Process for start-up of a multizone circulating reactor

US10471407B2 · kind B2 · utility

Assignee

• Basell Polyolefine GmbH · DE

Inventors

• Gabriele Mei · Ferrara, IT
• Massimo Covezzi · Ferrara, IT
• Gerhardus Meier · Frankfurt, DE
• Antonio Mazzucco · Ferrara, IT
• Pietro Baita · Rovigo, IT
• Ulf Schueller · Weiterstadt, DE
• Lorella Marturano · Ferrara, IT
• Enrico Balestra · Ferrara, IT

Key dates

• Filing date: Dec 22, 2017
• Grant date: Nov 12, 2019
• Expiry date: Apr 12, 2038

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B01J2208/00716
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

A process for starting a multizone circulating reactor containing no polyolefin particles, comprising the steps of conveying gas through the reactor and the gas recycle line, feeding a particulate material comprising a polymerization catalyst and optionally polyolefin into the reactor, controlling the gas flow in a vertical reactor zone equipped with a throttling valve at the bottom so that the upwards gas velocity in the bottom part of this reaction zone is lower than the terminal free-fall velocity of the particulate material fed into the reactor, and, after the weight of the particulate polyolefin in this reactor zone is higher than the drag force of the upward moving gas, controlling the circulation rate of the polymer particles within the multizone circulating reactor by adjusting the opening of the throttling valve and adjusting the flow rate of a dosing gas.