Fluid catalytic cracking of hydrocarbons

Claim 1

IN A CONTINUOUS PROCESS FOR CRACKING A HYDROCARBON CHARGE STREAM COMPRISING FRESH FEED AND RECYCLE OIL IN THE PRESENCE OF SUBDIVIDED CATALYST PARTICLES, WHEREIN THE HYDROCARBON STREAM IS SUBJECTED TO A FLUIDIZED CONVERSION OF THE PARTICLES IN A CONFINED REACTION ZONE, CONVERSION PRODUCTS ARE SEPARATED FROM THE CONTACTED PARTICLES, SEPARATED CATALYST PARTICLES CONTAINING A COKE DEPOSIT ARE SUBJECTED TO A FLUIDIZED CONTACTING OF AN OXYGENCONTAINING STREAM IN A SEPARATE CONFINED REGENERATION ZONE, COMBUSTION GAS PRODUCTS ARE SEPARTED FROM REGENERATED CATALYST PARTICLES AND SUCH REGENERATED CATALYST PARTICLES WITH A REDUCED COKE CONTENT ARE RETURNED TO THE REACTION ZONE FOR CONTACT WITH THE HYDROCARBON CHARGE STREAM, THE IMPROVED METHOD OF EFFECTING IMPROVED PRODUCT YIELDS FROM THE HYDROCARBON CHARGE STREAM BY OPERATING TO PROVIDE A HIGH TEMPERATURE LEVEL IN THE REGENERATION ZONE WHICH COMPRISES, INCREASING THE COMBINED FEED RATIO WITH AN INCREASE IN THE HEAVY RECYCLE OIL CONTENT OF THE CHARGE STREAM BEING INTRODUCED TO THE REACTION ZONE, EFFECTING BOTH A GREATER CONVERSION IN SAID REACTION ZONE AND AN INCREASED COKE DEPOSITION LEVEL ON THE CATALYST PARTICLES SUFFICIENT TO PROVIDE A TEMPERATURE ABOVE 1150*F. IN THE REGENERATION ZONE WHEN OXIDIZING THE COKE ON THE CATALYST PARTICLES IN THE PRESENCE OF A CONTROLLED OXYGEN CONTAINING STREAM INTRODUCED TO SUCH REGENERATION ZONE, AND REGULATING THE INTRODUCTION OF THE OXYGEN CONTAINING STREAM TO THE REGENERATION ZONE DIRECTLY RESPONSIVE TO A PREDETERMINED TEMPERATURE DIFFERENTIAL BETWEEN THE GAS OUTLET SECTION AND THE CATLYST CONTACTING SECTION OF THE REGENERATION ZONE TO MINIMIZE EXCESS OXYGEN THEREIN AND TO CONTROL AFTERBURNING IN THE UPPER PORTION OF THE REGENERATING ZONE.