As seen very currently in:
OSU Research Promising For Future of Coal - News, Sports, Jobs - The Intelligencer / Wheeling News-Register; concerning: "A 'dramatically different' energy generating process developed at Ohio State University could keep Ohio Valley residents working in local coal mines for generations to come. A research team led by Professor Liang-Shih Fan is using Coal-Direct Chemical Looping to generate electricity and capture 99 percent of the carbon dioxide that results from the process (and) American coal could continue to be a viable fuel for decades to come, even under strict federal limits on carbon emissions ... . Since 99 percent of the carbon dioxide produced can be captured, Fan said it can be used for ... chemical synthesis";
news is finally starting to emerge, though timidly and, from our perspective, incompletely, that we have some options available to us when it comes to dealing with the Carbon Dioxide emitted by our essential use of Coal in the generation of genuinely abundant, affordable, and truly reliable electric power, we thought it appropriate to make report of some of the CO2 capture technology being developed at, as in the above-cited article, the Ohio State University, by the accomplished Professor Liang-Shih Fan and his colleagues.
First, not mentioned in the above-cited article, even though it was published by a West Virginia newspaper, is the fact that OSU's Dr. Fan attended graduate school at, and was awarded his doctorate in Chemical Engineering by, West Virginia University.
More can be learned via: L.-S. Fan's Research Page.
We're certain that we made earlier report of the Carbon Dioxide capture research being conducted at OSU by Dr. Fan and his associates; but, danged if we can now find it among our several thousands of reports now accessible on the West Virginia Coal Association's Research and Development web site.
Further, the CO2-capture technology discussed in "OSU Research Promising For Future of Coal", is similar and related to other technologies about which we've reported, concerning "oxygen donor" technology, wherein a metal oxide provides the Oxygen to the Coal for combustion, or oxidation, and is thereby chemically "reduced" in the reaction to the base metal, or a less reactive metal oxide, as in, from the article:
"coal reacts with oxygen from iron oxide catalysts".
One correction needs to be made: The "iron oxide" isn't really serving as a catalyst, but, as an "oxidant"; or, perhaps more appropriately, an Oxygen Donor.
One upshot of the process is, that, not only can the metal oxide limit the amount of Oxygen provided to the Coal in the, as the article specifies, "sealed" combustion chamber, resulting, if desired, in the production of more of the chemically reactive Carbon Monoxide, relative to Carbon Dioxide, for subsequent "chemical synthesis"; but, the reduced metal, if reactive enough, and hot Iron is, can be converted back into the Oxygen donor metal oxide through reaction with, in part, Steam, H2O, which results as well in the production of Hydrogen, which can be added to the Carbon Monoxide to create a synthesis gas blend perhaps more suitable for, as the article intimates, "chemical synthesis".
Such anonymous "chemical synthesis" could include, we suggest, the venerable Fischer-Tropsch synthesis, with the end product being liquid hydrocarbon fuels.
We note, however, that Dr. Fan's technology, as specified in the article, seems to provide enough Oxygen so that oxidation is complete, and, as in:
"the process uses two reaction chambers. In the first chamber, the carbon from coal reacts with oxygen from iron oxide catalysts at high temperatures to form carbon dioxide while iron oxides are converted to iron. 'In this step, steam is also produced. Thus, the carbon dioxide and steam rise; the carbon dioxide can be easily separated and captured by cooling the steam to form water,' Fan said. Iron and coal ash are left behind, and Fan said the iron is easily separated from the coal ash because of the size difference. The coal ash is removed from the entire system. The iron is then delivered to a second chamber, where iron combustion takes place with air to produce heat that can be used for electricity generation. The combustion converts iron to iron oxides, which are then used again in the first chamber with fresh, unreacted coal",
nearly all of the Carbon in the Coal is converted into CO2, which greatly simplifies the following gas separation process and enables the efficient production of fairly pure Carbon Dioxide.
