Manufacture of gasoline and jet fuel by hydrocracking

Claim 1

A PROCESS FOR THE MANUFACTURE OF GASOLINE AND HIGHQUALITY JET FUEL BY THE HYDROCRACKING OF NITROGEN-CONTAMINATED FEEDSTOCKS, WHICH COMPRISES: (1) SUBJECTING A GAS OIL FEEDSTOCK BOILING ABOVE THE GASOLINE RANGE AND CONTAINING AT LEA ST ABOUT 50 PARTS PER MILLION OF NITROGEN IN THE FORM OF ORGANIC NITROGEN COMPOUNDS TO CATALYTIC HYDROFINING WITH ADDED HYDROGEN TO EFFECT DECOMPOSITION OF SAID ORGANIC NITROGEN COMPOUNDS WITHOUT SUBSTANTIAL CRACKING OF HYDROCARBONS; (2) SUBJECTING AMMONIA-CONTAINING EFFLUENT FROM SAID HYDROFINING, WITHOUT INTERVENING CONDENSATION OR SEPARATION, TO A FIRST STAGE OF CATALYTIC HYDROCRACKING IN THE PRESENCE OF A GROUP VIII METAL SULFIDE HYDROCRACKING CATALYST, AT A TEMPERATURE BETWEEN ABOUT 600* AND 850*F. AND UNDER CONDITIONS ADJUSTED TO GIVE A 20-50* CONVERSION PER PASS TO 400*F. ENDPOINT GASOLINE; (3) TREATING THE EFFLUENT FROM SAID FIRST-STAGE HYDROCRACKING TO SEPARATE OUT A FIRST-STAGE GASOLINE PRODUCT, AMMONIA, AND A HYDROCARBON RESIDUE BOILING ABOVE SAID FIRST-STAGE GASOLINE BOILING RANGE, SAID RESIDUE CONTAINING LESS THAN ABOUT 25 PARTS PER MILLION OF NITROGEN AND COMPRISING A SUBSTANTIAL PROPORTION OF HYDROCARBONS BOILING IN THE JET FUEL RANGE; (4) SUBJECTING SAID HYDROCARBON RESIDUE PLUS ADDED HYDROGEN TO A SECOND STAGE OF CATALYTIC HYDROCRACKING IN THE PRESENCE OF A GROUP VIII FREE METAL HYDROCRACKING CATALYST, AT A TEMPERATURE BETWEEN ABOUT 400* AND 800*F. UNDER CONDITIONS ADJUSTED TO GIVE A CONVERSION PER PASS TO 400*F. END-POINT GASOLINE WHICH IS (A) BETWEEN ABOUT 30% AND 70% BY VOLUME, AND (B) HIGHER THAN THE CONVERSION TO GASOLINE MAINTAINED IN SAID FIRST HYDROCRACKING STAGE; (5) FRACTIONATING THE EFFLUENT FROM SAID SECOND-STAGE HYDROCRACKING SEPARATELY FROM SAID FIRST-STAGE HYDROCRACKING EFFLUENT, TO SEPARATE OUT A SECOND-STAGE GASOLINE PRODUCT AND A JET FUEL FRACTION BOILING BETWEEN ABOUT 350* AND 550*F.; (6) WITHDRAWING AT LEAST A PORTION OF SAID JET FUEL FRACTION AS PRODUCT AND RECYCLING ANY REMAINING PORTION THEREOF TO SAID SECOND HYDROCRACKING STAGE; (7) SUBJECTING THE C7+FRACTION OF SAID SECOND-STAGE GASOLINE TO CATALYTIC REFORMING IN THE PRESENCE OF ADDED HYDROGEN; (8) SUBJECTING THE C7+ FRACTION OF SAID FIRST-STAGE GASOLINE TO CATALYTIC REFORMING IN THE PRESENCE OF ADDED HYDROGEN, BUT UNDER LESS SEVERE REFORMING CONDITIONS THAN THE CONDITIONS EMPLOYED FOR REFORMING SAID SECOND-STAGE GASOLINE; AND WHEREIN (9) SAID HYDROFINING STEP AND EACH OF SAID HYDROCRACKING STAGES ARE CARRIED OUT AT PRESSURES BETWEEN ABOUT 500 AND 3,000 P.S.I.G.