As in many of our examples of Coal liquefaction art, the Japanese inventors named in this United States Patent, for an improved process of indirect Coal liquefaction, don't really talk about Coal all that much.
They reveal only the details of an improved process for converting "the synthesis gas" into liquid hydrocarbons, and don't, until their exposition of Background, reveal where "the synthesis gas" comes from.
Some advance excerpts from that Background section, which won't be repeated in our fuller excerpts, should help to clarify for you their intent, as in:
"The surroundings of petroleum playing the leading part of energy at present are very unstable and it has been feared that a "valley" of energy will come in the last half of 1980s to the 1990s due to deficiency of petroleum. To this end, it is required to ... use an alternative energy for petroleum such as coal ... .
In particular, it has lately been watched with keen interest to develop the technique of C1 -chemistry to make up for the short supply of gasoline, kerosene and gas oil which demands will relatively be expanded by producing from other carbon sources than petroleum, e.g. coal ... which can be found in abundance ... .
Methods of producing hydrocarbons from coal can be classified mainly into two methods: direct method by liquefaction of coal and indirect method through the synthesis gas ... (and, the) indirect method, which has already been put to practical use by SASOL in South Africa, consists in a method of converting a carbon source into hydrocarbons by making carbon monoxide and hydrogen in the presence of air, oxygen or steam and reacting in the presence of a Fischer-Tropsch catalyst."
And, this group of Japanese scientists, as we read it, took the Coal liquefaction method already, by 1986, in "practical use ... in South Africa", and made it a little better by tweaking the catalysts.
Summary comment follows more extended excerpts from:
"United States Patent 4,622,308 - Production of Hydrocarbons from the Synthesis Gas
Date: November, 1986
Inventor: Minoru Koikeda, et. al., Japan
Assignee: Research Association for Petroleum Alternatives Development
Abstract: An improved catalyst suitable for use in the production of hydrocarbons from the synthesis gas comprises an iron-containing Fischer-Tropsch catalyst, a zeolite and at least one metal selected from the group consisting of ruthenium, rhodium, platinum, palladium, iridium, cobalt and molybdenum. This catalyst gives a high CO conversion and hydrocarbons enriched with ... gasoline fraction.
Claims: A catalyst for the production of hydrocarbons from the synthesis gas, which comprises the combination of an iron-containing Fischer-Tropsch catalyst, a zeolite and at least one metal selected from the group consisting of ruthenium, rhodium, platinum, palladium, iridium, cobalt and molybdenum, said metal being supported upon the iron-containing Fischer-Tropsch catalyst or supported upon a mixture of the iron-containing Fischer-Tropsch catalyst and the zeolite ... .
A process for the production of a catalyst, which comprises mixing intimately a high silica zeolite with a Fischer-Tropsch catalyst and then impregnating the mixture with a solution containing at least one metal salt selected from the group consisting of salts of ruthenium, rhodium, platinum, palladium, iridium, cobalt and molybdenum.
Background and Field: This invention relates to a process for the production of hydrocarbons having a high quality and a boiling point range of gasoline from mixed gases of carbon monoxide and hydrogen ... .
(The) Fischer-Tropsch process is known as a process for producing hydrocarbon mixtures from the synthesis gas in the presence of a catalyst based on iron, cobalt, nickel, ruthenium, thorium and rhodium. However, the use of this catalyst results in reaction products of hydrocarbons including paraffins and olefins, distributed widely from methane to wax, and of various oxygen-containing compounds including alcohols and ethers and thus it is impossible to obtain selectively valuable products with a specified boiling point range. That is, the yield of the most valuable gasoline fraction is not sufficient and the gasoline fraction is not usable as motor gasoline as it is and should be modified, for example, by catalytic reforming, since it contains little aromatic hydrocarbons or highly branched parrafins or olefins and has low octane number.
Iron catalysts used on a commercial scale as a Fischer-Tropsch catalyst comprise a precipitated catalyst and fused catalyst, to which copper or potassium is added to raise the selectively thereof. These catalysts are effective for increasing waxes in the product, but do not serve to increase the yield of gasoline fraction and the octane number. On the other hand, ruthenium catalysts are excellent in the formation of high molecular weight waxes, but give only a low conversion of carbon monoxide ... and produce liquid hydrocarbons enriched with n-paraffins whose estimation as gasoline is low. In addition, rhodium is known as a noble metal effective for the Fischer-Tropsch synthesis, but it results in a product consisting predominantly of oxygen-containing compounds in spite of its high activity. ... Nickel is a methanation catalyst rather than the Fischer-Tropsch catalyst, since it has a very high conversion activity of carbon monoxide, but the resulting hydrocarbon is substantially methane.
(Gosh, darn, some folks out there know quite a lot of detail about how Coal can get converted into Gasoline and other useful things, like Methane. Too bad none of them seem to reside in the Ohio Valley.
Moreover, a two-stage process is known wherein the synthesis gas is contacted with a carbon monoxide reducing catalyst and the product is then contacted with a high silica zeolite catalyst of specified type charged in a same or different reactor, thus converting the synthesis gas into hydrocarbons containing mainly gasoline fraction with high octane number.
The two-stage conversion process consists in producing gasoline fraction having high octane number in a high yield by converting once the synthesis gas into oxygen-containing compounds in the case of the methanol synthesis catalyst or converting the synthesis gas into hydrocarbons distributed widely from methane to waxes and oxygen-containing compounds in the case of the Fischer-Tropsch synthesis catalyst, and thereafter, contacting these products with a zeolite catalyst having a specified pore diameter.
Of late, processes for producing selectively hydrocarbons with a specified boiling point range from the synthesis gas by one stage have been found ... .
Summary: It is an object of the present invention to provide a catalyst for the production of hydrocarbons from the synthesis gas (and, to) provide an improved catalyst of Fischer-Tropsch type.
It is a further object of the present invention to provide a process for the production of hydrocarbons from the synthesis gas using an improved catalyst of Fischer-Tropsch type.
These objects can be attained by a catalyst for the production of hydrocarbons from the synthesis gas, which comprises an iron-containing Fischer-Tropsch, catalyst, a zeolite and at least one metal selected from the group consisting of ruthenium, rhodium, platinum, palladium, iridium, cobalt and molybdenum, and by a process for the production of hydrocarbons from the synthesis gas using the catalyst.
We, the inventors, have ... found that gasoline fraction with high octane number can be obtained from the synthesis gas in a high yield ... (and, our) present invention is based on this finding.
The synthesis gas used a feed gas in the process of the present invention can suitably be prepared by subjecting a carbon source such as coal ... to the prior art gasification technique ... ."
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In sum, more than two decades ago, our United States Government, via the Patent Office, confirmed that they had, in Japan, developed a way to produce a liquid fuel "with high octane number (and) in a high yield" from a "synthesis gas ... prepared by subjecting ... coal ... to the prior art gasification".
And, Japan achieved that by building on a Coal conversion technology base that had, more than two decades ago, "already been put to practical use by SASOL in South Africa".
Why do we remain ignorant of all of that in the Coal Country of the United States of America?