,447 - Conversion of Carbon Dioxide to Organic Products; March 4, 2014; Inventors: Andrew Bocarsly, NJ, and Emily Barton Cole, TX; Assignee: Princeton University, NJ; Abstract: The invention relates to various embodiments of an environmentally beneficial method for reducing carbon dioxide. The methods in accordance with the invention include electrochemically or photoelectrochemically reducing the carbon dioxide in a divided electrochemical cell that includes an anode, e.g., an inert metal counterelectrode, in one cell compartment and a metal or p-type semiconductor cathode electrode in another cell compartment that also contains an aqueous solution of an electrolyte and a catalyst of one or more substituted or unsubstituted aromatic amines to produce therein a reduced organic product. Government Interests: This invention was made with United States government support from National Science Foundation Grant No. CHE-0616475. The United States Government has certain rights in this invention. Claims: An environmentally beneficial method of producing methanol by electrochemical reduction of any available source of carbon dioxide, which comprises: providing a divided electrochemical cell comprising an anode in a first cell compartment and a cathode in a second cell compartment that also contains a catalyst which is one or more of a substituted or unsubstituted aromatic heterocyclic amine selected from the group consisting of a pyrazine, a pyridazine, and a pyrimidine, both compartments containing an aqueous solution of an electrolyte; providing carbon dioxide from an existing source into the second cell compartment; and electrochemically reducing the carbon dioxide in the second cell compartment to produce methanol".
We've also documented that Bocarsly and Cole have joined with other accomplished scientists to found a company, Liquid Light, Incorporated; which company is intended to further develop and to commercialize the Carbon Dioxide utilization technologies first established in Bocarsly's Princeton University laboratory. See, for one recent example, our report of:
More New Jersey CO2 to High-Energy Alcohol | Research & Development | News; concerning: "United States Patent 8,961,774 - Electrochemical Production of Butanol from Carbon Dioxide and Water; 2015; Inventors: Emily Barton Cole, Kyle Teamey, Andrew Bocarsly, and Narayanappa Sivasankar; Assignee: Liquid Light, Inc., Monmouth, NJ; Abstract: Methods and systems for electrochemical production of butanol are disclosed. A method may include, but is not limited to, steps (A) to (D). Step (A) may introduce water to a first compartment of an electrochemical cell. The first compartment may include an anode. Step (B) may introduce carbon dioxide to a second compartment of the electrochemical cell. The second compartment may include a solution of an electrolyte, a catalyst, and a cathode. Step (C) may apply an electrical potential between the anode and the cathode in the electrochemical cell sufficient for the cathode to reduce the carbon dioxide to a product mixture. Step (D) may separate butanol from the product mixture".
In point of fact, as we have commented a few times in our reports of the Carbon Dioxide utilization technologies being established by Bocarsly and Cole and their colleagues, both at Princeton University and at Liquid Light Incorporated, those CO2-conversion processes developed by them are now so numerous, and technically complex, that we have stopped making report of them while they are in the United States patent application process. We confine our reportage of their achievements only to issued patents and to published news reports concerning them - - which there should be many more of, especially in Coal Country, where our economically essential Coal industries are being threatened by blind predations focused on eliminating emissions of that valuable raw material resource, Carbon Dioxide, from our Coal-fired generators of abundant and affordable electric power.
In any case, herein we see that our United States Government just days ago confirmed, yet again, that Princeton University has developed an array of technologies wherein Carbon Dioxide can be used and consumed in a process like that disclosed in the above-cited, and identically-labeled, "United States Patent 8,663,447 - Conversion of Carbon Dioxide to Organic Products", which process can be powered, as in "photoelectrochemically", by light energy, presumably sunlight, and which process results in the production of, among other valuable products, fuel alcohol Methanol.
Comment follows and is inserted within excerpts from the initial link in this dispatch to:
"United States Patent 8,986,533 - Conversion of Carbon Dioxide to Organic Products
Conversion of carbon dioxide to organic products - Princeton University
March 24, 2015
Inventors: Andrew Bocarsly and Emily Barton Cole, NJ
Assignee: Princeton University, NJ
Abstract: The invention relates to various embodiments of an environmentally beneficial method for reducing carbon dioxide. The methods in accordance with the invention include electrochemically or photoelectrochemically reducing the carbon dioxide in a divided electrochemical cell that includes an anode, e.g., an inert metal counterelectrode, in one cell compartment and a metal or p-type semiconductor cathode electrode in another cell compartment that also contains an aqueous solution of an electrolyte and a catalyst of one or more substituted or unsubstituted aromatic amines to produce therein a reduced organic product.
