United States Patent: 9000056

We've many times reported on China's focused and large-scale development of industries that utilize Coal as the basic raw material in processes that synthesize any and all types of hydrocarbon fuels and chemicals.

One example would be:

China June 24, 2014, Coal and Biomass to Ethanol and Methanol | Research & Development | News; concerning: "United States Patent 8,759,596 - Liquid Fuel Production Process from Cellulosic Biomass and Coal; 2014; Assignee: China Fuel (Huaibei) Bioenergy Technology Development Co., Ltd., China; Abstract: A liquid fuel production process from cellulosic biomass and coal comprises providing a mixture of cellulosic biomass and coal, subjecting the mixture to gasification to obtain synthesis gas and converting the synthesis gas to a liquid fuel under the presence of catalyst. The catalyst includes molybdenum sulfide, alkali metal compound and a component activating the C--H bond in alkanes product, wherein the alkali metal compound is selected from the group of salts of Lithium, Sodium, Potassium, Rubidium and Cesium, the component activating the C--H bond in alkanes product is selected from Molybdenum, Vanadium, Osmium, Rhenium, Iridium, Platinum, Palladium, Cobalt, Rhodium, Nickel and their mixture. Additionally, co-gasification of cellulosic biomass and coal can reduce the ash fusion temperature of coal. ... The process ... wherein the content of the cellulosic biomass in the first step is 1-99 weight %, based on the total weight of the mixture. (In other words, the feed mixture can be nearly all "cellulosic biomass", or, nearly all Coal.) The process ...  wherein, the liquid fuel ... is methanol and/or ethanol".

In addition to liquid fuels, it is also a quite practical proposition to, as seen for just one example in:. 

USDOE 2013 Coal to 99% Methane | Research & Development | News; concerning: "Coal-Derived Warm Syngas Purification and CO2 Capture-Assisted Methane Production; Final Report; October, 2014; RA Dagle, et. al.; PNNL-23777; Pacific Northwest National Laboratory, United States Department of Energy; Executive Summary: Gasifier-derived synthesis gas (syngas) from coal has many applications in the area of catalytic transformation to fuels and chemicals. ... By combining syngas methanation, water-gas-shift, and CO2 sorption in a single reactor, single pass yield to methane of 99% was demonstrated";

convert Coal with a very high efficiency into substitute natural gas Methane.

And, we see herein that our United States Government very recently confirmed that China has developed their own technology for doing that; and, as in the above-cited  "United States Patent 8,759,596 - Liquid Fuel Production Process from Cellulosic Biomass and Coal", for including a certain amount of carbon-recycling and renewable Biomass with the Coal in the basic feed.

As explained in excerpts from the initial link in this dispatch to:

"United States Patent 9,000.056 - Method for Producing Methane by Catalytic Gasification of Coal

Method for producing methane by catalytic gasification of coal and device thereof - Enn Science & Technology Development Co.,

April 7, 2015

Inventors: Jicheng Bi, et. al., China

Assignee: Enn Science & Technology Development Co., Ltd., China

(The above is one component of a far larger company:

ENN Energy Holdings Limited; "ENN Energy is one of the largest clean energy distributors in China. The principal business of the Group is the investment in, and the operation and management of gas pipeline infrastructure, vehicle/ship gas refuelling stations, wholesale of gas, the sales and distribution of piped gas and other energy, the sale of gas appliances and equipment, the production of stored-value card gas meters and the provision of repair, maintenance and other services in connection with gas supply. The Group also operates vehicle/ship refuelling business in Europe and North America. As of 31 December 2014, the Group has 142 project cities in China in 16 provinces, municipalities and autonomous regions".

Other company info reveals, that:

"ENN is one of the largest private energy companies in China headquartered in Langfang, Hebei Province, P.R. China. Since its establishment in 1989, ENN has developed from a natural gas distributor to a conglomerate engaging in natural gas distribution, chemicals, solar energy, intelligent energy, energy R&D, cultural and health industry, hospitality, and real estate. Presently, ENN owns a large market share in China's natural gas downstream market and plans to provide integrated energy solution to our clients".)

Abstract: The invention relates to a gasifier comprising a syngas generation section, a coal methanation section and a syngas methanation section in the order from bottom to top. The invention also relates to a process for preparing methane by catalytically gasifying coal using such a gasifier. Optionally, the gasifier is additionally provided with a coal pyrolysis section above the syngas methanation section.

