We've presented you with a number of reports now, documenting the Coal utilization technology that was for a time being developed by the rather well-known Dow Chemical Company.
Among them have been, for only one example:
West Virginia Coal Association | Dow Chemical Coal to Methane | Research & Development; concerning: "United States Patent 4,609,679 - Producing Methane from Hydrogen and Carbon Monoxide; 1986; Assignee: Dow Chemical Company, MI; Abstract: Selectively produce methane under Fischer-Tropsch conditions using a catalyst consisting essentially of ruthenium supported on an oxide of tantalum, niobium, vanadium or mixtures thereof ".
We cite that one report since we'll be referring to it again in the future, relative to additional Carbon Dioxide recycling technologies based on the "bi-reforming" and "tri-reforming" of Methane with Carbon Dioxide, as seen, variously, for only two examples, in:
West Virginia Coal Association | Northwestern University CO2 + Methane = Hydrocarbon Syngas | Research & Development; concerning: "United States Patent 5,753,143 - Process for the Carbon Dioxide Reforming of Methane; 1998; Assignee: Northwestern University, (Illinois); Abstract: The present invention relates to a process for the carbon dioxide reforming of methane (CH4) in the presence of a catalyst to produce a synthesis gas comprising hydrogen and carbon monoxide. This invention relates to a process for producing synthesis gas by the carbon dioxide reforming of methane in the presence of a catalyst. Production of synthesis gas or syngas (mixtures comprising hydrogen and carbon monoxide) is an important first process step in the manufacture of numerous chemicals including ammonia and methanol"; and:
West Virginia Coal Association | Standard Oil 1950 CO2 + CH4 + H2O = Syngas | Research & Development; concerning: "United States Patent 2,522, 468 - Production of Synthesis Gas; 1950; Standard Oil Development Company; Abstract: (The) production of a mixture of carbon monoxide and hydrogen suitably proportioned for use as a feed-gas in the synthesis of hydrocarbons. It is a matter of record and commercial practice, particularly in countries foreign to the United States, to prepare hydrocarbons, including those boiling in the gasoline and gas oil range, by reacting a mixture of carbon monoxide and hydrogen. What I claim is: The method of continuously forming a mixture of carbon monoxide and hydrogen ... which consists essentially in charging a mixture of methane, steam and carbon dioxide to a reforming zone containing (a specified) catalyst (under specified conditions) ... and recovering from said zone, a product gas containing ... carbon monoxide and hydrogen".
However, referring to Dow's above-cited "United States Patent 4,609,679 - Producing Methane from Hydrogen and Carbon Monoxide", Dow tells us, herein, where they intended to get such a blend of "Hydrogen and Carbon Monoxide".
As seen in excerpts from the initial link in this dispatch to:
"United States Patent 4,872,886 - Two-stage Coal Gasification Process
Patent US4872886 - Two-stage coal gasification process - Google Patents
Two-stage coal gasification process - The Dow Chemical Company
Date: October 10, 1989
Inventors: John Henley, Stanley R. Pearson, et. al., LA and MI
(Please make note of Inventor Stanley R. Pearson. Subsequent to a long career at Dow, the accomplished Pearson went on to independently develop additional Carbon utilization technologies of interest, about which we will be making further report.)
Assignee: The Dow Chemical Company, MI
(Note that this Dow technology will seem closely related to another multi-stage Coal gasification process originally developed in Charleston, West Virginia, by the former Union Carbide Corporation; as seen, for just one example, in:
West Virginia Coal Association | 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; 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".Union Carbide became a wholly-owned subsidiary, or division, of Dow Chemical in 2001.)
Abstract: A two-stage upflow process for coal gasification and an apparatus useful therefor. An oxygen-containing gas and a first increment of a coal-in-water slurry are ignited in a horizontal fired slagging reactor by means of horizontal coaxial juxtaposed burner nozzles mounted in the reactor, thereby converting the oxygen, the coal, and the water into steam and gaseous combustion products. The discharge from the fired reactor is contacted overhead with a second increment of coal-water slurry in a vertical unfired heat-recovery unit connected to the upper end of the reactor. The heat evolved in the reactor is used in the heat recovery unit to convert the second increment of coal-water slurry into more steam, char and synthesis gas. The gas effluent is separated from the solid char, and synthesis gas is passed into a fire-tube boiler to recover heat and the cooled product gas is recovered as the desired fuel-rich product. The solid char is reslurried and recycled to the fired reactor for further combustion.