Moreover, as a further advantage, since the combustion is being conducted in a "sealed chamber", the products of the combustion, whether Carbon Dioxide or Carbon Monoxide, and, if some Water is added, Steam and/or Hydrogen, won't be contaminated with large quantities of Nitrogen and Nitrogen Oxides, as would be the case if plain air were used as the oxidant, as is the case in nearly all Coal-fired power plants.
Further, the Oxygen donor, "chemical looping", eliminates any future need, and associated costs, to purify Oxygen from air, as has been proposed as one way to reduce emissions of Nitrogen Oxides.
For more background on metal oxide Oxygen donor technology as it applies to the controlled oxidation and combustion, in some cases the intended partial combustion, of Coal, see:
West Virginia Coal Association | Standard Oil 1952 Oxygen Donor Coal Gasification | Research & Development; concerning: "United States Patent 2,592,377 - Manufacture of ... Carbon Monoxide and Hydrogen; 1952; Assignee: Standard Oil Development Company; Abstract: The present invention relates to the manufacture of gas mixtures containing carbon monoxide and hydrogen from ... carbonaceous materials such as coal (and) cellulosic materials ... and more particularly to the manufacture of such gas mixture as are suitable for the catalytic synthesis of hydrocarbons";
in which the use of Iron and Copper as the Oxygen transfer/donor metals is specified, and the combustion reaction is controlled so that more Carbon Monoxide, rather than Carbon Dioxide, is produced, along with Hydrogen. In another, perhaps more advanced, variation, seen in:
West Virginia Coal Association | Oklahoma Oxygen Donor Coal Gasification | Research & Development; concerning, as one example out of several: "United States Patent 4,496,370 - Zinc Oxide-Char Gasification Process; 1985; Assignee: Phillips Petroleum Company; Abstract: In the gasification of char with zinc oxide, the improvement which comprises reacting the off-gas stream of gaseous zinc and carbon monoxide with steam at elevated temperatures in a second reactor means thereby oxidizing the zinc to zinc oxide and yielding a second gaseous stream containing carbon monoxide and hydrogen";
the somewhat more reactive metal Zinc is used as the Oxygen donor/transfer agent in a way that allows the concurrent regeneration of the Zinc Oxide Oxygen donor and the generation of Hydrogen to be conducted in the product gas stream itself, with the result being that a gas mixture suitable for "chemical synthesis" is created at the same time, and in the same reaction step, as the Oxygen transfer agent is regenerated.
However, "OSU Research Promising For Future of Coal" concerns a process that requires an entirely new Coal-fired power plant to be built around it's specifications, in order for any Carbon Dioxide co-produced by that plant to be captured; and, It's worth reporting that Dr. Fan and his associates have, as well, developed CO2-capture processes which might be more suitable for retrofit on existing facilities, where they would still produce relatively-pure streams of Carbon Dioxide suitable for "chemical synthesis".
As seen in excerpts from the initial link in this dispatch to:
"US Patent 8,226,917 - Separation of CO2 from Gas Mixtures by Calcium Based Reaction Separation
Date: July, 2012
Inventors: Liang-Shih Fan, OH, Himanshu Gupta, VA, and Mahesh Iyer, TX
(Please recall that we have previously cited Dr. Fan's co-inventor, Mahesh Iyer, from the days when he, too, was a graduate student at West Virginia University, as, for example, in:
West Virginia Coal Association | WVU CO2 + CH4 = Hydrocarbon Syngas | Research & Development; concerning: "New Catalysts for Syngas Production from Carbon Dioxide and Methane; Mahesh V. Iyer;
Thesis submitted to the College of Engineering and Mineral Resources at West Virginia University in partial fulfillment of the requirements for the degree of Master of Science in Chemical Engineering. Department of Chemical Engineering; Morgantown, West Virginia; 2001"; and:
West Virginia Coal Association | USDOE-sponsored WVU CO2-Methane Bi-Reforming | Research & Development; concerning: "Kinetic Modeling for Methane Reforming with Carbon Dioxide; 2003; Mahesh Iyer, Laurence Norcio, Edwin Kugler and Dady Dadyburjor; Financial support from the US Department of Energy under Cooperative Agreement DE-AC22-99FT40540 with the Consortium of Fossil Fuel Science is gratefully acknowledged. (Abstract): A cobalt-tungsten carbide material was investigated as a precursor for a stable and active catalyst for the dry reforming of methane to produce synthesis gas. The kinetics of CH4/CO2 reforming were studied ... based on a detailed experimental design. Introduction: Existing industrial process use methane as a primary feedstock for synthesis gas (syngas), a mixture of carbon monoxide and hydrogen which serves as the feedstock for a variety of downstream processes: methanol synthesis, Fischer-Tropsch synthesis (etc.). Methane is also an unavoidable byproduct in the Fischer-Tropsch process (and) recovering Fischer-Tropsch methane back to syngas would play significant roles in the economics of the production of synthetic liquid fuels and chemicals".
