Exxon Hydrogen Converts Coal into Hydrocarbon Liquids and Gases

United States Patent: 4561964

As can now be accessed on the West Virginia Coal Association's web site, via:

West Virginia Coal Association | USDOE Efficient Hydrogen for Liquid Fuel Synthesis | Research & Development; concerning: "United States Patent Application 20120149789 - Apparatus and Methods for the Electrolysis of Water; 2012; Assignee: UT-Battelle, LLC; Oak Ridge, TN; This invention was made with government support under Contract Number DE-AC05-000R22725 between the United States Department of Energy and UT-Battelle, LLC. The U.S. government has certain rights in this invention. An apparatus for the electrolytic splitting of water into hydrogen and/or oxygen (and, a) method for producing hydrogen and oxygen gases from the electrolytic splitting of water ... wherein said electrolyzer is powered by a renewable energy source (and) wherein said renewable energy source comprises solar energy (or) wherein said renewable energy source comprises wind energy (and) wherein said electrolysis method is coupled to a process that utilizes hydrogen or oxygen gas.  The method ... wherein said process is a Fischer-Tropsch process for the synthesis of liquid hydrocarbons (or) wherein said process is a hydrogenation process";

we recently confirmed that our United States Department of Energy has been at work developing technologies which would enable, through the use of renewable, environmental energy, the efficient and large-scale production of elemental, molecular Hydrogen.

As we've previously documented, elemental Hydrogen enables the rather direct conversion of Coal into various hydrocarbons, a fact we believe first formally established by Nobel Prize-winner Freidrich Bergius, as seen separately, for a few examples, in:

Bergius process - Wikipedia, the free encyclopedia; "The Bergius Process is a method of production of liquid hydrocarbons for use as synthetic fuel by hydrogenation of high-volatile bituminous coal at high temperature and pressure"; and:

Friedrich Bergius - Biography of Friedrich Bergius; "Friedrich Bergius was a German chemist and Nobel laureate. Bergius developed a method to hydrogenate coal dust under high pressure to create gasoline and lubricating oils known as the Bergius process".

The Bergius concept for the direct hydrogenation of Coal was later refined and further developed by many others, as seen, for a few examples, in our reports of:

West Virginia Coal Association | California Rocket Scientists Liquefy Coal | Research & Development; concerning: "United States Patent 4,169,128 - Coal Liquefaction Apparatus; 1979; Assignee: Rockwell International Corporation; Abstract: Disclosure is made of an apparatus for reacting carbonaceous material with heated hydrogen to form hydrocarbon gases and liquids suitable for conversion to fuels wherein the reaction involves injection of carbonaceous material such as pulverized coal entrained in a minimum amount of gas and mixing the entrained coal at near ambient temperature with a separate source of heated hydrogen"; and:

West Virginia Coal Association | California Converts 87% of Coal to Gasoline and Oil | Research & Development; concerning: "United States Patent 4,331,530 - Process for the Conversion of Coal; 1982; Assignee: Occidental Research Corporation, California; Abstract: A process for the hydrogenation of coal and subsequent treatment of hydrogenated coal to produce useful fuels and chemicals which comprises comminuting coal ore to a particle size range of from about 150 mesh to about 250 mesh; hydrogenating the particulate coal in the presence of a hydrogenation catalyst and a source of hydrogen at a temperature of from about 100 to about 300 C. and a pressure of from about 500 to about 1,000 psi for a time sufficient to react hydrogen with the coal to form predominantly hydroaromatic coal; and recovering the hydrogenated coal. The hydrogenated coal is subsequently hydrocracked or pyrolyzed. The hydrogenated coal is hydrocracked at from about 500 to about 700 C. a pressure of from about 500 to about 2,000 psi for a time sufficient to crack the coal to produce benzene, toluene, xylene and gasoline"; and:

West Virginia Coal Association | USDOE Improves Direct Coal Hydrogenation and Conversion | Research & Development; concerning: "US Patent 4,735,706 - Process and Apparatus for Coal Hydrogenation; 1988; Assignee: The United States of America; Abstract: In the coal liquefaction process, an aqueous slurry of coal is prepared containing a dissolved liquefaction catalyst. A small quantity of oil is added to the slurry and then coal-oil agglomerates are prepared by agitation of the slurry at atmospheric pressure. The resulting mixture of agglomerates, excess water, dissolved catalyst, and unagglomerated solids is pumped to reaction pressure and then passed through a drainage device where all but a small amount of surface water is removed from the agglomerates. ... The agglomerates fall into the liquefaction reactor counter currently to a stream of hot gas which is utilized to dry and preheat the agglomerates as well as deposit catalyst on the agglomerates before they enter the reactor where they are converted to primarily liquid products under hydrogen pressure".

