We've lately begun to document for you how the already immense value of Coal can be maximized in an integrated facility that, through an initial process of Coal gasification, is capable both of generating electricity and of synthesizing hydrocarbon compounds; and, of varying the amounts of either electricity or hydrocarbons produced in response to changing demands.
There have been more recent developments made in that art by some companies more familiar to us in the United States, as seen for instance in our recent report of:
West Virginia Coal Association | Eastman Chemical Coal to Liquid Fuel, Chemicals and Electricity | Research & Development; concerning: "US Patent Application 20070129450 - Process for Producing Variable Syngas Compositions; 2007; Inventors: Scott Barnicki, et. al., TN; Correspondence (and presumed eventual Assignee of Rights): Eastman Chemical Company, TN; Abstract: Disclosed is a process for the production of a variable syngas composition by gasification. ... The process is useful for supplying syngas from multiple gasifiers for the variable coproduction of electrical power and chemicals across periods of peak and off-peak power demand".
But, most of those more recent achievements seem founded on a core of technology developed first in Germany, as represented by our report of:
West Virginia Coal Association | Germany Coal to Electricity, Methanol and Vinyl Acetate | Research & Development; concerning: "United States Patent 4,663,931 - Power Generating Station with and Integrated Coal Gasification Plant; 1987; Inventors: Ulrich Shiffers and Rainer Muller; Assignee: Kraftwerk Union, AG, Mulheim (Germany); Abstract: Power generating plant with an integrated coal gasification plant, with a heat exchanger and gas purification plant connected to the coal gasifier, with a gas turbine and steam power generating plant part connected to the heat exchanger and gas purification plant, and with a methanol synthesis plant. The methanol generated in the methanol synthesis plant as well as the synthesis exhaust gas of the methanol synthesis can be fed, at least partially, to a further subplant for a second chemical manufacturing process and the excess synthesis exhaust gas from the methanol synthesis and the exhaust from this further subplant, to the combustion chamber of the gas turbine power generating plant part".
And, before moving on to fuller exposition of more recent American achievements in the development of such and similar technology, we wanted herein to backtrack a bit and record for you some of the innovations developed, in Germany, precedent to and along with that embodied in the above "United States Patent 4,663,931 - Power Generating Station with and Integrated Coal Gasification Plant"; wherein both electrical power and valuable chemicals, primarily Methanol, can be concurrently produced, in a single facility, from by far our most abundant fossil energy resource: Coal.
First, as excerpted from the initial link in this dispatch, we have:
"United States Patent 4,590,760 - Medium-load Power Generating Station With An Integrated Coal Gasification Plant
Date: May, 1986
Inventors: Konrad Goebel, Ranier Muller and Ulrich Schiffers, Germany
Assignee: Kraftwerk Union, AG, Mulheim
(The above "Kraftwerk Union", as can be learned via:
Siemens History Site - Former Affiliates; "In 1969 ... AEG and Siemens founded Kraftwerk Union AG (but) crisis at AEG obliged the company to transfer its shares to Siemens AG, which subsequently integrated them into its Power Engineering Group";
is now a part of Siemens AG; who, as seen in our reports of:
West Virginia Coal Association | Siemens Gasifies All Ranks of Coal | Research & Development; concerning: "United States Patent 8,025,705 - Gasification of Coals of Widely Differing Degrees of Coalification; 2011; Assignee: Siemens Aktiengesellschaft, Munich"; and:
West Virginia Coal Association | Germany Awarded 2011 CO2 Recycling US Patent | Research & Development; concerning: "United States Patent 7,989,507 - Production of Fuel ... Utilizing Waste Carbon Dioxide; 2011; Assignee: Siemens Aktiengesellschaft (AG), Munich, Germany; Abstract: The present invention is directed to a method for utilizing CO2 waste comprising recovering carbon dioxide from an industrial process that produces a waste stream comprising carbon dioxide in an amount greater than an amount of carbon dioxide present in starting materials for the industrial process. The method further includes producing hydrogen using a renewable energy resource and producing a hydrocarbon material utilizing the produced hydrogen and the recovered carbon dioxide";
have continued to develop and refine some rather intriguing Coal, and Coal-related, technologies.)
