United States Patent Application: 0100105962
As accessible via: Saudi Arabia Coverts CO2 to Fuel | Research & Development; we some time ago reported, via exposition of: "United States Patent Application Publication Number US2010/0190874A1;
Catalytic Hydrogenation of Carbon Dioxide into Syngas Mixtures; July 29, 2010; Inventors: Agaddin Mamedov, Texas, and Abdulaziz Al-Jodai, et. al., Riyadh, Saudi Arabia; Abstract: The invention relates to a process of making a syngas mixture containing hydrogen, carbon monoxide and carbon dioxide comprising a step of contacting a gaseous feed mixture containing carbon dioxide and hydrogen with a catalyst (thus enabling) hydrogenation of carbon dioxide (and which process can be) integrated with other ... synthesis processes for making ... alcohols"; that:
Saudi Arabia, who might likely want a bit of Carbon Dioxide shipped to them for, under the guise of Geologic Sequestration, undertaking some secondary petroleum recovery, have figured out a way to convert any Carbon Dioxide they then might get their hands on back into various hydrocarbons, which they specify in that US Patent Application to include: "ethane, propane, ... dimethylether (and) methanol".
Herein, via the initial link in this dispatch, we learn that the same team of Saudi inventors had, precisely three months before publication of Application Number US2010/0190874, disclosed yet another Carbon Dioxide recycling technical process
In this case, the production of gases, i.e., "ethane" and "propane" can, if desired, be minimized; or, if those gases are wanted, more of them can, be deliberately co-produced.
And, the liquid product slate is shifted away from the versatile Methanol, and it's de-hydrogenated derivative, Dimethyl Ether, and toward more familiar, more conventional, liquid hydrocarbons.
Comment follows excerpts from the slightly different:
"US Patent Application 20100105962 - Catalytic Hydrogenation of CO2 into Syngas Mixture
Date: April 29, 2010
Inventors: Agaddin Mamedov, Texas, and Abdulaziz Al-Jodai, et. al., Riyadh, Saudi Arabia
Assignee: Saudi Basic Industries Corporation, Riyadh
Abstract: The invention relates to a process of making a syngas mixture containing hydrogen, carbon monoxide and carbon dioxide, comprising a step of contacting a gaseous feed mixture containing carbon dioxide and hydrogen with a catalyst, wherein the catalyst substantially consists of chromia/alumina. This process enables hydrogenation of carbon dioxide into carbon monoxide with high selectivity, and good catalyst stability over time and under variations in processing conditions. The process can be applied separately, but can also be combined with other processes, for example up-stream with other synthesis processes for making products like aliphatic oxygenates, olefins or aromatics.
(Note: The "oxygenates" might well indicate more alcohols, but, "olefins" and "aromatics" include classes of materials that can be used as Gasoline blending stocks.)
Claims: A process of making a syngas mixture containing hydrogen, carbon monoxide and carbon dioxide, comprising a step of contacting a gaseous feed mixture containing carbon dioxide and hydrogen with a catalyst, consisting essentially of chromium as active substituent, optionally at least one alkali metal or alkaline earth metal as promoter, and alumina as support (and) wherein the catalyst contains from 5 to 30 mass % of chromium.
(And) wherein the feed mixture contains hydrogen and carbon dioxide in a ratio of from 1 to 5.
(And) wherein the feed mixture further comprises methane.
Description: A drawback of the known process (as referenced) is the selectivity of the catalyst employed; that is methane formation from carbon dioxide is still observed as a side-reaction.
The object of the present invention is therefore to provide a catalyst that shows improved selectivity in reducing carbon dioxide with hydrogen into a syngas mixture, with only very little methane formation, and with good catalyst stability.
(Note that the Saudis confirm the general intent of the Sabatier process: Carbon Dioxide can be converted into, in this case unwanted, product Methane.)
A process for making a chemical product using a syngas mixture as an intermediate or as feed material comprising a step of contacting a gaseous feed mixture containing carbon dioxide and hydrogen with a catalyst consisting of chromium as active substituent, optionally at least one alkali metal or alkaline earth metal as promoter, and alumina as support.
