We earlier sent you information concerning the extensive library of Coal conversion technology documents developed and maintained by our United States Department of Defense.
Presuming you to have received that dispatch, we remind you that many of those documents appear to have resulted from work contracted by our Government, and were focused on the detailed mechanical specifics of Coal liquefaction processing equipment; with some of them making note, especially, of "corrosion" problems encountered in some components of that equipment during operation.
Herein, we see that a once-major US industrial manufacturer applied themselves to resolving such problems.
Comment follows excerpts from the above link to:
"United States Patent 4,327,058 - Capillary Processing Unit
Date: April, 1982
Inventor: John Tillinghast, NH
Assignee: Wheelabrator-Frye, Incorporated, NH
Abstract: A system for the manufacture of synthetic hydrocarbon products from coal or similar carbonaceous solids is described. This coal liquefaction system includes means for reducing the pressure of high pressure and temperature liquid reaction product streams without attendant corrosion of the metal parts in the pressure reducing unit. The pressure reducing means comprises at least one elongated tube defining relatively narrow fluid flow passage, the reduction in pressure being effected substantially entirely by friction of the fluid within the tube.
Background and Field: This invention relates to the manufacture of synthetic hydrocarbon products from coal and similar carbonaceous solids and is particularly concerned with overcoming corrosion problems of the pressure reducing systems used in these processes."
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Further excerpts seem unnecessary.
The point is: Coal liquefaction technology is so real and so practical that, three decades ago, industrial equipment manufacturers, expecting a need for sophisticated and efficient Coal liquefaction processing equipment, applied themselves to resolving such mechanical minutiae as "overcoming corrosion problems" in "pressure reducing systems used in" Coal conversion industrial facilities.
But, since none of these Coal conversion industrial processing improvements has, as far as we know, been subsequently reduced to commercial practice in the United States, we must ask:
What, in that past almost thirty years, has changed, except that the price of natural petroleum has continued to increase, while, as we documented in an earlier report, the cost of Coal, in real terms, has actually decreased?