Catalyst rejuvenating process

Claim 1

A PROCESS FOR REJUVENATING A SUPPORTED HYDROGENATING CATALYST WHICH, BEFORE LONG EXPOSURE TO HYDROCARBON FEED UNDER HYDROGENATIVE CONVERSION CONDITIONS, IS AN ACTIVE CATALYST COMPOSED OF AT LEAST ONE HYDROGENATING METAL COMPONENT SELECTED FROM THE GROUP CONSISTING OF GROUP VIII METALS AND COMPOUNDS THEREOF, OTHER THAN NOBLE METALS AND COMPOUNDS THEREOF, DISPOSED ON A HIGH SURFACE AREA SUPPORT SUSCEPTIBLE TO ATTACK BY STRONG ACIDS, BUT WHICH CATALYST AFTER LONG EXPOSURE TO HYDROCARBONS FEED UNDER HYDROGENATIVE CONVERSION CONDITIONS HAS ACCUMULATED CARBONACEOUS DEPOSITS AND HAS BECOME DEACTIVATED WITH THE METAL HYDROGENATING COMPONENT SO CHANGED THAT CONVENTIONAL REMOVAL OF THE ACCUMULATED CARBONACEOUS DEPOSITS DOES NOT RESULT IN RECOVERY OF A SUBSTANTIAL PERCENTAGE OF THE ORIGINAL HYDROGENATIVE CONVERSION ACTIVITY, WHICH PROCESS COMPRISES CONTACTING SAID DEACTIVATED CATALYST BEFORE REMOVAL OF SAID CARBONACEOUS DEPOSITS WITH AN AQUEOUS SOLUTION OF STRONG ACID HAVING A DISSOCIATION CONSTANT OF GREATER THAN 10**-2 AND CAPABLE OF FORMING SALTS WITH SAID HYDROGENATING METAL COMPONENT, SAID AQUEOUS SOLUTION CONTAINING ACID IN THE RANGE OF FROM 0.5 THE STOICHIOMETRIC AMOUNT TO NO MORE THAN IS STOICHIOMETRICALLY NECESSARY TO FORM SAID SALTS WITH THE HYDROGENATING METAL COMPONENT PRESENT IN THE DEACTIVATED CATALYST AND THE VOLUME OF SAID SOLUTION BEING NO MORE THAN FILLS THE PORES OF THE CATALYST BEING REJUVENATED, CONTINUING THE CONTACT BETWEEN SAID ACID AND SAID DEACTIVATED CATALYST UNTIL SAID HYDROGENATING METAL COMPONENT IS SUBSTANTIALLY COMPLETELY CONVERTED TO SAID SALTS, AND THEREAFTER DECOMPOSING SAID SALTS IN THE ACID-TREATED CATALYST AND REMOVING SAID CARBONACEOUS DEPOSITS.