Reforming process for carbon monoxide
More than a year ago, we documented for you that West Virginia scientists in the employ of the fabled chemical company, E.I. Dupont, had, very nearly four decades ago, figured out how to convert some of Coal Country's apparently-offensive Carbon Dioxide into liquid hydrocarbon fuels.
That report is accessible via: WV DuPont Patents CO2 + CH4 = Methanol | Research & Development; and, it includes details of: "US Patent 3,763,205 - Methanol Process with Recycle; 1973; Inventor: Ralph Green, Charleston, WV; Assignee: E.I. DuPont; Abstract: Methanol is made by a process that involves feeding natural gas, steam ... and ... carbon dioxide to a single bed type reactor."
The process of USP 3,763,205, as we read it, is a type of Carbon Dioxide-Methane "reforming" similar in concept and chemistry to CO2-recycling technologies we have many times reported and documented from many other sources, in addition to DuPont, as, for just one example, in:
Standard Oil 1987 CO2 + CH4 = Syngas | Research & Development; "US Patent 4,690,777 - Production of Synthesis Gas; 1987; Assignee: The Standard Oil Company; Abstract: Gas mixtures containing at least hydrogen and carbon monoxide are prepared by ... contacting the light hydrocarbons with carbon dioxide (and) wherein the light hydrocarbon is methane (and, which resulting) mixtures ... are particularly useful as feed gases in processes for producing higher hydrocarbons and oxygenated derivatives, such as Fischer-Tropsch and alcohol synthesis processes".
In any case, we see herein, via the initial link in this dispatch, that DuPont's West Virginia scientists were encouraged enough by the technology they had developed and, through US Patent 3,763,205, claimed ownership of, that, they continued their Carbon Dioxide recycling R&D efforts and were, several years later, awarded yet another US Patent for an advancement on their CO2-conversion science.
Comment, with some additional links, follows excerpts from the initial link in this dispatch to the somewhat misleadingly-titled:
"United States Patent 3,943,236 - Reforming Process for Carbon Monoxide
Date: March, 1976
Inventor: Ralph Green, Charleston, WV
Assignee: E. I. DuPont and Company, DE
Abstract: Hydrocarbons are reformed with steam to produce synthesis gas or hydrogen and carbon monoxide.
Carbon dioxide must be added ... to balance the hydrogen.
By this process larger quantities of carbon monoxide relative to the hydrogen produced can be realized.
(Please note, that, in schematics accompanying the Patent Disclosure, it is clearly shown that Carbon Dioxide is being introduced from an outside source, via a conduit that passes through a compressor driven by hot, pressurized gases from the "reformer" reaction vessel, before the subsequently pressurized CO2 is introduced into that reformer along with Steam and Methane.)
Catalytic steam-hydrocarbon reforming is the major method employed by industry for producing carbon monoxide or synthesis gas mixtures, e.g., carbon monoxide and hydrogen.
In this process gaseous hydrocarbons, such as methane ... are reacted with steam over a nickel catalyst.
In this conventional process, the reformer product or effluent contains hydrogen and carbon monoxide at a ratio of H2 to CO of at least 2:1 and as high as 5:1 to 7:1.
The lower ratios (can) be obtained by the addition of carbon dioxide to the reformer feed.
Summary: (The) conventional (steam-methane reforming) process can be improved if after the carbon monoxide has been removed from the reformer effluent, at least a portion of the reformer effluent is recycled to the reformer inlet.
In this process carbon dioxide must also be added to the reformer in an amount at least equivalent to the amount of hydrogen present in the recycle stream ... .
(Thus, the more Hydrogen we can make, the more Carbon Dioxide we can use.)
In the conventional process the ratio of steam to hydrocarbons, e.g., natural gas (i.e., Methane) is about 1.5 to 5.0:1.
In the process of the invention ... the ratio of steam to gas can be reduced to 1:1 or even lower.
(And, "reduced steam" means less energy needed to make that Steam.)
(But) hydrogen in the recycle, along with added carbon dioxide, will make needed steam in the reformer according to the following reaction: CO2 + H2 = CO + H2O.
It may (thus) be possible to eliminate the need for any (supplemental) steam (with its attendant costs) if the hydrogen and carbon dioxide can create the necessary amount of steam in the reformer.
