United States Patent: 4468315
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 developed 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, for which he was awarded the 1931 Nobel Prize in Chemistry, more about which can be learned via:
http://www.nobelprize.org/nobel_prizes/chemistry/laureates/1931/bergius-lecture.pdf; "Friedrich Bergius, 'Chemical Reactions Under High Pressure', Nobel Lecture (delivered May 21, 1932)".
Bergius covers a lot of ground in his Nobel lecture; so, if anyone out there surprises us by digging into it, we urge you to hang in there, the hydrogenation of Coal is dealt with after a fair amount of preliminary wandering.
What you'll discover is, that, his process is one which, in the presence of pressurized, elemental Hydrogen, hydrogenates and liquefies particles of Coal that are suspended in an "oil", which Oil is itself hydrogenated and converted into other, more desirable liquid hydrocarbons.
Now, that might seem to tie the direct hydrogenation of Coal into the processing of petroleum. It does not.
If you are careful to read the Bergius lecture, you will find that the oil in which the Coal is to be suspended is specified to be "naphthalene", and, as in:
Naphthalene - Wikipedia, the free encyclopedia; "Most naphthalene is derived from coal tar".
Should you recall our reports concerning WVU's "West Virginia Process" for the direct liquefaction of Coal, as, for one example, in:
WVU Hydrogenates Coal Tar | Research & Development; concerning: "Hydrogenation of Naphthalene and Coal Tar Distillate over Ni/Mo/Al2O3 Catalyst; Abhijit Bhagavatula; Thesis submitted to the College of Engineering and Mineral Resources at West Virginia University in partial fulfillment of the requirements for the degree of Master of Science in Chemical Engineering. John W. Zondlo, Ph.D., Chair; Elliot B. Kennel, M.S; Alfred H. Stiller, Ph.D; Department of Chemical Engineering; Morgantown, West Virginia. 2009. Abstract: The hydrogenation of naphthalene and coal-tar distillates has been carried out in a Trickle Bed Reactor, in which the liquid is allowed to flow through the catalyst bed in the presence of hydrogen. Direct liquefaction, the direct reaction between coal and hydrogen, involves the conversion of coal to refinable crude hydrocarbons, from which liquid fuels such as gasoline, diesel, kerosene, etc., can be produced";
you'll know that the Coal Oil Naphthalene can serve as a Hydrogen transfer agent that directly hydrogenates and liquefies Coal, using a supply of Hydrogen; and, thereby converts Coal into "crude (liquid) hydrocarbons" suitable for refining into a full range of liquid hydrocarbon fuels. .
There is, though, one interesting fact about such efficient, direct Coal conversion processes that utilize elemental Hydrogen to effect the Coal hydrogenation:
They involve exothermic chemical reactions that generate enough heat to, essentially, provide for all of the pressures and elevated operating temperatures required by the entire process of converting Coal into "crude hydrocarbons, from which liquid fuels such as gasoline, diesel, kerosene, etc., can be produced".
The potentials for such economies should become more apparent via the disclosure of the United States Patent we send along in this dispatch, wherein a very major, Germany-based multi-national chemical company, one whose name is likely familiar to nearly all our readers, explains that Coal can be converted into hydrocarbons via direct reaction with Hydrogen, in a process that is capable of generating all, or nearly all, of the energy required to drive that conversion of Coal into Hydrocarbons. As seen in excerpts from the initial link in this dispatch to:
"United States Patent 4,468,315 - Hydrogenation of Coal
(For backup, should the initial link fail, try:
Hydrogenation of coal - BASF Aktiengesellschaft or Energy Citations Database (ECD) - - Document #6440093.)
