Process for co-production of higher alcohols, methanol and ammonia - Patent 4886651
We've previously documented the expertise of Pennsylvania's Air Products corporation in the technology of coal conversion, via indirect synthesis gas production techniques.
As it turns out, they have parlayed their industrial gas chemistry skills into a technology for recycling Carbon Dioxide into valuable liquid fuels and chemicals.
And, they officially did so more than two decades ago, as evidenced via the enclosed link and following excerpt detailing their United States Patent on Carbon Dioxide recycling technology. We confess the quite lengthy patent description contains many technical details. Our excerpt, with some comment interspersed and following, is highly edited; and, like much of what we report to you, begs study by qualified individuals who could explain it more fully and clearly to the rest of us.
Some facts are quite plain, though, as we highlight in our abbreviated excerpts from:
"Process for co-production of higher alcohols, methanol and ammonia
United States Patent 4886651
An integrated process for producing higher alcohols, methanol and ammonia is set forth wherein two parallel reformations of methane are utilized to produce synthesis gas for the feed to the alcohol production and
hydrogen for the ammonia production.
Inventors: Patel, Nitin M. (Allentown, PA); Wang, Shoou-i (Allentown, PA)
Application Number: 07/195576; Publication Date: 12/12/1989; Filing Date: 05/18/1988
Assignee: Air Products and Chemicals, Inc. (Allentown, PA)
What is claimed is:
1. An integrated process for the production of higher alcohols, methanol and ammonia comprising the steps of:
(a) catalytically reforming a first methane-containing stream with steam and carbon dioxide to form a first hydrogen and carbon monoxide-containing synthesis gas;
(So, it all starts with Methane, Steam and Carbon Dioxide. And, never lose sight of the fact that Methane can itself be synthesized from both Coal and Carbon Dioxide. We will continue to emphasize that fact to the point of tedium. - JtM)
(b) removing carbon dioxide from said first synthesis gas and recycling at least a portion of the carbon dioxide to said reformation;
(Carbon Dioxide is used in the "first ... stream" of this process and "portion(s) of the" remaining CO2 will be recycled back into the "reformation".)
(c) rejecting at least a portion of the hydrogen content of said first synethsis gas to produce a first carbon monoxide-rich synthesis gas and a hydrogen stream;
(d) at least partially catalytically reforming a second methane-containing stream with steam and carbon dioxide to form an initial methane, hydrogen and carbon monoxide-containing synthesis gas and further reforming said initial synthesis gas by partial oxidation with an oxygen-enriched gas to result in a second hydrogen and carbon monoxide-containing synthesis gas;
(As in Penn State University's "Tri-reforming" process, Methane is reformed "with steam and carbon dioxide to form ... synthesis gas". And, we should all by now know what can be made with synthesis gas.)
(e) removing carbon dioxide from said second synthesis gas and recycling at least a portion of the carbon dioxide to said catalytic reformation of step (d);
(Again, more CO2 is recycled into the process.)
(f) combining said hydrogen stream with a nitrogen-rich stream and catalytically reacting the combined stream to produce ammonia;
(g) combining said first and second synthesis gas streams and catalytically reacting them to produce higher alcohols and a purge stream of residual unreacted synthesis gas at an elevated pressure; and
(h) reacting said purge stream to produce methanol.
2. The process of claim 1 wherein said oxygen-enriched gas is commercially pure oxygen.
(Note that, once again, as in earlier of our reports, "pure Oxygen", which has commercial value, is generated as a by-product Carbon Dioxide recycling; as in the air recycling system aboard the International Space Station, as we've documented, wherein CO2 is converted into pure O2 for the astronauts to breathe, and the by-product Methane is expelled into outer space.)
6. The process of claim 1 wherein said hydrogen stream is subjected to low temperature water gas shift and methanation to eliminate any residual carbon oxides.
(The "water gas shift' reaction, which we have several times documented, is again employed to recycle and react CO2 into hydrocarbons.)
7. The process of claim 1 wherein the removed carbon dioxide of the two catalytic reformations is combined and recycled to said reformations to maximize low hydrogen to carbon monoxide ratios.
(We note again the employment of CO2 to actually improve, it seems, the quality of the syngas.)
8. The process of claim 1 wherein an unreacted hydrogen-containing stream from the ammonia reaction is used as fuel for heating the catalytic reformations.
(And, as above and just below, as in our other citations of similar technology, processes like the one being explained herein can generate much of their own needed fuel and heat energy as by-products.)
9. The process of claim 1 wherein unreacted synthesis gas from the methanol reaction is used as fuel for heating the catalytic reformations.
10. The process of claim 1 wherein a portion of the hydrogen gas of step (c) is exported from the process.
(We don't know if the "exported" Hydrogen is to be sold commercially, or recycled back into the hydrogenation processes in the reaction steps above. Either way, it's valuable.)
Description: Technical Field
The process of the present invention is directed to the use of methane to synthesize methanol, lower alkanols and ammonia. Specifically, the process is related to the use of natural gas as a source for the synthesis of alcohols and ammonia using the integration of two trains of steam-methane reforming and air separation.
Background
Steam methane reforming to produce a hydrogen and carbon monoxide rich synthesis gas is well known in the prior art. In addition, it is known to use primary reformation for the catalytic conversion of methane and steam to produce hydrogen and carbon monoxide followed by secondary reforming in a thermal, partial oxidation of methane to produce a hydrogen and carbon monoxide-rich synthesis gas.
