Hydrocarbon desulfurization process

Claim 1

A PROCESS FOR EFFECTING SUBSTANTIALLY COMPLETE CHEMICAL UTILIZATION OF AN IMPUIRE HYDROGEN SUPPLY STREAM IN A COMBINATION HYDROFINING PROCESS WITHOUT EMPOLYING PURIFICATION STEPS EXTRANEOUS TO SAID HYDROFINING PROCESS, SAID HYDROGEN SUPPLY STREAM INITIALLY CONTAINING BETWEEN ABOUT 40% AND 85% BY VOLUME OF HYDROGEN, WHICH COMPRISES SUBJECTING A FIRST SULFUR-CONTAINING HYDROCARBON FEED TO MILD CATALYTIC HYDROFINING IN ADMIXTURE WITH SAID HYDROGEN SUPPLY STREAM TO EFFECT PARTIAL DESULFURIZATION THEREOF, COOLING AND CONDENSING THE EFFLUENT FROM SAID MILD HYDROFINING AT SUBSTANTIALLY THE REACTOR PRESSURE TO PRODUCE A PARTIALLY DESULFURIZED LIQUID PRODUCT AND A FIRST TAIL-GAS CONTAINING A HIGHER CONCENTRATION OF HYDROGEN THAN SAID IMPURE SUPPLY STREAM, WITHDRAWING SAID FIRST TAIL-GAS AND CONTINUOUSLY PASSING THE SAME IN ITS ENTIRETY TO A SEVERE CATALYTIC HYDROFINING ZONE IN ADMIXTURE WITH A SECOND SULFUR-CONTAINING HYDROCARBON FEED TO EFFECT AT LEAST ABOUT 95% DESULFURIZATION THEREOF, COOLING AND CONDENSING THE EFFLUENT THEREFROM AT SUBSTANTIALLY THE REACTOR PRESSURE THEREBY PRODUCING A DESULFURIZED LIQUID PRODUCT AND A SECOND TAIL-GAS CONTAINING A LOWER PROPORTION OF HYDROGEN THAN SAID FIRST TAILGAS, CONTINUOUSLY RECYCLING A FIRST PORTION OF SAID SECOND TAIL-GAS TO SAID MILD HYDROFINING AND CONTINUOUSLY RECYCLING THE REMAINDER TO SAID SEVERE HYDROFINING, WHEREBY SUBSTANTIALLY ALL THE HYDROGEN INITIALLY SUPPLIED IN SAID SUPPLY STREAM IS EVENTUALLY CONSUMED IN SAID MILD HYDROFINING AND SEVERE HYDROFINING ZONES, SAID MILD HYDROFINING BEING CARRIED OUT AT A SUBSTANTIALLY LOWER TEMPERATURE AND HYDROGEN/OIL RATIO THAN SAID SEVERE HYDROFINING.