Just yesterday our United States Government again confirmed that Coal, along with Carbon-recycling, renewable Biomass, can be indirectly converted, via an initial process of gasification, into liquid fuels; in this case, specifically, the fuel alcohols Ethanol and Methanol.
The technology disclosed herein seems closely similar, and derivative of, many we have reported to you previously, especially in terms of catalyst composition and certain aspects of processing the combined Coal and Biomass, specifically cellulose, feed.
But, for the sake of concision, we'll keep our references to past reports to a minimum.
One technology, however, which our subject herein specifically references as direct and precedent art, is discussed in our report of:
California Hydrogasifies Coal & Carbon-Recycling Wastes | Research & Development | News; concerning: "United States Patent 7,500,997 - Steam Pyrolysis ... to Enhance the Hydro-Gasification of Carbonaceous Materials; 2009; Inventors: Joseph Norbeck and Collin Hackett, Riverside, CA; Assignee: The Regents of the University of California; Abstract: A process and apparatus for producing a synthesis gas for use as a gaseous fuel or as feed into a Fischer-Tropsch reactor to produce a liquid fuel in a substantially self-sustaining process. In one embodiment, a slurry of carbonaceous material in water, and hydrogen from an internal source, are fed into a hydro-gasification reactor to generate methane rich producer gases which are fed into a steam pyrolytic reformer to generate synthesis gas comprising hydrogen and carbon monoxide. A portion of the hydrogen is used as the internal hydrogen source. The remaining synthesis gas is either used as fuel to produce electricity and/or process heat or is fed into a Fischer-Tropsch reactor to produce liquid fuel. In another embodiment of the invention, carbonaceous material can be heated simultaneously in the presence of both hydrogen and steam to undergo steam pyrolysis and hydro-gasification in a single step.(And) wherein the carbonaceous material comprises municipal waste, biomass, wood, coal, or a natural or synthetic polymer";
wherein the potentials for consuming and utilizing an array of carbon-containing wastes in a liquid hydrocarbon fuel synthesis process based, because of it's abundance and availability, on Coal, is especially emphasized.
That said, the primary innovation being revealed herein seems to us to involve treatment of the catalysts, so that the conversion process is more complete, and, selection of the catalyst materials so that the fuel alcohols Ethanol and Methanol, as opposed to a blend of hydrocarbons, are selected for as the main final products. As seen in excerpts from the initial link in this dispatch to:
"United States Patent 8,759,596 - Liquid Fuel Production Process from Cellulosic Biomass and Coal
Date: June 24, 2014
Inventors: Hongping Yie, et. al., China and California
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.
(As in our introductory comments, the technology being disclosed is derivative, or founded on, many similar we have reported previously. All of the catalytic metals, and their compounds, specified above have been earlier identified as effective in Coal gasification and conversion processes about which we have reported; and, as seen for example in:
West Virginia 1982 Coal to Ethanol | Research & Development | News; concerning: "United States Patent 4,333,852 - Production of Ethanol and Methanol Directly from Synthesis Gas; 1982; Inventor: Barbara Warren, Charleston, WV; Assignee: Union Carbide Corporation; Abstract: Alkanols are selectively produced as the major product directly from synthesis gas under mild conditions using a homogeneous ruthenium catalyst, a halogen or halide promoter and a phosphine oxide compound as solvent";
as extensive as our subject's list of Coal gasification/conversion catalysts is, it isn't all-inclusive. Further, as seen for one example in:
Exxon Recovers and Recycles Coal Conversion Catalyst | Research & Development | News; concerning: "United States Patent 4,157,246 - Hydrothermal Alkali Metal Catalyst Recovery Process; 1979; Assignee: Exxon Research and Engineering Company; Abstract: In a coal gasification operation or similar conversion process carried out in the presence of an alkali metal-containing catalyst wherein solid particles containing alkali metal residues are produced, alkali metal constituents are recovered from the particles primarily in the form of water soluble alkali metal formates by treating the particles with a calcium or magnesium-containing compound in the presence of water ... and in the presence of added carbon monoxide";
the use of the specified "alkali metal compound"s for such Coal conversion processes has been known for so long that complete techniques for recovering and reusing them were developed long ago.)
