Process for recovery of hydrocarbon oil from shale

Claim 1

IN THE CONTINUOUS PROCESS OF RECOVERING HYDROCARBON OIL FROM OIL-BEARING MINERALS BY DISTILLING SAID MINERALS IN A FLUIDIZED BED OF SOLIDS MAINTAINED IN A DISTILLATION ZONE, WITHDRAWING SPENT SOLID RESIDUE, BURNING WITHDRAWN RESIDUE WITH A COMBUSTION-SUPPORTING GAS IN A FLUIDIZED BED MAINTAINED IN A COMBUSTION ZONE, AND RETURNING HEATED RESIDUE FROM SAID COMBUSTION ZONE TO SAID DISTILLATION ZONE TO SUPPLY HEAT TO THE LATTER, THE IMPROVEMENT WHICH COMPRISES PREHEATING SAID COMBUSTION-SUPPORTING GAS IN DIRECT CONTACT WITH HOT FLUIDIZED SOLID DISTILLATION RESIDUE WITHDRAWN FROM SAID DISTILLATION ZONE, CARRYING OUT SAID BURNING IN TWO SEPARATE SUPERIMPOSED FLUID BEDS WITHIN SAID COMBUSTION ZONE, CARRYING A LIQUID BY HEAT EXCHANGE WITH THE UPPER ONE OF SAID SUPERIMPOSED BED, WITHDRAWING ALL OF TIALLY ALL THE HEAT GENERATED IN THE LOWER ONE OF SAID SUPERIMPOSED BEDS TO THE MATERIALS FORMING SAID LOWER SUPERIMPOSED BED, WITHDRAWING ALL OF SAID RETURNING HEATED RESIDUE FROM SAID LOWER SUPERIMPOSED BED, COOLING THE VOLATILE EFFLUENT OF SAID DISTILLATION ZONE JUST SUFFICIENT TO CONDENSE A HEAVY OIL FRACTION, MIXING AND RETURNING HEATED RESIDUE WITH SAID MINERALS AND SAID CONDENSED OIL FRACTION OUTSIDE SAID ZONES TO VAPORIZE SAID OIL FRACTION AND TO FORM A DILUTE SOLIDS-IN-GAS SUSPENSION, AND PASSING THE SUSPENSION SO FORMED TO SAID DISTILLATION ZONE.