Catalyst reactivation in process for improving lubricating oils and waxes

Claim 1

IN A PROCESS FOR IMPROVING COLOR CHARACTERISTICS OF A HYDROCARBON FRACTION SELECTED FROM THE GROUP CONSISTING OF AN UNFINISHED MINERAL LUBRICATING OIL AND AN UNFINISHED PETROLEUM WAX TO PRODUCE A HYDROCARBON FRACTION EFFLUENT HAVING SATISFACTORY COLOR CHARACTERISTICS THAT COMPRISES CONTACTING IN A REACTOR SAID HYDROCARBON FRACTION WITH A CATALYST IN A REACTOR SAID HYDROCARBON FRACTION WITH A CATALYST COMPRISING BETWEEN ABOUT 5 PERCENT AND ABOUT 20 PERCENT MOLYBDENA, BY WEIGHT, SUPPORTED UPON ALUMINA HAVING AN AVERAGE PORE DIAMETER VARYING BETWEEN ABOUT 110 A. AND ABOUT 600 A.; IN THE PRESENCE OF HYDROGEN CIRCULATED AT A RATE VARYING BETWEEN ABOUT 200 S.C.F./BBL. AND ABOUT 10,000 S.C.F./BBL.; AT A PRESSURE VARYING BETWEEN ABOUT 100 P.S.I.G. AND ABOUT 3000 P.S.I.G.; AT A LIQUID HOURLY SPACE VELOCITY VARYING BETWEEN ABOUT 0.1 AND ABOUT 15; AND AT A TEMPERATURE VARYING BETWEEN ABOUT 250*F. AND ABOUT 700*F.; THE IMPROVEMENT THAT COMPRISES INTRODUCING HYDROGEN SULFIDE IN AN AMOUNT OF FROM ABOUT 0.5 PERCENT TO ABOUT 10 PERCENT BY VOLUME OF THE HYDROGEN GAS IN THE REACTION AFTER A HYDROCARBON FRACTION EFFLUENT HAVING SATISFACTORY COLOR CHARACTERISTICS HAS BEEN PRODUCED, SAID INTRODUCTION OF HYDROGEN SULFIDE BEING DONE FOR A SHORT PERIOD OF TIME AND BEING STARTED WHEN SAID EFFLUENT HAS ATTAINED UNSATISFACTORY COLOR CHARACTERISTICS.