United States Patent Application: 0090126259
We've documented many times, that, through an initial process of gasification, followed by catalyst-promoted chemical condensation, Coal can be converted into the valuable alcohol, Methanol.
Such an operation is, in fact, being conducted on a profitable commercial basis by Eastman Chemical Company in Kingsport, Tennessee; again as we have documented, for just one example, in:
Coal to Methanol - Eastman & Air Products | Research & Development; which concerns Eastman's: "Commercial-Scale Demonstration of a Liquid-Phase Methanol Process; Abstract: The Eastman Chemical Company operates a coal gasification complex in Kingsport. Tennessee. The primary output of this plant is carbonylation-derived acetic anhydride. The required methyl acetate is made from methanol and acetic acid. Methanol is currently produced from syngas ... . (Syngas made from Coal.) An Air Products/Eastman joint venture, with partial funding from the Department of Energy under the Clean Coal Technology Program, has been formed to build a demonstration-scale liquid-phase methanol plant ... . In an array of integrated plants, coal is gasified and the resulting synthesis gas purified to a high degree. This gas, which consists chiefly of carbon monoxide and hydrogen, is used to feed the chemical plants. Methanol is produced in one plant by the Lurgi low-pressure gas-phase process".
We note that much of Eastman's Methanol output is devoted to the production of other, value-added industrial chemicals, instead of, as optionally could be the case, as seen in:
Mobil Oil Coal to Methanol to Gasoline | Research & Development; concerning: "United States Patent 4,447,310 - Production of Distillates through Methanol to Gasoline; 1984; Mobil Oil Corporation; Abstract: A process for producing a wide slate of fuel products from coal is provided by integrating a methanol-to-gasoline conversion process with coal liquefaction and coal gasification";
Gasoline. But, converting Coal, through an initial gasification, into Methanol, and then into other chemicals, does seem to be a profitable undertaking for them.
Note, that, as in all "indirect" processes for the conversion of Coal into more versatile liquid and gaseous products, the Coal is first "gasified", another term is "partially oxidized", and converted initially into a blend of, primarily, Hydrogen and Carbon Monoxide.
During such "partial oxidation", a number of co-reactants can be selected to react with the Coal, so as to influence the composition of the product synthesis gas, i.e., the relative ratios of Carbon Monoxide and Hydrogen contained in that synthesis gas.
Steam, i.e., H2O, for instance, can be utilized as a co-reactant for Coal; a practice which adds additional, and needed, Hydrogen to the product syngas; as seen, for one example, in our report of:
Charleston, WV, Coal + Steam = Hydrocarbon Syngas | Research & Development; concerning: "United States Patent 3,988,237 - Integrated Coal Hydrocarbonization and Gasification of Char; 1976; Inventors: Hubert Davis, Charles Albright, et. al.; all of West Virginia; Assignee: Union Carbide Corporation; Abstract: An integrated continuous process for the production of liquid and gaseous fuels wherein coal particles are hydrocarbonized with a hydrogen-rich gas supplied by a gasification process employing two separate and interconnected zones for combustion and gasification and wherein char produced by the hydrocarbonization of the coal particles provides the feed for the gasification zone ... wherein in said first zone, char particles are gasified with steam".
Carbon Dioxide, very intriguingly, as seen, again for just one example, in:
Conoco 2011 Coal + CO2 + H2O + O2 = Syngas | Research & Development; concerning: "United States Patent 7,959,829 - Gasification System and Process; 2011; Assignee: ConocoPhillips Company; Abstract: A system and process for gasifying carbonaceous feedstock ... wherein (the) carrier liquid (for the feedstock) is selected from group consisting of water, liquid Carbon Dioxide, (or) mixtures thereof (and) wherein said particulate carbonaceous material is ... coal";
can also be consumed in the Coal gasification process, like Steam, to influence the relative mix of products in the resulting synthesis gas.
That fact had been just a shade earlier established by Shell Oil Company, as seen in our report of:
Shell Oil Coal + CO2 + H2O = Hydrocarbon Syngas | Research & Development; concerning: "United States Patent 7,829,601 - Partial Oxidation Process of a Solid Carbonaceous Feed; 2010; Assignee: Shell Oil Company; Abstract: The invention is directed to a process for preparing a mixture comprising CO and H2 by operating a partial oxidation process of a solid carbonaceous feed, which process comprises the steps of:(Supplying) the solid carbonaceous feed and an oxygen-containing stream to a burner, wherein a CO2 containing transport gas is used to transport the solid carbonaceous feed to the burner; (and) partially oxidizing the carbonaceous feed in the burner wherein a gaseous stream comprising CO and H2 is being discharged from said burner into a reaction zone, wherein the temperature in the reaction zone is from 1200 to 1800C and wherein said reaction zone is at least partly bounded by a wall, which wall comprises conduits in which steam is prepared by evaporation of water, resulting in a flow of steam being discharged from said reaction zone; (And) wherein the solid carbonaceous feed is coal."
