Patent ID: 8217125
Filing Date: 2012-07-10
Classification: C08F

Abstract:
1. A process for producing polyolefins, comprising the steps of: polymerizing at least one olefin monomer to obtain a reaction mixture; separating at least a part of the reaction mixture to obtain a separated portion; dividing the separated portion of the reaction mixture into a polymer-lean fraction and a polymer-rich fraction, wherein the division is carried out in the liquid or super critical state; subjecting at least a part of the polymer-lean fraction to a purification step to obtain a purified polymer-lean fraction; recycling at least a part of the purified polymer-lean fraction back into the polymerizing step of the at least one olefin monomer; wherein the polymerizing step comprises slurry polymerization; the polymer-lean fraction is in liquid form or in a super critical state during all of the process steps; and the subjecting of the at least a part of the polymer-lean fraction to a purification step and the recycling of the at least a part of the purified polymer-lean fraction comprise: dividing the polymer-lean fraction into a first and a second stream; recycling the first stream to the polymerizing step of the at least one olefin monomer; purifying the second stream; and recycling at least a part of the purified second stream back to the polymerizing step of the at least one olefin monomer.