摘要 |
Hydrocarbons may be recovered from crushed oil shale by contacting the coarsely crushed oil shale material with a hydrogen doner solvent such as tetralin, alone or in combination with high pressure gaseous hydrogen for a period of time sufficient to cause disintegration of the oil shale lumps, after which the pretreated material is introduced into a vessel containing a free oxygen containing gas such as air in a fluid environment at a temperature range from 30 DEG to 43 DEG C. to remove organic fragments from the polymeric kerogen component of oil shale by oxidative scissions. The oxidation is conducted using a liquid phase solvent for the organic fractions removed from the kerogen. Preferred solvents are naphthalene, tetralin and phenanthracene. The solvent-organic fraction solution is then separated into solvent and organic fraction by sublimation with the solvent being recycled. The residual solids comprising oil shale material and unoxidized kerogen is then subjected to a bake-off to recover additional organic material from the kerogen. In addition to recovering a portion of the organic content from the kerogen, the oxidative scission reaction increases the susceptibility of the kerogen to recovery by pyrolysis under milder conditions than the unoxidized oil shale material. The pyrolysis is conducted at a temperature from 400 DEG F. to 750 DEG F. for a time period up to 2 hours.
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