Government Interests: This invention was made with United States government support from National Science Foundation Grant No. CHE-0616475. The United States Government has certain rights in this invention.
(At this point in the full disclosures of United States Patents, precedent and related patent art and pertinent scientific literature references are catalogued. Princeton's catalogue of citations herein is extensive, and includes a number of developments about which we've previously reported, as in, for just one example:
USDOE 1976 Atmospheric CO2 to Methanol | Research & Development | News; concerning: "United States Patent 3,959,094 - Electrolytic Synthesis of Methanol from CO2; 1976; Inventor: Meyer Steinberg, NY; Assignee: The USA as represented by the USDOE; Abstract: A method and system for synthesizing methanol from the CO2 in air using electric power. The CO2 is absorbed by a solution of KOH to form K2CO3 which is electrolyzed to produce methanol, a liquid hydrocarbon fuel. Summary: In accordance with a preferred embodiment of this invention, a solution of KOH is employed to absorb CO2 from air forming an aqueous solution of K2CO3, the solution is then electrolyzed to produce CH3OH (i.e., Methanol) and reform KOH in solution, the CH3OH is then removed, and make-up water is then added prior to repeating the aforementioned steps. Other products ... are also formed which can be separated and recovered as valuable products. By the process described above, it is seen that any source of electrical power may be employed, such as coal-fired power plants. However, from an environmental point of view ... solar energy generated power, would be preferred".)
Claims: A method of converting carbon dioxide into at least one product, comprising: reducing the carbon dioxide photoelectrochemically in a divided electrochemical cell comprising an anode in one cell compartment and a cathode electrode in another cell compartment, the cell compartment including the cathode including one or more substituted or unsubstituted aromatic heterocyclic amines, each compartment containing an aqueous solution of an electrolyte, and the cathode electrode is a p-type semiconductor responsive to illumination, wherein the aromatic heterocyclic amine is at least one of tertbutyl-pyridine, dimethyl-pyridine, 2,6-lutidine, 2-methylpyridine, 4-methylpyridine, dimethylamino-pyridine, 4-hydroxypyridine, or 4,4'-bipyridine, or mixtures thereof.
The method ... wherein the p-type semiconductor is at least one of p-Gallium Phosphide, p-Gallium Arsenide, (etc.,).
The method ... further comprising illuminating the cathode with light energy to provide energy to the cell.
The method ... further comprising receiving the carbon dioxide from an exhaust stream from a fossil fuel burning power or industrial plant, from a source accompanying natural gas or from a geothermal well.
Background and Description: (Carbon) capture and storage, the process of separating CO2 from emission sources and transporting it to a storage location for long-term (indefinite) isolation, and carbon sequestration, the process of permanently storing CO2 underground, have garnered the most attention to date. However, these technologies face significant challenges and are presently far from being cost effective. In addition, sequestration has raised serious environmental concern, legal and regulatory issues due to the unknown ramifications of permanently storing CO2 underground.
In accordance with embodiments of the invention, an electrocatalytic system is provided that allows carbon dioxide to be converted at very modest overpotentials to highly reduced species in aqueous solution.
In other words, carbon-carbon and/or carbon-hydrogen bonds are formed in aqueous solution under very mild condition utilizing a minimum of energy. In some embodiments, the required energy input may be generated from an alternative energy source or directly using visible light depending on how the system is implemented.
In embodiments of the invention, the reduction of carbon dioxide is suitably catalyzed by aromatic heterocyclic amines, e.g., pyridinium, imidazole and their substituted derivatives. These simple organic compounds have been found to be effective and stable homogenous electrocatalysts and photoelectrocatalysts for the aqueous multiple electron, multiple proton reduction of carbon dioxide to organic products such as formic acid, formaldehyde, and methanol.
It has previously been thought that metal-derived multi-electron transfer was necessary to achieve highly reduced products such as methanol. Surprisingly, the simple aromatic heterocyclic amine molecules in accordance with embodiments of the invention are capable of producing many different chemical species on route to methanol through multiple electron transfers instead of metal-based multi-electron transfer.
The invention thus relates to various embodiments of environmentally beneficial methods for reducing carbon dioxide. The methods in accordance with the invention include electrochemically or photoelectrochemically reducing the carbon dioxide in an aqueous, electrolyte-supported divided electrochemical cell that includes an anode, e.g., an inert metal counterelectrode, in one cell compartment and a metal or p-type semiconductor working cathode electrode in another cell compartment that contains a catalyst of one or more substituted or unsubstituted aromatic heterocyclic amines to produce a reduced organic product.
