United States Patent: 3764515
We have previously reported on Consolidation Coal Company's development, in their Pennsylvania laboratories, of the "Zinc Chloride Process" for liquefying Coal into hydrocarbon fuels; and, on the later patenting of a "Zinc Halide" Coal liquefaction process by Consol's new parent, Continental Oil Company, Conoco.
Herein, we see that they were not the only ones to discover how Zinc Halides could be employed to effectively and efficiently convert Coal into liquid hydrocarbons.
Comment follows excerpts from:
"United States Patent 3,764,515 - Process for Hydrocracking Heavy Hydrocarbons
Date: October, 1973
Inventor: Thomas Kiovsky, CA
Assignee: Shell Oil Company, NY
Abstract: There is disclosed a process for hydrocracking coal or other heavy hydrocarbon fractions employing a molten catalyst system, including a mineral acid that is stable at reaction conditions, and a metal halide catalyst selected from zinc chloride, bromide or iodide, antimony bromide or iodide, tin bromide, titanium iodide, arsenic bromide or iodide, mercuric bromide or iodide, gallium bromide, or bismuth bromide. If a halogen acid is employed as the mineral acid, it is preferred that the halogen in the metal salt correspond to the halogen in the acid.
Claims: (A) process for hydrocracking heavy hydrocarbons which comprises contacting the heavy hydrocarbons, at hydrocracking conditions under hydrogen pressure, with a molten metal halide catalyst system selected from the group consisting of zinc chloride, zinc bromide, zinc iodide, antimony bromide, antimony iodide, tin bromide, titanium iodide, arsenic bromide, arsenic iodide, mercuric bromide, mercuric iodide, gallium bromide and bismuth bromide, the improvement which comprises promoting the activity of said catalyst system by adding thereto a mineral acid that is stable at hydrocracking conditions.
Description: Extremely heavy hydrocarbon fractions, (such) as coal, ... have ... problems (in processing) to make lower boiling and more valuable materials from them. The heavy hydrocarbons are hydrogen deficient, that is, they contain proportionately less combined hydrogen than lower boiling hydrocarbon fractions. Accordingly, in order to process such hydrocarbons into lower boiling hydrocarbons it is necessary to provide hydrogen and both hydrogenating and cracking conditions. Coal ... (also contains) ingredients that are catalyst poisons, particularly poisons for the catalysts that are required for hydrocracking. Heteroatomic oxygen, sulfur and nitrogen in coal, for example, seriously affect the usual supported metal hydrogenating catalysts ... . Additionally, conditions under which cracking and hydrogenation of coal ... can be accomplished generally are such that the processes cannot be performed economically and are therefore unable to compete successfully with lower cost sources of hydrocarbons such as the distillate fractions of a crude oil.
Recently metal halide catalysts have been found that are both active enough and stable enough to be employed in hydrocracking coal ... .
The promoted catalyst systems of this invention are so active that hydrocracking (of Coal) can be accomplished at low temperatures and pressures whereby a very desirable product distribution is obtained. A desirable product distribution is one that contains large amounts of liquid hydrocarbons boiling in the gasoline range or higher ... ."
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We close our excerpts here, since, as in many similar Coal conversion technology patents we've brought to your attention, the full technical explanations are beyond our scope of reportage.
However, Shell Oil does note that mineral acids can be used in such a way as to enhance and improve the production of hydrocarbons from Coal in their Zinc Halide process; and, one of the performance-enhancing acids they specify is Sulfuric Acid.
You don't imagine that we would be able to make any Sulfuric Acid as a Coal-use byproduct, do you?
In any case, very nearly forty years ago, as herein, the petroleum industry and our United States Government confirmed that we could make "large amounts of liquid hydrocarbons boiling in the gasoline range" from Coal.