As we will see in a report or two to follow, Iyer continues his work in, as indicated herein, Texas, as an employee of Shell.)
Assignee: The Ohio State University, Columbus
Abstract: A reaction-based process has been developed for the selective removal of carbon dioxide (CO2) from a multicomponent gas mixture to provide a gaseous stream depleted in CO2 compared to the inlet CO2 concentration in the stream. The proposed process effects the separation of CO2 from a mixture of gases (such as flue gas/fuel gas) by its reaction with metal oxides (such as calcium oxide). The Calcium based Reaction Separation for CO2 (CaRS - CO2) process consists of contacting a CO2 laden gas with calcium oxide (CaO) in a reactor such that CaO captures the CO2 by the formation of calcium carbonate (CaCO3). Once "spent", CaCO3 is regenerated by its calcination leading to the formation of fresh CaO sorbent and the evolution of a concentrated stream of CO2. The "regenerated" CaO is then recycled for the further capture of more CO2. This carbonation-calcination cycle forms the basis of the CaRS - CO2 process. This process also identifies the application of a mesoporous CaCO3 structure, developed by a process detailed elsewhere, that attains >90% conversion over multiple carbonation and calcination cycles. Lastly, thermal regeneration (calcination) under vacuum provided a better sorbent structure that maintained reproducible reactivity levels over multiple cycles.
(Note that, in this case, unlike the process discussed in the article "OSU Research Promising For Future of Coal", the metal, Calcium, oxide, CaO, is not serving as an Oxygen donor, but only as an agent for Carbon Dioxide capture.)
Claims: A method for separating carbon dioxide and sulfur dioxide from a flow of gas comprising carbon dioxide and sulfur dioxide, said method comprising the steps of:
(a) directing said flow of gas to a gas-solid contact reactor, said gas-solid contact reactor containing a sorbent comprising a metal oxide;
(b) reacting said carbon dioxide and said sulfur dioxide with said sorbent so as to convert at least a portion of said sorbent to a metal carbonate and at least a portion of said sorbent to a metal sulfate;
(c) directing at least a portion of said metal carbonate to a calcinator;
(d) calcining said metal carbonate so as to form said metal oxide and carbon dioxide; and:
(e) replenishing said sorbent in said gas-solid reactor with said metal oxide formed in said calcinator.
(Since the Abstract specifically identified the "metal oxide" to be Calcium Oxide, CaO, we remind you that CaO is the primary component of Portland Cement, which is made from Limestone, CaCO3, a "metal carbonate" by calcining it in a kiln, a process which emits copious amounts of CO2, both from the calcined CaCO3 and from the combustion of fuel to provide the high calcination temperatures. Alternatives have been proposed, as seen in:
STEP cement: Solar Thermal Electrochemical Production of CaO without CO2 emission - Chemical Communications (RSC Publishing); concerning: "STEP Cement: Solar Thermal Electrochemical Production of CaO without CO2 Emission; 2012; Stuart Licht, et. al.; George Washington University; New molten salt chemistry allows solar thermal energy to drive calcium oxide production without any carbon dioxide emission. This is accomplished in a one pot synthesis, and at lower projected cost than the existing cement industry process".
