Abstract: Recovering hydrocarbons from oil shale can include injecting a heated working fluid into a first vessel containing particulate oil shale in a pyrolysis mode. The heated working fluid can have a temperature above a production temperature to pyrolyze kerogen in a stationary bed of the oil shale at or above the production temperature. An effluent can concurrently flow out of the first vessel to be injected into a second vessel in preheating mode. The second vessel containing particulate oil shale has an average temperature below the production temperature so as to capture heat from the effluent sufficient to increase the average temperature of the particulate oil shale and to condense condensable hydrocarbon product while also removing entrained mineral fines mists of condensed hydrocarbons from the effluent. Liquid hydrocarbons can concurrently be collected from the first vessel and/or the second vessel.

Abstract: Recovering hydrocarbons from oil shale can include injecting a heated working fluid into a first vessel containing particulate oil shale in a pyrolysis mode. The heated working fluid can have a temperature above a production temperature to pyrolyze kerogen in a stationary bed of the oil shale at or above the production temperature. An effluent can concurrently flow out of the first vessel to be injected into a second vessel in preheating mode. The second vessel containing particulate oil shale has an average temperature below the production temperature so as to capture heat from the effluent sufficient to increase the average temperature of the particulate oil shale and to condense condensable hydrocarbon product while also removing entrained mineral fines mists of condensed hydrocarbons from the effluent. Liquid hydrocarbons can concurrently be collected from the first vessel and/or the second vessel.