- Friday | 07/29/2011
We hesitated at first to present the Standard Oil Company Carbon Dioxide recycling technology we submit in this dispatch.
The official, United States Patent Disclosure of it bandies terms about that are so arcane as to be absolutely unintelligible to us mere Coal-digging troglodytes.
The exotic terminology they employ makes this technology feel, at first, as if it were something that would have to be employed and practiced somewhere between the third and fourth rings of Saturn; or, at least atop the highest and whitest of ivory towers.
That would be self-defeating misinterpretation.
They are using molecular structures well-known to organic chemists, complex molecules which are built up of common compounds, to facilitate and dramatically reduce the energy needed to convert Carbon Dioxide into Carbon Monoxide.
Only the names and terminology are unfamiliar; and, we deserve some orientation before heading in.
We'll be relying on our old friend, the Wikipedia to accomplish that orientation. And, we want first to affirm, that, although the Wikipedia is a secondary source, they do most often support their information with links to primary and authoritative references. And, they do a pretty good job of translation and summary.
First of all, Standard Oil talks a lot herein about some things called "macrocycles". And, as we can see in:
Macrocycle - Wikipedia, the free encyclopedia; they are fairly common, though complex, molecular structures, typically of biological origin, and count among their number some well-known substances such as Chlorophyll, Hemoglobin and Vitamin B-12. They are known and understood.
Standard Oil also employs the label, "porphyrin", and, as in:
Porphyrin - Wikipedia, the free encyclopedia; we can learn that, though not necessarily synonymous with "macrocycle", the term is related, and can as well be used to label complex organic molecules, again including Chlorophyll and a component of Hemoglobin.
More obtuse is Standard Oil's use of the phrase "square planar geometry", as it is applied to molecular structures. And, we learn in:
Square planar molecular geometry - Wikipedia, the free encyclopedia; that, the phrase is most often used to describe catalyst compounds based on Gold or Platinum Group metals, since molecules which incorporate those noble metals must assume some special shapes to "encapsulate", as it were, rather than chemically bind with, the atoms of those un-reactive elements.
Other highly-obtuse terminology is employed as well; but, all of it is related to the foregoing; and all of it, again, would likely be easily understood by organic chemists.
With apologies for that lengthy digression, and with the hope that it hasn't caused you to lose attention or interest, following, with even more comment inserted and appended, are excerpts from the initial link in this dispatch, explaining how, in a low-energy demand, catalyzed process, Carbon Dioxide can be efficiently transformed into the chemically-reactive, and thus quite useful, Carbon Monoxide:
"US Patent 4,668,349 - Electrocatalytic Reduction of CO2 by Square Planar Transition Metal Complexes
Date: May, 1987
Inventors: Edward Cuellar and Verna Gaylor, OH
Assignee: The Standard Oil Company, Cleveland
Abstract: A process for the electrocatalytic reduction of carbon dioxide comprises immersing a transition metal complex with square planar geometry into an aqueous or nonaqueous solution which has been acidified to a (specified) hydrogen ion concentration ... , adding the carbon dioxide, applying an electrical potential of from about -0.8 volts to about -1.5 volts ... , and reducing the carbon dioxide to carbon monoxide.
(Note that the energy, the electrical voltage, needed is quite low. With the proper catalysis, as specified, this could be a very efficient process. And, that voltage is certainly something that could be achieved via current photo-voltaic conversion cells, making Solar radiation a viable source of energy for the process.)
Claims: A process for the electrocatalytic reduction of carbon dioxide in an electrochemical cell having at least one working electrode which comprises: adding carbon dioxide to said cell containing an aqueous or nonaqueous solution which has been acidified (as specified, and) applying an electrical potential to said working electrode of from about -0.8 volts to about -1.5 volts ...; and,
reducing said carbon dioxide to carbon monoxide;
wherein said working electrode carries a transition metal complex with square planar geometry which is immersed in said solution (and) wherein said transition metal is Cobalt.
The process ... wherein said square planar geometry is provided for by a salen complex.
The process ... wherein said square planar geometry is provided for by a cyclam-type complex.
(As in: Salen ligand - Wikipedia, the free encyclopedia; and: Cyclam - Wikipedia, the free encyclopedia; "Salen" materials have been known, studied and used since 1938; and, some are commercially available and utilized industrially. "Cyclam" is one specific type, or class, of "Salen". It all has genuine meaning and significance for chemists with appropriate training and experience.)
The process ... wherein said electrolyte solution is acidified to a hydrogen ion concentration (as specified) by the addition of an acid selected from the group consisting of weak organic acids and strong mineral acids.
(And) wherein said weak organic acid is citric acid.
