Hydrodesulfurization of selected gasoline fractions

Claim 1

IN A HYDROCARBON CONVERSION PROCESS FOR THE TREATMENT OF A CRUDE CHARGE STOCK OF HIGH SULFUR CONTENT, WHEREIN SAID CHARGE STOCK IS INTIALLY SEPARATED INTO A LOW-BOILING STRAIGHT-RUN PRODUCTS FRACTION COMPRISING STRAIGHT-RUN GASOLINE, KEROSENE AND DIESEL OIL AND A TOPPED CRUDE FRACTION AND WHEREIN SAID TOPPED CRUDE FRACTION IS CATALYSTICALLY CRACKED AND THEN FRACTIONALLY DISTALLED TO RECOVER A BOTTOMS FRACTION COMPRISING HEAVY GAS OIL AND A CATALYTIC PRODUCTS FRACTION CONSISTING OF THE COMPONENTS BOILING LOWER THAN SAID HEAVY GAS OIL, THE METHOD FOR REMOVING SULFUR FROM BOTH SAID STRAIGHT-RUN AND CATALYTIC PRODUCTS FRACTIONS PRELIMINARY TO FURTHER TREATMENT THEREOF FOR ULTIMATE RECOVERY OF DESIRED END PRODUCTS, WHICH METHOD COMPRISES THE STEP OF: FURTHER FRACTIONATING SAID CATALYTIC PRODUCTS FRACTION TO SEPARATE THEREFORM A NAPHTHA FRACTION IN THE GASOLINE BOILING RANGE, LEAVING A GASOLINEFREE DISTILLATE FRACTION OF RELATIVELY HIGH SULFUR CONTENT INCLUDING CATALYTICALY CRACKED KEROSENE AND DIESEL OIL; COMBINING SAID DISTILLATE AND STRAIGHT-RUN PRODUCTS FRACTIONS ADDING HYDROGEN-CONTAINING GASEOUS MATERIAL TO SAID COMBINED FRACTIONS IN A HYDROGEN/OIL MOL RATIO OF BETWEEN ABOUT 1/1-5/1 AND SUBJECTING THE RESULTANT MIXTURE TO RELATIVELY SEVERE HYDRODESULFURIZATION TREATMENT IN THE PRESENCE OF COBALT-MOLYBDENA-ALUMINA CATALYST AT A SPACE RATE IN THE RANGE OF ABOUT 0.5-10, AT A VAPOR INLET TEMPERATURE OF ABOUT 600-800*F. AND AT A PRESSURE OF ABOUT 600-1000 P.S.I.G.; COOLING THE EFFLUENT OF SAID HYDRODESULFURIZATION TREATMENT AND REMOVING THEREFROM GASEOUS PRODUCTS CONTAINING HYDROGEN SULFIDE, THEREBY OBTAINING FOR SAID FURTHER TREATMENT A DESULFURIZED LIQUID PRODUCT COMPRISING STRAIGHT-RUN NAPHTHA, KEROSENE AND DIESEL OIL.