United States Patent: 593765

The two United States Patents we present, and center our discussion on, in this dispatch are related conceptually to a number of other technologies we have brought to your attention, wherein both Coal and CO2-recycling biomass can be combined and then gasified by a blend of gases, which blend actually includes Carbon Dioxide itself; CO2 that has been both collected from within the overall process and obtained additionally from an outside source - specifically, the exhaust gas of an industrial boiler.

It all results in the production of both a hydrocarbon synthesis gas, suitable for catalytic condensation, as via the Fischer-Tropsch process, for example, into hydrocarbons; a useful carbonaceous "Char"; and, a net consumption of Carbon Dioxide.

And, again:

The external source of Carbon Dioxide actually specified is a boiler that combusts fuel to generate steam and provide energy for some other process and purpose.

First, the named inventor of the US Patents we center our exposition on, one Fawzy T. Abdelmalek, of St. Louis, Missouri, likely won't be known to the vast majority of our Coal Country readers.

However, he is an accomplished scientist with a significant portfolio of United States Patents centering primarily on what we might generically label as industrial engineering; and, he is employed by a quite significant consulting and design engineering firm founded and owned by his family.

To establish his bona fides, more can be learned via:

http://www.abdelmalekgroup.com; which link will take you to an impressive  web site that is the home of: "Abdelmalek & Associates Inc. (AAI); 1851 Craig Park Court; Saint Louis, Missouri"; and, wherein we can learn that, since their founding in 1984, "AAI has designed, engineered, consulted and has provided construction management services for over 500 projects ... . AAI is a full service, industrial design and engineering firm";

and, via:

Fawzy T. Abdelmalek Patents; a compilation of United States Patents issued to Abdelmalek, which demonstrates, among other things, his breadth of industrial engineering knowledge.

In any case, from the initial link in this dispatch, with additional links and excerpts inserted and appended, we submit excerpts demonstrating how CO2 can be recycled, and utilized to help convert both Coal and Carbon-recycling Biomass into Hydrocarbon Synthesis Gas:

"United States Patent 5,937,652 - Coal or Biomass Gasification by Carbon Dioxide

Date: August, 1999

Inventor: Fawzy T. Abdelmalek, St. Louis, MO

Abstract: Carbon dioxide; from a boiler flue gas stream is separated, recycled and utilized for gasification of coal or biomass to increase fuel utilization and to decrease the carbon dioxide emissions into the atmosphere.

Claims: A process for gasification of coal using carbon dioxide extracted from fossil fueled boiler flue gas; the process which comprises the following steps; 

(a) receiving and conducting a feed of coal fines into a fluidized bed gasifier with sufficient carbon dioxide gas and steam at elevated temperature and pressure to effectively dry and gasify the coal;

(Note that this is, as well, a Steam gasification process, similar to that plainly described in our report:

Texaco 1951 Coal + CO2 + H2O + O2 = Syngas | Research & Development; concerning: "United States Patent 2,558,746 - Carbon Monoxide and Other Gases from Carbonaceous Materials; 1951; The Texas Company; This invention relates to a process and apparatus for the generation of ... a mixture of carbon monoxide and hydrogen, suitable as a feed for the synthesis of hydrocarbons, from powdered coal. The present invention is concerned with the generation of a mixture of carbon monoxide and hydrogen (and) is particularly suited to the production of a feed gas for the synthesis of hydrocarbons (in a process wherein) carbon dioxide ... in contact with hot carbon ... reacts with the carbon to produce carbon monoxide (and, wherein steam) also reacts with heated carbon to produce carbon monoxide and hydrogen.")

(b) conducting the synthesis gas and char flowing from the gasifier into a solids separator/classifier to effectively separate the synthesis gas and classify a relatively lighter char solids from relatively heavier char solids; 

(c) conducting the relatively lighter char solids back to the gasifier; 

(d) conducting the relatively heavier char solids into a steam boiler combustion chamber; 

(e) conducting the synthesis gas stream flowing from the solids separator into a steam generator heat exchanger to effect cooling the synthesis gas and evaporating the water stream to a superheated steam;

(Note, yet again, as in other of our reports, the potentials for the internal recycling of heat energy in a Carbon gasification process, with resultant energy economies.) 

(f) injecting the cooled synthesis gas products flowing from the steam generator heat exchanger into the steam boiler combustion chamber;

(Therein, above, lies what we would consider to be a shortcoming of this proposed technology, if, that is, we were hoping to derive liquid hydrocarbons from the synthesis gas. That syngas, generated by gasifying Coal and Biomass with Steam and Carbon Dioxide, is posited by the inventor to be burned in a boiler, along with a portion of the Char resulting from the gasification, and perhaps more Coal, to generate Steam for the generation of electricity, with some Steam generated as a co-product in various stages of the overall process also directed back to the initial Carbon gasification.

