Regeneration of noble metal catalysts

Claim 1

IN A METHOD OF REGENERATING A FIXED BED OF PLATINUMON-ALUMINA CATALYST PARTICLES CONTAINING CARBONACEOUS MATERIALS DEPOSITED DURING A PREVIOUS PERIOD OF REFORMING GASOLINE THE IMPROVEMENT WHICH CONSISTS ESSENTIALLY OF: SUBJECTING THE CATALYST BED TO A COMBUSTION-SUPPORTING GASEOUS MIXTURE CONSISTING PREDOMINANTLY OF NITROGEN, CONTAINING A RESTRICTED AMOUNT OF OXYGEN TO BRING ABOUT THE COMBUSTION OF CARBONACEOUS DEPOSITS ON THE CATALYST PARTICLES, SAID RESTICTED AMOUNT OF OXYGEN PROVIDING AN ABSOLUTE PRESSURE WITHIN THE RANGE FROM 10 MM. TO 20 MM. OF MERCURY, SAIDMGASEOUS MIXTURE BEING PURIFIED TO REMOVE ACIDIC GASES TO REDUCE THE CARBON DIOXIDE CONCENTRATION TO LESS THAN 1%, WITHDRAWING THE EFFLUENT FROM SUCH COMBUSTION OF THE CARBONACEOUS D LATING AT LEAST A PORTION OF SUCH EFFLUENT AFTER SUBJECTING SUCH EFFLUENT TO A STEP OF SCRUBBING WITH AN AQUEOUS ALKALINE SOLUTION CONSISTING ESSENTIALLY OF 10% SODIUM HYDROXIDE AND 90% WATER TO REDUCE THE CARBON DIOXIDE CONTENT OF THE GAS STREAM TO LESS THAN 1%, ADDING AN OXYGEN-CONTAINING GAS TO THE COMBUSTION-SUPPORTING GASEOUS MIXTURE TO PROVIDE A PARTIAL PRESSURE OF OXYGEN OF FROM ABOUT 10 MM. TO ABOUT 20 MM. OF MERCURY, THEREAFTER SUBJECTING THE CATALYST BED TO HYDROGEN AT 825%F., AND THEREAFTER SUBJECTING THE CATALYST BED FOR ABOUT FIVE HOURS TO A GAS STREAM CONSISTING ESSENTIALLY OF HYDROGEN AND HYDROGEN CHLORIDE PROVIDING AN ABSOLUTE PARTIAL PRESSURE OF HYDROGEN CHLORIDE OF FROM 0.2 TO 2 MM. OF MERCURY.