Abstract: Medium-load power generating station with an integrated coal gasification plant, a gas turbine power generating station part connected to the coal gasification plant, a steam power generating station part connected to the raw gas heat exchanger plant of the coal gasification plant, a methanol synthesis plant having a plurality of modules connected in parallel to each other, and a purified gas distribution system which connects the methanol synthesis plant to the gas turbine power generating station part and which includes a purified gas continuous flow interim storage plant and is connected on the gas side to the raw gas heat exchanger plant. The methanol synthesis plant is associated, for hydrogen enrichment, to a "cooler-saturator loop" which is connected to the raw gas heat exchanger plant and consists of the saturator, a converting plant, cooler and following gas purification plant. In one mode of operation, a water electrolysis plant is associated with the methanol synthesis plant and its hydrogen line is connected to the methanol synthesis plant, and its oxygen line is connected to the coal gasifier.
Claims: A medium-load power generating plant with an integrated coal gasification plant comprising
(a) a coal gasification plant for producing raw hot fuel gas-containing carbon monoxide and hydrogen,
(b) a raw gas heat exchanger installation having a first raw gas heat exchanger for indirect heat exchange between the hot raw gas from the coal gasification plant with feedwater to generate steam,
(c) a gas purifier for purifying the raw gas,
(d) a central purified gas distribution system,
(e) a purified gas supply line connected to the raw gas heat exchanger installation and passing into the central purified gas distribution system,
(f) a purified gas continuous-flow interim storage plant connected in parallel to the purified gas supply line,
(g) a gas turbine power generating plant connected to the coal gasification plant to receive fuel via the purified gas supply line,
(h) a methanol synthesis plant having parallel-connected modules for converting CO and H2 into methanol connected to the gas turbine power generating plant via the central purified gas distribution system, the combination therewith of
(i) a cooler-saturator loop connected to a gas line containing carbon monoxide produced in said coal gasification plant and converting it into a gas richer in hydrogen, comprising a saturator wherein the gas is saturated with moisture, a converter wherein at least part of the carbon monoxide in the gas saturated with moisture is converted to hydrogen and carbon dioxide; a cooler for cooling the products from the converter, a gas purification plant for the removal of carbon dioxide and hydrogen sulfide, if any, from the gas from the cooler, and connecting means for passing said purified gas to the methanol synthesis plant for hydrogen enrichment of synthesis gas to be converted into methanol.
Medium-load power generating station ... wherein the "cooler-saturator loop" is inserted into the purified gas line carrying the purified gas which leads to a module of the methanol synthesis plant (and) including another raw gas heat exchanger in the raw gas heat exchange plant for indirect heat exchange between the raw gas and water to heat the water and connecting means through which the saturator can be supplied with hot water from the heat exchanger of the raw gas heat exchanger plant.
Medium-load power generating station ... wherein the gas purification plant comprises a carbon dioxide scrubbing plant to remove carbon dioxide.
(And, as in our above reference to our report concerning: "United States Patent 7,989,507 - Production of Fuel ... Utilizing Waste Carbon Dioxide; 2011; Assignee: Siemens Aktiengesellschaft (AG)"; the folks at "Kraftwerk Union", now a part of Siemens AG, should have some pretty good ideas about what to do after they "remove carbon dioxide" in "the gas purification plant".)
Medium-load power generating station ... wherein following the gas purification plant, a hydrogen separation plant is included in which a hydrogen rich fraction is separated by liquification of the less volatile gaseous constituents.
Medium-load power generating station according to claim 1, including steam connecting means from the first raw gas heat exchanger of the raw gas heat exchanger plant to the saturator for introducing steam into the saturator.
A medium-load power generating plant with an integrated coal gasification plant comprising
(a) a coal gasification plant for producing raw hot fuel gas-containing carbon monoxide and hydrogen,
(b) a raw gas heat exchanger installation having a first raw gas heat exchanger for indirect heat exchange between the hot raw gas from the coal gasification plant with feedwater to generate steam,
(c) a gas purifier for purifying the raw gas,
(d) a central purified gas distribution system,
(e) a purified gas supply line connected to the raw gas heat exchanger installation and passing into the central purified gas distribution system,
(f) a purified gas continuous-flow interim storage plant connected in parallel to the purified gas supply line,
(g) a gas turbine power generating plant connected to the coal gasification plant to receive fuel via the purified gas supply line,
(h) a methanol synthesis plant having parallel-connected modules connected to the purified gas line to receive purified gas containing CO and H2 which is partially reacted in the modules to produce methanol and a methanol exhaust gas containing unreacted carbon monoxide,
(i) a cooler-saturator loop connected to the methanol synthesis plant for treating methanol exhaust gas therefrom containing carbon monoxide and converting it into a gas richer in hydrogen, comprising a saturator wherein the gas is saturated with moisture, a converter wherein at least part of the carbon monoxide in the gas saturated with moisture is converted to hydrogen and carbon dioxide; a cooler for cooling the products from the converter, a gas purification plant for the removal of carbon dioxide and hydrogen sulfide, if any, from the gas from the cooler, and connecting means for passing said purified gas to the methanol synthesis plant for hydrogen enrichment of synthesis gas to be converted into methanol.