(And) wherein said strong mineral acid is sulfuric acid.
(Note, that, as seen in:
USDOE Makes Hydrogen by Using Sulfur Dioxide | Research & Development; concerning: "United States Patent 4,244,794 - Hydrogen Production by the Decomposition of Water; 1981; Assignee: The United States of America; Abstract: How to produce hydrogen from water was a problem addressed by this invention. The solution employs a combined electrolytical-thermochemical sulfuric acid process. Additionally, high purity sulfuric acid can be produced in the process. Water and SO2 react in (an) electrolyzer ... so that hydrogen is produced at the cathode and sulfuric acid is produced at the anode";
we can make the needed "sulfuric acid", as a by-product of manufacturing Hydrogen, for use in Coal and Carbon Dioxide hydrogenation reactions that synthesize Hydrocarbons, from a blend of Water and Sulfur Dioxide, which could, perhaps, be scrubbed from a Coal-fired power plant's exhaust gases.)
Background and Field: The present invention is directed toward a method for the electrocatalytic reduction of carbon dioxide to carbon monoxide in an acidified aqueous or nonaqueous solution. The catalyst employed is a transition metal complex with square planar geometry.
It is well known in the art to employ various square planar transition metal complexes deposited on various electrodes to catalyze the electrocatalytic reduction of carbon dioxide.
One example is ... the electrochemical reduction of carbon dioxide to formic acid.
(See, for example:
Japan Converts CO2 to Formic Acid | Research & Development | News; which makes report of: "United States Patent 7,479,570 - Process for the Reduction of Carbon Dioxide; 2009; Japan Science and Technology Agency; A reducing process of carbon dioxide ... , comprising mixing carbon dioxide and water with an organometallic complex ... so as to reduce carbon dioxide (and produce) formic acid".)
Summary: In general, the subject invention provides a process for the electrocatalytic reduction of carbon dioxide to carbon monoxide in an acidified aqueous or nonaqueous solution. The process comprises the steps of immersing a transition metal complex with square planar geometry into an aqueous or nonaqueous solution which has been acidified to a (specified) hydrogen ion concentration ... and, reducing the carbon dioxide to carbon monoxide.
The reduction of carbon dioxide to carbon monoxide and organic compounds has been studied for years as a possible method for making synthetic hydrocarbons. However, the basic reactions of CO2 in aqueous and nonaqueous solutions ... which, despite a high conversion efficiency (are) uneconomical.
An alternative to the unecomonical aspect of high overpotentials is to lower the overpotential by the use of various transition metal complex electrocatalysts. This generally favors carbon monoxide as the resulting product which is a desirable product inasmuch as it can be used as a precursor in a number of other catalytic reactions such as the Fischer-Tropsch reaction for the production of organic complexes."
Well, well ... we start out with Carbon Dioxide and wind up with our old Coal-to-Liquid fuel friends, Fischer and Tropsch, who know, as seen in:
Fischer–Tropsch process - Wikipedia, the free encyclopedia; which says: "The Fischer-Tropsch process is a set of chemical reactions that convert a mixture of carbon monoxide and hydrogen into liquid hydrocarbons";
how to convert Carbon Monoxide and Hydrogen into liquid hydrocarbon fuels.
All that's needed, in addition to the Carbon Monoxide, generated so efficiently, as herein, via our subject process of "US Patent 4,668,349", from Carbon Dioxide, is Hydrogen, which we can rather efficiently obtain, in addition to that generated in the process of our above-cited "United States Patent 4,244,794 - Hydrogen Production by the Decomposition of Water", via, as seen in: .
USDOE Algae Make Hydrogen for Coal and CO2 Hydrogenation | Research & Development; concerning: "Photosynthetic Hydrogen and Oxygen Production by Green Algae; Oak Ridge National Laboratory; Abstract: Photosynthesis research at Oak Ridge National Laboratory is focused on hydrogen and oxygen production by green algae in the context of its potential as a renewable fuel and chemical feed stock";
the metabolic processes of certain Algae, who generate Hydrogen as a by-product of certain of those metabolic processes that function in the course of consuming and recycling Carbon Dioxide.
Or, we could, as Standard Oil themselves tell us, take the Carbon Monoxide they generate through their own process of "US Patent 4,668,349", from Carbon Dioxide, and, through another of their technologies, as we reported in:
Standard Oil Carbon Monoxide + Water = Gasoline | Research & Development; concerning: "United States Patent 4,559,363 - Process for Reacting Carbon Monoxide and Water; 1985; A process for reacting carbon monoxide and water ... for the direct production of gasoline";
rather simply add Water to that Carbon Dioxide-based Carbon Monoxide, and thereby make Gasoline.