Hydrocracking process

Claim 1

A PROCESS FOR CONVERTING A MINERAL OIL FEEDSTOCK CONTAINING AT LEAST AOUT 5% BY VOLUME OF MATERIAL BOILING ABOVE 700*F. AND AT LEAST ABOUT 0.02 WEIGHT-PERCENT OF ORGANIC NITROGEN, TO LOWER BOILING HYDROCARBONS, WHICH COMPRISES: (1) SUBJECTING SAID FEEDBACK TO CATALYTIC HYDROFINING IN THE PRESENCE OF ADDED HYDROGEN AND A SUBSTANTIALLY NON-CRACKING HYDROFINING CATALYST AT ELEVATED TEMPERATURES AND AT A PRESSURE ABOVE 2,000 P.S.I.G TO EFFECT DECOMPOSITION OF SAID ORGANIC NITROGEN COMPOUNDS WITH RESULTANT FORMATION OF AMMONIA; (2) SUBJECTING AMMONIA-CONTAINING EFFUENT FROM SAID HYDROFINING STEP TO CATALYTIC HYDROCRACKING AT ELEVATED TEMPERATURES AND A SPACE VELOCITY BETWEEN ABOUT 0.5 AND 10, AND AT A PRESSURE ABOVE ABOUT 1,8000 P.S.I.G., IN THE PRESENCE OF HYDROGEN AND A HYDROCRACKING CATALYST COMPRISING A MINOR PROPORTION OF A GROUP VIII METAL HYDROGENATING COMPONENT DEPOSITED UPON A ZEOLITE ALUMINO-SILICATE MOLECULAR SIEVE CRACKING BASE HAVING A SIO2/AL2O3 MOLE-RATIO BETWEEN ABOUT 3 AND 12, AND WHEREIN THE ZEOLITE CATIONS ARE SELECTED MAINLY FROM THE CLASS CONSISTING OF HYDROGEN IONS AND POLYVALENT METAL IONS; AND (3) RECOVERING DESIRED LOW-BOILING HYDROCARBONS FROM THE EFFLUENT FROM SAID HYDROCRACKING STEP.