Background and Field: The invention relates to a medium-load power generating station with an integrated coal gasification plant, with a gas turbine generating station part connected to the coal gasification plant with a steam power generating station part connected to the raw gas heat exchanger plant of the coal gasification plant, with a methanol synthesis plant consisting of several parallel-connected modules, and with a purified gas distribution system which connects the methanol synthesis plant to the gas turbine power generating station part and which includes a purified gas continuous-flow interim storage plant and is connected on the gas side to the raw gas heat exchanger plant.
The subject ... is a medium-load power generating station for generating electric power and methanol, in which a combination gas turbine/steam power generating station and a methanol synthesis plant having a plurality of modules which modules can be added into the stream separately, is connected via a purified gas distribution system, to a coal gasification plant. The waste heat of the raw gas is fed to the steam power generating station part via a raw gas heat exchanger plant and is utilized there. In this medium-load power generating station, the generated electric power can be adapted quickly to the instantaneous power demands of the electric network without the need of employing a further expensive secondary fuel for load peaks and without the need that in the event of a sudden load reduction or even load shedding due to a disturbance, a loss of fuel has to be tolerated. Instead, methanol is produced to a larger degree in this medium-load power generating station at times of reduced demand of electric power and excesses as well as shortfalls of pure gas are buffered by the purified gas continuous flow interim storage plant which is associated with the pure gas distribution system.
Therefore, the ... coal gasification plant can continue to be operated with constant output independently of the prevailing load demands of the electric network. Because the composition of the purified gas flowing toward the methanol synthesis plant is far from the stoichiometric ratio required for the methanol synthesis, the synthesis gas returned in the methanol synthesis reactors of the individual modules must be enriched with hydrogen in times of reduced energy demand to utilize the not completely reacted synthesis gas which can no longer be burned in the combustion chamber of the gas turbine. This hydrogen enrichment could be achieved by external feeding-in of hydrogen.
(The gist of it, as we understand it, is that relatively high-Carbon Monoxide syngas can be burned to generate power, thus leaving Hydrogen-enriched syngas to be converted into Methanol. But, when power demand is relatively low, there would be rather more Carbon Monoxide than could be balanced by the Hydrogen produced by the Coal gasification, so some Hydrogen from an external source would have to be added for complete and efficient Methanol synthesis.
And, as seen in our report of:
West Virginia Coal Association | Germany & Pennsylvania Hydrogen from Hydropower | Research & Development; concerning, in part: "United States Patent 6,841,893 - Hydrogen Production from Hydro Power; 2005; Inventors: Marco Maiwald, et. al., Germany; Assignees: Voith Siemens Hydropower Generation GmbH and Incorporated, Germany and York, PA; A method is provided for operating a hydroelectric power generating facility ... in first and second operating modes. ... The method comprises computing a first economic value for the generated electrical power when operating in the first operating mode, and computing a second economic value for the generated electrical power when operating in the second operating mode. ... The method ...wherein the facility includes hydrogen producing equipment and the first operating mode involves producing hydrogen from the generated electrical power. ... The method ... wherein the facility is connected to a utility grid and the second operating mode involves supplying the generated electrical power to the utility grid. The method ... wherein the generated electrical power is DC power and the hydrogen producing equipment includes an electrolyzer";
another Siemens operating group has developed technology which, using Carbon-free environmental energy to drive the process; and, in a balanced way analogous to the process of our subject, "United States Patent 4,590,760 - Medium-load Power Generating Station With An Integrated Coal Gasification Plant", directs it's product electricity to where, at any given time, it is most needed; i.e.: to the grid at times of peak power demand, or, to a water electrolysis system for the generation of Hydrogen, which could then be used to enrich the Coal syngas directed to Methanol synthesis, via the specified "external feeding-in of hydrogen", in the process of "United States Patent 4,590,760".)
