US 11,834,531 B2
Suspension process for preparing ethylene copolymers in a reactor cascade
Elke Damm, Bad Vilbel (DE); Reinhard Kuehl, Bornheim (DE); and Rodrigo Carvajal, Bonn (DE)
Assigned to Basell Polyolefine GmbH, Wesseling (DE)
Appl. No. 17/252,190
Filed by Basell Polyolefine GmbH, Wesseling (DE)
PCT Filed Jun. 19, 2019, PCT No. PCT/EP2019/066121
§ 371(c)(1), (2) Date Dec. 14, 2020,
PCT Pub. No. WO2019/243384, PCT Pub. Date Dec. 26, 2019.
Claims priority of application No. 18179141 (EP), filed on Jun. 21, 2018.
Prior Publication US 2021/0198387 A1, Jul. 1, 2021
Int. Cl. C08F 2/01 (2006.01); C08F 2/14 (2006.01); C08F 2/18 (2006.01); C08F 6/24 (2006.01); C08F 210/02 (2006.01); C08F 210/14 (2006.01); C08F 210/16 (2006.01); C08F 2/00 (2006.01); B01J 19/18 (2006.01)
CPC C08F 2/01 (2013.01) [C08F 2/001 (2013.01); C08F 2/14 (2013.01); C08F 2/18 (2013.01); C08F 6/24 (2013.01); C08F 210/02 (2013.01); C08F 210/14 (2013.01); C08F 210/16 (2013.01); C08F 2500/05 (2013.01)] 15 Claims
OG exemplary drawing
 
1. A process for preparing a multimodal ethylene copolymer in suspension in a reactor cascade comprising a first polymerization reactor and one or more subsequent polymerization reactors comprising the steps of:
polymerizing, in the reactor cascade, ethylene and one or more C3-C12-1-alkenes at temperatures of from 40 to 150° C. and pressures of from 0.1 to 20 MPa in the presence of a polymerization catalyst and forming a suspension of multimodal ethylene copolymer particles in a suspension medium comprising a diluent,
transferring the suspension of multimodal ethylene copolymer particles into a separator, wherein the suspension is separated into multimodal ethylene copolymer particles and recovered suspension medium,
purifying a first part of the recovered suspension medium in a purification section for producing purified components of the recovered suspension medium, and
recycling a first part of the purified components of the recovered suspension medium to the first polymerization reactor of the reactor cascade,
wherein the purified components of the recovered suspension medium recycled to the first polymerization reactor and comprise the diluent, undergo a catalytic hydrogenation before being introduced into the first polymerization reactor.