First of all, the technology disclosed by the United States Patent which is the focus of this dispatch requires free, molecular Hydrogen to accomplish the recycling of Carbon Dioxide.
And, we wanted to get that particular point out of the way, since many might view it as an economically prohibitive drawback.
It is not.
Petroleum refineries now routinely utilize Hydrogen, especially to upgrade "heavy" crude natural petroleum, and there are well-established commercial means for producing it.
And, there are alternative means for making Hydrogen which might be of more special interest to those of us in United States Coal Country.
As we have documented, for instance, in:
USDOE Algae Recycle More CO2 and Produce Hydrogen | Research & Development; concerning: "United States Patent 7,642,405 - Designer Algae for Photo-biological Hydrogen Production; 2010; This invention was made with Government support under Contract No. DE-AC05-00OR22725 awarded by the United States Department of Energy. The Government has certain rights in this invention";
wherein special strains of Algae, grown in "bio-reactors", can be fed industrial effluent Carbon Dioxide, and, in the cyclic course of their metabolism through periods of dark and light, produce, alternately, "bio-lipids" which could likely be readily converted into Diesel fuel, and, Hydrogen.
Another intriguing example of Hydrogen production potentials can be seen in our report of:
NASA Hydrogen from Water and Sunlight | Research & Development; concerning: "United States Patent 4,045,315 - Solar Photolysis of Water; 1977; NASA; Abstract: Hydrogen is produced by the solar photolysis of water".
And, Solar energy can also produce Hydrogen from a potential pollutant which could arise from the Steam gasification of high-Sulfur Coal, undertaken to generate an hydrogenated synthesis gas suitable for catalytic condensation into liquid hydrocarbons; as seen in:
Florida Hydrogen and Sulfur from H2S | Research & Development; concerning: "United States Patent 6,572,829 - Photocatalytic Process for Decomposing Hydrogen Sulfide; 2003; Assignee: University of Central Florida; Abstract: System for separating hydrogen and sulfur from hydrogen sulfide (H2S) gas produced from oil and gas waste streams";
wherein Hydrogen Sulfide, as might also be present, as they specify, in the waste gases of petroleum refineries, can be decomposed by sunlight into both Hydrogen and commercially-valuable Sulfur.
The point is, if we want Hydrogen, we can get it.
And, the expense of getting it would be well-justified, in light of the technology we report herein, where Carbon Dioxide, recovered from whatever source, can be reacted with Hydrogen, and be converted thereby into two products with very intriguing further potentials of their own.
As seen, with comment and additional links inserted and appended, in our excerpts from our initial link to:
"United States Patent 5,496,530 - Process for the Preparation of Carbon Monoxide Rich Gas
Date: March, 1996
Inventors: Rickard Vannby and Charlotte Nielsen, Denmark
Assignee: Haldor Topsoe, Denmark
(Haldor Topsoe - Wikipedia, the free encyclopedia: "Haldor Topsoe is a Danish catalyst company ... founded in 1940. The company ... develops process technology for petroleum refining, ammonia production, methanol production, and other industries. Haldor Topsoe specialises in the production of heterogeneous catalysts and the design of process plants based on catalytic processes. Focus areas include the fertiliser industry, chemical and petrochemical industries, and the energy sector (refineries and power plants.)
Abstract: Process for the preparation of carbon monoxide rich gas comprising reacting a mixed gas of hydrogen and carbon dioxide in the presence of a conversion catalyst to carbon monoxide rich gas, which process further comprises reacting part of the carbon dioxide and hydrogen in the gas feed exothermically to methane simultaneously with the carbon monoxide producing reaction and carrying out both reactions under adiabatic conditions, so that the exothermical methane producing reaction provides necessary heat for the endothermic carbon monoxide producing reaction.
(Note that both Methane and Carbon Monoxide are produced from Carbon Dioxide by this technical process, which, once started, requires the input of very little, if any, energy to keep going. The combination of the exothermic reaction with the endothermic reaction might result in a thermal energy balance.)
