Rejuvenation of platinum-type hydroforming catalysts

Claim 1

IN A FLUIDIZED, PLATINUM-CATALYST, NAPHTHA HYDROFORMING SYSTEM WHEREIN THE PLATINUM CATALYST EFFECTS HYDROFORMING OF NAPHTHA AT A TEMPERATURE IN THE RANGE OF ABOUT 850 TO 950*F. AND A PRESSURE OF ABOUT 50 TO 1000 P.S.I. IN THE PRESENCE OF A RECYCLED HYDROGEN GAS STREAM EMPLOYED AT A RATE IN THE RANGE OF 2,000 TO 10,000 STANDARD CUBIC FEET PER BARREL OF NAPHTHA CHARGE AND WITH A SPACE VELOCITY OF .5 TO 5 POUNDS PER HOUR OF NAPHTHA CHARGE PER POUND OF CATALYST IN A CONVERSION ZONE WHEREIN CATALYST CONTAINING CARBONACEOUS DEPOSITS IS CONTINUOUSLY WITHDRAWN FROM THE CONVERSION ZONE TO A REGENERATION ZONE AND THEREIN REGENERATED WITH A GAS STREAM HAVING AN OXYGEN CONTENT BETWEEN ABOUT .5 AND 20 PERCENT AT A TEMPERATURE IN THE RANGE OF 750 TO 900*F. EFFECTIVE FOR BURNING CARBONACEOUS DEPOSITS AT APPROXIMATELY THE SAME PRESSURE AS THE PRESSURE IN THE CONVERSION ZONE, WHEREIN THE REGENERATED CATALYST FROM THE REGENERATION ZONE IS CONTINUOUSLY RETURNED TO THE CONVERSION ZONE AND WHEREIN ON CONTINUED USE THE CATALYST WOULD NORMALLY LOSE ACTIVITY AND SELECTIVITY AND DIFFICULTY REMOVABLE CARBON BECOMES ACCUMULATED THEREON, THE IMPROVEMENT WHICH COMPRISES WITHDRAWING AT LEAST A PART OF THE CATALYST FROM THE REGENERATION ZONE TO A SEPARATE FLUIDIZED TREATING ZONE, FURTHER TREATING SAID CATALYST BY OXIDIZING ITS PLATINUM WITH AIR IN SAID TREATING ZONE AT A PRESSURE IN THE RANGE OF ABOUT 50 TO 1,000 P.S.I. AND AT A TEMPERATURE IN THE RANGE OF ABOUT 950 TO 1300*F. AND FOR A TIME IN THE RANGE OF .1 TO 36 HOURS, AND RETURNING CATALYST FROM THE TREATING ZONE BACK TO THE CONVERSION ZONE WHEREBY THE PLATINUM IS REDUCED WITH HYDROGEN AT A TEMPERATURE ABOVE 600*F., THE NORMAL LOSS OF ACTIVITY AND SELECTIVITY IS SUBSTANTIALLY PREVENTED AND THE CATALYST IN THE CONVERSION ZONE IS MAINTAINED AT SUBSTANTIALLY CONSTANT ACTIVITY.