The Devonian oil shales of the eastern United States constitute one of the nation's major energy resources. New process technology applicable to these shales increases the percentage

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of organic carbon extracted thereby doubling the yield of oil per ton. The process uses hydrogen at temperatures of 500 to 730°C and pressures of 20 to 50 atm. Experimental work in equipment capable of processing up to one ton of shale per hour has confirmed the technical and economic feasibility of above-ground hydroretorting of Devonian oil shales. Investigation of more than 550 samples from some 150 locations in 13 states indicates that IGT's HYTORT^TM process can give organic carbon recoveries from 2 to 2.5 times those of conventional retorting, resulting in yields of 25 to 30 gal/ton at many localities, compared with 10 to 15 gal/ton using Fischer Assay.

Resource estimates are based on above-ground hydroretorting and four criteria: overburden less than 200 ft (59 m), stripping ratio less than 2.5 to 1, shale thickness of 10 ft (3 m) or more, and organic carbon at least 10% by weight. Resource estimates include: Kentucky 190 billion bbl, Ohio 140 billion bbl, Tennessee 44 billion bbl, Indiana 40 billion bbl, Michigan 5 billion bbl, and Alabama 4 billion bbl. Seven other states have been sampled but recoverable resources were not identified. The total recoverable resource exceeds 440 billion bbl of synthetic oil if all near-surface shales of more quality were mined for above-ground hydroretorting.

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