Patent US3841991
We continue our roughly chronological documentation of Esso/Exxon's development of Coal liquefaction technologies, with this submission, from 1974.
In it, Exxon discloses, and our United States Government, as embodied in the Patent Office, affirms, that Coal can be converted into liquid hydrocarbons by using a solvent and certain compounds needed for hydrogenation, all of which are derived from Coal itself.
Comment follows excerpts from:
"US Patent 3,841,991 - Coal Conversion Process
Date: October, 1974
Inventor: Saul Cohen, NJ, et. al.
Assignee: Esso Research and Engineering
Abstract: A process for the preparation of liquid products from coal wherein finely divided coal particles are slurried in a hydrogen-rich liquid hydrocarbon solvent at low temperature and substantially atmospheric pressure and the resulting slurry is passed into a fluid bed coking unit where conversion of the coal, solids separation, and thermal cracking of a heavy product take place simultaneously. ... a portion of the product is recycled for use as coal solvent.
Background: This invention relates to the manufacture of liquid hydrocarbons from coal. There is substantial interest in the development of processes for the manufacture of synthetic crude oils and liquid hydrocarbons from coal.
This invention has numerous advantages over conventional coal liquefaction processes (which result in) savings in plant investment and operating costs.
Summary: This invention provides an improved process for the manufacture of liquid hydrocarbons from coal which ... permits conversion of the coal at relatively low cost.
Moreover ... the molecular hydrogen which is generally needed ... is not necessary."
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In essence, both the solvent needed to first liquefy Coal, and the Hydrogen needed to hydrogenate the resulting product, in order to make "synthetic crude oils and liquid hydrocarbons", are obtained from within the Coal conversion process itself.
And, as we have elsewhere and earlier documented, all of the energy needed for such Coal conversion can, as well, be produced from Coal.
