Basell Polyolefine Gmbh

Michael Witt

Andreas Deckers

Kaspar Evertz

Dieter Lilge

Paulus De Lange

Farid Rizk

Thomas Perner

The invention relates to a method and an apparatus for the polymerization of gaseous olefins, in particular of ethylene and at least one &agr;-olefin, in the gas phase in a stirred or fluidized, catalyst-containing polymerization zone ( ) and at least one decompression zone ( ) downstream of the polymerization zone ( ). The mixture of solid (co)polymer and unreacted monomers leaving the polymerization zone ( ) flows through a settling zone, in particular in the form of a settling leg ( ), before the decompression zone.

Gas phase polymerization method

The invention relates to a method for drying and degassing polyolefins in which the polymerization product leaving a polymerization reactor is brought into contact with a degassing medium and simultaneously decompressed. The degassing medium employed according to the invention is the monomer to be polymerized, which, in particular, flows through a decompression tank in a circulation process and which is preferably also enriched with ethylene or other low-boiling olefins in an amount in the range from 0 to 100 mol %, based on the total amount of circulating gas. A polymerization in an amount of up to 10%, based on the total polymerization conversion, takes place in accordance with the invention inside the decompression tank.

Method for drying and degassing polyolefins

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Rotorua, New Zealand

Michael Witt