California Captures CO2 for Conversion to Hydrocarbons

United States Patent: 7795175

Our headline might at first seem to be a little bit of an, perhaps unwarranted, extrapolation.

It is not.

As clearly indicated by one advance excerpt taken from the "Background" section of our subject herein:

"One way to mitigate CO2 emissions and their influence on the global climate is to efficiently and economically capture CO2 from its source, such as emissions from fossil fuel-burning power plants and other industrial factories, naturally occurring CO2 accompanying natural gas, and the air. Once captured, CO2 can be ... used as a raw material to synthesize fuel and synthetic hydrocarbons."

We'll support that US Government-approved contention further, with links to and excerpts from earlier of our reports concerning the Carbon Dioxide recycling accomplishments of, and United States Government-issued patents awarded to, the lead inventor of the technology we treat herein, the University of Southern California's resident Nobel Laureate, George Olah, and his USC colleagues.

As a start, here, from more than two years ago, is one of those prior reports:

California Patents CO2 Recycling | Research & Development; concerning:

"United States Patent: 7608743 - Efficient ... Recycling of Carbon Dioxide to Methanol

(Note that we include in our excerpts herein a fresh link to the official United States Patent and Trademark Office electronic file of "United States Patent 7,608,743". Due, we conclude, to not-uncommon "glitches" on the USPTO's web site, the original source file of the document was not accessible at the time we made our earlier report; and, we included in that report a link to a secondary site that maintains patent records.)

Date: October, 2009

Inventors: George Olah and Surya Prakash, CA

Assignee: University of Southern California, Los Angeles

Abstract: An efficient and environmentally beneficial method of recycling and producing methanol from varied sources of carbon dioxide including flue gases of fossil fuel burning powerplants, industrial exhaust gases or the atmosphere itself. Converting carbon dioxide by chemical or electrochemical reduction secondary treatment to produce essentially methanol, dimethyl ether and derived products."

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Of course, to convert "carbon dioxide (from the) flue gases of fossil fuel burning powerplants, industrial exhaust gases or the atmosphere itself" into such seemingly desirable things as "methanol" and the substitute Diesel fuel "dimethyl ether", along with other "products", you first have get yourself some CO2 in a way that doesn't break your bank.

And, that is the issue Nobel Laureate Olah and friends address herein, as seen in excerpts, with comment and additional references inserted and appended, from the initial link in this dispatch to:

"US Patent 7,795,175 - Absorbents for the Separation of CO2 from Gas Mixtures Including the Air

Date: September, 2010

Inventors: George Olah, et. al., CA

Assignee: University of Southern California, Los Angeles

Abstract: The invention relates to regenerative, supported amine sorbents that includes an amine or an amine/polyol composition deposited on a nano-structured support such as nanosilica. The sorbent provides structural integrity, as well as high selectivity and increased capacity for efficiently capturing carbon dioxide from gas mixtures, including the air. The sorbent is regenerative, and can be used through multiple operations of absorption-desorption cycles.

(First, alarmists will no doubt raise cries of protest about the specified "amine" and "polyol". Truth to tell, you likely wouldn't want either of them sneaking into your iced tea; but, as seen in:

http://ccarenergy.webs.com/co2%20capture%20short.pdf; "Amine scrubbing has been used to separate carbon dioxide (CO2) from natural gas ... since 1930";

the "amine"s have been, and will likely be further, used to extract the often shockingly-high natural Carbon Dioxide content of everyone's current golden-child fuel; so no one who's been loudly touting the economic and environmental glories of shale gas should have any non-hypocritical problems with it.

Further, as seen in:

Polyol - definition of Polyol in the Medical dictionary - by the Free Online Medical Dictionary, Thesaurus and Encyclopedia.; wherein we're told, that: "polyols (are)" just "substances made up of two or more alcohols";

and, as in:

Polyols Information Source: Sugar Alcohols as Sweeteners and Sugar Replacers; wherein we're told, that: "polyols" are "sugar alcohols", that is, "low-digestible carbohydrates" which can actually be "used as sugar replacers" in "reduced-calorie" food "products";

the "polyols" are relatively benign substances, some of which can even be safely ingested.