Claims: A process of producing fuel from a cellulosic biomass, comprising: a first step of providing a mixture of cellulosic biomass and coal; a second step of gasifying the mixture of the first step to produce a synthesis gas fuel; and a third step of converting the synthesis gas fuel produced in the second step into a liquid fuel in the presence of a catalyst, wherein the catalyst is calcinated in the presence of an ultrasonic field and comprises molybdenum sulfide and a component for activating a C--H bond in an alkane product.
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 in the second step, the gasification is carried out in the presence of an oxygen-containing gas, the oxygen-containing gas is selected from air, pure oxygen and a combination thereof, and the oxygen content in the oxygen-containing gas is (adjusted within defined parameters) on the basis of the carbon content in the coal and the cellulosic biomass.
The process ... wherein, the liquid fuel ... is methanol and/or ethanol.
The process ... wherein the catalyst has the following formula (1) Mo--S-M-L (1); where M is the component for activating the C--H bond in the alkane product; L is an alkali metal compound used as an activity enhancer of the catalyst; and a molar ratio of the formula (as defined and outlined using elements specified in the Abstract).
The process ... wherein a temperature of the mixture in the first step is 200-500 C (and) wherein a pressure of the mixture in the first step is 5-60 atmospheres.
(Some moderately high pressures and temperatures are needed; although the specified ranges are pretty broad, and it's difficult to tell what economies in those regards might be achieved relative to similar and related Coal conversion technologies.)
The process ... wherein the synthesis gas fuel of the third step comprises hydrogen and carbon monoxide, and wherein a molar ratio of the hydrogen to carbon monoxide is between 1:10 and 10:1.
(The broad range of "hydrogen to carbon monoxide" ratios isn't necessarily desired. As the full Disclosure makes clear, relatively high-carbon Coal is blended with relatively high-hydrogen Biomass in such proportions that a synthesis gas blend of Carbon Monoxide and Hydrogen in the proper proportions for Methanol and Ethanol synthesis is produced in the gasification stage.)
The process ... wherein a gasification temperature of the second step is 1000-1800 C (and) wherein the catalyst is calcinated at an ultrasonic field intensity of 2 kW/20 kHz.
(The above refers to the use of some sophisticated, and relatively new, techniques for the manufacture of the catalyst. As a literature search will reveal, high-frequency sound, "ultrasonic", waves can be used, by irradiating the chemical reactants with the ultrasonic waves, to lower the temperature at which the desired reaction takes place and to control to a certain extent the size and type of particles, in the case of solid reaction products, produced, among other things. The new field is known as "Sonochemistry"; and, a little more can be learned, if interested, via:
Sonochemistry - Wikipedia, the free encyclopedia.)
Background and Field: The present invention relates to a novel process for producing liquid fuel by using Cellulosic biomass as the raw material, more particularly to a process which comprises producing synthesis gas by co-gasifying Cellulosic biomass and coal, followed by producing liquid fuel from the synthesis gas.
Since the beginning of this century, the supply of oil energy sources has arrived at its peaks. According to the data specified in the "BP Statistical Review of the World Energy 2005", based on the present exploitation rate, the reserves of oil in the world can be further sustained for a little more than 40 years ... .
It can be expected that the liquid fuel can not be replaced during quite a long period based on the current technology of the human society. As can be seen, mankind has to face the most vital turning point in history.
Although the process of producing biomass derived ethanol fuel by fermentation is being widely spread in the field of liquid fuel, the actual application thereof is limited (in that) the process of producing ethanol fuel from starch will consume the food for mankind,
The process of producing liquid fuel from coal can be the leading trend since the reserves of coal is much higher than that of oil.
Currently, there are two coal liquefaction processes for producing liquid fuel, namely, coal direct liquefaction and indirect liquefaction. However, the production conditions used in the process of producing liquid fuel by direct coal liquefaction is too rigor and only limited types of coal can be used therein.
