Catalytic desulfurization of petroleum hydrocarbons

Claim 1

IN A CONTINOUS PROCESS FOR THE HYDROCATALYTIC DESULPHURIZATION OF A SULPHUR-AND-NAPHTHENE-CONTAINING HYDROCARBON OIL WHEREIN THE OIL IS CONTACTED IN A REACTION ZONE AT AN ELEVATED TEMPERATURE AND PRESSURE IN THE PRESENCE OF HYDROGEN WITH A DEHYDROGENATON-HYDROGENATION CATALYST WHICH HAS EEN PRETREATED WITH HYDROGEN SULPHIDE AND WHICH IS IMMUNE TO SULPHUR POISONING AND COMBINING ACTIVITY FOR THE DEHYDROGENATIN OF NAPHTHENES IN SAID OIL TO AROMATICS WITH ACTIVITY FOR THE HYDROGENATION OF ORGANICALLY COMBINED SULPHUR IN THE OIL TO HYDRO GEN SULPHIDE, THE METHOD OF OPERATING THE PROCESS SO THAT IT WILL BE SELF-SUPPORTING WITH RESPECT TO THE AMOUNT OF HYDROGEN NEEDED AND GIVE INCREASED DEHYDROENATION AND DESULPHURIZATION DURING THE EARLY HOURS ON STREAM AND CONSUME CONSIDERABLY LESS HYDROGEN THAN HEREFORE REQUIRED FOR THE PURPOSE OF PRETREATING THE CATALYST AND PRODUCE A DESULPHURIZED OIL; COMPRISSING THE STEPS OF PASSING THE HYDROCARBON OIL TO BE TREATED THROUGH SAID REACTION ZONE AND CONTACTING THE OIL THEREIN WITH HYDROGEN DERIVED SOLELY FROM THE OIL AND WITH SAID CATALYST WHICH HAS BEEN PRETREATED WITH HYDROGEN SULPHIDE DERIVED SOLELY FROM THE OIL, SAID CONDITIONS OF ELEVATED TEMPERATURE AND PRESSURE BEING SUCH THAT SUFFICIENT HYDROGEN IS PRODUCED BY DEHYDROGENATION OF NAPHTHENE HYDROCARBONS CONTAINED IN THE OIL TO EFFECT THE CONVERSIN OF SULPHUR COMPOUNDS CONTAINED I THE OIL HYDROGEN SULPHIDE AND TO PROVIDE A HYDROGEN-RICH GASEOUS MIXTURE WHICH IS RECYCLED TO THE CATALYTIC DESULPHURIZATION ZONE IN ORDER TO MAINTAIN THE NECESSARY PARTIAL PRESSURE OF HDROGEN THEREIN, PASSING THE DESULPHURIZED OIL TO A GAS SEPARATION STAGE MAINTAINED UNDER THE DESULPHURIZATIN PRESSURE BUT REDUCED TEMPERATURE, SEPARATING A HYDROGEN-RICH GAS MIXTURE, AND LEAVING A LIQUID PRODUCT CONTAINING THE BULK OF THE HYDROGEN-SULPHDE OBTAINED FROM THE REACTION IN SOLUTION, RECYCLING SAID HYDROGEN-RICH GAS MIXTURE TO THE REACTION ZONE TO CONSTITUTE THE WHOLE OF THE HYDROGEN SUPPLIED TO SAID ZONE, PASSING SAID HYDROGEN-SULPHIDE-CONTAINING LUQUID PRODUCT TO A STABILIZING STAGE FOR THE SEPARATION OF A HYDROGEN-SULPHIDE-RICH GAS, SEPARATELY REGENERATING CATALYST FOR USE IN SAID PROCESS, AND PASSING SAID HYDROGEN-SULPHIDE-RICH GAS BACK TO THE REGENERATION SYSTEM FOR TREATING THE CATALYST IN SAID REGENERATION SYSTEM JUST AFTER IT HAS BEEN REGENERATED.