Claims: A process for preparing methane by catalytically gasifying coal, comprising the following steps:

(a) providing a gasifier comprising a syngas generation section, a coal methanation section and a syngas methanation section, and carrying out methanation reaction by reacting the coal with a syngas-including gas stream coming from the syngas generation section in the presence of coal methanation catalyst in the coal methanation section, so as to generate a methane-containing gas stream and reacted char;

(b) the reacted char enters downwardly the syngas generation section and reacts with a gaseous oxidant introduced into the syngas generation section, producing the syngas-including gas stream and ash residues, wherein the syngas-including gas stream enters upwardly the coal methanation section to carry out step (a), while the ash residues exit the gasifier; and,

(c) the methane-containing gas stream from step (a) enters upwardly the syngas methanation section, and the syngas is subjected to methanation reaction in the presence of a syngas methanation catalyst to produce additional methane, so as to obtain a gaseous product containing more methane; wherein solid materials move from top to bottom, and finally exit the gasifier via an ash residue exit at the bottom of the gasifier, while gaseous materials move from bottom to top, and finally exit the gasifier via a gas exit at the top of the gasifier; in the gasifier the solid materials contact with the gaseous materials basically in counter current mode. 

The process ...  wherein at least part of the coal is introduced into the gasifier at the coal methanation section and/or syngas methanation section of the gasifier. 

The process ... wherein at least part of the coal is introduced into the gasifier at the coal pyrolysis section (and) wherein the coal methanation catalyst is introduced into the gasifier at the coal methanation section and/or syngas methanation section and/or syngas generation section of the gasifier. 

(The "coal pyrolysis section" would operate, as we read it, much like the process disclosed, for one example, in;

California Rocket Scientists Liquefy Coal | Research & Development | News; concerning: "United States Patent 4,169,128 - Coal Liquefaction Apparatus; 1979; Assignee: Rockwell International Corporation, El Segundo (California); 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".

In this case, though, it seems that the Coal pyrolysis is being effected with hot syngas, and, as we read it, with some of the product Methane and the syngas, not pure Hydrogen, much as seen in:

Standard Oil Converts Coal with Methane and Hydrogen | Research & Development | News; concerning: "United States Patent 4,326,944 - Rapid Hydropyrolysis of Carbonaceous Solids; 1982; Assignee: Standard Oil Company of Indiana, Chicago; Abstract: A method is disclosed for recovering liquids and gases by a rapid hydropyrolysis of carbonaceous solids".) 

The process ...  wherein the coal methanation catalyst is selected from alkali metal carbonate, alkali metal hydroxide, alkali metal oxide, alkali earth metal carbonate, alkali earth metal hydroxide, alkali earth metal oxide or a mixture thereof.

(Note that there is a combination of gasification and catalytic processes going on. The Coal/Biomass gasification itself results in a blend of Methane and of synthesis gas, i.e., Carbon Monoxide and Hydrogen, much as in our more recent report of:

WV and PA USDOE 2014 Coal to Methane and Syngas | Research & Development | News; concerning: "United States Patent 8,920,526 - Production of Methane-rich Syngas from Hydrocarbon Fuels; 2014; Inventors: Nicholas Siefert, et. al., PA and Morgantown, WV; Assignee: United States Department of Energy, Washington, DC; Abstract: The disclosure provides a gasification process for the production of a methane-rich syngas at temperatures exceeding 700 C through the use of an alkali hydroxide MOH, using a gasification mixture comprised of at least 0.25 moles and less than 2 moles of water for each mole of carbon, and at least 0.15 moles and less than 2 moles of alkali hydroxide MOH for each mole of carbon. These relative amounts allow the production of a methane-rich syngas at temperatures exceeding 700 C by enabling a series of reactions which generate H2 and CH4, and mitigate the reforming of methane. The process provides a methane-rich syngas comprised of roughly 20% (dry molar percentage) CH4 at temperatures above 700 C, and may effectively operate within an IGFC cycle at reactor temperatures between 700-900 C and pressures in excess of 10 atmospheres. Government Interests: The United States Government has rights in this invention pursuant to the employer-employee relationship of the Government to the inventors as U.S. Department of Energy employees and site-support contractors at the National Energy Technology Laboratory";

with that followed by the pyrolysis, resulting in more Methane and more syngas.)

The process ... wherein the syngas methanation catalyst is selected from a sulfur-tolerant methanation catalyst ... selected from molybdenum sulfide, molybdenum oxide, cobalt oxide or molybdenum-cobalt-nickel eutectic supported on an alumina support or zirconia support.