(The above is no longer really true. Although what might be thought of as the original "direct coal liquefaction" process, developed by Friedrich Bergius, as discussed for two examples in our reports of:
Bergius 1928 Coal Liquefaction | Research & Development | News; "United States Patent 1,669,439 - Process for Distilling and Liquefying Coal; 1928; Inventor: Friedrich Bergius, Germany; Abstract: This invention relates to improvements in a correlated process for distilling and liquefying coal"; and:
CoalTL Wins Nobel Prize - in 1931 | Research & Development | News; which relates how Bergius was awarded the 1931 Nobel Prize in Chemistry for devising a means for "obtaining oils from" both Coal and "timber by high-pressure processing";
did require high pressures and high temperatures, even then the "types" of Coal weren't necessarily limited, and, even then, Biomass, i.e., "timber", could be processed, as well. And, now, as seen for example in:
WVU May 28, 2013, Carbon-recycling Coal Liquefaction | Research & Development | News; concerning: "United States Patent 8,449,632 - Sewage Material in Coal Liquefaction; 2013; Inventor: Alfred H. Stiller, Morgantown, WV; Assignee: West Virginia University; Abstract: The present disclosure provides methods and systems for coal liquefaction using a sewage material. A method of obtaining a de-ashed coal extract includes exposing a coal to a sewage material in the presence of a coal-derived solvent to form a slurry, elevating the temperature of the slurry to facilitate liquefying the coal and ... wherein the coal extract is suitable for downstream processing. ... The method ... wherein the coal-derived solvent is selected from a group comprising recycled liquefied coal, coal tar distillate, and coal tar pitch (and) wherein the temperature is elevated to between 300 and 600 Celsius (and wherein the coal ... is selected from one or more of a sub-bituminous coal, a bituminous coal, a lignite coal and an anthracite coal (and) wherein the sewage material is lignin-containing sewage sludge. ... The present invention relates to coal-to-liquid technology, and specifically to a system and method for liquefying coal using solvents that hydrogenate under mild conditions";
more modern derivatives of the Bergius direct Coal liquefaction process require much milder, that is, lower energy, processing conditions and can still incorporate a pretty broad range of "Biomass".)
The process currently used for producing methanol through indirect coal liquefaction mainly comprises two steps as follows: in the first step, the coal is gasified to produce synthesis gas, and in the second step, the synthesis gas is converted into methanol in the presence of catalyst. Relatively developed coal gasification process mainly comprises the gasification of solid coal powder feedstock and the gasification of aqueous coal slurry feedstock. The process of gasification of aqueous coal slurry feedstock is more homogeneous and highly reliable, so the yield of synthesis can be more readily enhanced by carrying out the gasification under high pressure. Therefore, the process of the gasification of aqueous coal slurry feedstock is generally adopted, while the gasification of solid coal powder feedstock is still operated by some manufactures. However, the process of producing methanol through indirect coal liquefaction still possesses the following drawbacks that need to be improved:
First of all, since the coal is generally rich in carbon but lack of hydrogen, the composition of the synthesis gas derived from most types of coal is far lower than the ratio required for producing methanol (hydrogen:carbon monoxide=2:1). The methods previously used for solving above problem comprises: (1) installing a separate production line for generating hydrogen from coal so as to supplement the hydrogen; (2) installing a separate converter in the gasification process for converting carbon monoxide into hydrogen (by reacting carbon monoxide and water to produce carbon dioxide and hydrogen) so as to supplement. However, both of the above methods still include the limitations of increasing the cost and the complexity of the process, and consumption of water and coal. It is well known that the short supply of water will be more and more severe in the future. The difficulties in gasification is even more severe for some types of coal, such as the coal produced from the Eastern China, which not only are rich in carbon and lack of hydrogen but also comprise excessive ash content with high ash fusion temperature (1500 C or even higher), etc.
In additional to synthesizing methanol liquid fuel, the synthesis gas can also be used for producing other liquid fuel such as ethanol. The chemical mechanism of producing ethanol from synthesis gas is similar with the mechanism of producing methanol. Accordingly, the catalyst used for producing methanol can be used as a basis and modified to obtain the catalyst used for producing ethanol. Besides, the reaction equipments used for the process of producing ethanol may be the same with the reaction equipments used for the methanol with tiny variation, which is mainly because the process of producing ethanol emits more heat (about 2.5 times of the process of producing methanol), thus the reaction vessel has to be modified so that the heat can be dissipated rapidly.
In addition to the eager need for improving the process of producing liquid fuel through coal gasification, the process of producing methanol through direct Cellulosic biomass gasification also encounters many issues. Firstly, the Cellulosic biomass is of low density, rendering an excessively low efficiency of the gasification furnace and high specific cost of the product; secondly, the Cellulosic biomass is rich in hydrogen and lack of carbon, rendering the excessive hydrogen in the synthesis gas cannot be effectively used for the synthesis of methanol, and consequently leading to high specific cost of the production.
