US Patent 7419582 Process for hydrocracking a hydrocarbon feedstock

A hydrocracking process wherein the feedstock is hydrotreated and the liquid and gaseous effluent from the hydrotreater is directly introduced into the upper end of a hydrocracking vessel which provides a liquid seal to prevent the passage of the gaseous stream containing hydrogen sulfide and ammonia from the hydrotreater to enter the hydrocracking zone containing hydrocracking catalyst. Fresh hydrogen is then introduced into the hydrocracking zone. An apparatus for hydrocracking a hydrocarbon feedstock is also disclosed.