The Carbon Dioxide resulting from that combustion, for the generation of electricity, is to be recycled back to that initial Coal and Biomass gasification, thus making the electricity what we could call "Carbon-neutral".

But there is, in other words, no synthesis gas product originating from the process, only electricity.

The inclusion of Carbon-recycling Biomass in the gasification, of course, could make the process essentially "Carbon-negative", with regards to electricity generation, except, that: With continuous recycling of Carbon Dioxide from the boiler, and no provision for "take-away" of Carbon, preferably as contained in the synthesis gas, to another, external, Carbon-utilization process, preferably a hydrocarbon synthesis unit, there would be, likely a rather rapid if Coal were to be supplied along with the syngas and the Char to the boiler, build up of oxidized Carbon in the system, and, it would become self-extinguishing.

There has to be an outlet for the Carbon, preferably via withdrawal of some of the syngas for use in separate hydrocarbon synthesis processes.

Otherwise, and withdrawal of some portion of the syngas for other purposes might actually demand that, to keep things rolling up to specs, there has to be some partial input of external energy to the boiler, or, a discharge of Carbon, in one form or another, to the environment, although, depending upon the amount of Biomass gasified with the Coal, the amount of Carbon discharged by the process would be less than the amount of non-fossil Carbon fed to it.

That, at least, is as opined by one of our informal consultants who claims some modest education in such matters.

We'll address that issue again in comments below; but, Inventor Abdelmalek touches on some, at least partial, solution to the conundrum in additional Claims.)

(g) conducting the flue gases flowing from said steam boiler into a condensing heat exchanger to exchange heat energy contained therein and preheat a boiler combustion air stream and a boiler feed water stream; 

(h) conducting the cooled flue gases flowing from the flue gas condensing heat exchanger to a carbon dioxide gas separating plant; 

(i) conducting the carbon dioxide flowing from the gas separating plant into the coal gasifier; 

(j) conducting and injecting the superheated steam flowing from the steam generator heat exchanger into the coal gasifier.

The combination of a carbon dioxide coal gasifier and a steam power plant where a steam boiler is fueled with a synthesis gas and char produced by gasification of coal in absence of oxygen using carbon dioxide separated from the boiler flue gas, the combination which comprises: a coal fluidized bed gasifier where sufficient carbon dioxide and steam are injected to provide proper fluidization velocity and residence time for the coal to dry, devolatize, and for carbon in the coal to react with carbon dioxide and steam to produce synthesis gas and solid char products.


(Note that no free Oxygen is required in the initial gasification process, unlike the above-cited Texaco process of "United States Patent 2,558,746". And, since Steam is utilized to help gasify the Coal, it could be labeled as a direct, gaseous hydrogenation, or extraction, of the Coal, thus resulting in the co-production of some residual, unconverted carbonaceous "Char", which Abdelmalek proposes to use as boiler fuel, as well, with the subsequent production of more Carbon Dioxide for use in the Coal gasification.

There are other options, since, as seen in:

Pittsburgh USBM Recycles CoalTL Residue | Research & Development; concerning: "United States Patent 2,634,286 - Hydrocarbon Synthesis Gas from Coal; 1953; Inventors: Martin Elliott, et. al., Pittsburgh, PA; 
Assignee: The United States of America; Abstract: This invention relates to the production of synthesis gas and more particularly to the production of a low-sulfur content mixture of carbon monoxide and hydrogen by gasifying the char obtained as a byproduct of the direct hydrogenation of coal ... . It has now been found that this char may be obtained from the hydrogenation reaction zone in a condition that renders it eminently suited for the production of  low sulfur content synthesis gas (and that) the hydrogen-carbon monoxide mixture produced by the gasification of this char with steam according to the usual water gas procedure contains a correspondingly small amount of sulfur compounds. The low-sulfur content synthesis gas produced by gasification of this low-sulfur content char will find one of it's most advantageous uses in processes such as the Fischer-Tropsch ... to form liquid and gaseous hydrocarbons";

our US Government has known for more than half a century that such carbonaceous "Char" resulting from an initial Coal gasification and conversion process, such as Abdelmaleks', can be further converted into more, advantageously low-sulfur, syngas that can be used "to form liquid and gaseous hydrocarbons".

And, such use of Char, extracted from the process, could resolve the seeming Carbon "imbalance" we noted in above comments.)