Thus, the CaO absorbent is regenerated while a relatively pure stream of CO2 is co-produced, which, as the above-cited Stuart Licht and George Washington University have told us, as seen in our reports of:
West Virginia Coal Association | Washington, DC, Recycles CO2 | Research & Development; concerning: "US Patent Application 20100200418 - Electrosynthesis of Energetic Molecules; 2010; Inventor: Stuart Licht, Virginia; Assignee: The George Washington University, Washington, DC; Abstract: A process for the production of energetically rich compounds comprising: using externally supplied thermal energy to heat an electrolyzable compound to a temperature greater than the ambient temperature; generating electricity from a solar electrical photovoltaic component; subjecting the heated electrolyzable compound to electrolysis with the solar generated electricity to generate an energetically rich electrolytic product. (And) wherein the electrolyzable compound comprises carbon dioxide. (And) wherein the externally supplied thermal energy comprises solar energy (and) thermal energy from exhaust gasses. (And) wherein the energetically rich electrolytic product comprises carbon monoxide, and the process further comprises combining the carbon monoxide with hydrogen to form alcohols"; and:
West Virginia Coal Association | Washington, DC, Recycles More CO2 | Research & Development; concerning: "US Patent Application 20130001072 - Process for Electrosynthesis of Energetic Molecules; 2013; Inventor: Stuart Licht; Assignee: The George Washington University; Abstract: A process for the production of energetically rich compounds comprising: using externally supplied thermal energy to heat an electrolyzable compound to a temperature greater than the ambient temperature; generating electricity from a solar electrical photovoltaic component; subjecting the heated electrolyzable compound to electrolysis with the solar generated electricity to generate an energetically rich electrolytic product (and) wherein the energetically rich electrolytic product comprises CO. This process is frequently referred to herein as the STEP (Solar Thermal Electrochemical Photo) process or STEP driven process. (The) STEP driven energy conversion process (i.e., the generation of energetic molecule formation process) can convert anthropogenic CO2 generated in burning fossil fuels, and eliminate CO2 emissions ... . Potential products of CO2 splitting include carbon and carbon monoxide. Carbon monoxide is ... an important syngas component and a reactant to form a wide variety of fuels, which can be formed through the reaction of carbon monoxide with H2. ... CO with H2 can be important reactants in implementing reactions to form a wide variety of organic compounds, such as alcohols, or the Fischer Tropsch generation of fuels. The STEP process has been derived for the efficient solar removal/recycling of CO2";
can be recycled, using the principles of the "STEP" process, into "alcohols" and other "fuels".)
The method ... additionally comprising the step of: separating said metal carbonate from said flow of gas in a cyclone.
The method ... wherein said metal oxide is calcium oxide (of specified surface area and pore size).
The method ... wherein said step of calcining said metal carbonate is performed by steam.
(The above stipulation is an important one, as we emphasize in appended comment.)
The method ... wherein said metal oxide is selected from the group consisting of: ZnO, MgO, MnO2, NiO, CuO, PbO, and CaO.
The method ... wherein said sorbent has substantially the same sorption capacity after calcining as said sorbent had prior to absorbing said carbon dioxide.
Background and Field: The present invention relates to the application of chemical sorbents for the separation of CO2 from gas mixtures. As used herein, the term "supersorbent" shall mean a sorbent as taught in U.S. Pat. No. 5,779,464 entitled "Calcium Carbonate Sorbent and Methods of Making and Using Same", the teachings of which are hereby incorporated by reference.
(We have separate report of "U.S. Pat. No. 5,779,464" in process.)