Summary: One object of the present invention is to provide a highly effective novel process of producing synthesis gas and liquid fuel by using a combination of coal and Cellulosic biomass. The novel process effectively takes advantage of coal which is rich in carbon and lack of hydrogen as well as the Cellulosic biomass which is rich in hydrogen and lack of carbon, so that synthesis gas having composition approaching the optimal ratio for producing alcohol products, such as methanol and ethanol can be obtained by an one-step gasification.
(Although a "one-step gasification" is specified, it is actually more of a two-stage gasification process that is more fully described, wherein heat from the first helps to drive the second, with a consequent reduction in the amount of CO2 co-produced).
Another object of the present invention is to provide a process of producing liquid fuel from Cellulosic biomass with high conversion, without biomass pretreatment and the separation of the components.
In one aspect of the present invention, a process for producing fuel from the Cellulosic biomass is provided, wherein the process comprises the following steps:
the first step, a mixture of cellulose and coal is provided; and
the second step, the mixture of the first step is gasified to produce a synthesis gas fuel.
In one particular embodiment of the invention, the process of producing fuel from the Cellulosic biomass of the present invention comprises the following steps: the first step, a mixture of cellulose and coal at a proper ratio is provided, wherein the "proper ratio" means that said mixture will exhibit lower ash fusion temperature and the combustion value meeting the requirement on the efficiency of the gasification furnace; the second step, the mixture of the first step is gasified to produce a synthesis gas, wherein the sulfur content in the synthesis gas is notably lower than that of the synthesis gas produced by solely using coal. The synthesis gas of the present invention can be solely used as fuel, namely synthesis gas fuel.
Preferably, the content of the Cellulosic biomass in the first step is 1-99 wt. %, based on the total weight of the mixture; (and),
the mixture of the first step comprises 25-50 wt. % of water, based on the weight of the mixture, to obtain a aqueous slurry; (and),
the temperature of the mixture in the first step is between 200 C and 500 C; (and),
the pressure of the mixture in the first step is between 5 and 60 atm.
Preferably, in the second step, the gasification is carried out in the present of a oxygen-containing gas, wherein the oxygen-containing gas is selected from air, pure oxygen or a combination thereof, and the oxygen content of the oxygen-containing gas is 0.8-1.5 molar equivalence on the basis of the carbon content in the coal and Cellulosic biomass; (and) the gasification temperature of the second step is between 1000 C and 1800 C.
(Our read of it is that the needed temperatures and pressures can be achieved by control and use of the thermal energy released during the initial gasification - which implies the need to balance the ratios of Coal and Biomass in the feed not just to allow for proper Carbon Monoxide-Hydrogen ratios in the product synthesis gas, but, to enable the production of enough thermal energy, which would come primarily from the Coal, to drive the entire process.)
Furthermore, the process comprises the following step: the third step, the synthesis gas fuel produced in the second step will be converted into liquid fuel.
Preferably, the liquid fuel of the third step is methanol and/or ethanol; and/or
the conversion of the third step is operated in the present of catalyst; and/or
the synthesis gas fuel of the third step comprises hydrogen and carbon monoxide, wherein the molar ratio of the hydrogen to carbon monoxide is between 1:10 and 10:1.
Preferably, said catalyst is a catalytic system comprising molybdenum sulfide and a component (as specified in terms of ratios and processing, etc.);
In another aspect of the present invention, there is provided a use of the Cellulosic biomass, and specifically, co-gasifying the Cellulosic biomass and coal so as to reduce the ash fusion temperature of the coal gasification.
Furthermore, the process comprises the following step: the third step, the synthesis gas fuel produced in the second step will be converted into liquid fuel.
Preferably, the liquid fuel of the third step is methanol and/or ethanol (and) the synthesis gas fuel of the third step comprises hydrogen and carbon monoxide, wherein the molar ratio of the hydrogen to carbon monoxide is between 1:10 and 10:1.
The present invention relates to a process of producing synthesis gas and liquid fuel through co-gasification of Cellulosic biomass and coal. The present invention can effectively lower the ash fusion temperature of coal, so that the coal with high ash fusion temperature can be used for producing liquid fuel through indirect process. In particular, when coal and Cellulosic biomass are co-gasified under specified ratio, the defects of them can be effectively eliminated, resulting in an improved process for producing methanol and ethanol with reduced cost.