The present invention takes advantage of the reaction of carbon dioxide with the carbon in the coal to reduce the carbon emissions and increase the fuel utilization in coal fired or biomass fueled power plants. This innovative technology will support the need to continue using the coal as a viable domestic fuel. It will be economically feasible to repower conventional pulverized coal power plants for both atmospheric and pressurized steam boiler systems with synthesis gas and char produced from carbon dioxide gasification of coal in an Integrated Gasification Combined Cycle (IGCC) configuration to achieve the goal of high efficiency/low emission coal fired power plants."



And, thus, the true intent of this technology is to enable the construction and operation of Coal-fired, and/or Coal-Biomass co-fired, power plants that have much-reduced CO2 emissions.

The basis of the technology should not be missed, however:

It consists of the simple fact that both Steam, i.e., H2O, and Carbon Dioxide, CO2, will react with hot Carbon, i.e., Coal and/or CO2-recycling Biomass, to form a blend of Synthesis Gas, consisting of Hydrogen and Carbon Monoxide, that can, as herein, be simply burned for additional power generation,or, that, with the addition of some externally-supplied source of thermal energy, can be directed both to the synthesis of hydrocarbons and to the generation of electricity.

Once again, our, or at least our consultants', analysis of the technology is that there has to be at least some "take away" of the synthesis gas, derived from the reaction between Carbon Dioxide, Steam and Carbon; or, of the Char; and/or, some input of external energy to the boiler and/or the gasification unit, to avoid an ultimate overwhelming off of the system by accumulated Carbon.

And, actually, thermal energy supplied, in lesser or greater quantities, by two or three options we've earlier documented might do the trick, as represented, for one example, by:

USDOE Hydrogasifies Coal with Solar Power | Research & Development; concerning: "United States Patent 4,415,339 - Solar Coal Gasification Reactor; 1983; The USA, as represented by the Department of Energy;  Coal (or other carbonaceous matter, such as biomass) is converted into a duct gas that is substantially free from hydrocarbons. The coal is fed into a solar reactor, and solar energy is directed into the reactor onto coal char, creating a gasification front and a pyrolysis front. Steam, injected into the reactor adjacent to the gasification zone, reacts with char to generate product gases. Solar energy supplies the energy for the endothermic steam-char reaction";

wherein Char resulting from the Steam-gasification of Coal and Biomass, just as in the process of our subject, is forced to react with more Steam via the input of Solar heat energy.

Closely similar technology is disclosed in our report of:

Solar Power Converts CO2, H2O and Coal to Hydrocarbon Syngas | Research & Development; "US Patent 4,177,120 - Photolytic Process for Gasification of Carbonaceous Material; 1979; Assignee: Solarco Corporation, Rockville (MD); Abstract: Process and apparatus are disclosed for converting carbon dioxide to carbon monoxide by subjecting the carbon dioxide to radiation in the presence of carbonaceous material such as coal to form carbon monoxide. The preferred form of radiation is solar energy, and the process is preferably carried out in an atmosphere essentially free of oxygen";

wherein the initial Coal gasification itself is driven by Solar heat, with little residual Char likely remaining.

Following, with comment inserted and appended, we present just one further example of Abdelmalek's Coal gasification technology, which helps to explain how not only is the Carbon Dioxide efficiently extracted from the flue gas of the electricity-generating "steam boiler" of the above "United States Patent 5,937,652", but, as a part of that process, so are any objectionable Sulfur compounds, and, the work is accomplished through the conversion of waste heat in the flue gases into electricity:

"United States Patent: 5133190 - Flue Gas Cleaning by Separation ... of Sulfur Dioxide and Carbon Dioxide

Date: July, 1992

Inventor: Fawzy Abdelmalek, St. Louis, MO

Abstract: Sulfur dioxide and carbon dioxide, emitted in flue gases are separated by gas centrifuge separators, and liquefied by gas mechanical compression and cooling means.

Claims: A method for recovering sulfur dioxide, carbon dioxide, and cleaning flue gases emitted from power plant, comprising: 

a. Electronically treating the flue gases to neutralize its electrostatic charges and to enhance the coagulation of its molecules and particles; 

b. Exchanging sensible and latent heat of the neutralized flue gases to lower its temperature down to a temperature approaching the ambient temperature while recovering its heat energy to co-generate electric power;

(Note, with apologies for what will be a lengthy interruption, as we mentioned, the above use of waste flue gas heat to generate at least some of the electricity required, some of which is needed for "Electronically treating the flue gases to neutralize its electrostatic charges and to enhance the coagulation of its molecules and particles"; which we take to mean an electrostatic precipitator, of the sort described in:


Particulate Controls - Institute of Clean Air Companies; wherein we're told that: "Electrostatic precipitators, which have been used for particulate control since 1923, use electrical fields to remove particulate from boiler flue gas. Because precipitators act only on the particulate to be removed, and only minimally hinder flue gas flow, they have very low pressure drops, and thus low energy requirements and operating costs. In an electrostatic precipitator, an intense electric field is maintained between high-voltage discharge electrodes, typically wires or rigid frames, and grounded collecting electrodes, typically plates. A corona discharge from the discharge electrodes ionizes the gas passing through the precipitator, and gas ions subsequently ionize fly ash (or other) particles. The electric field drives the negatively charged particles to the collecting electrodes. Periodically, the collecting electrodes are rapped mechanically to dislodge collected particulate, which falls into hoppers for removal."

