Method and apparatus for recovering shale oil from oil shale

Claim 1

A METHOD FOR RECOVERING SHALE OIL FROM OIL SHALE WHICH COMPRISES PERMITTING CRUSHED OIL SHALE TO GRAVITATE SUCCESSIVELY THROUGH A PREHEATING ZONE, A RETORTING ZONE, A COMBUSTION ZONE, AND AN AIR PREHEATING ZONE; CONTACTING SAID OIL SHALE IN DIRECT, CONCURRENT HEAT EXCHANGE RELATIONSHIP WITH HEATED VAPORIZED PREHEATING MEDIUM COMPRISING PRODUCT SHALE OIL VAPORS IN THE PREHEATING ZONE; CONTACTING PREHEATED OIL SHALE IN DIRECT, COUNTERCURRENT HEAT EXCHANGE RELATIONSHIP WITH HEATED VAPORIZED RETORTING MEDIUN COMPRISING PRODUCT SHALE OIL VAPORS IN THE RETORTING ZONE, WHEREBY SHALE OIL VAPORS ARE RELEASED FROM SAID OIL SHALE; WHITHDRAWING PRODUCT SHALE OIL VAPROS TOGETHER WITH SPENT PREHEATING MEDIUN AND RETORTING MEDIUM FROM THE UPPER PORTION OF THE RETORTING ZONE; SEPARATING THE PRODUCT SHALE OIL VAPORS INTO A RELATIVELY HIGHER BOILING FRACTION AND A RELATIVELY LOWER BOILING FRACTION; REMOVING SAID RELATIVELY LOWER BOILING FRACTION AS PRODUCT; HEATING SAID RELATIVELY LOWER BOILING FRACTION TO BY INDIRECT HEAT EXCHANGE AS HEREINAFTER DESCRIBED; RECYCLING THE HEATED RELATIVELY LOWER BOILING FRACTION TO THE PREHEATING AND THE RETORTING ZONES FOR CONTACT WITH FURTHER PORTIONS OF RAW OIL SHALE; CONTACTING WITH SHALE FROM THE RETORTING ZONE WITH PREHEATED AIR IN THE COMBUSTION ZONE TO OXIDIZE THE COMBUSTION MATERIAL ON THE SPENT SHALE; WITHDRAWING HOT COMBUSITION GASES FROM THE UPPER PORTION OF THE COMBUSTION ZONE; INTRODUCING A LIQUID HYDROCARBON HEAT TRANSFER MEDIUM AT ABOUT ITS VAPORIZATION TEMPERATURE INTO THE COMBUSTION ZONE IN INDIRECT HEAT EXCHANGE RELATIONSHIP WITH THE SPENT SHALE THEREIN, WHEREBY SAID LIQUID HYDROCARBON HEAT TRANSFER MEDIUM IS VAPORIZED; CONTACTING THE VAPORIZED HYDROCARBON HEAT TRANSFER MEDIUM IN INDIRECT HEAT EXCHANGE RAELATIONSHIP WITH SAID RELATIVELY LOWER BOILING SHALE OIL FRACTION WHEREBY SAID VAPORIZED HYDROCARBON HEAT TRANSFER MEDIUM IS CONDENSED AND SAID SHALE OIL FRACTION IS HEATED FOR RECIRCULATION TO THE PREHEATING AND THE RETORTING ZONE; RECYCLING THE CONDENSED HYDROCARBON HEAT TRANSFER MEDIUM TO THE COMBUSTION ZONE; DIRECTLY CONTACTING THE HOT SHALE ASH FROM THE COMBUSTION ZONE WITH THE AIR IN THE AIR PREHEATING ZONE, WHEREBY THE AIR IS PREHEATED FOR US IN THE COMBUSTION ZONE, AND REMOVING COOLED SHALE ASH FROM THE AIR PREHEATING ZONE.

Claim 2

A METHOD FOR RECOVERING SHALE OIL FROM OIL SHALE WHICH COMPRISES PERMITTING CRUSHED OIL SHALE TO GRAVITATE SUCCESSIVELY THROUGH A PREHEATING ZONE, A RETORTING ZONE, A COMBUSTION ZONE, AND AN AIR PREHEATING ZONE; CONTACTING SAID OIL SHALE IN DIRECT, CONCURRENT HEAT EXCHANGE RELATIONSHIP WITH HEATED VAPORIZED PREHEATING MEDIUM COMPRISING PRODUCT SHALE OIL VAPORS IN THE PREHEATING ZONE; CONTACTING PREHEATED OIL SHALE IN DIRECT, COUNTERCURRENT HEAT EXCHANGE RELATIONSHIP WITH HEATED VAPORIZED RETORTING MEDIUN COMPRISING PRODUCT SHALE OIL VAPORS IN THE RETORTING ZONE, WHEREBY SHALE OIL VAPORS ARE RELEASED FROM SAID OIL SHALE; WHITHDRAWING PRODUCT SHALE OIL VAPROS TOGETHER WITH SPENT PREHEATING MEDIUN AND RETORTING MEDIUM FROM THE UPPER PORTION OF THE RETORTING ZONE; SEPARATING THE PRODUCT SHALE OIL VAPORS INTO A RELATIVELY HIGHER BOILING FRACTION AND A RELATIVELY LOWER BOILING FRACTION; REMOVING SAID RELATIVELY LOWER BOILING FRACTION AS PRODUCT; HEATING SAID RELATIVELY LOWER BOILING FRACTION TO BY INDIRECT HEAT EXCHANGE AS HEREINAFTER DESCRIBED; RECYCLING THE HEATED RELATIVELY LOWER BOILING FRACTION TO THE PREHEATING AND THE RETORTING ZONES FOR CONTACT WITH FURTHER PORTIONS OF RAW OIL SHALE; CONTACTING WITH SHALE FROM THE RETORTING ZONE WITH PREHEATED AIR IN THE COMBUSTION ZONE TO OXIDIZE THE COMBUSTION MATERIAL ON THE SPENT SHALE; WITHDRAWING HOT COMBUSITION GASES FROM THE UPPER PORTION OF THE COMBUSTION ZONE; INTRODUCING A LIQUID HYDROCARBON HEAT TRANSFER MEDIUM AT ABOUT ITS VAPORIZATION TEMPERATURE INTO THE COMBUSTION ZONE IN INDIRECT HEAT EXCHANGE RELATIONSHIP WITH THE SPENT SHALE THEREIN, WHEREBY SAID LIQUID HYDROCARBON HEAT TRANSFER MEDIUM IS VAPORIZED; CONTACTING THE VAPORIZED HYDROCARBON HEAT TRANSFER MEDIUM IN INDIRECT HEAT EXCHANGE RAELATIONSHIP WITH SAID RELATIVELY LOWER BOILING SHALE OIL FRACTION WHEREBY SAID VAPORIZED HYDROCARBON HEAT TRANSFER MEDIUM IS CONDENSED AND SAID SHALE OIL FRACTION IS HEATED FOR RECIRCULATION TO THE PREHEATING AND THE RETORTING ZONE; RECYCLING THE CONDENSED HYDROCARBON HEAT TRANSFER MEDIUM TO THE COMBUSTION ZONE; DIRECTLY CONTACTING THE HOT SHALE ASH FROM THE COMBUSTION ZONE WITH THE AIR IN THE AIR PREHEATING ZONE, WHEREBY THE AIR IS PREHEATED FOR US IN THE COMBUSTION ZONE, AND REMOVING COOLED SHALE ASH FROM THE AIR PREHEATING ZONE.