Patent ID: 6454932
Filing Date: 2002-09-24
Classification: C10G

Abstract:
A method of hydrocracking a high boiling hydrocarbon feedstock comprising the steps of:a. partially hydrocracking said feedstock comprising contacting said feedstock with hydrogen in a first reactor containing an ebullating bed of catalyst particles thereby forming an effluent mixture of C4-light ends and lower boiling hydrocarbons and higher boiling hydrocarbons; b. passing said partially hydrocracked effluent mixture from said first reactor into a separation/stripping zone at a pressure in the range of 1500 to 3000 psig and separating therein said partially hydrocracked effluent mixture into a vapor portion containing C4-light ends and lower boiling hydrocarbons and a liquid portion containing higher boiling hydrocarbons and concurrently stripping therein said higher boiling liquid portion with hydrogen to separate an additional vapor portion containing additional C4-light ends and lower boiling hydrocarbons and produce a combined vapor stream containing said vapor portion and said additional vapor portion and produce a stripped liquid stream containing more concentrated higher boiling hydrocarbons; c. further hydrocracking said stripped liquid stream comprising contacting said stripped liquid stream with hydrogen in a second reactor containing an ebullating bed of catalyst particles thereby forming a further effluent stream containing additional lower boiling hydrocarbons and the remaining unconverted higher boiling hydrocarbons; d. combining said combined vapor stream from step b and said further effluent stream from step c; and e. separating said combined streams from step d into a plurality of hydrocarbon product streams.