The "collected particulate", we submit, could be combined with the Coal ash from the initial gasification, and, as seen in:

Iowa Mines Metals from Coal Ash for the USDOE | Research & Development; concerning: "United States Patent 4,386,057 - Recovery of Iron Oxide from Coal Fly Ash", and, the closely-related: "United States Patent 4,397,822 - Process for the Recovery of Alumina from Fly Ash";

be subjected to an extraction process for the recovery of valuable metals. The remaining inert ash could then be utilized in a further process, such as that described in:

Exxon Converts Coal Conversion Residues to Cement | Research & Development; concerning: "United States Patent 4,260,421 - Cement Production from Coal Conversion Residues; 1981; Exxon Research and Engineering Company; 1983";

and be converted into a substitute for Portland cement, a product whose manufacture entails the emission, through the roasting of limestone, CaCO3, to make the Calcium Oxide component of cement, of enormous quantities of Carbon Dioxide, and thus contribute, along with our subject processes of United States Patents  "5,133,190" and "5,937,652", to a truly significant reduction in the total, combined emissions of Carbon Dioxide arising, if both were to be accounted together, from the generation of electrical power and the production of Portland cement.

Further, such total CO2 reduction would be enhanced and magnified by the inclusion, as specified by "United States Patent 5,937,652", of Carbon-recycling "Biomass", with Coal, in the initial gasification.

And, all of that could be in addition to the potentials for producing a blend of "carbon monoxide and hydrogen", a "synthesis gas" likely suitable for use, as suggested above by our earlier report of  "United States Patent 2,634,286 - Hydrocarbon Synthesis Gas from Coal", "in processes such as the Fischer-Tropsch ... to form liquid and gaseous hydrocarbons".)

Background and Summary: The present invention relates generally to cleaning of the flue gases emitted from industrial and electric utility coal fired boilers. More particularly, it relates to a method for removing acidic vapors, sulfur dioxide and carbon dioxide by mechanical and condensation method.

It is therefore, a principle object of the present invention to provide flue gas cleaning system which is economical to install and to operate. 

It is also, a principle object of the present invention to reduce the sulfur dioxide, and carbon dioxide emitted in the flue gases from boilers in electric power plants. 

It is also, a principle object of the present invention to separate and recover the sulfur dioxide, and as desired part of the carbon dioxide gas components from the flue gas stream by mechanical means, also to produce high quality liquefied sulfur dioxide and liquefied carbon dioxide products."


Note that such Coal flue gas purification generates what are referred to as "high quality liquefied sulfur dioxide and liquefied carbon dioxide products", and, that is exactly how they should be viewed.

The Sulfur Dioxide, for one example, as explained in our report of:

USDOE Makes Hydrogen by Using Sulfur Dioxide | Research & Development; concerning: "United States Patent 4,244,794 - Hydrogen Production by the Decomposition of Water; 1981; Assignee: The United States of America; A process for producing hydrogen comprising: passing an electric current from a cathode to an anode through water containing sulfur dioxide so as to produce hydrogen gas at the cathode and so as to oxidize the sulfur dioxide to form sulfuric acid at the anode";

can be used to make both Hydrogen, for use, perhaps, in a process such as described in:

WVU Hydrogenates Coal Tar | Research & Development; concerning: "Hydrogenation of Naphthalene and Coal Tar Distillate over Ni/Mo/Al2O3 Catalyst; West Virginia University; 2009";

to help synthesize a Hydrogen donor solvent for the direct conversion of Coal into liquid hydrocarbons; and, Sulfuric Acid, which is a product of nearly-immense commercial value, that, as seen in:

Sulfuric Acid; wherein we're told: "Sulfuric acid ...is ... the largest-volume industrial chemical produced in the world (the uses for which include the making of) fertilizers (and) dyes, alcohols, plastics, rubber, ether, glue, film, explosives, drugs, paints, food containers, wood preservatives, soaps and detergents, pharmaceutical products, petroleum products, pulp and paper";

could bring in even more revenue to an industrial facility founded on the core technologies of our subjects herein, United States Patents "5,937,652" and "5,133,190", which begin with an initial "gasification of coal using carbon dioxide extracted from fossil fueled boiler flue gas".

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