Rejuvenation of platinum catalysts after deactivation in a high temperature hydrocarbon conversion process

Claim 1

THE METHOD OF RESTORING THE CATALYTIC PROPERTIES OF A PLATINUM-ON-ALUMINA CATALYST WHICH HAS BECOM DEACTIVATED AND WHICH HAS ACCUMULATED CARBONACEOUS, SULFURCONTAINING DEPOSITS DURING ON STREAM USE IN THE HYDROFORMING OF NAPHTA, WHICH METHOD COMPRISES BURNING COMBUSTIBLE DEPOSITS FROM THE CATALYST WITH AN OXYGENCONTAINING GAS STREAM AT A COMBUSTION ZONE TEMPERATURE IN GHE RANGE OF 825 TO 1300*F. FOR A TIME SUFFICIENT TO BURN MOST OF THE CARBONACEOUS DEPOSITS FROM THE CATALYST AND TO OXIDIZE SULFUR CONTAINED THEREIN WHEREBY THE CATALYST IN SULFUR-DEACTIVATED, PURGING OXYGEN FROM THE CATALYST WITH AN INERT GAS, THEN TREATING SAID SULFUR-DEACTIVATED CATALYST WITH HYDROGEN AT A TEMPERATURE IN THE RANGE OF 650 TO 1300*F. UNTIL THE EVOLUTION OF SULFUR COMPOUNDS FROM THE CATALYST SUBSTANTIALLY CEASES, PURGING THE HYDROGEN AND LIBERATED SULFUR COMPOUNDS FROM THE CATALYST, AND THEN CONTACTING THE CATALYST WITH A GAS CONTAINING FREE OXYGEN AN HAVING AN OXYGEN PARTIAL PRESSURE IN THE RANGE OF ABOUT .4 TO 4 ATMOSPHERES AT A TEMPERATURE IN THE RANGE OF ABOUT 900 TO 1100*F. FOR A PERIOD OF TIME LEVELS OF ACTIVITY SELECTIITY AND STABILITY.

Claim 2

THE METHOD OF RESTORING THE CATALYTIC PROPERTIES OF A PLATINUM-ON-ALUMINA CATALYST WHICH HAS BECOM DEACTIVATED AND WHICH HAS ACCUMULATED CARBONACEOUS, SULFURCONTAINING DEPOSITS DURING ON STREAM USE IN THE HYDROFORMING OF NAPHTA, WHICH METHOD COMPRISES BURNING COMBUSTIBLE DEPOSITS FROM THE CATALYST WITH AN OXYGENCONTAINING GAS STREAM AT A COMBUSTION ZONE TEMPERATURE IN GHE RANGE OF 825 TO 1300*F. FOR A TIME SUFFICIENT TO BURN MOST OF THE CARBONACEOUS DEPOSITS FROM THE CATALYST AND TO OXIDIZE SULFUR CONTAINED THEREIN WHEREBY THE CATALYST IN SULFUR-DEACTIVATED, PURGING OXYGEN FROM THE CATALYST WITH AN INERT GAS, THEN TREATING SAID SULFUR-DEACTIVATED CATALYST WITH HYDROGEN AT A TEMPERATURE IN THE RANGE OF 650 TO 1300*F. UNTIL THE EVOLUTION OF SULFUR COMPOUNDS FROM THE CATALYST SUBSTANTIALLY CEASES, PURGING THE HYDROGEN AND LIBERATED SULFUR COMPOUNDS FROM THE CATALYST, AND THEN CONTACTING THE CATALYST WITH A GAS CONTAINING FREE OXYGEN AN HAVING AN OXYGEN PARTIAL PRESSURE IN THE RANGE OF ABOUT .4 TO 4 ATMOSPHERES AT A TEMPERATURE IN THE RANGE OF ABOUT 900 TO 1100*F. FOR A PERIOD OF TIME LEVELS OF ACTIVITY SELECTIITY AND STABILITY.