CO2 is continuously bubbled through the cathode electrolyte solution to saturate the solution.
For electrochemical reduction, the electrode may be chosen from any suitable metal electrode, such as Gold, Silver, Zinc, Palladium, (etc.). Platinum and hydrogenated Palladium have been found to be especially suitable. For photoelectrochemical reduction, the electrode may suitably be chosen from p-type semiconductors such as p-GaAs, p-GaP, p-InN, p-IndiumP, p-CadmiumTelluride, p-GaInP.sub.2 and p-Silicon.
The catalyst for conversion of carbon dioxide electrochemically or photoelectrochemically may be selected from any substituted or unsubstituted aromatic heterocyclic amine. Suitable amines are heterocycles which are 5- or 6-member rings with at least one ring nitrogen. For example, pyridine, imidazole and their substituted derivatives have been found to be especially suitable as catalysts for either the electrochemical reduction or the photoelectrochemical reduction. It is also envisioned the other aromatic amine, e.g., quinolines, are also effective electrocatalysts.
Embodiments of the present invention relate to the simple, efficient, and economical conversion of carbon dioxide to reduced organic products, such as methanol, formic acid and formaldehyde.
It has been previously known that carbon dioxide can be photochemically or electrochemically reduced to formic acid with formaldehyde and methanol being formed in only smaller amounts. Catalytic hydrogenation of carbon dioxide using heterogeneous catalysts is also known to provide methanol together with water as well as formic acid and formaldehyde. Also known is the reduction of carbon dioxide to methanol with complex metal hydrides, such as lithium aluminum hydride, a process which is extremely costly, and therefore, not suited for the bulk production of methanol. Such known current processes are highly energy-consuming, and are not efficient ways for a high yield, economical conversion of carbon dioxide to organic products, e.g., methanol.
On the other hand, the use of processes for converting carbon dioxide to reduced organic products in accordance with embodiments of the invention ... produces methanol and related products without the need of adding extra reactants, such as a hydrogen source. The resultant product mixture requires little in the way of further treatment. For example, a resultant 1 M methanol solution may be used directly in a fuel cell. For other uses, simple removal of the electrolyte salt and water are readily accomplished.
Advantageously, the carbon dioxide used in the embodiments of the invention can be obtained from any sources, e.g., an exhaust stream from fossil-fuel burning power or industrial plants, from geothermal or natural gas wells or the atmosphere itself. Most suitably, however, carbon dioxide is obtained from concentrated point sources of its generation prior to its release into the atmosphere.
For example, high concentration carbon dioxide sources are those frequently accompanying natural gas in amounts of 5 to 50%,
(Other sources are) those from flue gases of fossil fuel ... burning power plants, and nearly pure CO2 exhaust of cement factories and from fermenters used for industrial fermentation of ethanol. Certain geothermal steams also contains significant amounts of CO2.
In other words, CO2 emissions from varied industries, including geothermal wells, can be captured on-site. Separation of CO2 from such exhausts is well-developed. Thus, the capture and use of existing atmospheric CO2 in accordance with embodiments of the invention allows CO2 to be a renewable and unlimited source of carbon.
(Concerning the above discussion about capturing CO2 from various sources for use in the process of our subject, "United States Patent 8,986,533 - Conversion of Carbon Dioxide to Organic Products", see, for only a few examples, our reports of:
Columbia University Practical Extraction of Atmospheric CO2 | Research & Development | News; concerning: "United States Patent 8,246,731 - Systems and Methods for Extraction of Carbon Dioxide from Air; 2012; Inventors: Klaus Lackner and Frank Zeman, NY; Assignee: The Trustees of Columbia University in the City of New York"; and:
USDOD Harvests More CO2 for Hydrocarbon Synthesis | Research & Development | News; concerning: "United States Patent 20130008792 - Electrodialytic Separation of CO2 Gas from Seawater; 2013; Inventors: Matthew Eisaman and Karl Littau; Assignee: Palo Alto Research Center Incorporated, Palo Alto, CA; Government Interests: This invention was made with Government support under contract HR0011--10-C-0147 awarded by DARPA, an agency of the United States Department of Defense"; and:
USDOE Hires WVU to Capture CO2 for Hydrocarbon Synthesis | Research & Development | News; concerning: "United States Patent 8,658,561 - Layered Solid Sorbents for Carbon Dioxide Capture; 2014; Inventors: Bingyun Li, et. al., West Virginia and Pennsylvania; Assignee: West Virginia University, Morgantown, WV; Abstract: A solid sorbent for the capture and the transport of carbon dioxide gas is provided.)