Please note, however, that there are a number of well-known manufacturers who actually produce various polyols in several chemical plants along the rivers of our more local portion of US Coal Country; and, it's possible that a few of our readers have seen a drum or two of that industrial polyol, and read the labels.

We urge, that, if the warnings on those labels cause concern, readers take another, closer look at them, and/or consult a chemist familiar with them. Polyols are produced and compounded, most often, so that they can be reacted with other substances and compounds, as in the manufacture of polyurethane foam. The health effect warnings on polyol labels, and in their material safety data sheets, most often relate to other materials, such as metal, or other, catalysts, that are added to the basic poly alcohol to improve it's rate of reaction with another compound; or, to influence the physical properties of the end product, usually some type of plastic, that results from the reaction of the polyol with the other compound.

The use of polyol, or appropriate amines, in an industrial setting, for the collection of Carbon Dioxide, especially for the recycling and reuse of that Carbon Dioxide, can have no logical, reality-based argument raised against it.

Finally, the sorbents specified herein, as will be seen, are to be used as dispersed on, and contained in and by, a porous solid substrate; kind of like a hard sponge. They are not going to "leak", or travel unassisted, from the place where they are used.)

Claims:  A solid carbon dioxide sorbent for absorbing carbon dioxide from a gas mixture and which is capable of releasing the absorbed carbon dioxide when treated for regeneration, the sorbent comprising an amine in an amount of at least 25% by weight of the sorbent and nano-sized solid particles having a primary particle size that is less than about 100 nanometers for providing structural integrity and support for the amine and a high surface area for amine-gas contact.

The sorbent ... wherein the nano-structured support is a nanosilica, silica-alumina and the like fumed or precipitated oxide, calcium silicate, carbon nanotube, or mixture thereof.

(The descriptor "nano" just means extremely small. The "fumed ... calcium silicate", for example, means that it's like very fine dust, or soot. The "nanotube" just means that it's a particle of, essentially, dust, that also happens to be hollow, like a microscopic soda straw.)

The sorbent ... wherein the amine is a primary, secondary, or tertiary amine or alkanolamine, aromatic amine, or mixtures or combinations thereof (of a further specified wide variety). 

The sorbent ... in which the amine is present in an amount of about 25% to 75% by weight of the sorbent. 

The sorbent ... which further comprises a polyol in an amount up to about 25% by weight of the sorbent. 

The sorbent ... wherein the polyol is selected from the group consisting of glycerol, oligomers of ethylene glycol, polyethylene glycol, polyethylene oxides, and ethers, modifications and mixtures thereof.

(Since "glycerol" is one polyol that can be used, a closer look at it, as in:

Glycerol - Wikipedia, the free encyclopedia; "Glycerol (or glycerine, glycerin) is a simple polyol compound. It is a colorless, odorless, viscous liquid that is widely used in pharmaceutical formulations. Glycerol is ... of low toxicity";

should help to assuage any safety fears and doubts. The "ethylene glycol", as can be learned via:

Ethylene glycol - Wikipedia, the free encyclopedia;

is commonly used as a component of automotive antifreeze, so it's not something we're unfamiliar with and don't already handle a lot of; although you definitely wouldn't want to drink it.

But, the "polyethylene glycol", as can be learned via:

Polyethylene glycol - Wikipedia, the free encyclopedia;

is so non-toxic that it's used as a component in some over-the-counter medicines, such as laxatives and eye drops.)


The sorbent ... which releases absorbed carbon dioxide when treated for regeneration. 

The sorbent ... wherein the sorbent is treated with sufficient heat, reduced pressure, vacuum, gas purge, or a combination thereof to release a substantial amount or all the absorbed carbon dioxide. 