The amount of (required) hydrocarbon feed (such as Methane) is also reduced in the process of the invention.
As previously set forth, when the recycle stream, principally hydrogen, is fed to the reformer, at least an equivalent amount of carbon dioxide must be fed to the reformer.
Note that (even) if the reforming process previously used carbon dioxide in the feed, ... additional ... carbon dioxide ... must still be added.
Claims: In the manufacture of carbon monoxide ... the improvement comprising ... adding carbon dioxide to the reformer feed."
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Note that this isn't just about "the manufacture of carbon monoxide", as immediately above, but, as they earlier specify, a "synthesis gas" that "contains hydrogen and carbon monoxide at a ratio of H2 to CO of at least 2:1 and as high as 5:1 to 7:1".
They can, in other words, produce, using Carbon Dioxide and Methane in variable ratios, a hydrocarbon syngas of variable, and specifiable, composition; and, which syngas can thus be tailored to be suitable in composition for catalytic condensation, via the venerable Fischer-Tropsch process, or it's many variants, as can be seen in: Fischer–Tropsch process - Wikipedia, the free encyclopedia; into a wide variety of liquid fuels and chemicals, through and including hydrocarbons in the gasoline range and various alcohols.
Further, it seems as if, as above, that DuPont's process of USP 3,943,236 can be adjusted so that there could be Carbon Monoxide, produced, from Carbon Dioxide, in excess of what could be reacted with the Hydrogen also produced in their system.
If so, as in: Pittsburgh 1951 Carbon Monoxide + Water = Hydrocarbons | Research & Development; concerning: "United States Patent 2,579,663 - Process of Synthesizing Hydrocarbons; 1951; Assignee: Gulf Research and Development Company, Pittsburgh; Abstract: This invention relates to a process for synthesizing hydrocarbons ... (from) carbon monoxide and steam";
we can simply react any excess Carbon Monoxide generated by DuPont from CO2, according to Gulf Oil's process of USP 2,579,663, with plain old H2O, and thereby synthesize even more "hydrocarbons".
And, as far as getting the Methane, required herein by DuPont to react with the Carbon Dioxide, we remind you, yet again, as in:
Consol 1953 Coal to Hydrogen & Methane with No CO2 | Research & Development; concerning: "United States Patent 2,654,661 - Gasification of Carbonaceous Solid Fuels; 1953; Assignee: Consolidation Coal Company; Abstract: This invention relates to the gasification of carbonaceous solid fuels, and particularly to the production of ... high B.t.u. gas ... rich in methane (and) rich in hydrogen ... from such fuels"; that:
we can make all of the Methane we might want, via processes involving the Steam-gasification of Coal; which processes are so productive they can also generate extra Hydrogen, which could be utilized, via standard petroleum refinery technologies, to "hydro-treat" and further refine hydrocarbon liquids derived from Coal.
Or, as in:
CO2 to Methane - Penn State | Research & Development | News; concerning the story: "Sunlight Turns Carbon Dioxide to Methane" from 2009, and which details how scientists at Penn State University have developed a technology for converting: "carbon dioxide and water vapor into methane" by using "solar power";
we can, using freely-available environmental energy, convert CO2, reclaimed from whatever handy source, perhaps a brewery, into the Methane needed by the WV-originated process of US Patent 3,943,236, to be "reacted with steam over a nickel catalyst" and with "the addition of" even more "carbon dioxide", to create a synthesis gas that "contains hydrogen and carbon monoxide at a ratio" that can be deliberately varied, through the addition of more or less CO2, between "at least 2:1 and as high as 5:1 to 7:1"; and, thus, be made suitable for, as noted above, catalytic condensation, via the Fischer-Tropsch process and it's many variants, into a complete range of liquid hydrocarbons: anything we now derive from increasingly-scarce natural petroleum.
Finally, once more, it is demonstrated:
Carbon Dioxide, as arises in only a small way, relative to semi-natural sources of emission, such as from the extensive rot in swamps built up behind hydro-electric dams, from our varied and productive uses of Coal, is a valuable raw material resource.
We can use CO2 to produce the elements and compounds from which we can synthesize liquid hydrocarbon fuels and plastics manufacturing raw materials.