Continuous gas-phase polymerization processes

US10358509B2 · kind B2 · utility

Assignee

• Basell Polyolefine GmbH · DE

Inventors

• Volker Fraaije · Frankfurt, DE
• Michael W. Lynch · Sharonville, US
• Shahram Mihan · Bad Soden, DE
• Gerhardus Meier · Frankfurt, DE
• Ulf Schueller · Weiterstadt, DE

Key dates

• Filing date: Mar 23, 2016
• Grant date: Jul 23, 2019
• Expiry date: Mar 27, 2036

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08F2500/07
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

The present disclosure relates to a continuous process for the preparation of ethylene homopolymers or ethylene copolymers comprising polymerizing ethylene or copolymerizing ethylene and one or more other olefins in the presence of a chromium catalyst in a gas-phase polymerization reactor which is equipped with a cycle gas line for withdrawing reactor gas from the reactor, leading the reactor gas through a heat-exchanger for cooling and feeding the reactor gas back to the reactor, wherein the polymerization is carried out at a temperature from 30° C. to 130° C. and a pressure of from 0.1 to 10 MPa and an aliphatic carboxylic acid ester having from 8 to 24 carbon atoms is added.