Fluidized catalyst regeneration by oxidation in a dense phase bed and a dilute phase transport riser

Claim 1

A PROCESS FOR THE REGENERATION OF A ZEOLITE-CONTAINING OR 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 RANGE FROM ABOUT NORMAL ATMOSPHERIC PRESSURE TO ABOUT 50 P.S.I.G. AND COMPRISES THE STEPS OF: A. PASSING SAID 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 BY EMPLOYING A TEMPERATURE WITHIN THE RANGE OF ABOUT 1,250*F. TO ABOUT 1,400*F., A SUPERFICIAL 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 REGENERATED CATALYST AND PARTIALLY SPENT REGENERATION GAS CONTAINING CO; B. PASSING SAID PARTIALLY REGENERATED AND CATALYST AND PARTIALLY SPENT REGENERATION GAS TO A DILUTE PHASE TRANSPORT RISER COMMUNICATING WITH AND SUPERIMPOSED OVER SAID FIRST DENSE BED AND THEREIN CONTROLLING CONVERSION CONDITIONS INCLUDING CONTROLLING THE TEMPERATURE WITHIN THE RANGE OF ABOUT 1,275*F. TO 1,425*F. AND THE SUPERFICIAL GAS VELOCITY WITHIN THE RANGE OF ABOUT 10 TO 25 FEET PER SECOND OF CONVERT CO TO CO2, TO PRODUCE SPENT REGENERATION GAS; C. SEPARATING THE THUS-REGENERATED CATALYST FROM SAID REGENERATION GAS; AND D. INTRODUCING SAID REGENERATED CATALYST TO A SECOND DENSE BED OF PARTICULATE MATERIAL, FROM WHICH SAID REGENERATED CATALYST IS RETURNED TO SAID REACTION ZONE.