United States Patent Application: 0030113244
As seen in one recent report:
West Virginia Coal Association | California Thermochemical Hydrogen Production | Research & Development; concerning: "United States Patent 7,960,063 - Hydrogen Production by a Thermochemical Water Splitting Cycle; 2011; Assignee: The Regents of the University of California; Abstract: A novel thermochemical cycle for the decomposition of water is presented. Along with water, hydrogen, and oxygen, the cycle involves an alkali or alkali earth metal based process intermediate and a variety of reaction intermediates. The cycle is driven by renewable energy sources";
we're getting better and better at extracting Hydrogen from Water, H2O, in efficient processes that can be driven by freely-available environmental, or "renewable", energy.
And, herein, we highlight one potentially quite valuable use for such economical Hydrogen, in the reduction, and the utilization, of Carbon Dioxide.
We remind you that, as seen for one example in our report of:
West Virginia Coal Association | Bayer Improves Coal + CO2 = Carbon Monoxide | Research & Development; concerning: "United States Patent 7,473,286 - Carbon Monoxide Generator; 2009; Assignee: Bayer Material Science, AG, Germany";
wherein is disclosed a process for manufacturing Carbon Monoxide via the reaction between Carbon Dioxide and hot Coal, we already have established processes available to us whereby we can produce Carbon Monoxide, for use, as Bayer intended, in the synthesis of polymers, or for other purposes, from Carbon Dioxide, via direct chemical reduction reactions between CO2 and a source of carbon.
The advantages of such a process should be obvious: we can reduce the total amount of Carbon Dioxide in our environment while producing a product, Carbon Monoxide, that has broad industrial utility and value.
There is, however, an alternative way to go about the conversion of Carbon Dioxide into Carbon Monoxide, an alternative that would allow us to conserve our precious Coal while utilizing, instead, Hydrogen produced, using environmental energy, as via the above-cited process of "United States Patent 7,960,063 - Hydrogen Production by a Thermochemical Water Splitting Cycle".
As seen in excerpts from the initial link in this dispatch to:
"United States Patent Application 20030113244 - Method for Producing Carbon Monoxide by Reverse Conversion with an Adapted Catalyst
Method for producing carbon monoxide by reverse conversion with an adapted catalyst - Dupont, Rene
Date: June, 2003
Inventor: Rene Dupont, et. al., France
Assignee: Air Liquide
(Air Liquide - Wikipedia, the free encyclopedia; "L'Air Liquide S.A., or Air Liquide is a French multinational company which supplies industrial gases and services to various industries including medical, chemical and electronic manufacturers. Founded in 1902, it is the world's largest supplier of industrial gases by revenues, and has operations in over 80 countries.")
Abstract: The invention concerns a method for producing carbon monoxide by reverse conversion, in gas phase, of carbonic acid gas and gaseous hydrogen while minimising the production of methane. The invention is characterised in that the reaction is carried out at a temperature between 300 and 520 C and under pressure between 10 to 40 bars in the presence of an iron-free catalyst based on zinc oxide and chromium oxide. Said method is preferably carried out continuously and comprises preferably the following steps which consist in:
a) preparing a gas mixture rich in carbon dioxide and in hydrogen ... between 300 and 520 C;
b) reacting said gas mixture, forming carbon monoxide and water vapour, by passing said mixture through a catalytic bed based on zinc oxide and chromium oxide maintained under pressure between 10 and 40 bars;
c) cooling the gas flux derived from the catalytic bed so as to cause condensation of all or part of the water vapour formed;
d) separating the condensed water from said gas fluid;
e) optionally, re-treating at least once the resulting gas stream. previously brought to a temperature between 300 and 520 C, by performing steps b) to d) above, so as to increase the proportion of carbon monoxide in the gas stream, each step b) being carried out in a different catalytic bed.
(Note, that, by "reverse conversion" they are actually referring to the long-known "reverse water gas shift", or RWGS, reaction, which is the obverse of the "water gas shift", wherein Carbon Monoxide reacts with Water to produce Hydrogen. For background, see:
Water gas shift reaction - Wikipedia, the free encyclopedia)
Claims: A process for the production of carbon monoxide by reverse conversion, in the gas phase, of gaseous carbon dioxide and gaseous hydrogen, while minimizing the production of methane, characterized in that the reaction is carried out at a temperature of 300 to 520 C and at a pressure of 10 to 40 bar in the presence of a catalyst based on zinc oxide and chromium oxide and not containing iron.
(Note, in the above, they are trying to prevent the Sabatier reaction, i.e., "the production of methane", via reactions between Carbon Dioxide and Hydrogen, See our report of:
West Virginia Coal Association | CO2 Solution Wins Nobel Prize - in 1912 | Research & Development; concerning: "Paul Sabatier; The Nobel Prize in Chemistry 1912; Nobel Lecture, December 11, 1912"; wherein Sabatier explains that with Hydrogen, "carbon dioxide" can be "changed immediately into methane, which can therefore be synthesized with the greatest ease".)
The process ... characterized in that said catalyst includes no more than 2.5% by weight of nickel (and) in that the weight ratio of zinc oxide to chromium oxide is ... preferably between 1.5 and 2.5. .