Summary: there is provided in accordance with the invention a medium-load power generating plant with an integrated coal gasification plant comprising:
- a coal gasification plant for producing raw hot fuel gas-containing carbon monoxide and hydrogen,
- a gas turbine power generating plant connected to the coal gasification plant to receive fuel via the purified gas supply line,
- a methanol synthesis plant having parallel-connected modules for converting CO and H2 into methanol connected to the gas turbine power generating plant ... ."
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We'll close there, although the full Disclosure is much more detailed, to remind you, that, once Methanol is produced, as herein, along with electrical power, from Coal, that Methanol can then, as seen for one example in our report of:
West Virginia Coal Association | ExxonMobil Coal to Methanol to Gasoline | Research & Development; concerning, in part: "United States Patent 4,035,430 - Conversion of Methanol to Gasoline; 1977; Assignee: Mobil Oil Corporation; Abstract: The conversion of methanol to gasoline boiling products in a plurality of sequentially arranged catalyst beds";
be rather directly converted into Gasoline.
In any case, following is even further exposition of such technology, for the co-conversion of Coal into both electricity and Methanol, as developed by the scientists at Kraftwerk Union, later part of Siemens AG:
United States Patent: 4631915 - Gas Turbine and Steam Power-Generating Plant with Integrated Coal Gasification Plant
Date: December, 1986
Inventors: Hans Frewer, Rainer Muller, Ulrich Schiffers, Germany
Assignee: Kraftwerk Union AG, Mulheim
Abstract: Gas turbine and steam power generating station with an integrated coal gasification plant which is supplied with oxygen via an air decomposition plant, with a methanol synthesis plant connected to the coal gasification plant, with a steam generating station part connected to the exhaust heat boiler of the gas turbine, as well as with a nitrogen line leading from an air decomposition plant to the combustion chamber of the gas turbine. The coal gasifier for the hydrogenating coal gasification is connected to a hydrogen supply line; the coal gasifier is followed, for utilizing the residual coke, by an iron bath gasifier, which is followed on the exhaust gas side by a converting plant and a carbon dioxide scrubbing plant connected to the hydrogen supply line. The exhaust gas line of the coal gasifier is connected via a gas purifier to a methanol synthesis plant and the exhaust gas line of the methanol synthesis plant is connected to the combustion chamber of the gas turbine.
(Note that there is provision made for recovery of Carbon values in the still carbonaceous Coal gasification residues, as in "utilizing the residual coke, by an iron bath gasifier". We some years ago made report on molten metal bath Coal gasification technologies, which do offer some unique technical characteristics and advantages. We can't at the moment track down any of our old reports on such technology in the West Virginia Coal Association R&D archive; but will, in a few reports to follow, reintroduce and further explain the technology.)
Claims: A gas turbine and steam power-generating plant with an integrated coal gasification plant and with a methanol synthesis plant, comprising a hydrogenating coal gasifier for partially converting coal containing sulfur in the presence of hydrogen into a gas containing principally hydrogen and methane and lesser amounts of carbon monoxide and hydrogen sulfide leaving residual coke containing sulfur, coal feed means for feeding coal containing sulfur into the hydrogenating coal gasifier, a hydrogen supply line connected to the hydrogenating coal gasifier for feeding hydrogen thereto, an exhaust gas line from the hydrogenating coal gasifier connected to a gas purifier for removal of hydrogen sulfide, connecting means for the transfer of purified gas containing principally hydrogen and methane from the gas purifier to a methanol synthesis plant for converting hydrogen and carbon monoxide into methanol, a coke line for conducting the residual coke from the hydrogenating coal gasifier to an iron bath gasifier having a molten iron body with slag floating thereon wherein the residual coke is oxidized with oxygen fed to the iron bath gasifier to produce a gas containing carbon monoxide and the sulfur contained in the residual coke is bound into the slag, a dosing device for feeding-in lime into the iron bath gasifier to aid in binding the sulfur in the slag, a slag outlet for the discharge of slag containing sulfur from the iron bath gasifier, an air separation plant into which air is fed and separated into an oxygen fraction and a nitrogen fraction, an oxygen line from the air separation plant to supply the oxygen fed to the iron bath gasifier to oxidize the residual coke therein to produce a gas containing carbon monoxide, a first exhaust gas line for conducting a portion of the gas containing carbon monoxide from the iron bath gasifier into a converting plant in which at least part of the gas containing carbon monoxide is reacted with steam to convert the carbon monoxide to hydrogen