http://sktk.che.itb.ac.id/indarto/book/Chapter-5.pdf
In an earlier dispatch, we reported on developments made by Exxon, wherein microwave radiation could be utilized to cleanly and efficiently drive "reforming" reactions between Methane, Carbon Dioxide and H2O, and thereby convert them all into a blend of Carbon Monoxide and Hydrogen, a synthesis gas, or "syngas", we would presume to be well-suited in composition for Fischer-Tropsch, and related, catalytic chemical condensation into hydrocarbon compounds.
That report is accessible via:
Exxon 1993 CO2 + CH4 + H2O = Hydrocarbon Syngas | Research & Development; and concerns: "United States Patent 5,266,175 - Conversion of Methane, Carbon Dioxide and Water using Microwave Radiation; November, 1993; Exxon Research and Engineering Company; Abstract: A mixture of methane, water and carbon dioxide can be effectively converted to carbon monoxide and hydrogen by subjecting the mixture to microwave radiation in the presence of at least one plasma initiator that is capable of initiating an electric discharge in an electromagnetic field."
We note that Exxon's microwave-based Carbon Dioxide recycling technology is actually, we're told, similar to others about which we have reported, that have originated in Switzerland, among other places, as seen, for just one instance, in:
Switzerland Recycles CO2 to Fuel | Research & Development; concerning: "Hydrogenation of carbon dioxide to methanol with a discharge-activated catalyst; B. Eliasson, et. al., ABB Corporate Research, Switzerland; Abstract: To mitigate greenhouse gas CO2 emissions and recycle its carbon source, one possible approach would be to separate CO2 from the flue gases of power plants and to convert it to a liquid fuel, e.g., methanol. Hydrogenation of CO2 to methanol is investigated in a dielectric-barrier discharge (DBD) with and without the presence of a catalyst."
We've also documented that US Patents have been awarded to, and applied for by, the Swiss ABB, and associated, scientists for such Carbon Dioxide utilization processes; and, we will attempt in coming days to organize and summarize them for you.
Our take on it all is that the technologies differ only in the ways in which relatively low-temperature electrical discharges are generated within and applied to the mix of CO2, CH4 and, when used, H2O, gases; and, in how the resulting reactions, to form blends of Hydrogen and Carbon Monoxide hydrocarbon synthesis gas, are catalyzed.
Even our usually-opinionated consultants for now defer comment on the technical differences between those Carbon Dioxide conversion processes, suggesting that Coal Country public media, if at all interested in attempting to clarify the variants for their audience, should consult with genuine experts at regional universities, who are no doubt willing and well-able to advise.
In any case, we see herein that scientists in other nations, as well, have recognized the potentials of using electrical discharges, produced in a way that seems very similar to the Exxon technology disclosed by "United States Patent 5,266,175", to effect reactions between Carbon Dioxide and Methane targeted on the production of blends of Carbon Monoxide and Hydrogen syngas.
Comment follows excerpts from the initial link in this dispatch to:
"Syngas Production by CO2 Reforming of CH4 Under Microwave Heating
B. Fidalgo and J. Menendez; Instituto Nacional del Carbon; Spain
Abstract: The main industrial process used to produce synthesis gas (H2 + CO) and its resulting byproducts is the steam reforming of natural gas.
Methane reforming with carbon dioxide, or dry reforming, is a promising alternative that may lead to the reduction of CO2 emissions and the production of a syngas with a lower ratio of H2/CO.
The main obstacle to the industrial implementation of CH4 reforming with CO2 is that there are no commercial catalysts that can operate without undergoing deactivation due to carbon deposition.
Consequently, new catalysts are being developed and changes are being introduced in the process in order to achieve high and steady conversions
The microwave-assisted CO2 reforming of CH4 over carbon-based catalysts combines the catalytic and dielectric properties of carbonaceous materials with the advantages of microwave heating, which favors catalytic heterogeneous reactions due to, among other reasons, the generation of hot spots or microplasmas. Under certain operating conditions, the microwave-assisted dry reforming reaction can be considered as a combination of CH4 decomposition and CO2 gasification of carbon deposits, leading to the continuous regeneration of active centers.
(Note, that, in confirmation of some of our separate reports, Carbon Dioxide can, under certain circumstances, be used as an agent of gasification for Carbon, i.e., Coal, and, through the reaction outlined too simply as "CO2 + C = 2CO", be made to generated reactive, and quite useful, Carbon Monoxide. We have otherwise documented, and will further report, that the inclusion of H2O in such reforming reactions tends to help reduce "carbon deposits"; or, like Carbon Dioxide, as in the above passage, H2O, steam, can be used to gasify such deposits, with the net production of both Carbon Monoxide and Hydrogen.)
The use of catalysts with a good catalytic activity gives rise to high conversions ... (thus) making it possible to produce large amounts of syngas.
Of the catalysts evaluated the most suitable for the microwave-assisted dry reforming of methane (with Carbon Dioxide) proved to be mixtures of carbonaceous material and metal catalyst. The carbon
material should be microporous and have a good reactivity towards CO2.
(Can anyone say "Coke"?)
The metal catalyst with the best catalytic activity is Nickel/alumina.