Date: August, 1984
Inventor: Helmut Romberg, Germany
Assignee: BASF Aktiengesellschaft (AG)
Abstract: A process for hydrogenating coal which has been mixed with oils, by bringing the coal slurry to the reaction pressure by pumping, heating the slurry and catalytically hydrogenating it with hydrogen, wherein some or all of the hot gases and vapors formed during hydrogenation are intimately re-mixed with the coal slurry in a plurality of stages. After the first mixing stage, the gases are freed from the product, and the product-free gases, especially hydrogen, are used as a thermal medium.
Claims: A process for hydrogenating coal in a slurry of coal and oil which comprises:
- contacting the slurry of coal and oil with hydrogen and a hydrogenation catalyst in a reactor;
- passing the hot vapors from the reactor to a first mixing zone wherein the vapors are mixed with a preheated coal and oil slurry and wherein the vapors heat the slurry to a temperature of at least 350C while the vapors are correspondingly cooled;
- separating the vapors from the slurry;
- pumping the heated slurry to the reactor; cooling the vapors and separating reaction product from product free gases; and
- thereafter mixing the product-free gases, which include hydrogen, with the coal and oil slurry in a second mixing zone, said product-free gases being used as a thermal medium to preheat said slurry.
The process ... wherein, after the first mixing stage, heat exchange between the gas and the coal slurry is effected (and) wherein the first mixing stage is operated at from 380 to 440C.
(and) wherein the amount of gas, consisting essentially of hydrogen, which serves as the thermal medium is increased by recycling a part-stream so as to permit better utilization of the heat of reaction and to minimize any additionally required external heat.
(Some Hydrogen seems to be generated within the process, either from Water or naturally entrained hydrocarbons, in addition to the Hydrogen from an outside source; but, not all of the Hydrogen is consumed initially in the Coal hydrogenation reaction, and, the Hydrogen that isn't consumed is made very, very hot by the exothermic hydrogenation, and, it can be used as a heat transfer agent to recycle the generated heat back into other, energy-consuming steps in the total process, which serves "to minimize any additionally required external heat".)
Background and Description: In the conventional process for hydrogenation of coal, the economics greatly depend on the utilization of the heat of reaction generated in the process. Conventionally, the heat content of the reaction vapors leaving the reactor is utilized in order to pre-heat the coal slurry, for the reaction, in counter-current in tube bundle heat exchangers. This presents major problems due to crust formation on the heat exchanger surfaces and due to difficulties in distribution of the two-phase mixture on the slurry side of the exchanger, the difficulties being the greater, the larger the size of the apparatus.
Direct heat exchange between reaction vapors and coal slurry would offer advantages. The type of mixing zone required for direct heat exchange is less affected by problems of distribution of the two-phase mixture and there is no danger of cracking occurring at superheated heat exchanger surfaces. Moreover, using the hydrogen as an essential constituent of the thermal gas ensures that the heating of the coal slurry always takes place in the presence of hydrogen.
Direct heat exchange in one step, or in a counter-current apparatus over a limited temperature range, has also already been employed. In both cases, a proportion of the vaporous reaction product condenses out in the coal slurry; this restricts the application of the direct heat exchange principle to relatively high temperatures. Extensive heat recovery by direct exchange is not possible by this method.
I have found that better utilization of the heat of reaction is achieved if some or all of the hot gases and vapors formed during the hydrogenation are intimately mixed with the coal slurry in a plurality of stages, and after the first mixing stage the gases are freed from the product, and the product-free gases, especially hydrogen, are used as a thermal medium.
In the hydrogenation process according to the invention, the gases and vapors leaving the reaction are cooled, in a first mixing stage, to a temperature of not less than 350C, preferably from 380 to 440C, especially from 390 to 410C. The high-boiling oils are then removed in an intermediate separator.