and carbon dioxide, a steam line leading into the converting plant for supplying the steam for reaction with carbon monoxide, a discharge line for conducting the exhaust gas containing hydrogen and carbon dioxide from the converting plant to a carbon dioxide scrubbing plant to remove said carbon dioxide leaving a gas containing principally hydrogen which goes to the hydrogen supply line, a second exhaust gas line for conducting another portion of the gas containing carbon monoxide from the iron bath gasifier into the methanol synthesis plant for reaction with hydrogen therein to produce methanol, a gas turbine with a combustion chamber coupled with an electric generator for generating electricity, an exhaust gas line of the methanol synthesis plant connected to the combustion chamber of the gas turbine to supply fuel for combustion in the combustion chamber, a compressor with a connecting air line for feeding combustion air to the combustion chamber, a nitrogen line leading from the air separation plant to feed nitrogen into the combustion chamber of the gas turbine to minimize nitrogen oxide emission, a steam power generating plant having a waste heat boiler for generating steam connected to an exhaust line from the gas turbine, a steam turbine connected to the waste heat boiler to receive steam to drive the steam turbine, a generator coupled with the steam turbine to generate electricity, and a condenser, pump and tank for recirculating steam condensate from the steam turbine to the waste heat boiler.
Summary: An object of the invention is to provide a new and improved power-generating station in which power can be manufactured more cheaply and in which the exhaust gases are free of sulfur and suitable for conversion into methanol."
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There's a good bit going on in "US Patent 4,631,915"; and, as in many of the Coal utilization technologies we've brought to your attention, the process would be made much more clear by a full schematic.
One paragraph excerpted from the "Preferred Embodiments" section of the full Disclosure might, to a certain extent, sum it up a little better:
"The invention relates to a gas-turbine and steam power-generating station with an integrated coal gasification plant supplied with oxygen via an air separation plant and a methanol synthesis plant connected to the coal gasification plant, with a steam power-generating plant connected to the waste heat boiler of the gas turbine, as well as with a nitrogen line leading from an air decomposition plant to the combustion chamber of the gas turbine. In such a power generating station, the problem arises to employ the residual coke with high sulfur content produced in the coal gasification as usefully as possible without exceeding the emission limit for sulfur dioxide and, at the same time, to minimize the investment for such a power-generating station. For this purpose, the invention provides that the coal gasifier for the hydrogenating coal gasification is connected to a hydrogen supply line; the coal gasifier is followed by an iron bath gasifier for utilizing the residual coke and the iron bath gasifier is followed on the exhaust gas side by a converting plant and a carbon dioxide scrubbing plant and the exhaust gas line of the coal gasifier is connected via a gas purifier to a methanol synthesis plant and the exhaust gas line of the methanol synthesis plant is connected to the combustion chamber of the gas turbine".
In brief, Coal syngas can be converted to Methanol or used to generate electric power via combustion in a gas turbine system, as conditions warrant. Further, not all of the syngas is converted into Methanol in the Methanol synthesis reactor, especially when less of the Carbon Monoxide is being used for power generation; and, the still-combustible tail gas from the Methanol synthesis, consisting mostly of un-reacted
Carbon Monoxide, and, if needed, even some of the Methanol itself, can as well be forwarded for combustion and the generation of electricity. Even further, some of the exhaust gas from the electricity generating turbine can be used and consumed in the Methanol synthesis.
In this way, to extrapolate only a little, Methanol might be seen as the byproduct of a combined Coal gasification electrical power generator.
Again, as we indicated in our opening comments, especially via citation of our separate report concerning Eastman Chemical's "US Patent Application 20070129450 - Process for Producing Variable Syngas Compositions", some significant advances have been made on such technology for the co-production of fuels, chemicals and electricity from Coal. And, we trust that the technical processes for extracting such value from Coal, and the terminologies which have been devised to describe them, will become more clear, be made plainer, in reports to follow.
For now, it is clear, as established very nearly three decades ago in Germany, and as confirmed by technical experts in the employ of our US Government, we can, in one integrated and contiguous facility and process, generate electricity and synthesize valuable fuels and chemicals, all from our one most abundant and most valuable fossil fuel resource:
Coal.