A method for continuously capturing and separating carbon dioxide from a gas mixture with a sorbent, which comprises exposing the sorbent (as described and specified herein) to the gas mixture to effect absorption of carbon dioxide by the sorbent and treating the sorbent that contains absorbed or entrapped carbon dioxide to release a substantial amount or all the absorbed carbon dioxide.

(And, now, folks, be sure you pay attention to, and don't miss, the following claims.)

The method ... which further comprises reacting the released carbon dioxide to form useful products.

The method ... wherein carbon dioxide is used to produce methanol by (a) electrochemical reduction of carbon dioxide in water or (b) reducing carbon dioxide under conditions sufficient to produce an intermediate compound and catalytically hydrogenating the intermediate compound with hydrogen under conditions sufficient to form methanol.

(Concerning the above, "electrochemical reduction of carbon dioxide in water", see, for example:

West Virginia Coal Association | California Recycles More and More Carbon Dioxide | Research & Development; concerning:

"United States Patent 7,704,369 - Electrolysis of Carbon Dioxide ... for Production of Methanol; 2010; Inventors: George Olah and Surya Prakash; Assignee: University of Southern California; Abstract: An environmentally beneficial method of producing methanol from varied sources of carbon dioxide including flue gases of fossil fuel burning power plants, industrial exhaust gases or the atmosphere itself. Converting carbon dioxide by an electrochemical reduction of carbon dioxide in a divided electrochemical cell that includes an anode in one cell compartment and a metal cathode electrode in another cell compartment that also contains an aqueous solution comprising methanol and an electrolyte of one or more alkyl ammonium halides, alkali carbonates or combinations thereof to produce therein a reaction mixture containing carbon monoxide and hydrogen which can be subsequently used to produce methanol while also producing oxygen in the cell at the anode".

Another example can be seen in:

Standard Oil Electrolyzes CO2 to Carbon Monoxide | Research & Development; concerning: "United States Patent 4,668,349 - Electrocatalytic Reduction of CO2 by Square Planar Transition Metal Complexes; 1987;  Assignee: The Standard Oil Company; 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.")

The method ... which further comprises reducing the carbon dioxide under conditions sufficient to (obtain) carbon monoxide, reacting the carbon monoxide with methanol under conditions sufficient to obtain methyl formate, and catalytically hydrogenating the methyl formate under conditions sufficient to produce methanol (and) dehydrating the methanol under conditions sufficient to produce dimethyl ether.

(Don't miss the implication of the above claim, in light of our immediately-precedent comment: Once we have Methanol, made from Carbon Dioxide, we can react that Methanol with Carbon Monoxide, also made from Carbon Dioxide, to make an intermediate product, "methyl formate", from which we can make an even greater quantity of Methanol.) 

The method ... which further comprises heating the dimethyl ether in the presence of an acidic-basic or zeolitic catalyst under conditions sufficient to form ethylene and/or propylene. 

The method ... which further comprises converting the ethylene and/or propylene under conditions sufficient to higher olefins, a synthetic hydrocarbons, aromatics, or a product produced therefrom, for use as a feedstock for chemicals or as transportation fuel. 

The method ... which further comprises hydrating the ethylene or propylene under conditions sufficient to form ethanol or propanol.

(All of the above valuable products, mind you, are made herein out of, basically, as specified, "carbon dioxide" captured "from gas mixtures, including the air".)

Summary: The invention provides supported amine sorbents comprising an amine or an amine/polyol composition deposited on a nano-structured support, which provide structural integrity and increased CO2 absorption capacity. 

The support for the amine and amine/polyol compositions is composed of a nano-structured solid.

The amine can be a primary, secondary, or tertiary amine or alkanolamine, aromatic amine, mixed amines or combinations thereof.

The polyol can be selected from, for example, glycerol, oligomers of ethylene glycol, polyethylene glycol, polyethylene oxides, and ethers, modifications and mixtures thereof, and can be provided in an amount up to about 25% by weight of the sorbent. 

