Process for distilling and liquefying coal
Since we are, today, via separate dispatch, sending along report of multiple Coal liquefaction technologies developed by Chevron, in California, as disclosed by: "US Patent 4,350,582 - Two-Stage Coal Liquefaction Process with Process-Derived Solvent" and "US Patent 4,358,359 - Two-Stage Coal Liquefaction Process", we wanted herein to more fully explain an earlier Coal liquefaction process that is specifically cited as prior art by those Chevron inventions.
The "Bergius Process", as in a few of our previous reports, was a Coal conversion technology developed by one Friedrich Bergius, of Heidelberg, Germany, in the decade following World War I.
So apparently successful was the Bergius process - developed, it seems, somewhat prior to the much better-known Fischer-Tropsch Coal conversion technology - that Bergius was, as we once reported a few years ago, awarded the 1931 Nobel Prize in Chemistry, for having developed specific chemical processing techniques which he intended for employment in his process of Coal liquefaction.
More information concerning those facts can be gained via:
Friedrich Bergius - Wikipedia, the free encyclopedia; wherein we see that:
"Friedrich Bergius (1884 - 1949) was a German chemist known for the Bergius process for producing synthetic fuel from coal (and was awarded the) Nobel Prize in Chemistry (1931) ... in recognition of contributions to the invention and development of chemical high-pressure methods.
(He developed) techniques for the high-pressure and high-temperature chemistry of carbon-containing substrates ... (resulting in) a patent on the Bergius process in 1913. In this process liquid hydrocarbons used as synthetic fuel are produced by hydrogenation of lignite (brown coal)."
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The 1913 patent noted above by the Wikipedia was, we believe, the original German patent issued to Bergius for his Coal liquefaction process.
It was followed, a decade and half later, by a United States Patent wherein the same, or closely similar, Coal conversion technology was disclosed.
As seen in our excerpts from the initial link in this dispatch to:
"United States Patent 1,669,439 - Process for Distilling and Liquefying Coal
Date: May, 1928
Inventor: Friedrich Bergius, of Heidelberg, Germany
Abstract: This invention relates to improvements in a correlated process for distilling and liquefying coal.
In liquefying coal by hydrogenation under great pressure and at elevated temperatures (for instance by means of the Bergin-process) large quantities of hydrogen are necessary for the hydrogenation as well as large quantities of oil for transforming the pulverized coal into a paste and for its own hydrogenation.
(Note, above, mention of yet another Coal conversion technology, "the Bergin-process", with which, we confess, we are unfamiliar. But, note as well that Bergius intends to deal with a modern-day objection that has been raised against Coal liquefaction; i.e., that "large quantities of hydrogen", with it's attendant expense, "are necessary". In early confirmation of later sources, we have already documented for you, Bergius, herein, in the course of his Disclosure, refutes that contention.)
On the other hand the Bergin-process furnishes as by-product a rich gas (Bergin-gas) whose ... quantity is ordinarily too small that it might serve for providing towns with gas.
(We call to your recollection our earlier reports of a "town gas", or "producer gas", i.e., a synthetic natural gas, for residential and commercial heating and lighting purposes, being generated from Coal in a number of US cities in the latter 1800's and earlier 1900's.)
The present invention has for its purpose to care for the great quantities of hydrogen and oil necessary for the treatment in the high-pressure vessel of the Bergin-plant in an efficient and economical manner as well as advantageously to utilize the Bergin-gas escaping from the high-pressure vessel of the Bergin-plant.
The purpose of the invention are obtained by producing the gas necessary for the hydrogenation ... from a gas plant or a coke-oven-plant (coal gas retorts) whereas the Bergin-gas of high heating power is added to the gas produced in the coal-gas-retorts (distillation-gas).
(In other words, high-heating power "Bergin-gas", itself generated from Coal, is added to, essentially, Coke oven gas, as described and explained in earlier of our reports, to form a mixed gas that can be utilized in "the hydrogenation" or more Coal.)
For the further supply of the Bergin-plant from the coal-gas-retorts, towards the end of the distilling period steam is introduced into the distilling chambers for forming water-gas which is transformed into hydrogen (hydrogenating gas) in a known manner.
(Once again, we see that a Coal conversion process, through an integral process for the dissociation of Steam, can provide all of the Hydrogen needed to hydrogenate the Carbon in the Coal.)
The tar produced in the coal-gas-retorts may participate in forming the coal paste for the high pressure vessel of the Bergin plant.
(Again, we have many times documented that primary Coal tars, or Coal oils, as can be generated in Coke ovens, can be utilized to form "pastes" or "slurries" with raw Coal, prior to gasification.)
If the coal-gas-retorts should not provide sufficient hydrogen, the remainder may be produced from the coke residue in the coal-gas-retorts, the coke being treated with steam for producing water-gas in the coking chamber or in a special generator as commonly known.
(Not so "commonly known" in US Coal Country, sadly, is the fact that needed Hydrogen can be generated, as above, via the Steam-gasification of still-carbonaceous Coal processing residues.)
(The) distilling process in the coal-gas-retorts may be conducted in such a manner that more or less quantities of tar are produced. The quantity of tar can be increased by the low-temperature-coking-process.
(It sounds a lot, to us, like the 1920's-era Low Temperature Carbonization process developed by Lewis Karrick, as we have earlier reported, at the US Bureau of Mines. And, keep in mind that the "tar" is utilized in the formation of the initial "coal paste".)
The combination of the Bergin-plant with the coal-gas-retorts gives the possibility of suitably utilizing different kinds of coal ... (and) affords the possibility of economically utilizing different kinds of coal.
Claims: Process which comprises subjecting coal to distillation treatment whereby there are produced ammonia, coke, tar, a gaseous fraction relatively poor in hydrogen but of high heating value and a gaseous fraction relatively rich in hydrogen, admixing the said tar with coal and subjecting the mixture to liquefaction and hydrogenation treatment with the gaseous fraction relatively rich in hydrogen at elevated temperature and under great pressure whereby there are produced ammonia, oil, and a gas of high heating value, combining the gas of high heating value with said gaseous fraction relatively poor in hydrogen, and separately recovering the said oil."
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So, it seems that multiple Coal distillation and gasification procedures are required for the Bergius process.
One of them can be made to produce a gas "fraction relatively rich in hydrogen", which we will presume to be similar to, or the same as, "water gas", which has been described in earlier of our reports; and, another gas that is "relatively poor in hydrogen", which we must presume to be mostly a blend of Carbon oxides, perhaps Carbon Monoxide primarily, whose utility in Coal gasification, and in productive reactions with Water, we have previously documented.
In any case, as above, "all of the gas necessary for the hydrogenation" comes from "a coke-oven-plant"; or, from, as specified, "a special", we presume to be Water Gas, "generator as commonly known".
Coal "tar" is also generated during the distillation processes; and, it is blended back into more raw Coal for further gasification with a blend made from the generated gases; with the end result being more processing gases, and "oil".
Our take on the whole thing is that, as the process goes on, you might wind up with a surplus of gas; which is not necessarily a bad thing. Excess gas could be recycled internally for process heating purposes; or, perhaps, if compositionally-suited, directed into a Fischer-Tropsch, or similar, catalytic processor for condensation into various hydrocarbon liquids.
In any case, we have herein an early Coal conversion technology, based on Nobel Prize-winning chemical processing innovations, that was used, more than half a century later, as in our separate report noted above concerning Chevron, as the basis for Coal liquefaction processes developed by a modern component of the international petroleum industry.