And, we see herein that the process of direct Coal hydrogenation was, at about the same time as Occidental Petroleum and our USDOE, as above, were confirming the practicality of the concept, being made less energy-demanding and more efficient by one of the world's major petroleum companies, through the development of catalysts specifically intended to promote and support the direct reaction between Carbon, as found in Coal, and Hydrogen, in order to synthesize hydrocarbons.

Comment follows excerpts from the initial link in this dispatch to:

"United States Patent 4,561,964 - Catalyst for the Hydroconversion of Carbonaceous Materials

Patent US4561964 - Catalyst for the hydroconversion of carbonaceous materials - Google Patents

Catalyst for the hydroconversion of carbonaceous materials - Exxon Research and Engineering Co.

Date: December, 1985

Inventors: Gopal Singhal, et. al., Texas

Assignee: Exxon Research and Engineering Company, NJ

Abstract: An improved hydroconversion process for carbonaceous materials wherein a monohydrocarbyl substituted dithiocarbamate of a metal selected from Group VIII-A of the Periodic Table of Elements or a mixture thereof is used as a catalyst precursor. The improved process is effective for both normally solid and normally liquid carbonaceous materials and for carbonaceous materials which are either solid or liquid at the conversion conditions. The hydroconversion will be accomplished at a temperature within the range from about 500 to about 900 F., at a total pressure within the range from about 500 to 7000 psig and at a hydrogen partial pressure within the range from about 400 to about 5000 psig.

(The needed temperatures and pressures are still pretty high; but, more manageable than the original Bergius process. Our general read of the available literature is that temperatures and pressures in the lower ends of the ranges provided would have to be workable in order for this to fall into the ranges of general industrial practice; although, keep in mind that the original Bergius high-pressure process was practiced successfully at multiple sites in Europe during WWII. And, we are likely to have gotten at least a bit more proficient at making the needed processing equipment in the decades since.

Further, the "Periodic Table of Elements" has been juggled and rearranged a tad since this patent was published. Don't go by modern versions of the Table; Exxon specifies what they mean further on.)

Claims: An improved process for hydroconverting carbonaceous materials comprising:

(a) forming a mixture of a carbonaceous material and a monohydrocarbyl substituted dithiocarbamate of a metal selected from Group VIII-A of the Periodic Table of the Elements;

(b) subjecting this mixture to hydroconversion conditions; and

(c) recovering a product from the conversion effluent.

The improved process ... wherein said carbonaceous material is a normally solid carbonaceous material. 

The improved process ...  wherein the hydroconversion is accomplished at a temperature within the range from about 750 to about 860 F at a total pressure within the range from about 1500 to about 2500 psig and with a hydrogen partial pressure within the range from about 1200 to about 1600 psig.

The improved process ...  wherein a sufficient amount of monohydrocarbyl substituted dithiocarbamate  of a metal selected from Group VIII-A of the Periodic Table of the Elements or mixture thereof is added to said mixture to provide from about 10 to about 10,000 ppm metal by weight based on a carbonaceous material during the hydroconversion of step (b).

(We can't explain "monohydrocarbyl" chemistry to you; but, it is in certain circles understood, and is used in the making of such mundane things as laundry detergent. The "dithiocarbamate" is made by the reaction of simple carbamic acid, NH2COOH, with sulfur. The stuff isn't nearly as rare or expensive as it sounds; and, there are folks out there to whom it makes perfect sense. The parameters of the formulas for both are specified in the full Disclosure; but, we won't reproduce the details here.)

The improved process ... wherein a sufficient amount of monohydrocarbyl substituted dithiocarbamate of a metal selected from Group VIII-A of the Periodic Table of the Elements or mixture thereof is added to said mixture to provide from about 100 to about 1000 ppm metal by weight based on carbonaceous material during the hydroconversion of step (b) (and) wherein the amount of monohydrocarbyl substituted dithiocarbamate of a metal selected from Group VIII-A of the Periodic Table of the Elements or mixture thereof added to feed mixtures is reduced by recycling at least a portion of the bottoms product. 

The improved process ... wherein said metal is selected from the group consisting of iron, nickel and cobalt.

(Told you above that the "Group VIII-A" of the old "Periodic Table" wouldn't be anything too exotic.) 

An improved process for hydroconverting a carbonaceous material comprising:

(a) forming a mixture of a carbonaceous material, a monohydrocarbyl substituted dithiocarbamate of a metal selected from Group VIII-A of the Periodic Table of the Elements or mixture thereof and a suitable solvent or diluent;

(b) subjecting the mixture from step (a) to hydroconversion conditions; and

(c) recovering a product from the effluent of step (b). 

The improved process ... wherein said carbonaceous material is a normally solid material (and) wherein said normally solid hydrocarbonaceous material is selected from the group consisting of coal, lignite and peat.

