The fact that technology exists for recycling the Carbon Dioxide by-product of our fossil fuel use should, by now, be old news to our readers.
What should continue to be surprising, though, is the increasing number of ways we're finding through which Carbon Dioxide conversion, into hydrocarbon fuels and organic chemical manufacturing raw materials, can be accomplished.
From Penn State University, we now know that Methane, which can itself be manufactured, via the Nobel-winning Sabatier process, and other technologies, from Carbon Dioxide, or, via long-known gasification techniques, from Coal, can be combined, in a "Tri-Reforming" process, to synthesize methanol or other, valuable, higher hydrocarbons.
The enclosed report in this submission validates and confirms other reports, from Singapore and elsewhere, wherein microwave radiation, in combination with specific catalysts, can facilitate the reaction between Carbon Dioxide and Methane.
The attached document is lengthy and detailed, and we won't excerpt much of it, because of it's technical complexity. Following are some brief selections from the text, with comment appended:
"Carbon dioxide reforming of methane with Pt catalysts using microwave dielectric heating
Catalysis Letters Vol. 88, Nos. 3–4, June 2003 (# 2003)
Xunli Zhanga; Colleen S.-M; Leea, D; Michael P. Mingosa and David O. Hayward
Department of Chemistry, Imperial College of Science, Technology and Medicine, South Kensington, London SW7 2AY, UK
Department of Chemistry, The University of Hull, Hull HU6 7RX, UK
St. Edmund Hall, The University of Oxford, Oxford OX1 4AR, UK
March 2003
Microwave heating was applied to the catalytic reforming reaction of methane with carbon dioxide over platinum catalysts. It was found that CO2 and CH4 conversions and the product selectivity ... were generally higher under microwave conditions than that obtained with conventional heating at the same measured temperature. The effect of microwave heating was attributed to the formation of hot spots with higher temperature than that measured in the bulk catalyst bed.
1. Introduction Synthesis gas (syngas), which is a mixture of CO and H2, is an important feedstock for the chemical industry. The established commercial method employed for synthesis gas production is the steam reforming of methane... .
(Again: Keep in mind, through this dissertation, that Methane can itself be synthesized from either Coal or Carbon Dioxide.)
The (syngas) can then be introduced to a methanol synthesis reactor. ... Alternatively, the initial syngas mixture can be further modified with water to enhance the hydrogen concentration by the water-gas shift reaction over a catalyst such as Cu=ZnO=Al2O3.
("Cu=ZnO=Al2O3" would be a zeolite-type mineral catalyst, we believe, and thus similar to the catalyst employed by ExxonMobil in their "MTG"(r), methanol-to-gasoline, technology.)
This (syngas can be made) suitable for use in an ammonia synthesis industrial reactor.
A critical parameter for subsequent reaction of the synthesis gas is the H2 =CO ratio that must be adjusted close to unity for some syntheses such as the manufacture of oxo-alcohols and acetic acid.
The carbon dioxide reforming of methane, in fact, has been of interest for a long time, dating back to as early as the 1920’s ... .
This process has many desirable advantages over steam reforming:
(a) Synthesis gas has an H2 =CO ratio of unity without further, post-reformer reactions.
(b) The use of CO2 means that it is an attractive route toward CO2 mitigation in stationary anthropogenic sources.
(FYI: A coal-fired power plant would be one of your basic "stationary anthropogenic sources".)
(c) It allows the conversion of methane, previously a waste component of oil reserves, into an economically attractive feedstock.
This process can also be used as a chemical energy storage and an energy transmission system. In this system, solar energy is used to drive the endothermic forward reaction, and the energy thus stored can be transported via pipelines such as syngas and liberated at will by the reverse reaction at any location or time. The highly endothermic reaction could be an option to store solar energy in hot regions.
(The immediately foregoing echoes the developments and proposals for using CO2 conversion as a transportable "storage medium" for environmental energy from our US Sandia and Brookhaven National Laboratories, as we have documented.)
... the main concern of many CO2-reforming studies is to develop suitable catalysts and optimize the lifetime stability of the catalysts used.
Numerous materials have been tested as potential catalysts for reforming of CH4 with CO2, and most of them have been focused on Group VIII metals on a variety of supports. The metals studied include Co, Ni, Ru, Rh, Pd and Pt. La and Zr have also been used. Oxides such as CeO2, Al2O3, La2O3, MgO, CaO, SiO2; TiO2 and ZrO have been employed as support materials. Among the catalysts examined, nickel-based catalysts, as well as supported noble metal catalysts, have been found to exhibit promising catalytic activities in terms of methane conversion and selectivity to synthesis gas.
Microwave radiation has been shown to have the potential to increase the reaction rate of some heterogeneous reactions ... . It provides a new way to induce the heterogeneous catalytic reforming of CH4 with CO2.
It is interesting to note that the conversions of CO2 and CH4 were always higher under microwave conditions than those obtained with conventional heating and an almost constant difference was observed."
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We were compelled to edit our excerpt in the extreme. In essence, these British researchers defined very specific and very detailed parameters, involving relations between reaction temperature, catalyst type, gas mixture, microwave density, etc., to outline or indicate the optimal combinations of variables, for the most efficient conversion of Carbon Dioxide and Methane into more valuable and useful products.
Like the evidence we have presented concerning the technologies for converting Coal into liquid fuels, this submission supports our companion thesis that the technologies for recycling Carbon Dioxide into fuels and other products, are, in certain circles, well-known and well-understood; and, are being continuously improved.
Why we haven't been publicly informed of it all is another issue; but, herein, it is again demonstrated that the Carbon Dioxide, which arises in a small way, relative to natural sources of emission, such as volcanoes and swamps, from our use of Coal, is a potentially valuable raw material resource. We don't need to punish our vital Coal industries because they produce it for us.
