Basell Polyolefine Gmbh

Klaus Berhalter

Rainer Karer

Iakovos Vittorias

Manfred Hecker

Paulus De Lange

Gerd Mannebach

Cyrus Ahmadzade-Youssefi

Andrei Gonioukh

Stephan Schmitz

Barbara Gall

Eberhard Herrmann

Jörg Halpap

Thomas Herrmann

Axel Hamann

Horst Klassen

Paulus-Petrus Maria De Lange

Christian-Ulrich Schmidt

Walter Schicketanz

Gerald Lutz

Sebastian Weiand

Axel Sperber

Laurent Hautier

Christoph Treis

Thomas Andreas Hora

Steve Makin

Kevin Taylor

Jürgen Schwind

Robert Gelinas

Ursula Krügers

David Finotto

Gilles Rieu

Gerard Duc

Markus Busch

Process for polymerizing or copolymerizing ethylenically unsaturated monomers in the presence of free-radical polymerization initiators at pressures in the range of from 110 MPa to 500 MPa and temperatures in the range of from 100&#xb0; C. to 350&#xb0; C. in a continuously operated polymerization apparatus, wherein the reaction gas composition is compressed to the polymerization pressure by at least two sequentially operating compressors in which a low-pressure compressor first compresses the reaction gas composition to a pressure of from 10 MPa to 50 MPa and a high-pressure compressor then further compresses the reaction gas composition to the polymerization pressure wherein the high-pressure compressor is operated with a polyalkylene glycol based synthetic lubricant and oxygen is introduced into the fresh gas feed or into the polymerization apparatus in an amount that the gas composition to be compressed in the high-pressure compressor has an oxygen content in the range of from 0.01 ppm to 0.9 ppm.

Process for polymerizing or copolymerizing ethylenically unsaturated monomers in the presence of free-radical polymerization initiators

Process and apparatus for discharging polyolefin particles from a gas-phase polymerization reactor of a pressure from 1.0 MPa to 10 MPa to a discharge vessel of a pressure from 0.1 MPa to 1.0 MPa wherein the discharging is carried out discontinuously through at least two discharge lines in which the polyolefin particles are transported horizontally or upwards.

Method and apparatus for discharging a polymer from a gas-phase reactor

Process for the preparation of ethylene homopolymers or copolymers in the presence of free-radical polymerization initiator at from 100&#xb0; C. to 350&#xb0; C. and pressures in the range of from 160 MPa to 350 MPa in a high-pressure polymerization unit comprising a high-pressure reactor with one or more reaction zones, to each of which free-radical polymerization initiator is fed, which is controlled by a model based predictive controller carrying out the steps.

Process for the preparation of ethylene homopolymers or copolymers in a high-pressure reactor controlled by a model based predictive controller

Continuous feed of auxiliaries for the polymerization reaction of ethylene, propene, and other higher homologous olefins in the preparation of homo- and copolymers, avoiding production of inhomogeneities, such as lumps or chunks which are present because the condition of the auxiliaries is not suitable for precise metering, becomes possible when auxiliaries in paste or solid form, in particular antistatic auxiliaries, are subjected, prior to feed, to a heat treatment in the presence of a solvent at a temperature of from 20 to 80&#xb0; C., and then recooled, and then fed to the polymerization reaction.

Continuous feed of auxiliaries for the polymerization of olefins

An apparatus for the polymerization of olefins, in particular ethylene, comprising a gas-phase fluidized-bed reactor (), a recycle gas line () connected to the reactor for discharging and recirculating the recycle gas stream comprising the unpolymerized olefin and a cyclone () located in the recycle gas line for the reduction and precipitation of the solid particles entrained in the recycle gas from the reactor, with the cyclone comprising an upper section () which has an essentially vertical central axis, whose wall extends along a rotationally symmetric body and which is provided with a cyclone inlet () arranged eccentrically relative to the central axis, a middle section () which adjoins the upper section () and whose wall extends along a rotationally symmetric body which tapers in a downward direction, a lower section () for discharging the solid particles precipitated from the recycle gas which adjoins the middle section () and whose wall extends along a rotationally symmetric body and a tube () extending essentially axially symmetrically down into the upper section and, if appropriate, the middle section for discharging the recycle gas which has been freed of the particles. According to the invention the ratio Hof the distance hfrom the lower end of the tube () extending downward into the cyclone to the intersection () of an imaginary extension of the wall of the downward-extending tube () with the wall of the middle section () to the diameter dof the downward-extending tube () is from 3 to 8, in particular from 4 to 7.

Apparatus for the gas-phase polymerization of olefins, in particular ethylene

Apparatus for the polymerization of olefins, in particular ethylene, comprising a gas-phase fluidized-bed reactor (), a product offtake line () for taking polymer particles either continuously or discontinuously from the reactor (), which line () is connected to a depressurization vessel () for separating polymer particles and gas, a recycle gas filter () for freeing the gas of entrained fine particles connected to the depressurization vessel (), a compressor which compresses the gas which has been freed of fine particles and recirculates it into the reactor (), with the recycle gas filter () having an inlet chamber () provided with a gas inlet (), an outlet chamber () provided with a gas outlet (), an essentially vertical sheet-like filter medium () for retaining the fine particles which separates the inlet chamber () from the outlet chamber () and a particle outlet (). The inlet chamber () has a dividing wall () which is arranged essentially parallel to the filter medium () and separates the inlet chamber () into an inflow region (), which is connected to the gas inlet (), and a filter region () in which the filter medium is located and has an upper opening and a lower opening which are dimensioned so that from 60 to 90% of the volume flow flows through the upper opening so that flow along the filter medium () from the top downward results.

Apparatus and process for the gas-phase polymerization of olefins

A process for preparing polyethylene from 'feed ethylene' comprises: a) a hydrogenation stage in which 'feed ethylene' containing impurities or secondary components such as acetylene and ethane is reacted with hydrogen to remove the acetylene by catalytic hydrogenation to form ethylene and part of the ethylene is converted into ethane, and b) a polymerization stage in which the ethylene leaving stage a) is reacted in the gas phase in a fluidized-bed reactor to form polyethylene, where the fluidizing gas used comprises, on entering the reactor, ethene and from 20 to 70% by volume of ethane, based on the total volume of the fluidizing gas, possibly together with further components, where, in a), ethylene is converted in a targeted manner into ethane in addition to the ethane already present in the &#x201c;feed ethylene&#x201d; so that the concentration specified in b) results. An apparatus for carrying out the process is also provided. In the process claimed, ethane is used to increase the heat capacity of the fluidizing gas used.

Optimization of heat removal in a gas-phase fluidized-bed process

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Bornheim-Dersdorf, Germany

Klaus Berhalter