Maintenance of catalyst activity using methyl cloride

Claim 1

A CYCLIC-REGENERATIVE PROCESS FOR HYDROFORMING A PETROLEUM NAPHTHA WHICH COMPRISES THE STEPS OF PASSING A MIXTURE OF SAID NAPHTHA AND HYDROGEN-CONTAINING GAS AT A TEMPERATURE OF BETWEEN ABOUT 850 AND 1050* F., A HYDROGEN PARTIAL PRESSURE OF BETWEEN ABOUT 50 AND 1000 POUNDS PER SQUARE INCH, A HYDROGEN RATE IN THE RANGE OF ABOUT 1000 TO 10,000 STANDARD CUBIC FEET PER BARREL OF SAID PETROLEUM NAPHTHA, AND AN HOURLY WEIGHT SPACE VELOCITY IN THE RANGE OF ABOUT0.5 TO 10, THROUGH A BED OF PLATINUM-ALIMINA CATALYST CONTAINING BETWEEN ABOUT 0.05 TO 1 PERCENT BY WEIGHT OF PLATINUM AND ABOUT 0.4 TO 1 WEIGHT PERCENT CHLORIDE, WHICH BED OF CATALYST UNDER SUCH ON-STREAM CONDITIONS TENDS TO BECOME GRADUALLY DEACTIVATED, REMOVING SAID BED OF CATALYST FROM ON-STREAM CONDITIONS AFTER DEACTIVATION THEREOF, CONTACTING SAID BED OF CATALYST WITH DILUTE OXYGEN AT A TEMPERATURE ABOVE ABOUT 800* F. AND BELOW ABOUT 1300* F. FOR A PERIOD IN EXCESS OF ABOUT 0.25 HOUR, COOLING SAID BED OF CATALYST TO A CONTACTING TEMPERATURE IN THE RANGE OF ABOUT 100 TO 250* F., CONTACTING SAID CATALYST AT SAID CONTACTING TEMPERATURE WITH A GAS CONTAINING EXCESS METHYL CHLORIDE AT A PRESSURE BELOW THE VAPOR PRESSURE OF METHYL CHLORIDE AT SAID CONTACTING TEMPERATURE FOR A PERIOD IN EXCESS OF ABOUT 0.1 SECOND, RETURNING SAID BED OF CATALYST TO SAID ON-STREAM CONDITIONS, AND PERIODICALLY REPEATING ABOVE STEPS.