Process for suppressing carbonate decomposition in vapor phase water retorting
AssigneeMarathon Oil Company
InventorVictor D. Allred
Life of this patent
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Abstract
Oil shale containing relatively large quantities of alkaline carbonate minerals is retorted utilizing superheated water vapor at temperatures of from about 425.degree. C. to about 510.degree. C. Retorting with a sufficient carbon dioxide partial pressure effectively suppresses decomposition of the alkaline carbonates to obtain an environmentally acceptable retorted shale.
Claims7
In a process for the recovery of organic values from oil shale containing alkaline metal carbonates by contacting said oil shale with superheated water vapor in a retort wherein the recovery of said hydrocarbon values is enhanced by contacting particles of said oil shale with said superheated water vapor at a superficial gas velocity of at least 10 cm per second and at a pressure in the range of from about 6.9 to about 1,034 kPaa and by providing said contact with said superheated water vapor at a temperature of from about 425.degree. C. to about 510.degree. C. to produce an effluent stream comprising superheated water vapor, hydrocarbon vapors, hydrogen, and carbon oxides, the improvement comprising:
- providing a carbon dioxide partial pressure during said contacting which is sufficient to effectively suppress thermal decomposition of said carbonates to oxides.
Dependencies are inferred from the claim text.