Multi-zone hydrocaracking process

Claim 1

A PROCESS FOR PRODUCING GASOLINE AND MIDDLE DISTILLATES FROM A HYDROCARBON FEED STOCK SELECTED FROM THE GROUP CONSISTING OF NITROGEN-CONTAINING PETROLEUM DISTILLATES AND PETROLEUM RESIDUA BOILING ABOVE 350*F., WHICH COMPRISES SELECTING TWO FEED FRACTIONS EACH HAVING DIFFERENT BOILING RANGES, THE HIGHER BOILING OF SAID FRACTIONS BOILING ABOUT 560*F., HYDROCRACKING SAID HIGHER BOILING FRACTION IN THE PRESENCE OF FROM 1000 TO 10,000 S.C.F. OF HYDROGEN PER BARREL THEREOF IN A FIRST CONVERSION ZONE AT A TEMPERATURE OF FROM 500*F., A PRESSURE ABOVE 500 P.S.I.G., AN LHSV OF FROM 0.1 TO 4.0, AND A PER-PASS CONVERSION OF MORE THAN ABOUT 40 VOLUME PERCENT OF SAID HIGHER BOILING FRACTION TO PRODUCTS BOILING BELOW THE INITIAL BOILING POINT THEREOF, WITH A HYDROFINING-HYDROCRACKING CATALYST HAVING NO MORE THAN WEAK ACIDITY COMPRISING AT LEAST ONE HYDROGENATING COMPONENT SELECTED FROM THE GROUP VI METALS AND COMPONENTS OF GROUP VI METALS AND AT LEAST ONE HYDROGENATING COMPONENT SELECTED FROM THE GROUP VII METALS AND COMPOUNDS OF GROUP VII METALS IN INTIMATE ASSOCIATION WITH A SILICA-CONTAINING SUPPORT, RECOVERING AT LEAST ONE PRODUCT BOILING BELOW 550*F. FROM SAID FIRST CONVERSION ZONE, HYDROFINING THE LOWER BOILING OF SAID FRACTIONS WITH A HYDROFINING CATALYST IN A SECOND CONVERSION ZONE TO REDUCE THE NITROGEN CONTENT THEREOF UNDER CONDITIONS THAT ACCOMPLISH IN SAID SECOND ZONE A CONCURRENT HYDROCRACKING CONVERSION OF LESS THAN 30 VOLUME PERCENT OF THE FEED THERETO TO PRODUCTS BOILING BELOW THE BOILING RANGE OF SAID FEED, PASSING TO A THIRD CONVERSION ZONE FROM SAID FIRST ZONE A FRACTION BOILING ABOVE 550*F. AND BELOW THE INITIAL BOILING POINT OF THE FEED TO SAID FIRST ZONE, REMOVING AMMONIA FROM THE HYDROFINED FRACTION FROM SAID SECOND CONVERSION ZONE AND PASSING THE RESULTING HYDROFINED FRACTION TO SAID THIRD CONVERSION ZONE, AND HYDROCRACKING IN SAID THIRD CONVERSION ZONE SAID FRACTIONS PASSED THEREBY TO PRODUCE ADDITIONAL PRODUCTS BOILING BELOW 550*F.