To achieve the above temperature in the intermediate separator, a preheating zone at a lower temperature is needed, in which the coal slurry is preheated. In the case of direct heat exchange, such treatment cools the reaction gas to below 350C. However, below 350C too high a proportion of the reaction products precipitates and is returned, with the coal slurry, to the reactor. This accumulation of reaction products in the coal slurry and in the reaction zone is prevented by first discharging the reaction products from the reaction gases in a cold separator at about ambient temperature. The remaining gas, which has been freed from oil vapor, is then reheated in a heat exchanger in counter-current to the product-laden gas flowing to the cold separator, the latter gas thereby being cooled. The heated product-free gas can then serve as a thermal medium and supply the requisite heat to the coal slurry by direct heat exchange. If external heat is additionally needed to cover peak demand, then this external heat can be employed to heat the product-free gas, and accordingly no cracking reaction or carbon deposition occurs on the heat transfer surfaces.
The advantage of the process according to the invention is essentially that only clean gases enter the heat exchanger in which external heat is supplied, while the coal slurry is subjected to direct heating in multi-phase mixing zones, which require substantially simpler and accordingly cheaper apparatus and where there is no danger of cracking reactions, of blockage of individual tubes or of superheating at the heat exchanger surfaces. The heating of the coal slurry is moreover always effected in the presence of hydrogen. Given suitable choice of the number of direct heating stages, the efficiency achievable is substantially the same as on the counter-current principle. It is also possible to construct the mixing stages, which are operated below 400C and where heat is supplied by gas from which the product has already condensed out, as a counter-current apparatus, so as to achieve even better heat utilization.
During indirect heat exchange between the gas from the reactor, which flows to the cold separator and contains product, and the residual gas which has been freed from product, a proportion of the useful heat content (for example the heat of condensation) is lost for regeneration purposes. If this heat is also to be utilized in the process, the amount of the residual gas must be increased. This is readily possible if the off-gas from coal slurry preheating, which has been cooled to room temperature and is to be subjected to gas purification, is split, a part-stream being admixed to the thermal gas (thus creating a circulatory system).
The advantage of the process according to the invention is that the coal slurry, which is difficult to treat, is brought to the reactor entry temperature by direct mixing with gases coming from the process, making it possible--in contrast to a one-step arrangement--to dispense entirely with external heat supply in most cases, or at least to reduce such external heat supply substantially."
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We apologize for the over-long, excessively-dense excerpts. We felt them needed to get to the key point emphasized immediately above, which is:
Proper management of the heat energy generated by the Coal hydrogenation can "dispense entirely with" any need for an "external heat supply".
The system could be made to be almost self-sufficient in terms of energy supply, an economy that could very well cover the cost of supplying elemental Hydrogen, as via, for one example, the above-cited process of "United States Patent Application 20120149789 - Apparatus and Methods for the Electrolysis of Water".
And, that is the primary claim, or intent, of this Coal conversion process: it is self-sufficient, or nearly so, in terms of energy supply. Not only that, but, the design of the process helps to prevent unwanted, and perhaps costly, "cracking reaction"s and "carbon deposition".
BASF doesn't bother to specify, beyond "gases and vapors" and "high-boiling oils", what the products of such efficient Coal hydrogenation might be; but, since, aside from the operational design, the overall process seems closely related to that described by the above-cited "Hydrogenation of Naphthalene and Coal Tar Distillate over Ni/Mo/Al2O3 Catalyst; Abhijit Bhagavatula; West Virginia University", wherein the final, end products of such similar Coal hydrogenation, and subsequent refining, can include "liquid fuels such as gasoline, diesel (and) kerosene", we can, we are convinced, safely assume that such would be the end products towards which the energy self-sufficient process of our subject, "United States Patent 4,468,315 - Hydrogenation of Coal", is directed.
And, that assumption, we assure you, will be confirmed via reports in process, wherein closely similar direct Coal hydrogenation technologies - - enabled by other technologies like that described in our report concerning "United States Patent Application 20120149789 - Apparatus and Methods for the Electrolysis of Water", which make possible the efficient and economical supply of elemental, molecular Hydrogen - - have been developed and established by major constituents of the international petroleum industry, i.e.: Big Oil.
