Patent ID: 6086749
Filing Date: 2000-07-11
Classification: B01J,C10G

Abstract:
A method for hydroprocessing a hydrocarbon feed stream that is upflowing through a hydroconversion reaction zone having catalysts of different densities comprising the steps of:(a) disposing a plurality of first catalyst particles in a hydroconversion reaction zone, with each of said first catalyst particles having a first catalyst base and a first catalyst density;(b) upflowing into said plurality of first catalyst particles a hydrocarbon feed stream having a liquid component and a hydrogen-containing gas component;(c) disposing a plurality of second catalyst particles in the hydroconversion reaction zone, with each of said second catalyst particles comprising a second catalyst base and a second catalyst density to produce a catalytic mixture which includes the first catalyst particles of step (a) and the second catalyst particles;(d) continuing upflowing into said catalytic mixture of step (c) the hydrocarbon feed stream;(e) withdrawing a volume of at least partially spent catalyst from said hydroconversion reaction zone; and(f) adding fresh catalyst into said hydroconversion reaction zone at a volume to substantially replace said volume of said at least partially spent catalyst.