Patent ID: 6066701
Filing Date: 2000-05-23
Classification: B01J,C08F

Abstract:
A method for polymerizing olefins comprising:(a) introducing into a first reaction zone a fresh olefin polymerization catalyst;(b) contacting said fresh olefin polymerization catalyst in said first reaction zone with a first vent mixture at a first feed rate and under conditions sufficient to form and avoid melting a polyolefin, wherein first vent mixture comprises unreacted olefins and diluent vented from a second reaction zone;(c) withdrawing a vent product of unreacted olefins and diluent from said first reaction zone;(d) withdrawing from said first reaction zone a first product mixture comprising said catalyst and said polyolefin;(e) passing said first product mixture to said second reaction zone;(f) contacting said first product mixture in said second reaction zone with a second vent mixture at a second feed rate and under conditions sufficient to form and avoid melting said polyolefin, wherein said second vent mixture comprises a material selected from the group consisting of a fresh feed and a mixture comprising unreacted olefins and diluent from a third reaction zone; and(g) withdrawing from said second reaction zone a second product mixture comprising said catalyst and said polyolefin.