Simultaneous hydrofining of coker gas oil, vacuum gas oils and virgin kerosene

Claim 1

A combined hydrofining process comprising: feeding a coker gas oil stream boiling from about 600* to 900* F. to the inlet of a combined hydrofining reactor unit at a predetermined temperature and rate with an excess of hydrogen, passing the coker gas oil stream in admixture with said hydrogen through a first hydrofining zone in a first hydrofining zone containing therein a nickel molybdate catalyst under hydrofining conditions to obtain a first zone effluent; feeding a first vacuum gas oil stream boiling from about 675* F. to about 800* F. to said combined hydrofining reactor unit between said first hydrofining zone and a second hydrofining zone to admix with said first zone effluent, said first vacuum gas oil stream being fed at a temperature and rate of feed calculated to quench an amount of heat in said first zone effluent substantially equal to the heat generated by the hydrofining reactions in said first hydrofining zone; passing said first zone effluent and first vacuum gas oil mixture through said second hydrofining zone containing therein a nickel molybdate catalyst under hydrofining conditions to obtain a second zone effluent; feeding a second vacuum gas oil stream boiling from about 800* F. to 1,000* F. to said combined hydrofining reactor unit between said second hydrofining zone and a third hydrofining zone to admix with said second zone effluent, said second vacuum gas oil stream being fed at a temperature and rate of feed calculated to quench an amount of heat in said second zone effluent substantially equal to the heat generated by the hydrofining reactions in said second hydrofining zone; passing said second zone effluent and second vacuum gas oil mixture through said third hydrofining zone containing therein a nickel catalyst selected from nickel molybdate and nickel tungsten, under hydrofining conditions to obtain a third zone effluent; feeding a virgin kerosene stream boiling from about 300* F. to 500* F. to said combined hydrofining reactor between said third hydrofining zone and a fourth hydrofining zone to admix with said third zone effluent, said virgin kerosene stream being fed at a temperature and rate of feed calcUlated to quench an amount of heat in said third zone effluent substantially equal to the heat generated by the hydrofining reactions in said third hydrofining zone; passing said third zone effluent and virgin kerosene mixture through said fourth hydrofining zone containing therein a nickel tungsten catalyst, under hydrofining conditions; the feed rates of said coker gas oil, said first and said second gas oil and said virgin kerosene streams and the hydrofining conditions in said first, second, third and fourth hydrofining zones being correlated to effect a predetermined hydrodesulfurization and hydrodenitrogenation of said streams in said reactor unit; removing the combined hydrofined effluent from said fourth hydrofining zone, and recovering light ends, jet fuel and an upgraded catalytic cracker feed from said combined hydrofined effluent.