Hydrocarbon synthesis process with two-stage coke gasification

Claim 1

AN IMPROVED PROCESS FOR THE CATALYST SYNTHESIS OF HYDROCARBONS FROM CO AND H2 WHICH COMPRISES PASSING STEAM AND CARBONACEOUS SOLIDS TO AN INITIAL GASIFICATION STAGE, CARRYING OUT A WATER GAS REACTION IN SAID STAGE, PASSING WATER GAS WHEREIN THE H2 TO CO RATIO IS AT LEAST 1.0 TO AN INITIAL HYDROCARBON SYNTHESIS REACTION ZONE, MAINTAINING A FLUIDIZED BED OF IRON-CONTAINING SYNTHESIS CATALYST AND HYDROCARBON SYNTHESIS CONDITIONS IN SAID ZONE, WITHDRAWING FROM SAID ZONE A TAIL GAS COMPRISING CO2 AND HAVING A HIGHER H2/CO RATIO THAN SAID FEED GAS TO SAID ZONE, PASSING AT LEAST A PORTION OF SAID TAIL GAS TO A SECOND STAGE HYDROCARBON SYNTHESIS REACTION ZONE, PASSING PARTIALLY SPENT CARBONACEOUS SOLIDS OF RELATIVELY LOW CARBON CONTENT FROM SAID PRIMARY GASIFICATION ZONE TO A SECOND GASIFICATION ZONE, PASSING STEAM, CO2, AND A FREE OXYGEN CONTAINING GAS TO SAID LAST-NAMED ZONE, MAINTAINING WATER GAS GENERATION CONDITIONS IN SAID LASTNAMED ZONE TO GIVE A RELATIVELY HIGH STEAM CONVERSION, CONVERTING AT LEAST A PORTION OF SAID CO2 TO CO, WITHDRAWING FROM SAID SECOND GASIFICATION ZONE A GASEOUS MIXTURE COMPRISING H2 AND CO WHEREIN THE H2/CO RATIO IS LESS THAN UNITY, PASSING AT LEAST A PORTION OF SAID GAS MIXTURE TO SAID SECOND HYDROCARBON SYNTHESIS ZONE RESPONSIVE TO THE H2/CO RATIO OF SAID TAIL GAS FROM SAID FIRST HYDROCARBON SYNTHESIS REACTION ZONE TO PRODUCE A TOTAL GAS FEED TO SAID SECOND HYDROCARBON SYNTHESIS ZONE ADAPTED TO PRODUCE HIGH YIELDS OF HYDROCARBONS, AND MAINTAINING AN IRON-COMPRISING CATALYST IN SAID ZONE.