According to an embodiment, the sorbent is regenerative. The sorbent can be desorbed and regenerated by applying heat, reduced pressure, vacuum, gas purge, lean sweep gas, or a combination thereof. 

The invention also relates to preparation of the sorbent and the particular use of the sorbent for capturing and separating carbon dioxide from a gas source. The carbon dioxide can be released and used to produce methanol. The method comprises reduction of carbon dioxide and water, or reduction of carbon dioxide under conditions sufficient to produce an intermediate compound followed by catalytic hydrogenation of the intermediate compound with hydrogen to form methanol. 

In one embodiment, methanol is produced by catalytic hydrogenation of an intermediate compound, e.g., methyl formate, wherein the hydrogen used in the hydrogenation is obtained by electrolysis of water obtained from the air.

(See, for example:

Hydrogen from Wind Power | Research & Development; concerning: "United States Patent 7,329,099 - Wind Turbine and Energy Distribution System; 2008; Abstract: A new design of vertical axis wind turbine is disclosed ... . An apparatus for conversion of a wind energy resource into rotational power ... wherein the apparatus ... is coupled to electrical generating means, and said electrical generating means is connected to an electrical load, whereby; said rotational power is converted to electrical power delivered to said electrical load; (And, which) electrical load comprises at least one electrolysis cell, said at least one electrolysis cell connected to an output stream of hydrogen gas and further connected to an input stream of water".

However, we'll also note that free, elemental Hydrogen isn't, strictly speaking, needed, since, as seen in:

Standard Oil Carbon Monoxide + Water = Gasoline | Research & Development; concerning: "United States Patent 4,559,363 - Process for Reacting Carbon Monoxide and Water; 1985; Abstract: A process for reacting carbon monoxide and water ... for the direct production of gasoline";

the technology exists to react the Carbon Monoxide, as produced herein from Carbon Dioxide, directly with plain old Water, and thereby synthesize some seemingly-desirable stuff.)

Methanol produced according to the invention can be further processed to any desired derivative or modified compounds. For example, methanol can be dehydrated to produce dimethyl ether, which can also be further treated under conditions sufficient to form compounds such as ethylene and propylene. Ethylene and propylene can be converted to higher olefins, a synthetic hydrocarbons, aromatics, or related products, and therefore are useful as a feedstock for chemicals or as transportation fuel.

(And, don't forget, that, as seen in:

West Virginia Coal Association | ExxonMobil Coal to Methanol to Gasoline | Research & Development; concerning both:

"United States Patent 4,348,486 - Production of Methanol via Catalytic Coal Gasification; 1982; Assignee: Exxon Research and Engineering Company; Abstract: Methanol is produced by gasifying a carbonaceous feed material with steam ... . A process for the production of methanol from a carbonaceous feed material (by) gasifying said carbonaceous feed material with steam ... and added hydrogen and carbon monoxide (and) wherein said carbonaceous feed material comprises coal. This invention provides a process for producing methanol by the substantially thermoneutral reaction of steam with coal"; and:

"United States Patent 4,035,430 - Conversion of Methanol to Gasoline; 1977; Assignee: Mobil Oil Corporation; Abstract: The conversion of methanol to gasoline boiling products in a plurality of sequentially arranged catalyst beds ... . This invention relates to the method and system for converting methanol to gasoline boiling components";

the "transport fuel" into which we can convert Methanol, no matter which of our precious natural raw materials we make the Methanol from, whether, as in the above-cited "US Patent 4,348,486 - Production of Methanol via Catalytic Coal Gasification", our abundant Coal; or, as in the processes described and referenced by our subject herein, "United States Patent 7,795,175 - Absorbents for the Separation of CO2 from Gas Mixtures Including the Air", some Carbon Dioxide extracted from the very air we breathe, can well be that which we now mortgage the future of our nation to OPEC and Big Oil for the supply of: Gasoline.