US 12,460,022 B2
Suspension process for preparing ethylene polymers comprising workup of the suspension medium
Reinhard Kuehl, Bornheim (DE); Volker Dolle, Bensheim (DE); Peter Rohrbach, Hofheim/Ts. (DE); and Elke Damm, Bad Vilbel (DE)
Assigned to Basell Polyolefine GmbH, Wesseling (DE)
Appl. No. 17/912,618
Filed by Basell Polyolefine GmbH, Wesseling (DE)
PCT Filed Mar. 19, 2021, PCT No. PCT/EP2021/057088
§ 371(c)(1), (2) Date Sep. 19, 2022,
PCT Pub. No. WO2021/191076, PCT Pub. Date Sep. 30, 2021.
Claims priority of application No. 20165161 (EP), filed on Mar. 24, 2020.
Prior Publication US 2023/0133399 A1, May 4, 2023
Int. Cl. C08F 210/16 (2006.01); C08F 6/00 (2006.01); C08F 6/24 (2006.01); C08F 10/02 (2006.01)
CPC C08F 6/003 (2013.01) [C08F 6/24 (2013.01); C08F 10/02 (2013.01); C08F 210/16 (2013.01); C08J 2323/08 (2013.01); C08J 2323/16 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A process for preparing an ethylene polymer in a suspension polymerization in a polymerization reactor or a series of polymerization reactors comprising the steps of:
polymerizing ethylene or copolymerizing 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 ethylene polymer particles in a suspension medium comprising a hydrocarbon diluent,
transferring the suspension of ethylene polymer particles into a solid-liquid separator, wherein the suspension is separated into ethylene polymer particles and mother liquor,
transferring a first part of the mother liquor into a work-up section comprising an evaporation unit for producing a wax-depleted portion of the mother liquor, wherein a protic agent is added to the part of the mother liquor which is transferred into the work-up section, and
recycling a first part of the wax-depleted portion of the mother liquor to the polymerization reactor or the series of polymerization reactors.