(The above "molybdenum" has a long history of use in Coal hydrogenation processes of one sort or another. See, for one example:

More Dow Chemical Direct Coal Hydrogenation | Research & Development | News; concerning: "United States Patent 4,172,814 - Emulsion Catalyst for Hydrogenation Processes; 1979; Assignee: The Dow Chemical Company, MI; Abstract: In the catalytic hydrogenation of a substance in a water-immiscible organic liquid medium, a metallic hydrogenation catalyst is conveniently and effectively dispersed in the reaction mixture by addition as an emulsion of an aqueous solution of a salt of the metal in the liquid medium. The method is particularly applicable to the liquefaction of coal. The process ... wherein a hydrocarbonaceous substance is hydrogenated to lower boiling products by contacting a dispersion of said substance in a liquid hydrocarbon medium with hydrogen at elevated temperature and pressure (and) wherein the metal is molybdenum".)

The process ... wherein the gaseous oxidant is selected from a mixture of steam and oxygen or a mixture of steam and air (and) wherein the gaseous product from step (c) or step (d) exits the gasifier and then enters a cyclone separator to carry out gas/solid separation, and the separated solid is optionally returned to any section of the gasifier. 

The process ... wherein the syngas methanation catalyst is used as the dust-removing particles in the particle moving bed to generate additional methane gas (and) wherein the syngas methanation catalyst is selected from a sulfur-tolerant methanation catalyst (such as the above-noted) molybdenum sulfide, molybdenum oxide, cobalt oxide or molybdenum-cobalt-nickel eutectic supported on an alumina support or zirconia support.

The process ...  wherein the gaseous oxidant is introduced into the gasifier via a gas distributing plate located in the syngas generation section (and) wherein the gaseous oxidant is divided into two sub-streams and then introduced into the syngas generation section, one sub-stream is introduced upwardly along the axial direction of the gas distributing plate at or near its bottom center, the other sub-stream is introduced upwardly in a certain angle with the axial direction of the gas distributing plate (and) wherein the temperature of the syngas generation section is controlled at a temperature suitable for generating syngas by regulating the feeding rate and/or composition of the gaseous oxidant entering the syngas generation section.

The process ... wherein the temperature suitable for generating syngas is 800-1200C (and) wherein the mass ratio between the steam in the syngas generation section and the coal entered the gasifier is 0.5-5, and the mass ratio between the oxygen and the coal entered the gasifier is 0.1-1.

The process ... wherein the temperature of the coal methanation section is regulated by adding additional coal to this section and adjusting the amount of said additional coal. 

The process ... wherein the coal is selected from bituminous coal, anthracite or lignite (and wherein a portion of) the coal (can be) replaced with ... biomass. 

The gasifier ...  which is additionally provided with a coal pyrolysis section above the syngas methanation section, the coal pyrolysis section is used to heat and partially pyrolyze the coal introduced into gasifier at the coal pyrolysis section by the gaseous product containing more methane coming from the syngas methanation section.

The gasifier ... which additionally comprises: feeding devices for feeding the gaseous oxidant, the coal and the catalyst into the gasifier, respectively; and discharging devices for discharging the gaseous product and solid product out of the gasifier, respectively (and) which additionally comprises a gas distributing plate located in the syngas generation section (and) which additionally comprises an inner structure element located in the syngas methanation section, said inner structure element is made of the syngas methanation catalyst.

Background and Field: The invention relates to a field of substitute natural gas production by gasifying coal, in particular, relates to a process for methane production by catalytic coal gasification, especially, relates to a process for methane production by catalytic coal gasification in a multi-sections gasifier.

With the rapid economic development and the increasingly strict environmental regulations, in the next ten years, China's demand for the clean energy of the natural gas will grow explosively, but the production of natural gas, though have increased, will still well lower than the increasing trend of its demand, so the contradiction between supply and demand has become increasingly prominent and the supply gap is increasing year by year.

(Hmmm. Sound familiar?)

In view that China's energy source state is characterized in that coal is abundant, petroleum and natural gas are insufficient, so, an energy consumption structure that coal will be the major energy source will not change in the short term. (Accordingly) converting coal to natural gas ... is a shortcut to eliminate energy crisis and ensure the energy safety.

Now, the process for preparing methane from coal can classified as indirect methanation and direct methanation. Indirect methanation is also called coal methanation process in two steps, wherein the first step is preparing syngas by gasifying coal, and the second step is preparing methane from the syngas (i.e., the purified coal gas in which H2/CO ratio having been adjusted). The direct methanation of coal refers to a process in which the coal is directly converted to the methane-rich gas product under a certain temperature and pressure. In this direct methanation process, the coal gasification operation and methanation operation, are not two separate operation.

