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US 5,041,210 AGranted
Oil shale retorting with steam and produced gas
AssigneeMarathon Oil Company
InventorsLaVaun S. Merrill, Jr., Larry D. Wheaton
Life of this patent
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Abstract
A process for retorting oil shale in a vertical retort. Recycle gas containing steam and produced gas is separated from the retort off-gas and used to heat the oil shale. The steam is present in amount by volume of the recycle gas of at least 40% and preferably 70%. The minimum particle size of the oil shale is such that the particles are retained on a screen having 1/4 inch openings. The maximum particle size is such that the particles are capable of passing through a screen having 3 inch openings.
Claims11
A process for retorting oil shale in a vertical retort, comprising the steps of:
- introducing particles of oil shale into the retort, said particles of oil shale having a minimum size such that the particles are retained on a screen having openings 1/4 inch in size;
- contacting the particles of oil shale with hot gas to heat the particles of oil shale to a state of pyrolysis, thereby producing retort off-gas;
- removing the off-gas from the retort;
- cooling the off-gas;
- removing oil from the cooled off-gas;
- separating recycle gas from the off-gas, the recycle gas comprising steam and produced gas, the steam being present in amount, by volume, of at least 50% of the recycle gas so as to increase the yield of said oil;
- and
- heating the recycle gas to form said hot gas.
5 more elements
Dependencies are inferred from the claim text.