(Our admittedly limited understanding is that Carbon Dioxide in this process, and similar reactions, serves as an agent for the "partial oxidation of methane to produce ... synthesis gas". But, we don't really think that "Steam methane reforming to produce ... synthesis gas", with all of the technology's implications, is all that "well known". If it is, why aren't we doing it?)
Description:
The process of the present invention is directed to the use of methane to synthesize methanol, lower alkanols and ammonia. Specifically, the process is related to the use of natural gas as a source for the synthesis of alcohols and ammonia using the integration of two trains of steam-methane reforming and air separation.
It is also known to produce alcohols by various processes including the catalytic reaction of methane to produce methanol.
Brief Summary:
The present invention is an integrated process for the production of higher alcohols, methanol and ammonia, comprising the steps of: catalytically reforming a first methane-containing stream with steam and carbon dioxide to form a first hydrogen and carbon monoxide-containing synthesis gas, removing carbon dioxide from said first synthesis gas and recycling at least a portion of the carbon dioxide to said reformation, rejecting at least a portion of the hydrogen content of said first synthesis gas to produce a first carbon monoxide-rich synthesis gas and a hydrogen stream, at least partially catalytically reforming a second methane-containing stream with steam and carbon dioxide to form an initial methane, hydrogen and carbon monoxide-containing synthesis gas and further reforming said initial synthesis gas by partial oxidation with an oxygen-enriched gas to result in a second hydrogen and carbon monoxide-containing synthesis gas, removing carbon dioxide from said second synthesis gas and recycling at least a portion of the carbon dioxide to said catalytic reformation, combining said hydrogen stream with a nitrogen-rich stream and catalytically reacting the combined stream to produce ammonia, combining said first and second synthesis gas streams and catalytically reacting them to produce higher alcohols and a purge stream of residual unreacted synthesis gas at an elevated pressure, and reacting said purge stream to produce methanol."
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We close the excerpts at this point. The full technical dissertation begs reading by someone qualified both to fully understand it, and then to translate it for the rest of us.
The point of it all is this: Methane can be converted into higher hydrocarbons, including Methanol and, even, if we understand the terminology correctly, some gasoline-range hydrocarbon liquids. Those, in addition to other organic compounds, such as Methanol, useful for the synthesis of plastics.
Ammonia, too, which has it's own commercial applications, is produced.
Methanol, as you should by now know, can be itself converted directly into gasoline, as well as a variety of plastics manufacturing feedstocks.
Careful reading will reveal that recoverable, and industrially-useful Oxygen, is also generated.
What demands very careful reading, though, is the fact that Carbon Dioxide is required for this patented reforming of Methane. It is specified to be added to the Methane being reformed at several stages of the Methane reforming process. Carbon Dioxide is consumed in the process of converting Methane into higher hydrocarbons.
That might be clearer in the following, US Government, record of this patent. Additional comment follows the link and excerpt:
Energy Citations Database (ECD) - - Document #6961828
Title: Process for co-production of higher alcohols, methanol and ammonia
Author: N.M. Patel, S.I. Wang
Publication Date: December, 1989; OSTI ID: 6961828; US Patent US 4886651; File Date: May 18, 1988.
Abstract: This patent describes an integrated process for the production of higher alcohols, methanol and ammonia. It comprises: catalytically reforming at first methane-containing stream with steam and carbon dioxide to form first a hydrogen and carbon monoxide-containing synthesis gas; removing carbon dioxide from the first synthesis gas and recycling at least a portion of the carbon dioxide to the reformation; rejecting at least a portion of the hydrogen content of the first synthesis gas to produce a first carbon monoxide-rich synthesis gas and a hydrogen stream; at least partially catalytically reforming a second methane-containing stream with steam and carbon dioxide to form an initial methane, hydrogen and carbon monoxide-containing synthesis gas and further reforming the initial syntheses gas by partial oxidation with an oxygen-enriched gas to result in a second hydrogen and carbon monoxide-containing synthesis gas; removing carbon dioxide from the second synthesis gas and recycling at least a portion of the carbon dioxide to the catalytic reformation; combining the hydrogen stream with a nitrogen-rich stream and catalytically reacting the combined stream to produce ammonia; combining the first and second synthesis gas streams and catalytically reacting them to produce higher alcohols and a purge stream of residual unreacted synthesis gas at an elevated pressure; and reacting the purge stream to produce methanol. Patent Assignee: Air Products and Chemicals Inc., Allentown, PA."
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That's the sum of it: A major corporation has known, our United States Government has known, officially, for more than two decades, that we can make Synthesis Gas from Methane reformed with Steam and Carbon Dioxide.
With that Synthesis Gas, we can make "ammonia ... higher alcohols ... and ... methanol".
The higher alcohols likely include gasoline-range hydrocarbons.
And, we remind you: The needed Methane can be itself synthesized, via Sabatier-type technology, from Carbon Dioxide; or, through gasification technology, from Coal; all as we have thoroughly documented in the West Virginia Coal Association's R&D Blog.
Moreover: Those needed CO2 and Coal conversion technologies, for Methane production, have been known and well-documented since the first half of the last century.
Finally, we'll note again the similarity between this Allentown, Pennsylvania, corporation's patented technology for recycling Carbon Dioxide via Methane reforming, and the "Tri-reforming" process for converting Methane and Carbon Dioxide together into higher hydrocarbons, as explained by Song and Grimes, et. al., as we have documented, at Penn State University.
And, we'll note the similarities between this Air Products US Patent and several others, issued in about the same era, to corporate proxies of our US Department of Defense, which define similar technologies that enable the conversion of Carbon Dioxide into liquid fuels.