Exxon Corporation in USA has carried out much experimental studies to the process for preparing methane from coal by one-step process. U.S. Pat. No. 4,318,712 discloses a whole process chart for the direct methanation of coal ...in which the coal is premixed with catalyst and then is introduced into a gasifier.

(Concerning the above, see:

Exxon Coal + CO2 + H2O Combo Gasification & Conversion | Research & Development | News; concerning: "United States Patent 4,318,712 - Catalytic Coal Gasification Process; 1982; Assignee: Exxon Research and Engineering, NJ; Abstract: A carbonaceous feed material, a potassium compound having a relatively poor catalytic activity as compared to that of potassium carbonate, and a sodium or lithium salt are introduced into a gasification reactor. The carbonaceous material is then gasified in the presence of the added potassium and sodium or lithium constituents. The added sodium or lithium salt apparently activates the relatively noncatalytic potassium compound thereby producing a substantial catalytic effect on the gasification reactions. In general, activation of the noncatalytic potassium compound will take place when the sodium or lithium compound introduced into the reactor is either a salt of a weak acid or a salt of a strong acid that is converted to a sodium or lithium salt of a weak acid in the reactor at gasification conditions. Claims:  A process for the catalytic steam gasification of coal .... . The process ... is one for the gasification of bituminous coal, subbituminous coal, lignite, organic waste materials or similar carbonaceous solids in the presence of added sodium and potassium compounds. It will be understood that the invention ... may be employed in ... gasification operations ...  to promote the reaction of steam, hydrogen, carbon dioxide, or a similar gasification agent with (carbon) ... . As a result, the overall cost of the product gas may be substantially reduced".) 

U.S. Pat. No. 4,077,778 proposes a process for catalytically gasifying coal by using multiple stages fluidized bed. This process eliminate the shortage of previous process and let the gasification more effective by making good use of the feeding carbon resource and increasing carbon conversion. The operating gas velocity of the primary fluidized bed is relative high to entrain some carbon particles into secondary fluidized bed, where the gasification reaction is carried out at a relative low gas velocity. In this way the residence time of the solid is increased, so the carbon conversion is maximized. The multiple stages gasification can increase the carbon utilization rate from 70-85% to above 95%, compared with single stage gasification. This process for catalytically gasifying coal by using multiple stages fluidized bed uses several fluidized bed reactors, so the invest for the equipments is high and the operation is relatively complicated.

(For more info about the above, see our report of:

Exxon Converts 99% of Coal to Methane | Research & Development | News; concerning: "United States Patent 4,077,778 - Process for the Catalytic Gasification of Coal; 1978;  Assignee: Exxon Research and Engineering Company, NJ; Abstract: A process for the production of synthetic natural gas from a carbon-alkali metal catalyst or alkali-metal impregnated carbonaceous feed, particularly coal, by reaction of said feed with water (steam) in the presence of a mixture of hydrogen and carbon monoxide (both made within the system, as noted above,  from Coal and Water)".) 

The invention made a modification to the traditional process for preparing methane from coal.

The invention integrates three operation process, i.e., the preparation of syngas from coal, the catalytically methanation of coal and the methanation of syngas, into a single reactor, so as to make good use of the energy.

In one aspect, the invention relates to a process for preparing methane by catalytically gasifying coal, comprising steps:

(a) providing a gasifier comprising a syngas generation section, a coal methanation section and a syngas methanation section, and carrying out methanation reaction by reacting the coal with a syngas-including gas stream coming from the syngas generation section in the presence of coal methanation catalyst in the coal methanation section, so as to generate a methane-containing gas stream and reacted char;

(b) the reacted char enters downwardly the syngas generation section and reacts with a gaseous oxidant introduced into the syngas generation section, producing the syngas-including gas stream and ash residues, wherein the syngas-including gas stream enters upwardly the coal methanation section to carry out step (a), while the ash exits the gasifier; and:

(c). the methane-containing gas stream from step (a) enters upwardly the syngas methanation section, and the syngas is subjected to methanation reaction in the presence of a syngas methanation catalyst to produce additional methane, so as to obtain a gaseous product containing more methane.