(We've documented numerous examples of such multi-stage Coal gasification/conversion processes, in addition to the above-cited Union Carbide technology of "United States Patent 3,988,237", as, for just one more instance, in our report of:
West Virginia Coal Association | Exxon Gasifies Coal, and Steam-Gasifies the Char | Research & Development; concerning: "United States Patent 5,055,181 - Hydropyrolysis-Gasification of Carbonaceous Material; 1991; Assignee: Exxon Research and Engineering Company; Disclosed is a process for obtaining liquids and gases from carbonaceous material, such as coal. The carbonaceous material is first treated with a gasification catalyst, and optionally a hydrogenation catalyst, and hydropyrolyzed for an effective residence time, below the critical temperature at which methane begins to rapidly form, to make liquid products. The resulting char is gasified in the presence of steam at a temperature from about 500C to about 900C";
with all of them intended to maximize the extraction or utilization of the Carbon content in the Coal.)
Claims: A non-catalytic two-stage upflow process for gasification of a carbonaceous material, which process comprises the steps of
(a) combusting in a fired horizontal slagging reactor a stream comprising an oxygen-containing gas and a first increment of a slurry of particulate carbonaceous material in a liquid carrier at a temperature of between 2400 and 3000 F and at a pressure of from 50 psig to 600 psig by means of opposed horizontal burner nozzles, thereby evolving heat and forming a liquid, molten slag and a gaseous products stream and entrained byproduct sticky, molten slag particles;
(b) separating said liquid, molten slag;
(As we will see in reports to follow, specific methods have been developed for the above "separating said liquid, molten slag", with implications for the follow-on use of that slag.)
(c) contacting, in an unfired vertical second stage, said gaseous products stream and said entrained byproduct sticky, molten slag particles from the fired horizontal reactor with a second increment of a slurry of particulate carbonaceous material in a liquid carrier at a temperature of between 1600 and 2000 F, whereby a substantial portion of the heat evolved in the said step (a) is recovered by converting the second increment of carbonaceous material and carrier liquid into steam, vapor from the carrier liquid, synthesis gas and char, whereby at least a portion of the entrained byproduct sticky, molten slag particles are cooled below the temperature of adherence to heat transfer surfaces and at least a portion of said entrained sticky, molten slag particles are absorbed onto said char preventing the fouling of the downstream heat recovery equipment; and: (d) recovering another portion of the heat values from said gaseous combustion products in a high temperature heat recovery system, including a fire-tube boiler, whereby the gaseous combustion products are cooled to a temperature of about 450 to about 550 F.
The process ... further comprising the step of: (e) recycling to step (a) the char leaving in said step (c) as a suspension in a liquid defining a solids concentration of from 20 percent to 40 percent by weight (by) separating the char from the synthesis gas; contacting the char with said liquid thereby forming the suspension of char in said liquid; and: recycling the char suspension to said fired reactor.
The process ... wherein the carrier liquid is water.
The process ... wherein the oxygen-containing gas is air, oxygen-enriched air, or oxygen.
(Purified "oxygen" is better, since it prevents formation of wasteful Nitrogen oxides, which are produced when any form of Air is used. And, we have now some intriguing ways of getting that Oxygen, which could be synergistic with this, or other, Coal and CO2 conversion/utilization processes, since, as seen in:
West Virginia Coal Association | General Electric 2010 Hydrogen from Sunlight and Water | Research & Development; concerning, in part: "United States Patent 7,820,022 - Photoelectrochemical Cell and Method of Manufacture; 2010; Assignee: General Electric Company; A photoelectrochemical cell ... to produce gaseous hydrogen and oxygen";
we can generate it, using environmental energy, sunlight, from Water, as a co-product with Hydrogen, which Hydrogen, as we emphasize in the above-cited report, can be of great value in other Coal conversion, and Carbon Dioxide recycling, processes.)
The process ... wherein the oxygen-containing gas is air and the initial atomic ratio of free elemental oxygen to carbon in the reactor is between 1.5:1 and 2.5:1.(And) wherein said carbonaceous material is coal ... .
Background: This invention relates to the gasification of carbonaceous materials. More particularly, the invention relates to the conversion of a solid carbonaceous fuel into gaseous products having increased fuel value.
Three basic processes have been developed for the gasification of carbonaceous materials such as coal:
(1) fixed-bed gasification,
(2) fluidized-bed gasification, and
(3) suspension or entrainment gasification.
The present invention relates to the third type of process, suspension or entrainment gasification.
An inherent disadvantage of entrainment gasifiers is that they generate hot product gases. The heat must be recovered from the gases in order to utilize fully the heating value of the coal. It is known to quench partial oxidation gasification reactions directly (or) to partially cool the effluent gases by indirect heat exchange. However, large amounts of high temperature heat are lost in quenching the effluent gases without enhancing the fuel value of the synthesis gas produced.
