HYDROCRACKING OF HEAVY HYDROCARBON OILS WITH IMPROVED GAS AND LIQUID DISTRIBUTION

摘要

A process for hydrocracking a heavy hydrocarbon oil which comprises passing (a) a slurry feed comprising a mixture of a heavy hydrocarbon feedstock and from about 0.01-4.0% by weight (based on fresh feedstock) of coke-inhibiting additive particles having an average size of less than about 30 .mu.m and (b) a hydrogen-containing gas, upward through a confined hydrocracking zone in a vertical, elongated, cylindrical vessel with a generally dome-shaped bottom head, the hydrocracking zone being maintained at a temperature between about 350.degree.C and 600.degree.C and a pressure of at least 3.5 MPa and removing from the top of the hydrocracking zone a mixed effluent containing a gaseous phase comprising hydrogen and vaporous hydrocarbons and a liquid phase comprising heavy hydrocarbons. The slurry feed mixture and a portion of the hydrogen-containing gas are fed into the hydrocracking zone through a feed injector at the bottom of the dome-shaped bottom head and the balance of the hydrogen-containing gas is fed into the hydrocracking zone through a plurality of injection nozzles arranged within of the hydrocracking zone at a location above the slurry-feed injector. The temperature of the hydrogen-containing gas entering through the nozzles is at a temperature higher than the temperature of the combined slurry feed and hydrogen-containing gas entering through said bottom feed injector and the combined slurry feed and hydrogen-containing gas enter through the bottom feed injector at a velocity of at least 5m/s whereby the additive particles are maintained in suspension throughout the vessel and coking reactions are prevented.