In other aspect, the invention also relates to a process for preparing methane by catalytically gasifying coal, comprising steps:

(a) providing a gasifier comprising a syngas generation section, a coal methanation section, a syngas methanation section and a coal pyrolysis section, and carrying out methanation reaction by reacting the coal with a syngas-including gas stream coming from the syngas generation section in the presence of coal methanation catalyst in the coal methanation section, so as to generate a methane-containing gas stream and reacted char;

(b) the reacted char enters downwardly the syngas generation section and reacts with a gaseous oxidant introduced into the syngas generation section, producing the syngas-including gas stream and ash residues, wherein the syngas-including gas stream enters upwardly the coal methanation section to carry out step (a), while the ash exits the gasifier; and,

(c) the methane-containing gas stream from step (a) enters upwardly the syngas methanation section, and the syngas is subjected to methanation reaction in the presence of a syngas methanation catalyst to produce additional methane, so as to obtain a gaseous product containing more methane; and:

(d) the gaseous product containing more methane enters upwardly the coal pyrolysis section and heats the coal introduced into the coal pyrolysis section to pyrolyze the coal and produce additional methane, and all gases in this section exit the gasifier, while the pyrolyzed coal moves downwardly along the gasifier.

In a further aspect, the invention relates to an apparatus for preparing methane by catalytically gasifying coal, said apparatus is also called gasifier in the art, which comprises a syngas generation section, a coal methanation section and a syngas methanation section in the order from bottom to top, wherein,

- the coal methanation section is used to carry out methanation reaction by reacting the coal with a syngas-including gas stream coming from the syngas generation section in the presence of coal methanation catalyst, so as to generate a methane-containing gas stream and reacted char;

- the syngas generation section is used to react the reacted char from coal methanation section with a gaseous oxidant introduced into the syngas generation section, producing the syngas-including gas stream and ash residues, wherein the syngas-including gas stream enters upwardly the coal methanation section, while the ash residues exit the gasifier;

- the syngas methanation section is used to let the syngas in the methane-containing gas stream from the coal methanation section subjected to methanation reaction in the presence of a syngas methanation catalyst to produce additional methane, so as to obtain a gaseous product containing more methane.

Various embodiments of the invention have been described hereinbefore, but it is obvious for the skilled in the art that many obvious modifications can be made to the invention according to the teaching of the invention. Though the invention is described by taking coal as an example, it is obvious that the process of the invention can also used to treat ... biomass".

-------------------------------- 

This is a sophisticated multi-stage Coal and biomass gasification process; but, we remind you, that, as seen in other of our reports, for instance:

Charleston, WV, Coal + Steam = Hydrocarbon Syngas | Research & Development | News; 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, NY; 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. Claims: (A) process employing two separate and interconnected fluid-bed reaction zones, a first zone for gasification and a second zone for combustion of char particles; wherein in said first zone, char particles are gasified with steam ... to produce modified char particles and a first hydrogen-rich gas product; wherein said second zone, said modified char particles from said first zone are burned with air at a temperature sufficient to produce tacky ash particles that accrete to larger ash particles; and wherein said larger ash particles from said second zone provide the heat required to effect the gasification reaction in said first zone by descending in said first zone and transferring their sensible heat to said char particles and said steam";

such multi-stage Coal gasification processes, and, even as seen in:

Standard Oil Co-Gasifies Coal & Carbon-Recycling Biomass | Research & Development | News; concerning: "United States Patent 2,633,416 - Gasification of Carbonaceous Solids; 1953; Assignee: Standard Oil Development Company; Abstract: The present invention relates to the production of gases from non-gaseous carbonaceous materials and, more particularly, to the production of gas mixtures containing carbon monoxide and hydrogen ... from such solid carbonaceous materials as ... various coals (and) cellulosic materials"; and:

Texaco Makes Methane from Coal & "Stuff" | Research & Development | News; concerning: "United States Patent 3,888,043 - Production of Methane; 1975; Assignee: Texaco Incorporated, New York;  
Abstract: Continuous process for the production of a gaseous stream comprising at least 90 mole % of methane (dry basis) from a sulfur containing hydrocarbonaceous fuel without polluting the environment ... . The product gas ... may be used as a substitute for natural gas or as a feedstock for organic chemical synthesis. The process ... wherein said hydrocarbonaceous fuel is a pump-able slurry of solid carbonaceous fuels selected from the group consisting of coal (and) concentrated sewer sludge in a vaporizable carrier such as water";

options for the inclusion of Biomass with Coal in the gasification process, have been available to us for literally decades. It's just sad that China are the ones now likely to take advantage, and benefit, from them, while we, in the United States of America, especially those of us in United States Coal Country, seem doomed to labor on in the interlocking myths of either energy insufficiencies, or, potentials for energy abundance locked away deep in the ancient shale beds.  

Coal, in combination with Biomass, as herein, could put a merciful end to our wasting any more time on both or either of those fallacies.


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