Reaction based processes, as promulgated in this work, can be applied to separate CO2 from gas mixtures. This process is based on a heterogeneous gas-solid non-catalytic carbonation reaction where gaseous CO2 reacts with solid metal oxide (represented by MO) to yield the metal carbonate (MCO3). The reaction can be represented by: MO + CO2 = MCO3.
Once the metal oxide has reached its ultimate conversion, it can be thermally regenerated to the metal oxide and CO2 by the calcination of the metal carbonate product."
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One note: Careful readers will see that "sulfur dioxide", too, is named once or twice in the full Disclosure as an additional product that can be harvested by the technology described herein. Sulfur is an issue separate from the focus of our discussion; one which we have treated separately in previous dispatches and one which we will again address separately in the future.
And, there is quite a lot more to it, especially regarding illustrative examples and formulas. Interestingly, Fan suggests that the invention could, in addition to Coal-fired power plants, be used on Coal Gasification systems, which are being used to convert Coal into synthesis gas for the manufacture of hydrocarbons.
But, of additional interest to us is the fact that the "metal oxide" CO2 absorbent is regenerated by calcination of the metal carbonate, which calcination releases the Carbon Dioxide gas; and, that, as stipulated in the Claims, the:
"said step of calcining said metal carbonate is performed by steam".
Thus, a gaseous stream composed of Steam and Carbon Dioxide would be generated; and, we remind you, that, as seen in just two examples:
West Virginia Coal Association | Utah Recycles CO2 | Research & Development; wherein, among other things, is discussed the: "Co-Electrolysis of Steam and Carbon Dioxide as Feed to a Methanation Reaction; Ceramatec, Inc., Salt Lake City, UT; Abstract: Solid oxide fuel cells can be operated in reverse by applying an electric potential across the fuel cells and forcing the oxygen ion to flow in the opposite direction from the fuel cell mode. If a mixture of high temperature steam and carbon dioxide are fed to a fuel cell stack operating in this electrolysis mode, the result will be a mixture of carbon monoxide and hydrogen. By adjusting the input ratios of steam and carbon dioxide, the output of the electrolysis system can be modified to be in the proper ratio for the formation of a number of different hydrocarbons by catalytic process through either Fischer Tropsch or methanation reactions"; and:
West Virginia Coal Association | More USDOE CO2 "Syntrolysis" | Research & Development; concerning: "Co-Electrolysis of Steam and Carbon Dioxide for Production of Syngas; 2007; Idaho National Laboratory, USDOE; and Ceramatec, Inc.; Abstract: An experimental study has been completed to assess the performance of single-oxide electrolysis cells ... simultaneously electrolyzing steam and carbon dioxide for the direct production of syngas. Introduction: A research project is underway at the Idaho National Laboratory (INL) to investigate the feasibility of producing syngas by simultaneous electrolytic reduction of steam and carbon dioxide ... . Syngas, a mixture of hydrogen and carbon monoxide, can be used for the production of synthetic liquid fuels via Fischer-Tropsch processes";
once we have a gaseous stream composed of Steam and Carbon Dioxide, as in the effluent formed by the process disclosed by our subject herein, "US Patent 8,226,917 - Separation of CO2 from Gas Mixtures by Calcium Based Reaction Separation", which process extracts "CO2 from a mixture of gases (such as flue gas/fuel gas)", we can do some fairly entertaining, and productive, things with that mix of Steam and Carbon Dioxide.
It's good, and very refreshing, to see, for a change, some Coal Country print, as in "OSU Research Promising For Future of Coal", being dedicated to Coal Country's largest, by far, energy resource.
In point of fact, though, the issue of efficient and cost-effective Carbon Dioxide capture, in conjunction with the potentials for utilizing such captured Carbon Dioxide in the synthesis of gaseous and liquid hydrocarbon fuels, is worthy of far more than just one, though commendable, article.
Some Coal Country newspaper, somewhere, ought to plan a Sunday supplement for a fuller exposition of it.
After they do one centered on the conversion of Coal into gasoline.