The process ... characterized in that it is carried out continuously and in that it comprises the step consisting in making a gas mixture rich in hydrogen and carbon dioxide pass (through the catalyst bed).
The process ... characterized in that the molar ratio of hydrogen to carbon dioxide in said gas mixture is between 0.5 and 15.
The process ... characterized in that the gas mixture, the product of the reaction, which comprises carbon monoxide, carbon dioxide and hydrogen, is treated so as to isolate the carbon monoxide or a carbon monoxide/hydrogen mixture.
(The above final claim is of some importance. A "carbon monoxide/hydrogen mixture" can, as you should, presuming you to have followed our posts thus far, by now know, can also be labeled as "synthesis gas", or, just "syngas", as in:
Syngas - Wikipedia, the free encyclopedia; "Syngas, or synthesis gas, is a fuel gas mixture consisting primarily of hydrogen, carbon monoxide, and very often some carbon dioxide. The name comes from its use as intermediates in creating synthetic natural gas (SNG) and for producing ammonia or methanol. Syngas is also used as an intermediate in producing synthetic petroleum for use as a fuel or lubricant via the Fischer-Tropsch process.")
Description: The invention relates to a process for the production of carbon monoxide by reverse conversion, in the gas phase, of hydrogen and carbon dioxide.
The reaction of hydrogen with carbon dioxide results, under appropriate operating conditions, in a mixture of water and carbon monoxide. This reaction leads to an equilibrium between the various constituents and metal catalysts are generally used to approach this equilibrium in times compatible with an acceptable size of the reactors. To shift the equilibrium towards the formation of carbon monoxide, it is known to operate in the presence of metal catalysts.
The invention relates in general to a process for the production of carbon monoxide by reverse conversion in the gas phase of CO2 and H2, characterized in that the reaction is carried out in the presence of a catalyst based on zinc oxide and chromium oxide, and not containing iron.
The simultaneous presence of zinc oxide (ZnO) and chromium oxide (Cr2O3) in the catalyst is, according to the invention, essential for obtaining a good reaction rate for the conversion of CO2 into CO.
According to one particularly advantageous method of implementation, the process of the invention comprises a subsequent step of treating the gas stream recovered at the end of the process, consisting in isolating the carbon dioxide produced or in isolating a carbon monoxide/hydrogen mixture, together with the steps for recycling the CO2 and the excess hydrogen."
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In other words, any CO2 that might slip through can simply be extracted and recycled back into the reactor for reaction with Hydrogen and conversion into Carbon Monoxide.
And, as seen for one example in:
"United States Patent: 7351275 - Carbon Monoxide Production Process; 2008; Assignee: The BOC Group, Inc., NJ; The present invention provides for a process for producing carbon monoxide. A feed gas stream of hydrogen, carbon monoxide and carbon dioxide is directed to a membrane unit which separates the feed gas stream into two streams. The stream containing carbon monoxide is directed to second membrane unit for further purification and the steam containing the carbon dioxide and hydrogen is fed to a reverse shift reactor to produce more carbon monoxide. The carbon monoxide recovered from the reverse shift reactor is purified in a third membrane unit and directed back to the first membrane unit and is further purified and recovered as additional carbon monoxide product";
the technologies do exist to effect such gas separation.
Again, the key to this Carbon Dioxide utilization process is the availability of economical Hydrogen, as we can, as seen for yet another example in our report of:
West Virginia Coal Association | USDOE Renewable Hydrogen for Coal Liquefaction | Research & Development; concerning: "'Renewable Hydrogen Production for Fossil Fuel Processing'; 1994; Oak Ridge National Lab., TN; Sponsor: USDOE; Abstract: The objective of this mission-oriented research program is the production of renewable hydrogen for fossil fuel processing. This program will build upon promising results that have been obtained in the Chemical Technology Division of Oak Ridge National Laboratory on the utilization of intact microalgae for photosynthetic water splitting. In this process, specially adapted algae are used to perform the light-activated cleavage of water into its elemental constituents, molecular hydrogen and oxygen";
obtain, one way or another, from Water, via processes dependent upon one form or another of renewable, or environmental, energy.
And, to the Carbon Monoxide produced by the process of our subject herein, we can add more Hydrogen, perhaps generated by the earlier-cited process of "United States Patent 7,960,063 - Hydrogen Production by a Thermochemical Water Splitting Cycle", and thereby form a hydrocarbon synthesis gas suitable for use in a process like that described in our report of:
West Virginia Coal Association | Mobil Upgrades Fischer-Tropsch Fuel | Research & Development; concerning: "United States Patent 4,041,094 - Upgrading Products of Fischer-Tropsch Synthesis; 1977; Assignee: Mobil Oil Corporation, NY; Abstract: Upgrading of Fischer-Tropsch synthesis product ... . It is considered desirable to effectively and more efficiently convert synthesis gas ... to highly valued hydrocarbons such as motor gasoline with high octane number, petrochemical feedstocks, liquefiable petroleum fuel gas, and aromatic hydrocarbons"';
and, through it all, make some stuff we seem to have great need of, all while utilizing and consuming that abundant and freely-available, though unacknowledged, natural resource: Carbon Dioxide.