Multistage process for the polymerization of olefins

US9133291B2 · kind B2 · utility

Assignee

• Basell Polyolefine GmbH · DE

Inventors

• Massimo Covezzi · Ferrara, IT
• Giuseppe Penzo · Mantova, IT
• Gabriele Mei · Ferrara, IT
• Giulia Mei · Ferrara, IT
• Pietro Baita · Rovigo, IT
• Gerhardus Meier · Frankfurt, DE
• Antonio De Lucia · Amsterdam, NL
• Ulf Schueller · Weiterstadt, DE
• Gianpiero Ferraro · Ferrara, IT

Key dates

• Filing date: Dec 4, 2012
• Grant date: Sep 15, 2015
• Expiry date: Dec 4, 2032

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08F10/02
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

Process for transferring polyolefin particles from a first gas-phase polymerization reactor to a second gas-phase polymerization reactor in a multistage polymerization of olefins carried out in at least two serially connected gas-phase polymerization reactors,wherein the first gas-phase reactor is a fluidized-bed reactor comprising a gas distribution grid and a settling pipe, which is integrated with its upper opening into the distribution grid and contains a bed of polyolefin particles which moves from top to bottom of the settling pipe,the process comprising the steps ofintroducing a fluid into the settling pipe in an amount that an upward stream of the fluid is induced in the bed of polyolefin particles above the fluid introduction point;withdrawing polyolefin particles from the lower end of the settling pipe; andtransferring the withdrawn polyolefin particles into the second gas-phase polymerization reactor,process for polymerizing olefins comprising such a process for transferring polyolefin particles, reactor suitable as first gas-phase polymerization reactor in the process for polymerizing olefins and process for discharging polyolefin particles from a fluidized-bed reactor.