And, herein, we see that Shell Oil has taken that technology some sophisticated steps further; and, actually recommends Carbon Dioxide as a primary co-reactant for Coal, in a gasification process intended to result, ultimately, in the production of liquid fuels.
Such utilization of Carbon Dioxide might be missed by an inattentive, cursory read, so, immediately following is a brief advance excerpt from the document that is the primary focus of this dispatch:
"Examples of suitable carrier gasses to transport the dry and solid feed to the burners are steam, nitrogen, synthesis gas and preferably carbon dioxide. Carbon dioxide is preferred because it achieves a better selectivity to synthesis gas and avoids build-up of nitrogen in downstream gas recycle streams."
"Carbon Dioxide is" the "preferred" co-reactant for Coal in the manufacture of hydrocarbon "synthesis gas".
As will be seen again in our more complete excerpts from the initial link in this dispatch to:
"United States Patent Application 20090126259 - Process to Prepare Methanol or Dimethyl Ether
Date: May, 2009
Inventors: Robert Van Den Berg, et. al., Netherlands
Correspondence Address (and presumed Assignee): Shell Oil Company, Houston, Texas
Abstract: A process to prepare methanol and/or dimethylether from a solid carbonaceous feedstock comprising the steps of (a) feeding an oxygen-comprising gas and the carbonaceous feedstock to a burner firing into a reactor vessel, (b) performing a partial oxidation of the carbonaceous feedstock in said burner to obtain a stream of hot synthesis gas and a liquid slag whereby both the hot synthesis gas and the liquid slag flow downwardly relative to the burner, (c) cooling the hot synthesis gas by direct contact with a liquid water-containing cooling medium, (d) performing a water shift reaction on at least part of the synthesis gas, to obtain a synthesis gas effluent, (e) performing an oxygenate synthesis using the synthesis gas effluent of step (d), to obtain a methanol and/or dimethylether containing oxygenate effluent and a first liquid water-rich by-product,wherein at least part of the first liquid water-rich by-product is used in step (c), forming at least part of the liquid water-containing cooling medium.
(We are compelled to note, that, like the above Abstract, the full Disclosure is complicated and difficult to understand. One of our consultants sketched it out for us, and that helped. The point is that there is some internal recycling of heat, and of product, going on, which serves to improve the overall efficiency. For those not familiar with "dimethylether", or, more commonly, "dimethyl ether" and "DME", it is, as we understand it, a chemically modified version of Methanol that, as seen in:
Conoco Converts Coal to Methanol and Dimethyl Ether | Research & Development; concerning: "United States Patent 6,638,892 - Syngas Conversion and Catalyst Employed Therefor; 2003; Assignee: ConocoPhillips Company, Houston; Abstract: A process for the conversion of syngas by contact of syngas under conversion conditions with catalyst having as components zinc oxide, copper oxide, aluminum oxide, ... zeolite and clay in ... a one step process for conversion of syngas to dimethyl ether (and) a two step process for conversion of syngas to light olefins ... .Dimethyl ether is a clean and efficient alternative diesel fuel which can be produced by the dehydration of methanol which can be synthesized from syngas";
can serve as a perfectly-acceptable, even cleaner, substitute for petroleum-derived Diesel fuel. Furthermore, a close read, as we will emphasize through our excerpts, reveals that this Shell technology also contains within it an integral process for the conversion of the product Methanol and DME into Gasoline.)
Claims: A process to prepare methanol and/or dimethylether from a solid carbonaceous feedstock comprising the steps of(a) feeding an oxygen-comprising gas and the carbonaceous feedstock to a burner firing into a reactor vessel,(b) performing a partial oxidation of the carbonaceous feedstock in said burner to obtain a stream of hot synthesis gas and a liquid slag whereby both the hot synthesis gas and the liquid slag flow downwardly relative to the burner,(c) cooling the hot synthesis gas by direct contact with a liquid water-containing cooling medium,(d) performing a water shift reaction on at least part of the synthesis gas, to obtain a synthesis gas effluent,(e) performing an oxygenate synthesis using the synthesis gas effluent of step (d), to obtain a methanol and/or dimethylether containing oxygenate effluent and a first liquid water-rich by-product,wherein at least part of the first liquid water-rich by-product is used in step (c), forming at least part of the liquid water-containing cooling medium.
(Yes, the first Claim seems merely to repeat the Abstract. It gets somewhat complicated after that.)
The process ... wherein step (e) comprises the steps of (el) converting at least part of the synthesis gas effluent to a methanol containing effluent and a second liquid water-rich by-product;(e2) converting at least part of the methanol containing effluent to a dimethylether containing effluent and a third liquid water-rich by-product,wherein the second and third liquid water-rich by-products form part of the first liquid water-rich by-product.
The process ... wherein at least part of the second water-rich by-product is recycled to step (c).
(Again, there is a lot of internal recycling of product going on, and, the point, ultimately, is to process, to recycle, any product, Methanol or Dimethyl Ether, that "leaks", our term, through the initial product separation stages, with the Water, back into the synthesis gas generator. That conserves the "building blocks", so to speak, and energy, while supplying, with the Water, Hydrogen to the Coal gasification. And, it is easier and less expensive than trying to separate the Methanol and the Dimethyl Ether from by-product Water streams where they are present in low concentrations.)