Claims: Process for the preparation of carbon monoxide rich product gas comprising reacting a gas feed of hydrogen and carbon dioxide preheated to a temperature between 400C and 650C in a molar H2 /CO2 ratio of between 1.5 and 6.5 in the presence of a reforming catalyst at a pressure between 5 and 50 bar to carbon monoxide rich gas, which process comprises reacting part of the carbon dioxide and hydrogen in the gas feed exothermically to methane simultaneously with the carbon monoxide producing reaction and carrying out both reactions under adiabatic conditions, so that the exothermic methane producing reaction provides necessary heat for the endothermic carbon monoxide producing reaction, and the outlet temperature of the product gas is higher than the temperature to which the gas is preheated.
The process ... wherein the mixed gas is preheated by heat exchange with the carbon monoxide rich gas leaving the process.
(Note that the temperatures and pressures required seem high; but, they are well within the realm of currently practiced industrial and chemical engineering. They are not out of the realm of the ordinary.
Note further the reference to "heat exchange", with the implications for energy balance.)
Description: This invention is directed to the preparation of carbon monoxide rich gas. In particular, the invention concerns utilization of carbon dioxide and hydrogen ... for the preparation of valuable carbon monoxide rich synthesis gas by an economic and energy efficient process.
Carbon monoxide is a useful reactant in a large number of industrial processes. To name a few, carbon monoxide is used in the manufacture of alcohols, carboxylic acids and isocyanates.
(See, for instance:
Germany 1957 Carbon Monoxide + H2O = Hydrocarbons | Research & Development; concerning: "United States Patent 2,786,863 - Catalytic Steam-Carbon Monoxide Synthesis; 1957; Germany;
Germany 98% Pure Carbon Monoxide from Coal, CO2 and O2 | Research & Development; which states, in part, that: "Many valuable organic chemicals-both as intermediate or final products-can be made from high purity carbon monoxide (CO). Mainly, this includes: Diisocyanates; Polyurethane; Fatty acid derivatives; Acrylic glass.")
The general object of this invention is to utilize industrial off-gases containing carbon dioxide and hydrogen in the preparation of carbon monoxide rich gas without the need of external energy sources or oxygen.
(See, for instance:
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"; and, wherein it's stated, that: "Carbon monoxide gas is frequently produced in the art by means of a continuous process in which carbon-containing raw materials are reacted with oxygen and carbon dioxide".
In Haldor Topsoe's process herein, of "US Patent 5,496,530", neither Oxygen nor "carbon-containing raw materials" are needed to produce Carbon Monoxide from Carbon Dioxide, which should, given that Carbon Monoxide is a profitable end product to have, more than offset the expense of producing the free Hydrogen required by the process of "US Patent 5,496,530", to convert Carbon Dioxide intoboth Carbon Monoxide and Methane.)
Accordingly, the invention provides a process for the preparation of carbon monoxide rich gas from a feed stock of hydrogen and carbon dioxide by reaction of hydrogen and carbon dioxide to carbon monoxide. In the process, a part of the carbon dioxide and hydrogen is exothermically converted to methane simultaneously with the carbon monoxide producing reaction. The reactions are carried out under adiabatic conditions in the presence of a conversion catalyst, whereby the exothermic methane producing reaction provides necessary heat for the endothermic carbon monoxide producing reaction.
On contrary to the conventional processes, which include a reformer furnace or a partial oxidation reactor together with fuel and steam systems, the process of the invention is accomplished in relatively simple process equipment. .
In operating the inventive process, hydrogen and carbon dioxide containing feed gas is mixed in conventional mixing devices. As previously mentioned, both gases are readily available as industrial by-products from a number of processes. Thus, carbon dioxide is practically present in all synthesis gas mixtures based on gasification of hydrocarbons or coal, and is separated therefrom by conventional removal methods, such as scrubbing, pressure swing adsorption and cryogenic separation methods.
(In other words, as above, Haldor Topsoe suggests that we could use this technology to recycle Carbon Dioxide reclaimed from the primarily Carbon Monoxide and Hydrogen hydrocarbon "synthesis gas" generated by the "gasification of ... coal".)
Hydrogen is commonly obtained as by-product from purge gas in e.g. petrochemical or ammonia plants by recovery in cryogenic separation, and used as fuel in those plants.