Another disadvantage of entrainment gasifiers is that they produce a substantial excess temperature in the gas product which requires quenching or cooling for subsequent heat recovery in conventional radiant heat water tube boilers. Thus, the product gas must be substantially cooled before it can be conducted to heat recovery boilers. As such, substantial quantities of otherwise useful high temperature heat are lost. Further, the capital investment for radiant heat boilers is quite high. Therefore, an alternative heat recovery boiler is an economic necessity for the entrainment gasifier processes.
A further disadvantage of entrainment gasifier processes is that sticky slag particles are carried through the partial gasification reactor and tend to foul the heat transfer surfaces of the heat recovery equipment.
Some of the reactions in a coal gasifier are exothermic and some are endothermic. A coal gasification process in which the heat generated by the exothermic reactions is used to provide the heat required for the endothermic reactions would be extremely desirable and energy efficient. Thus, it is an object of the present invention to provide an exothermic reactor partially oxidizing carbonaceous material with an oxygen-containing gas combined with a unfired second stage reactor to permit the endothermic reactions to proceed efficiently by reacting additional carbonaceous material with water, producing enhanced quality synthesis gas. This and other objects are accomplished in accordance with the present invention ... .
In general, the present invention provides a non-catalytic two-stage upflow process for gasification of carbonaceous fuels which produces a non-fouling gas product allowing the use of fire-tube waste heat recovery units. The first stage or step of the process comprises the combustion, in a fired horizontal slagging reaction zone, or first stage reactor, of a stream of oxygen-containing gas and a first increment of a slurry of particulate carbonaceous solids in a liquid carrier. The solids concentration of the slurry may be from 30 to 70 percent by weight. Combustion occurs at a temperature between 2400 and 3000 F ... .
The oxygen, carbonaceous solids and liquid carrier are converted into steam, vapor from the liquid carrier, slag, char, and gaseous combustion products. The slag which forms in the reactor flows by gravity to the bottom of the reactor and out of the reactor through a tap hole.
In the second stage, or step, the steam, vapor from the liquid carrier, char, and gaseous products from the fired horizontal reactor are contacted, in an unfired vertical second stage reactor, with a second increment of slurry of particulate carbonaceous solids in a liquid carrier to yield steam, vapor from the liquid carrier, synthesis gas and char entrained in the gaseous effluent.
As used herein, the term "unfired" means that further combustion is not promoted by the addition of a second oxygen-containing gas stream. The vertical second stage reactor does not promote additional combustion and exothermic reactions such as which occur in the fired horizontal reactor. In the vertical second stage reactor, endothermic reactions predominate using heat produced by the combustion in the fired horizontal reactor. The second increment of particulate carbonaceous solids in a liquid carrier is injected into the vertical second stage reactor by means of a nozzle, with steam or other atomizing gas for atomization of the slurry of particulate carbonaceous solids to provide better reaction. Injecting the second increment of slurry at a point downstream of the original injection point reduces the temperature of the gases exiting from the fired horizontal reactor and provides a more efficient use of the heat produced in the process.
Thus, while the fired horizontal reactor is primarily a combustion reactor, the vertical second stage reactor is primarily a quench reactor which also increases the heating value of the gases.
The synthesis gas and char entrained in the gaseous effluent from the unfired vertical second stage reactor exit from the top and are separated in a cyclone separator. The char exiting the cyclone separator is mixed with a liquid carrier forming a dilute slurry which is thereafter concentrated in a settling tank to a solids concentration of from 10 to 30 percent by weight. Then from 5 to 20 percent of the concentrated, or recycle, char slurry, based on the total amount of solid carbon fuel to the first stage, is added to the first stage horzontal slagging reactor zone, preferably after mixing with one or more streams of particulate carbonaceous solids comprising the first increment fed to the horizontal fired slagging reactor.
After exiting the cyclone, the gaseous products proceed into high temperature heat recovery system. Usually, such equipment would be a radiant heat type boiler or water-tube boiler, but in this instance the capital investment for such a boiler is extremely high. Therefore, a fire-tube boiler provides the necessary heat exchange capacity with the simplicity of operation and low capital investment involved to advantageously meet the requirements of heat recovery operations. The operation can be augmented by the further addition of a steam superheater.
(Note that multiple heat-recovery processes are incorporated into the design, thus minimizing, or even eliminating, the need for any externally-supplied energy. The process, once started, can be made to be entirely self-sustaining.)
However, this additional equipment is only practical if the operation of the fired combustion reaction and the unfired second stage reaction step provide a gaseous stream which is non-fouling. The gas also contains small particles of molten slag, of up to 5 micron size, which have an alkaline surface with a slightly lower melting temperature and tend to adhere to interior heat transfer surfaces, then the heat transfer surfaces of the boiler will become quickly fouled, inefficient, and eventually plugged. It is thus essential that the process of the present invention provide a gas product stream which in non-fouling and sufficiently cool to render the sticky slag particles more solid and less sticky. Thus, the present invention should cool the gas product stream to a temperature below the initial deformation temperature of the entrained slag particles in the presence of carbonaceous particulate material upon which the sticky slag can be absorbed.