Energy consumption in the process of microwave-assisted reforming of methane with CO2 is (seen) to be promising ... compared to the energy consumption in the steam reforming of methane. Therefore, the process promises to be competitive, both from the point of view of conversion and energy consumption.
Synthesis gas can be obtained through various chemical and thermochemical processes from almost any carbon source, such as ... carbon (i,e,, Coal), biomass or biodegradable waste.
Steam reforming involves the endothermic conversion of methane and steam into hydrogen and carbon monoxide (in) a H2/CO ratio of 3:1, which is higher than the ratio needed for the synthesis of ... methanol or derivatives from the Fischer-Tropsch reaction. (And,) alternative processes to steam reforming are being investigated (such as) CO2 reforming.
The CO2 reforming of methane ... yields a syngas with a lower ratio of H2/CO, i.e. 1:1 for a complete conversion. This ratio is preferable for the synthesis of higher hydrocarbons via Fischer-Tropsch and adequate for the production of oxygenated derivatives (i.e., Methanol), which eliminates the need to adjust H2/CO ratio.
Dry (CO2) reforming of methane constitutes a promising option for the (production of) syngas mainly due to the environmental benefits that it offers.
The dry reforming reaction turns two greenhouse gases (CH4 and CO2) into a valuable feedstock.
(Always keep in mind, that, as seen for just one out of now many examples in our previous report of:
Chicago Recycles CO2 to Methane | Research & Development; which concerns: "United States Patent 4,609,440 - Electrochemical Synthesis of Methane; 1986; Gas Research Institute, Chicago; Abstract: A method is described for electrochemically reducing carbon dioxide to form methane";
numerous technologies exist which enable the synthesis of the Methane, required by our subject Spanish process to be reacted with Carbon Dioxide, and form through that reaction a hydrocarbon synthesis gas, from Carbon Dioxide itself.)
In general, the dry reforming of methane may be the most effective process wherever carbon dioxide is a
byproduct and available for utilization, for instance, in power plants ... and in petrochemical industries, where effluents of light gases can be processed with waste streams of CO2
(Further) excess coke oven gases (GOG), consisting mainly of H2, CH4, CO and N2, may be turned into synthesis gas by means of dry reforming.
The syngas can then be used to produce a variety of compounds (including) methanol.
The combination of dry reforming with steam reforming and/or partial oxidation (partial combustion of CH4 with oxygen) offers several advantages compared to the individual processes: (i) the H2/CO ratio can be adjusted by varying the CO2/H2O/O2 ratio in the feed; (ii) the presence of oxidant agents, such as H2O and O2, inhibits the process of carbon deposition; and, (iii) as partial oxidation is an exothermic reaction, the energy requirement of the process is reduced when O2 is introduced. In addition, alternatives to the conventional heating used in the process are being evaluated, such as, the direct conversion of CH4 and CO2 by using plasma or the microwave-assisted dry reforming of methane."
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And, we have documented all of the above Carbon Dioxide recycling potentials, outlined in the concluding, excerpted paragraph, many times previously, as a search of the West Virginia Coal Association R&D archives, using their very facile search engine, would quickly reveal.
Carbon deposition can be reduced, and the composition of the resulting synthesis gas can be intentionally varied for specific end-use conversions, by the inclusion of varying amounts of Steam, in a "tri-reforming" process, such as best explained by Penn State University, as, for just one example, in:
More Penn State CO2 Recycling with Methane | Research & Development | News; which concerns the: "'Catalytic Tri-reforming of Methane Using Flue Gas from Fossil Fuel-based Power Plants'; The Pennsylvania State University; The present work is an exploratory study on a new process for the production of synthesis gas (CO + H2) using CO2 in flue gas from fossil fuel-based electric power plants".
And, which processes are made even more significant, since, as explained for another example in:
Texaco Photosynthetic CO2 Recycling | Research & Development; which makes report of: "United States Patent 4,545,872 - Method for Reducing Carbon Dioxide to Provide a Product; 1985; Assignee: Texaco, Incorporated; Abstract: A process and apparatus for reducing carbon dioxide to at least one useful product (and, wherein) the predominant product produced is ... methane";
we can synthesize the Methane, required by both Spain, as per our subject document herein, and by Penn State University in their own "tri-reforming" process, to react with Carbon Dioxide and thus generate a hydrocarbon synthesis gas, from Carbon Dioxide itself.
Or, if preferable, as seen in:
Exxon Converts 99% of Coal to Methane | Research & Development | News; concerning: "United States Patent 4,077,778 - Process for the Catalytic Gasification of Coal; 1978; Assignee: Exxon Research and Engineering Company; Abstract: A process for the production of synthetic natural gas from a carbon-alkali metal catalyst or alkali-metal impregnated ... coal (and wherein the) synthetic natural gas (consists) essentially of methane";
we can make the Methane, specified herein by the Spanish scientists as the reactant needed in their process of converting Carbon Dioxide - - what we should now see as a valuable raw material resource we are on the verge of having hijacked from us via Cap and Trade taxation and/or mandated Geologic Sequestration in leaky old oil wells - - into a synthesis gas which can be used "to produce a variety of compounds (including) methanol", very efficiently from just some of our abundant Coal.