A process to prepare an olefin-containing product or a gasoline product from a solid carbonaceous feedstock comprising the steps of(a) feeding an oxygen-comprising gas and the carbonaceous feedstock to a burner firing into a reactor vessel,(b) performing a partial oxidation of the carbonaceous feedstock in said burner to obtain a stream of hot synthesis gas and a liquid slag whereby both the hot synthesis gas and the liquid slag flow downwardly relative to the burner,(c) cooling the hot synthesis gas by direct contact with a liquid water-containing cooling medium,(d) performing a water shift reaction on at least part of the synthesis gas, to obtain a synthesis gas effluent,(e) performing an oxygenate synthesis using the synthesis gas effluent of step (d), to obtain a methanol and/or dimethylether containing oxygenate effluent and a first liquid water-rich by-product; and (f) converting the oxygenate effluent to an olefin-containing product or a gasoline product and a fourth liquid water-rich by-product,wherein at least part of the first liquid water-rich by-product is used in step (c), forming at least part of the liquid water-containing cooling medium.
(There, above, we have mention made of the integral Methanol-to-Gasoline process, similar in function to our above-cited "US Patent 4,447,310 - Production of Distillates through Methanol to Gasoline".)
Background and Field: The present invention relates to improvements relating to a solid carbonaceous feed to a methanol and/or dimethylether process.
Methanol and dimethylether are useful feedstocks for preparing olefins in so-called oxygenate-to-olefins processes or as feedstock for preparing gasoline in a so-called oxygenate-to-gasoline process. Such an oxygenate-to-olefins process can convert methanol and/or dimethylether over a catalyst to a product stream that is typically rich in lower olefins, including ethene, propene, as well as butenes, pentenes, hexenes, and also higher olefins and other hydrocarbons and some by-products. The oxygenate feedstock can be obtained from synthesis gas, also referred to as syngas.
Summary and Description: In accordance with the invention there is provided a process to prepare methanol and/or dimethylether from a solid carbonaceous feedstock ... .
An advantage of the claimed process is that it is not needed to perform a sophisticated separation of methanol from the liquid water-rich by-product. By recycling these components with the water as cooling medium they can remain in the overall process as such, thereby improving the overall efficiency. Depending on the temperature of the synthesis gas ... part or all of the methanol and/or dimethylether may be converted into hydrogen and carbon monoxide and form part of the synthesis gas.
Synthesis gas is a gas comprising carbon monoxide (CO), hydrogen (H2) and optionally carbon dioxide (CO2). Optionally, synthesis gas may also include methane (CH4), ethane, propane, heavier hydrocarbons, or other compounds. A particularly interesting source of synthesis gas is from the gasification of a solid carbonaceous feedstock such as coal.
Preferred solid carbonaceous feeds as used in step (a) are ash and sulphur containing feedstocks, preferably coal, biomass, for example wood, ... and waste. More preferably the solid carbonaceous feed is substantially (i.e. more than 90 wt. %) comprised of naturally occurring coal ... . Suitable coals include lignite, bituminous coal, sub-bituminous coal, anthracite coal, and brown coal.
(Coal, coal, and, more coal. And, some Carbon-recycling "biomass" and "wood". Coal is what makes the element of sustainability even feasible.)
(An) oxygen-comprising gas and the carbonaceous feedstock are fed to a burner firing into a reactor vessel. In step (b) a partial oxidation of the carbonaceous feedstock in said burner is performed to obtain a stream of hot synthesis gas. This stream of hot synthesis gas flows downwards relative to the burner and a liquid slag flows downwards relative to the burner.
The gasification is preferably carried out in the presence of oxygen-comprising gas and optionally some steam, the purity of the oxygen-comprising gas preferably being at least 90% by volume, nitrogen, carbon dioxide and argon being permissible as impurities. Substantially pure oxygen is preferred, such as prepared by an air separation unit (ASU). The oxygen-comprising gas may contain some steam. Steam acts as moderator gas in the gasification reaction.
In order to achieve a more rapid and complete gasification, initial pulverisation of the solid carbonaceous feed is preferred. The partial oxidation reaction is preferably performed by combustion of a dry mixture of fine particulates of the carbonaceous feed and a carrier gas with oxygen in a suitable burner.
Examples of suitable carrier gasses to transport the dry and solid feed to the burners are steam, nitrogen, synthesis gas and preferably carbon dioxide."
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So, some amount of Carbon Dioxide can be utilized, and reacted, with Coal, and with a relatively smaller amount of naturally Carbon-recycling "wood", and "waste", and be made to form, through such reaction, a "synthesis gas" that can, as an integral part of the process, be condensed into an immensely valuable alcohol, Methanol, and substitute Diesel fuel, Dimethylether; and, even, "a gasoline product".
Only one question would seem to remain:
When do we get started?