Reactivation of sulfide catalysts

Claim 1

IN THE REACTIVATION OF A CATALYST HAVING AS AN ACTIVE PROMOTER A COMBINATION OF A SULFIDE OF A METAL OF THE IRON GROUP AND A SULFIDE OF A METL OF THE LEFTHAND COLUMN OFOF GROUP VI WHICH CATALYST HAS BEEN REDUCED IN ACTIVITY AMONG OTHER THINGS BY CARBONACEOUS MATTER WHICH HAS DEPOSITED ON THE CATALYST THROUGH PROCESSING A CARBONACEOUS FEED AT AN ELEVATED PROCESSING TEMPERATURE UPWARD OF 300*C., SAID REACTIVATION INVOLVING THE REMOVAL OF SUCH CARBONACEOUS MATTER AND SULFUR BY CONTROLLED OXIDATION AT A TEMPERATURE IN THE RANGE OF ABOUT 400 TO ABOUT 650*C.. WHEREBY THE SAID METALS ARE CONVERTED TO THE OXIDES, THE IMPROVEMENT WHICH COMPRISES COOLING THE CATALYST FROM SAID OXIDATION TEMPERATURE TO A TEMPERATURE DOWNWARD OF ABOUT 250*C. IN A NON-REDUCING ATMOSPHERE AND THEN TREATING THE COOLED CATALYST AT A TEMPERATURE BETWEEN ABOUT 100*C. AND 250*C. FOR A TIME UPWARD OF ABOUT 1/2 HOUR WITH A MIXTURE OF HYDROGEN AND HYDROGEN SULFIDE IN A MOL RATIO BETWEEN ABOUT 2:1 AND ABOUT 50:1 PRIOR TO RAISING THE TEMPERATURE OF THE CATALYST UP TO THE SAID PROC-ESSING TEMPERATURE PREPARATOR TO STARTING A NEW PROCESS PERIOD.