Abstract A process conducted in a regeneration zone comprising a first dense bed, a dilute phase transport riser, and a second dense bed wherein coke-contaminated spent catalyst is regenerated to a controllable temperature independent of the residual coke on regenerated catalyst and CO thereby produced is essentially completely burned to CO2. Spent catalyst is regenerated in the first dense bed and passed through a dilute phase transport riser wherein CO and sufficient additional combustible fluid are combusted to heat the regenerated catalyst to the desired regenerated catalyst delivery temperature. By controlling the regenerated catalyst delivery temperature, the process allows the refiner to directly and conveniently control the degree of primary cracking of the feedstock in the reaction zone and thereby to easily and efficiently control the product yields and quality. At the same time combustion of CO within the regeneration zone substantially eliminates CO pollution of the atmosphere and recovers the heat of combustion without the need for a CO boiler which decreases feed preheat requirements. Higher velocities and higher oxygen concentrations employed in the process result in shorter catalyst and gas residence times, reduced catalyst inventory, lower catalyst makeup rate, improved regeneration, and improved catalyst stability.
A PROCESS FOR THE REGENERATION OF A ZEOLITE-CONTAINING OR AN AMORPHOUS COKE-CONTAMINATED SPENT HYDROCARBON CRACKING CATALYST, REMOVED FROM A REACTION ZONE, AND THE CONVERSION OF CARBON MONOXIDE, RESULTING FROM THE OXIDATION OF COKE FROM SAID CATALYST, TO CARBON DIOXIDE, WHICH PROCESS IS OPERATED WITHIN A PRESSURE RANGING OF FROM ABOUT NORMAL ATOMOSPHERIC TO ABOUT 50 PSIG, SAID PROCESS COMPRISING THE STEPS OF: A. PASSING CATALYST AND A FRESH FREE OXYGEN-CONTAINING REGENERATION GAS TO A FIRST DENSE BED OF FLUIDIZED PARTICULATE CATALYST IN A REGENERATION ZONE AND OXIDIZING COKE IN SAID FIRST DENSE BED MAINTAINED AT OXIDIZING CONDITIONS INCLUDING A TEMPERATURE WITHIN THE RANGE OF ABOUT 1250* TO ABOUT 1400:F., A SUPERICAL GAS VELOCITY WITHIN THE RANGE OF ABOUT 3 TO ABOUT 10 FEET PER SECOND, AND A CATALYST RESIDENCE TIME OF LESS THAN TWO MINUTES, TO PRODUCE PARTIALLY SPENT REGENERATION GAS, CONTAINING CO, AND REGENERATED CATALYST HAVING RESIDUAL COKE THEREON; B. PASSING SAID REGENERATED CATALYST AND PARTIALLY SPENT
Claim 2
Dependent Claim
158 words
A PROCESS FOR THE REGENERATION OF A ZEOLITE-CONTAINING OR AN AMORPHOUS COKE-CONTAMINATED SPENT HYDROCARBON CRACKING CATALYST, REMOVED FROM A REACTION ZONE, AND THE CONVERSION OF CARBON MONOXIDE, RESULTING FROM THE OXIDATION OF COKE FROM SAID CATALYST, TO CARBON DIOXIDE, WHICH PROCESS IS OPERATED WITHIN A PRESSURE RANGING OF FROM ABOUT NORMAL ATOMOSPHERIC TO ABOUT 50 PSIG, SAID PROCESS COMPRISING THE STEPS OF: A. PASSING CATALYST AND A FRESH FREE OXYGEN-CONTAINING REGENERATION GAS TO A FIRST DENSE BED OF FLUIDIZED PARTICULATE CATALYST IN A REGENERATION ZONE AND OXIDIZING COKE IN SAID FIRST DENSE BED MAINTAINED AT OXIDIZING CONDITIONS INCLUDING A TEMPERATURE WITHIN THE RANGE OF ABOUT 1250* TO ABOUT 1400:F., A SUPERICAL GAS VELOCITY WITHIN THE RANGE OF ABOUT 3 TO ABOUT 10 FEET PER SECOND, AND A CATALYST RESIDENCE TIME OF LESS THAN TWO MINUTES, TO PRODUCE PARTIALLY SPENT REGENERATION GAS, CONTAINING CO, AND REGENERATED CATALYST HAVING RESIDUAL COKE THEREON; B. PASSING SAID REGENERATED CATALYST AND PARTIALLY SPENT
Claim 3
Dependent Claim
23 words
The process of claim 1 further characterized in that said regenerated catalyst is stripped of spent regeneration gas in said second dense bed.
Claim 4
Dependent Claim
31 words
The process of claim 1 further characterized in that the total residence time of regeneration gas in said first dense bed and dilute phase transport zone is less than 10 seconds.