In the production process of the present invention, by making use of the mixture of cellulose and coal, the ash fusion temperature and hence the optimal operation temperature of the coal gasification are both decreased, and the incorporation of the fluxing agent such as calcium oxide can also be avoided.
Besides, the energy consumption during the coal gasification, the production of methane and ethane through the reaction between hydrogen and carbon in the system, as well as the fusion corrosion rate of the firebrick can all be decreased.
Meanwhile, in the unique process, the yield of ash content as well as the consumptions of oxygen and coal and the cost can be reduced. The blackwater treatment and fouling in the thermal exchanging system can be alleviated, so that the total cost can be remarkably reduced.
In the unique process, since the ash fusion temperature during the gasification is decreased, more types of coal, for example the coal having extremely high ash fusion temperature such as the coal from Eastern China, can be used as the starting material for coal gasification to produce synthesis gas, and subsequently used for the indirect coal liquefaction.
Besides, the synthesis gas produced by present invention exhibits favorable ratio of hydrogen to carbon monoxide. For example, the content of hydrogen may be 37-60 vol. %, based on the total volume of the synthesis gas.
Cellulosic biomass according to the invention is defined as biomass containing cellulose. The cellulose of the present invention includes, but not limited to polysaccharide celluloses and hemicelluloses. Biomass refers to residual substances rich in biomass energy after removing their edible parts. The biomass of the present invention includes, but not limited to the inedible parts of various crops, such as corn stalk, broomcorn stalk, wheat straw, soy stalk, cotton stalk, as well as other biomass including reed, bamboo, various hard and soft wood, weeds, etc.
The coal of the present invention is not particularly limited, as long as the object of the present invention will not be hindered thereby. In common words, the process of the present invention is applicable to all kinds of coal.
In the present invention, the "synthesis gas fuel" refers to the gas fuel produced during the gasification, which can be used for the subsequent synthesis. For example, the synthesis gas fuel may comprises hydrogen and carbon monoxide, and can be used for preparing methanol and/or ethanol. In a particular example, the high temperature gas from the gasification furnace is cooled in a heat exchanger, and the recovered heat can be used for other procedures such as drying the Cellulosic biomass. The cooled gas undergoes the procedures of gas filter, water scrubber, oil scrubber and acid stripping, and then can be used as synthesis gas for preparing methanol and/or ethanol".
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Similar processes exist for Ethanol, but, we remind you specifically, that, as seen in our report of:
ExxonMobil Coal to Methanol to Gasoline | Research & Development | News; concerning both;
"United States Patent 4,348,486 - Production of Methanol via Catalytic Coal Gasification; 1982; Exxon Research and Engineering Company; Claims: A process for the production of methanol from a carbonaceous feed material (by)gasifying said carbonaceous feed material with steam ... and added hydrogen and carbon monoxide (and) wherein said carbonaceous feed material comprises coal"; and:
"United States Patent 4,035,430 - Conversion of Methanol to Gasoline; 1977; Mobil Oil Corporation; Claims: (A) method for converting methanol to gasoline ... . This invention relates to the method and system for converting methanol to gasoline";
once we do have an alcohol, like Methanol, made, as via the process of our subject herein, "United States Patent 8,759,596 - Liquid Fuel Production Process from Cellulosic Biomass and Coal", that alcohol can be rather directly converted, through known and established technology, into Gasoline.
Other options for the use of Methanol and Ethanol, in the synthesis and production of plastics and polymers, is, as we've also documented, being practiced on an industrial basis in China.
But, the take-away is this:
As confirmed just yesterday by our United States Government, we can convert any grade of Coal, in combination, in a blend, with various sorts of otherwise waste and Carbon-recycling Biomass, in a thermally self-sustaining process, into a synthesis gas blend of Carbon Monoxide and Hydrogen in the proper proportions for subsequent catalytic, chemical condensation into the fuel alcohols Methanol and Ethanol.
Our abundant United States Coal thus affords us a great many potentials - for freedom from OPEC, for increased domestic United States employment, and vastly enhanced United States security.
As noted, we have Coal and Biomass conversion technologies available to us in the United States that are in essence equivalent to the Chinese innovation disclosed in our subject, US Patent 8,759,596.
Whether or not we, in the United States, put such Coal conversion technologies to work, what do you suppose China will be doing with theirs?