The improved process ... wherein the hydroconversion is accomplished in the presence of molecular hydrogen at a temperature within the range from about 500 to about 900 F, a total pressure within the range from about 500 to about 7000 psig and at a hydrogen partial pressure within the range from about 400 to about 5000 psig. 

The improved process ... wherein a sufficient amount of monohydrocarbyl substituted dithiocarbamate of a metal selected from Group VIII-A of the Periodic Table of the Elements or mixture thereof is added to said mixture to provide from about 100 to about 1000 ppm metal by weight based on carbonaceous material during the hydroconversion of step (b).

Description and Background: Heretofore, several catalytic processes for hydroconverting solid carbonaceous materials such as coal, lignite, peat and the like to lower molecular weight products ... have been proposed. The lower molecular weight products may be gaseous or liquid or a mixture of both. In general, the production of liquid products is particularly desirable since liquid products are more readily stored and transported and the lower molecular weight liquid products are conveniently used as motor fuels. 

Recently, ... it has been proposed to use certain dihydrocarbyl substituted dithiocarbamates of certain metals and/or mixtures thereof as catalyst precursors to eliminate ... limitations encountered in the prior art catalytic hydroconversion processes. ... (The) present invention relates to ... improved catalyst precursors and is drawn to an improved hydroconversion process wherein one or more ... surprisingly effective catalyst precursors is used.

Summary: It ... is, therefore, an object of this invention to provide an improved catalytic process for the conversion of carbonaceous materials to lower molecular weight products. It is another object of this invention to provide such a catalytic process wherein the active catalyst species or species formed is either relatively small or at least is more uniformly distributed thereby yielding increased conversions. It is still a further object of this invention to provide such a catalytic process wherein a treatment with a sulfur compound is not needed.

In accordance with the present invention, the foregoing and other objects and advantages are accomplished by converting a carbonaceous material to lower molecular weight products in the presence of a catalyst believed to be a metal sulfide or a mixture of such sulfides of a metal from Group VIII-A of the Periodic Table of Elements formed either prior to or during the conversion process through the decomposition of a metal monohydrocarbyl substituted dithiocarbamate or from a mixture of such ... and in the presence of molecular hydrogen at an elevated temperature and pressure.

After the carbonaceous material conversion is completed, and the several products, separated, the gaseous product may be upgraded to a pipeline gas, a high purity synthesis gas, or the same may be burned to provide energy for the conversion process. Alternatively, all or any portion of the gaseous product may be reformed to provide hydrogen for the liquefaction process.

The liquid product may be fractionated into essentially any desired product distribution and/or a portion thereof may also be used directly as a fuel or upgraded using conventional techniques. Generally, a naphtha boiling range fraction will be recovered and the naphtha fraction will be further processed to yield a high quality motor gasoline or similar fuel boiling in the naptha range.

Also, a middle distillate fraction may be separated from the liquid product and upgraded for use as a fuel oil or as a diesel oil.

The bottoms product may be gasified, depending upon its carbon content, to produce hydrogen for the conversion process or burned to provide heat for the conversion process. In the case of relatively high conversion, however, and when the carbon content is too low to make either gasification or combustion feasible, the bottoms product may simply be disposed of as a waste material. In this case, all or a portion of the catalyst may be recovered in either an active or inactive form."

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Alternatively, as Exxon themselves propose, as in our report of:

West Virginia Coal Association | Exxon Converts Coal Conversion Residues to Cement | Research & Development; concerning: "US Patent 4,260,421 - Cement Production from Coal Conversion Residues; 1981; Assignee: Exxon Research and Engineering Company, New Jersey; Abstract: Cement is produced by feeding residue solids containing carbonaceous material and ash constituents obtained from converting a carbonaceous feed material into liquids and/or gases into a cement-making zone and burning the carbon in the residue solids to supply at least a portion of the energy required to convert the solids into cement";

the "bottoms product" could also be productively, and completely, consumed in the making of Cement, leaving no "waste material" to be disposed of.

In any case, this is a very direct process for converting "coal, lignite and peat" into "pipeline gas", "high quality motor gasoline", and "diesel oil".

Aside from some, admittedly expensive, high-pressure processing equipment and some common metals to serve as catalysts, "nickel" is specified in the full Disclosure as most preferred, all that's needed herein to convert Coal into "pipeline gas", "gasoline" and "diesel" is elemental, molecular Hydrogen, which, as seen for yet another example in our report of:

West Virginia Coal Association | General Electric 2010 Hydrogen from Sunlight and Water | Research & Development; concerning: "US Patent 7,820,022 - Photoelectrochemical  Cell and Method of Manufacture; 2010; Assignee: General Electric Company; Abstract: A photoelectrochemical cell  ... to produce gaseous hydrogen and oxygen";

we are getting better and better at extracting from Water, in processes powered by various forms of what we could and should think of as freely-available environmental energy.