Catalytic dehydrogenation of hydrocarbon oils

Claim 1

IN A PROCESS FOR THE CATALYTIC DEHYDROGENATION OF A NORMALLY LIQUID HYDROCARBON OIL CONTAINING IN THE ORDER OF 0.1% TO 0.25% SULFUR WHEREIN THE SAID HYDROCARBON OIL TO BE DEHYDROGENATED IS PASSED THROUGH A DEHYDROGENATED REACTION ZONE UNDER DEHYDROGENATION CONDITIONS OF TEMPERATURE AND PRESSURE IN CONTACT WITH A FIIXED BED OF A METAL OXIDE DEHYDROGENATION CATALYST IN THE PRES ENCE OF AT LEAST TEN ATMOSPHERES PARTIAL PRES SURE OF RECYCLED PRODUCTT GAS RICH IN HYDROOGEN FOR A PERIOD OF TIME SUBSTANTIALLY IN EXCESS OF 50 HOURS CALLED THE PROCESS PERIOD, AND WHEREIN THR ACTIVITY OF THE SAID METAL OXIDE DEHYDROGENATION CATALYST IS RESTORED AFTER EACH SUCH PROCESS PERIOD BY BURNING COMBUSTIBLE DEPOSITS THEREFROM DUURING A SO-CALLED REGENERATION PERIOD, THE IMPROVEMENT WHICH COMPRISES ADDING BETWEEN 0.1% AND 0.6% OF ELEMENTAL SULFUR TO SAID HYDROCARBON OIL TO BE DEHYDROGENATED DURINNG THR FIRST 2-50 HOURS ONLY TO EACH PROCESS PERIOD, COMMINGLING SAID FEED WITH AT LEASST TEN ATMOSPHERES PARTIAL PRESSURE OF RECYCLED PRODUCT GAS AND PASSING THE MIXTURE THROUGH SAID REATION ZONE IN CONTACT WITH A COBALT OXIDE-MOLYBDENUM OXIDE DEHYDROGENA-