Basell Polyolefine Gmbh

Other

Elenac Gmbh

Peter Kölle

Shahram Mihan

Kaspar Evertz

Joachim Wulff-Döring

Rainer Karer

Hans-Jacob Feindt

Andreas Deckers

Wolfgang Rohde

Guido Funk

Heinz Vogt

Martin Lux

Philipp Rosendorfer

Wolfgang Micklitz

Andreas Haufe

Ingo Treffkorn

Wolfgang Gsella

Joachim Berthold

Frank Peter Alt

Markus Meierhöfer

The invention relates to a continuous process for preparing polyolefins having a bimodal or multimodal molar mass distribution in suspension in at least two reactors R, R.x, R.y which are connected in series and in which different reaction conditions are set. In this process, the offgases A, A.x, A.y, Aand Aleaving all the reactors connected in series are firstly collected, the collected offgases are then compressed in a compression stage, the compressed offgases are subsequently cooled and the cooled material is separated into a gaseous fraction and a liquid fraction. The separated fractions are then recirculated to the polymerization process at different points. The process of the invention allows the total conversion of the polymerization, based on monomer and comonomer used, to be increased to a surprising extent.

Process for preparing polyolefins in suspension

Gas-phase fluidized-bed reactor for polymerizing ethylenically unsaturated monomers, comprising a reactor chamber () in the form of a vertical tube, if desired a calming zone () following the upper section of the reactor chamber, a circulation gas line (), a circulation gas compressor () and a cooling device (), where, in the region of transition of the reaction gas from the circulation gas line into the reactor chamber and in the lower section of the reactor chamber itself, there is either no gas distributor plate at all or only a gas distributor plate the total surface area of whose gas orifices is more than 20% of the total surface area of said gas distributor plate.

Gaseous phase fluidized-bed reactor

Catalyst for the polymerization and/or copolymerization of olefins which is obtainable by application to a finely divided inorganic support and concluding calcination at temperatures of from 350 to 1050&#xb0; C. and has a chromium content of from 0.1 to 5% by weight and a zirconium content of from 0.5 to 10% by weight, in each case based on the element in the finished catalyst, with the molar ratio of zirconium to chromium being from 0.6 to 5.

Catalyst comprising chromium and zirconium for the polymerization and/or copolymerization of olefins

Process for preparing a supported catalyst for the polymerization and/or copolymerization of olefins which has a chromium content of from 0.01 to 5% by weight, based on the element, which comprises

Process for preparing a chromium-based catalyst for the polymerization and/or copolymerization of olefins

Process for polymerizing at least one olefinic monomer in a loop reactor at from 20 to 150&#xb0; C., but below the melting point of the polymer to be formed, and a pressure of from 5 to 100 bar, where the polymer formed is present in a suspension in a liquid or supercritical suspension medium and this suspension is circulated by means of an axial pump, wherein the loop reactor comprises a cyclic reactor tube whose diameter varies by at least 10%, based on the predominant reactor tube diameter, and in which there is at least one widening and narrowing in a region other than that of the axial pump.

Loop reactor with varying diameter for olefin polymerization

Method of metering at least one solid, particulate catalyst into a reactor containing a fluidized bed () of particles in an at least partly gaseous medium, in which the catalyst is metered discontinuously at prescribed time intervals into the fluidized bed () at at least one metering point (). According to the present invention, a fluid stream is firstly introduced into the reactor () so that a region having a reduced particle density is formed in the fluidized bed () around the metering point () and the catalyst is subsequently metered into this region. As a result of the prior introduction of a fluid stream ('preblowing') before the actual introduction of the catalyst, the catalyst can penetrate significantly deeper into the fluidized bed from the metering point due to the reduced particle density and is dispersed better.

Discontinuous metering of catalysts and process auxilliaries into a gas-phase fluidized-bed reactor

Process for polymerizing at least one olefinic monomer selected from ethylene, propylene and 1-butene in a loop reactor in the presence of a polymerization catalyst at from 20 to 150&#xb0; C., but below the melting point of a polymer to be formed, and a pressure of from 43 to 80 bar, where the polymer formed is present in a suspension in a liquid or supercritical suspension medium and wherein the suspension is circulated by means of an axial pump, wherein the polymerization is carried out at an average solids concentration in the reactor of more than 53% by weight, in the case of continuous product discharge, and at an average solids concentration in the reactor of more than 45% by weight, in the case of discontinuous product discharge, and wherein the polymerization is carried out at an ethylene concentration of at least 10 mol %, based on the suspension medium.

The invention relates to a process for preparing a catalyst for the polymerization of olefins, which comprises:

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Köln-Rodenkirchen, Germany

Peter Kölle