(As noted and documented in our introductory comments, getting the needed Hydrogen shouldn't be seen as a barrier. We can get it, and we can get it economically.)
Preheating of the gas may be obtained by heat exchange with a hot process fluid and preferably with the hot product stream, which leaves the adiabatic reactor. The outlet temperature from the reactor is considerable higher than the required inlet temperature of the mixed gas due to the reactions proceeding at adiabatic conditions in the gas.
(Again, the potentials for energy efficiency are noted.)
(At the specified conditions), the carbon dioxide and hydrogen in the process gas react to carbon monoxide by the endothermic reverse shift reaction
Methane is formed simultaneously by the exothermic reaction
The exothermic methanation reaction produces sufficient heat to maintain the endothermic reversed shift reaction.
Both reactions proceed to equilibrium in the presence of any conventional reforming catalyst including commercially available nickel, iron oxide, copper or zinc containing catalyst.
(Nothing too expensive, in other words.)
The final composition of the product gas leaving the process is controlled by the equilibrium of the above shift and methanation reactions. The actual product composition will, therefore, depend on the process conditions. By varying the H2 /CO2 ratio, the temperature and pressure, at which the mixed gas is introduced into the adiabatic reactor, different product gas compositions can be obtained. Thus, it is possible to obtain different product gas compositions being useful as synthesis gas in different processes.
(By) appropriate adjustment of the process conditions the carbon monoxide rich gas from the above process can be used directly as synthesis gas in the preparation of methanol."
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We'll close our excerpts with that little kicker, since, if we want to forego on the production of, separately, Carbon Monoxide and Methane from Hydrogen and Carbon Dioxide, we can, instead, just make a Methanol synthesis gas.
The many virtues of Methanol aside, if we just keep the products made from Carbon Dioxide limited to the two actually focused on by Haldor Topsoe, i.e., Carbon Monoxide and Methane, as in, above: "Methane is formed simultaneously by the exothermic reaction", then, aside from the utility of Carbon Monoxide, as exemplified in our above citation of "United States Patent 2,786,863", wherein valuable Alcohols can be synthesized by reacting Carbon Monoxide with plain old H2O, we submit that the Methane, co-produced so efficiently herein from Carbon Dioxide, can then be utilized in one of the many processes related to that explained to us by Haldor Topsoe themselves, as seen in our earlier report of:
Denmark CO2 + Methane = Hydrocarbon Syngas | Research & Development; concerning: "United States Patent 7,094,363 - Preparation of a Synthesis Gas; 2006; Assignee: Haldor Topsoe; Abstract: Process and apparatus for the preparation of synthesis gas by catalytic steam and/or CO2 reforming of a hydrocarbon feedstock (wherein additional) carbon dioxide (can be) added";
and, wherein "methane" is specified by Haldor Topsoe in the full Disclosure to be a suitable "hydrocarbon feedstock" to be reacted with Carbon Dioxide, to form a "synthesis gas" suitable for catalytic chemical condensation into various hydrocarbons.
Thus, the Methane, co-produced with Carbon Monoxide from Carbon Dioxide, via our subject process herein of Haldor Topsoe's "United States Patent 5,496,530" can be utilized in the process of Haldor Topsoe's "United States Patent 7,094,363" to generate hydrocarbon synthesis gas from even more Carbon Dioxide.
We don't know about you, but, we are just about sick to death from all of the Baloney Sandwiches about Carbon Dioxide - and Cap & Trade taxation and mandated petroleum industry subsidization through Geologic CO2 Sequestration - our government and our popular press have been feeding us over the past few decades.
Carbon Dioxide, as herein, is a valuable, maybe even a precious, raw material resource. If we make the effort to generate, economically, through any of the many known processes, a little Hydrogen, we can, according the United States Government-affirmed process of "United States Patent 5,496,530", convert Carbon Dioxide into one product, Carbon Monoxide, with which we can, using only Water as a co-reactant, make liquid hydrocarbon fuels; and, another product, Methane, with which we can make even more liquid hydrocarbon fuels by reacting that Methane with even more Carbon Dioxide.
Far, far past time that truth started getting told, ain't it?