A process for aliphatic oxygenates production, olefin synthesis, aromatics production, or carbonylation of methanol or olefins comprising a step of contacting a gaseous feed mixture containing carbon dioxide and hydrogen with a catalyst consisting of chromium as active substituent, optionally at least one alkali metal or alkaline earth metal as promoter, and alumina as support.
The invention relates to a catalytic process for producing a syngas mixture from carbon dioxide ... .
With the process according to the present invention carbon dioxide can be hydrogenated into carbon monoxide with high selectivity, the catalyst showing good stability over time and under variations in processing conditions.
Preferably, the catalyst used in the process according to the invention is a chromia/alumina catalyst that has been used in an alkane dehydrogenation process, for example a propane or iso-butane dehydrogenation process. Such catalyst is referred to herein as spent dehydrogenation catalyst. Such spent catalyst is typically removed from a reactor, because the catalyst showed too low residual activity in said dehydrogenation process, most likely due to deactivation caused by coke formation, for continued use in said reactions. Coke deposition on the catalyst is generally thought to result in a change in physical properties of the catalyst particles, like a lower surface area and increased pore size; and the resulting decreased activity of the dehydrogenation catalyst cannot be increased again by a regeneration process. Regeneration with e.g. oxygen will remove coke, but will not restore the original structure. Such spent catalyst therefore has to be disposed of after its use in alkane dehydrogenation. It is therefore a great advantage and highly surprising that such spent dehydrogenation catalyst can be used in the process according to the invention, and that this process can be operated during prolonged times with good stability.
The amount of hydrogen in the feed gas, that is the value for n in the above reaction scheme, may vary widely, for example from n=1 to n=5, to result in a syngas composition, e.g. expressed as its H.2/CO ratio or as the stoichiometric number (SN), which can consequently vary within wide limits. The advantage thereof is that the syngas composition can be adjusted and controlled to match the desired use requirements.
(It is thus) possible to apply the syngas mixture obtained as a starting material in the synthesis of various other products; like alkanes, such as ethane, propane and iso-butane ... .
Recycling such carbon dioxide as starting material in the process of the invention thus contributes to reducing the amount of carbon dioxide emitted to the atmosphere (from a chemical production site).
The hydrogen in the feed may also originate from various sources, including streams coming from other chemical processes, like ethane cracking, methanol synthesis, or conversion of methane to aromatics."
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Speaking of Methane, as first mentioned far above, the full Disclosure does reveal that it can be added to the initial blend of Carbon Dioxide and Hydrogen used as feed stock for this process. And, some Methane can also be made from this process.
Regardless, if it is, for some reason, advantageous to add Methane to the feed mixture of Carbon Dioxide and Hydrogen, remember that we can, as seen in, for just one example:
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, Pittsburgh; Abstract: This invention relates to the gasification of carbonaceous solid fuels, and particularly to the production of hydrogen or high B.t.u. (specified to be Methane) gas from such fuels";
via a process more than half a century old that enables the gasification of Coal with H2O to completely gasify the Carbon in the Coal, generate a product comprising a blend of both Methane gas and the required elemental Hydrogen.
We can, of course, as 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, Orlando; Abstract: System for separating hydrogen and sulfur from hydrogen sulfide (H2S) gas produced from oil and gas waste streams";
obtain any needed extra Hydrogen, along with valuable Sulfur, by processing waste gases generated by oil and natural gas refineries.
And, if we want even additional Methane, to add to the Carbon Dioxide being recycled by the process herein, of US Patent Application 20100105962, perhaps along with the Hydrogen from industrial exhaust gases, as in the process of United States Patent 6,572,829, we can make that Methane, using environmental energy, as seen in:
Penn State Solar CO2 + H2O = Methane | Research & Development | News; concerning: "High-Rate Solar Photocatalytic Conversion of CO2 and Water Vapor to Hydrocarbon Fuels; The Pennsylvania State University; 2009; Efficient solar conversion of carbon dioxide and water vapor to methane";
by using sunshine to form it out of nothing but Water and, that increasingly-valuable raw material resource, Carbon Dioxide.