Shale retorting process

Claim 1

IN A PROCESS WHEREIN (1) OIL SHALE SOLIDS ARE PASSED UPWARDLY AND SUCCESSIVELY THROUGH A DISENGAGING ZONE, A SOLIDS PREHEATING ZONE AND AN EDUCTION ZONE, (2) A HOT EDUCTION GAS IS SIMULTANEOUSLY INTRODUCED INTO THE TOP OF SAID EDUCTION ZONE AND IS PASSED DOWNWARDLY AND SUCCESSIVELY THROUGH SAID EDUCTION ZONE, SAID SOLIDS PREHEATING ZONE AND SAID DISENGAGING ZONE IN DIRECT CONTACT WITH SAID SOLIDS, (3) WITHIN SAID EDUCTION ZONE SAID HOT EDUCTION GAS EDUCTS HYDROCARBON PRODUCTS FROM THE SAID SOLIDS THEREIN, (4) WITHIN SAID SOLIDS PREHEATING ZONE THE SAID SOLIDS THEREIN ARE PREHEATED BY HEAT EXCHANGE AGAINST SAID HYDROCARBON PRODUCTS AND SAID EDUCTION GAS, (5) WITHIN SAID DISENGAGING ZONE THE SAID HYDROCARBON PRODUCTS AND SAID EDUCTION GAS ARE SEPARATED FROM THE SAID SOLIDS THEREIN, (6) THE SAID SEPARATED HYDROCARBON PRODUCTS AND EDUCTION GAS ARE WITHDRAWN FROM SAID DISENGAGING ZONE AND INTRODUCED INTO A SEPARATION ZONE WHEREIN THE GAS PHASE IS SEPARATED FROM THE LIQUID PHASE, AND (7) SPENT SOLIDS ARE WITHDRAWN FROM THE TOP OF SAID EDUCTION ZONE AND ARE PASSED DOWNWARDLY THROUGH A SPENT SOLIDS COOLING ZONE, THE IMPROVEMENT WHICH CONSISTS IN WITHDRAWING THE GAS PHASE FROM SAID SEPARATION ZONE, INTRODUCING A FIRST PORTION OF SAID GAS PHASE INTO A COMBUSTION ZONE AND THEREIN BURNING SAID FIRST PORTION IN THE PRESENCE OF AN OXYGEN-CONTAINING GAS AND OUT OF CONTACT WITH SAID SOLIDS AND SAID SEPARATED LIQUID PHASE TO FORM A FIRST HOT RECYCLE GAS, INTRODUCING A SECOND PORTION OF SAID SEPARATED GAS PHASE INTO SAID SPENT SOLIDS COOLING ZONE AND PASSING SAID SECOND PORTION UPWARDLY THERETHROUGH IN DIRECT COUNTERCURRENT CONTACT WITH THE SPENT SOLIDS THEREIN, WHEREBY SAID SECOND PORTION IS HEATED BY HEAT EXCHANGE AGAINST SAID SPENT SOLIDS TO FORM A SECOND HOT RECYCLE GAS, AND INTRODUCING SAID FIRST AND SECOND HOT RECYCLE GASES INTO THE TOP OF SAID EDUCTION ZONE AS SAID HOT EDUCTION GAS, THE AMOUNT OF OXYGEN-CONTAINING GAS SUPPLIED TO SAID COMBUSTION ZONE BEING SUCH THAT SUBSTANTIALLY NO COKE COMBUSTION AND CARBONATE DECOMPOSITION OCCURS IN SAID EDUCTION ZONE AND THE FLOW RATES OF SAID FIRST AND SECOND RECYCLE GASES BEING CONTROLLED SO AS TO MAINTAIN AN EDUCTION TEMPERATURE WITHIN SAID EDUCTION ZONE.