Process and apparatus for the catalytic cracking of hydrocarbons

Claim 1

IN A PROCESS FOR THE CATALYTIC CRACKING OF HYDROCARBONS IN A FIRST ZONE FLUIDIZED LAYER OF A CATALYST WITH SIMULTANEOUS REGENERATION OF SAID CATALYST IN A SECOND ZONE FLUIDIZED LAYER TO REMOVE CARBON DEPOSITS WHICH HAVE ACCUMULATED ON THE CATALYST DURING CRACKING, THE CATALYST BEING IN FLOWING COMMUNICATION AND CONTINUOUS EXCHANGE BETWEEN SAID FIRST AND SECOND ZONES, THE IMPROVEMENT WHICH COMPRISES: REGENERATING SAID CATALYST IN A VERTICAL COLUMNAR REGENERATION ZONE OF A SUFFICIENT HEIGHT TOGETHER WITH THE SPEED OF A FLUIDIZING OXYGEN-CONTAINING GAS INTRODUCED AT THE BOTTOM OF SAID REGENERATION ZONE SUCH THAT THE OXYGEN IS PRACTICALLY COMPLETELY CONSUMED AT THE TOP OF SAID REGENERATION ZONE, AND INTRODUCING HYDROCARBON VAPORS FOR CRACKING UPWARDLY IN A SEPARATE VERTICAL COLUMNAR CRACKING ZONE LOCATED AT LEAST PARTLY ABOVE ABOVE SAID REGENERATION ZONE SUCH THAT THE FLUIDIZED CATALYST IS IN FLOWING COMMUNICATION AND CONTINUOUS EXCHANGE BETWEEN SAID TWO ZONES ONLY AT THE TOP OF SAID REGENERATION ZONE, SAID TWO ZONES FORMING TOGETHER A SINGLE DENSE PHASE FLUIDIZED LAYER OF CATALYST WITH A SINGLE TOP SURFACE, THE TOP OF SAID REGENERATION ZONE BEING AT A SUFFICIENT DISTANCE BELOW SAID TOP SURFACE OF THE FLUIDIZED LAYER FOR EXCHANGE OF CATALYST PARTICLES BETWEEN SAID TWO ZONES.