(Thus, recovering heat for recycling into other segments of the process actually further improves the overall process efficiency, by making the product gas stream "cool" enough so that the "slag particles" aren't as "sticky", thus making them "non-fouling".)
The process is applicable to any particulate carbonaceous material. Moreover, the nature and concentration of the carbonaceous material in the two stages need not be the same. Preferably, however, the particulate carbonaceous material is coal which, without limitation, includes lignite, bituminous coal, sub-bituminous coal, or any combination thereof.
Additional carbonaceous materials are coke from coal, coal char, coal liquefaction residues, particulate carbon, ... concentrated sewer sludge, bits of garbage, rubber and mixtures thereof.(Note, that, as seen in our reports of:
West Virginia Coal Association | Pittsburgh 1938 Coal to Hydrocarbon Syngas | Research & Development; concerning: "United States Patent 2,132,533 - Production of Gas Suitable for the Synthesis of Hydrocarbons; 1938; Assignee: Koppers Company, Pittsburgh, PA; The invention relates to the production of gases, suitable for the catalytical synthesis of hydrocarbons, for instance motor fuel, from carbon monoxide and hydrogen and especially to such a process for producing said gases, which work continuously, so that a continuous stream of useful gases may be obtained (from) bituminous non-caking coal, wood, shells of coconuts or any other suitable fuel containing carbon"; and:West Virginia Coal Association | California Synfuels from Coal and Carbon-Recycling Wastes | Research & Development; concerning: "US Patent 7,208,530 - Production of Synthetic Transportation Fuels (via) Self-Sustained Hydro-Gasification; 2007; Assignee: The Regents of the University of California. Abstract: A process and apparatus for producing a synthesis gas for use as a gaseous fuel or as feed into a Fischer-Tropsch reactor to produce a liquid fuel in a substantially self-sustaining process. ... In particular, the present invention provides (for a) general purpose solid carbonaceous material feed system that can accept arbitrary combinations of coal, urban and agricultural biomass, and municipal solid waste for hydro-gasification (and) a Fischer-Tropsch (synthesis gas-to-liquid) fuel synthesizer ... to convert the synthesis gas ... into a sulfur-free clean-burning liquid transportation fuel";
we've known for a long time, and all across the country, that renewable, Carbon-recycling wastes, as well as, as, as specified herein by Dow, and as seen separately, for just one example, in:
West Virginia Coal Association | Consol Hydrogasifies CoalTL Residues | Research & Development; concerning: "United States Patent 4,248,605 - Gasification of Coal Liquefaction Residues; 1981; Inventor: Michael Lancet, Pittsburgh; Assignee: Conoco, Inc., CT; A method for gasifying the bottoms fraction from a coal liquefaction process";
still carbonaceous "coal liquefaction residues" can be gasified right along with Coal, in order to form, as herein, "gaseous products having increased fuel value".
But, the real "kicker" follows.)
The liquid carrier for carbonaceous solid materials can be any liquid which is capable of vaporizing and participating in the reactions to form desired gaseous products, particularly carbon monoxide and hydrogen. The most readily considered liquid carrier is water which forms steam in both reactor(s). The steam is capable of reacting with carbon to form gaseous products which are constituents of synthesis gas.
In addition, liquids other than water may be used to slurry the carbonaceous material. Preferably, the liquid is water, but it may also be ... liquid CO2."---------------------------
And, that seems a good place to close our excerpts.
According herein to Dow Chemical Company, and as verified by our own US Government experts in the United States Patent and Trademark Office, we can convert our abundant Coal, along with renewable and Carbon-recycling wastes, such as "concentrated sewer sludge (and) bits of garbage", and, even, "liquid CO2", into the "constituent of synthesis gas", suitable, we presume, for at least, as via Dow's process of their above-cited "United States Patent 4,609,679 - Producing Methane from Hydrogen and Carbon Monoxide", the catalytic synthesis of Methane; and/or, as in the now Dow-owned process of the above-cited "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; An integrated continuous process for the production of liquid and gaseous fuels", some other stuff we could use at least a little bit of.We confess to being stumped in trying to find a way to sum all of this up, but:
In a process founded on Coal, we can use the renewable products of our forests and fields, the wastes from our cities, and the Carbon Dioxide we all breathe out, to make any and all of the stuff we now drill and frack for, i.e., "Methane"; and, all of the other stuff we indenture ourselves and our progeny to the alien nations of OPEC to keep ourselves supplied with.
The question is begged as to why we aren't.
The fact that we aren't even openly, publicly exposing and discussing the facts, especially in the public venues of US Coal Country, is beyond comprehension.