It has now been found that the use of electrochemical or photoelectrochemical reduction of carbon dioxide (CO2), tailored with certain electrocatalysts, produces methanol and related products in a high yield of about 60 to about 100%, based on the amount of CO2, suitably about 75 to 90%, and more suitably about 85 to 95%. At an electric potential of about -0.09 to -0.5 V ... methanol can be produced with good faradaic efficiency at the cathode.
The effective electrochemical/photoelectrochemical reduction of carbon dioxide disclosed herein provides new methods of producing methanol and other related products in an improved, efficient, and environmentally beneficial way.
(And,) the methanol product of reduction of carbon dioxide can be advantageously used as:
(1) a convenient energy storage medium, which allows convenient and safe storage and handling;
(2) a readily transported and dispensed fuel, including for methanol fuel cells; and:
(3) a feedstock for synthetic hydrocarbons and their products currently obtained from oil and gas resources", including polymers, biopolymers and even proteins, which can be used for animal feed or human consumption. Importantly, the use of methanol as an energy storage and transportation material eliminates many difficulties of using hydrogen for such purposes. The safety and versatility of methanol makes the disclosed reduction of carbon dioxide further desirable.
In summary, embodiments of the invention provide that carbon dioxide can be efficiently converted to value added products, using either a minimum of electricity (that could be generated from an alternate energy source) or directly using visible light".
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The full Disclosure notes almost in passing the value of the product Methanol. Keep in mind that it can, for instance, as seen for one example in our report of:
ExxonMobil Coal to Methanol to Gasoline | Research & Development | News; concerning, in part: "United States Patent 4,035,430 - Conversion of Methanol to Gasoline; 1977; Inventors: Francis Dwyer, et. al., NJ and PA; Assignee: Mobil Oil Corporation, NY; Abstract: The conversion of methanol to gasoline boiling products in a plurality of sequentially arranged catalyst beds comprising a dehydration catalyst followed by a special class of crystalline zeolite conversion catalyst is described. Claims: (A) method for converting methanol to gasoline boiling products in a plurality of sequentially arranged catalyst beds ... .Summary: This invention relates to the method and system for converting methanol to gasoline boiling components";
be directly converted into Gasoline via well-established and long-known processes. But, it has so many other uses and industrial applications, including the synthesis of certain high-volume plastics and polymers, wherein any CO2 consumed in the synthesis of the Methanol would remain chemically and permanently, and profitably, "sequestered". As can be learned via:
Methanol Applications - Methanol Institute; "Methanol is one of the most versatile compounds developed and is the basis for hundreds of chemicals, thousands of products that touch our daily lives, and is second in the world in amount shipped and transported around the globe every year";
Methanol, as can be made, as herein, in a photosynthetic process, from Carbon Dioxide, is a commodity of already immense value. The associated CO2-based product, Formaldehyde, too, can be and is being used in the industrial synthesis of plastics and polymers; and, without documenting the details, more formaldehyde, aka "methanal", can be easily made from Methanol.
In sum, instead of closing Coal-fired power plants because of suspect concerns about Carbon Dioxide emissions, and thereby killing jobs and skyrocketing the cost of electricity for millions of United States citizens, and for United States industries, we could, instead, start harvesting Carbon Dioxide from whatever source most convenient to us, and, then, in the process of our subject, "US Patent 8,986,533 - Conversion of Carbon Dioxide to Organic Products", a process which can be powered by freely-available, albeit low-grade, solar energy, we can start converting that Carbon Dioxide into Methanol, and, then, as via for just one example the Mobil Oil process of "United States Patent 4,035,430 - Conversion of Methanol to Gasoline", into just about anything and everything we now squander our national treasure and put our young men and women in uniform at risk in order to continue buying from the lovable folks at OPEC.
Moreover, we could be creating a ton of new industries and new jobs in Coal Country, new industries which even our fellow United States citizens concerned, rightly or wrongly, about the role Carbon Dioxide plays or might play in whatever climate change might or might not be occurring, could plausibly feel good about supporting and participating in.
Herein, we have more win-win potentials laid out before us. Do we have the courage to start making those potentials real, or at least to start talking about them openly and publicly?