Basell Polyolefine Gmbh

Basf Aktiengesellschaft

Other

Elenac Gmbh

Basf Se Corporation

Kaspar Evertz

Hans-Jacob Feindt

Rainer Karer

Philipp Rosendorfer

Wolfgang Micklitz

Paulus De Lange

Andreas Deckers

Guido Funk

Manfred Hecker

Rainer Konrad

Peter Kölle

Peter Bauer

Roland Saive

Armin Lange

Dieter Lilge

Dieter Littmann

Hans-Joachim Mueller

Siegfried Weber

Peter Jutzi

Peter K&ouml;lle

Ingrid Mieling

Michael Witt

Shahram Mihan

Bernhard Rieger

Guenther Schweier

Joachim Berthold

Heinz Friedrich Sutoris

Andreas Daiss

G&uuml;nther Schweier

Stefan Bitterlich

Hans Gropper

Georg Groos

Frank-Olaf Mähling

Günther Schweier

Werner Roell

Peter Koelle

Thomas Letzelter

Frank-Olaf M&auml;hling

Hans Brintzinger

Farid Rizk

Rueger Schlund

Walter Schicketanz

Frank Peter Alt

Hendrik Schönfelder

Thomas Perner

Joachim Werther

Ruerger Schlund

Winfried Mengele

Stefan Wietfeldt-Haltenhoff

Manfred Sandk&uuml;hler

Michael K&auml;mmerer

Thomas Brauch

Hans Werner Siebenhandl

Michael Kämmerer

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

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

A method for the treatment of catalysts or catalyst carriers by: a) introducing and distributing a gas in the lower section of a reactor containing a catalyst or catalyst carrier bulk material; b) forming a fluidized bed in the reactor; c) treating the particles in the fluidized bed while removing the fine particles an/or retaining the course particles by means of a separating organ and d) discharging the reactor. To this end, a reactor bottom which tapers downwards is used.

Fluidized bed method and reactor for the treatment of catalysts and catalyst carriers

In a process for preparing polyethylene in tube reactors with or without autoclaves, where a free-radical initiator is introduced with or without cold ethylene into a flowing ethylene- and comonomer-containing medium, rotation is generated between two streams () to be mixed at an angle () or by provision of a swirl element () in the flow cross section (). In the region of a feed point () for a free-radical initiator, there is provided a cross-sectional constriction () at which the free-radical initiator is introduced through an optimized off-center outlet opening () of an introduction finger () into the rotating flow ().

Device for feeding reactor initiators

A continuous vapor-phase fluidized-bed process for the preparation of ethylene homopolymers and copolymers having a density of from 0.87 to 0.97 g/cmin which ethylene or mixtures of ethylene and C-Ca-monoolefins are (co)polymerized in the presence of a supported chromium catalyst in the polymerization zone of a vapor-phase fluidized-bed reactor under pressures ranging from 1 to 100 bar and at temperatures ranging from 30&#xb0; to 125&#xb0; C. in the vapor phase in an agitated bed of bulk material comprising particulate polymer, the resultant heat of polymerization is removed by cooling the recirculated reactor gas and the resulting (co)polymer is removed from the vapor-phase fluidized-bed reactor, wherein, for the preparation of a (co)polymer of a specific density d, the (co)polymerization is carried out at a temperature which is in a range restricted by an upper envelope defined by equation Iand a lower envelope defined by equation IIin which the variables have the following meanings:

Vapor-phase fluidized-bed process and ethylene homopolymers and copolymers produced thereby

In a process for producing Phillips catalysts in which an oxidic support material is treated in suspension with a chromium salt solution and subsequently, after removing the solvent, calcined in an oxygen-containing atmosphere at above 300&deg; C., the oxidic support material and/or the catalyst after calcination are/is, according to the present invention, comminuted until a mean particle size of <100 &mgr;m has been reached and the proportion of particles having a size of <50 &mgr;m is at least 30%, preferably in the range from 40 to 80%. A process for preparing homopolymers or copolymers of ethene in a loop reactor at from 30 to 150&deg; C. under a pressure in the range from 0.2 to 15 MPa in the presence of a catalyst produced by the process of the present invention is also provided.

Method for producing Phillips catalysts for polymerizing olefins with better productivity rates in the particle-form process

Method for the discontinuous thermal treatment of catalyst material

Gas phase fluidized bed method and ethylene homo- and copolymers obtained using said method

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

In a process for the polymerization or copolymerization of ethylenically unsaturated monomers in the presence of polymerization initiators which decompose to form free radicals in a continuously operated polymerization apparatus comprising a fresh gas feed line, a precompressor, a postcompressor, a reactor, a pressure maintenance valve, a high-pressure circuit having a high-pressure product separator and a high-pressure circulation gas return line, a product valve and a low-pressure circuit having a low-pressure product separator and a low-pressure circulation gas return line, nitrogen monoxide or oxygen is introduced as inhibitor into the high-pressure circuit, into the low-pressure circuit and/or the precompressor.

Method for carrying out radical ethylene high-pressure polymerization while preventing undesired polymer deposits

A method for the treatment of catalyst or catalyst support material in an apparatus in which the treatment is carried out continuously in such a way that the physical and/or chemical conditions change during entry of the catalyst or catalyst support material into the apparatus and/or during exit thereof from the apparatus and/or the catalyst or catalyst support material is transported in the apparatus through zones ( ) having different physical and/or chemical conditions.

Method and apparatus for the continuous treatment of catalyst and catalyst support material

Polyolefins, preferably polyethylene, are prepared in a continuous gas-phase polymerization process in which the fluid monomeric component, preferably ethylene, and, optionally, one or more comonomers is/are polymerized in the polymerization zone of a fluidized-bed reactor in the presence of one or more catalysts, optionally with the addition of various auxiliaries, under reaction conditions where the fluidizing gas is circulated to remove the heat of polymerization or reaction and the polymerization product is taken from the circuit and the corresponding amount of monomer and, optionally, comonomers and optionally further auxiliaries are fed in, wherein the fluidizing gas discharged from the fluidized-bed reactor is cooled by means of a direct cooling apparatus in which the coolant is brought into direct contact with the fluidizing gas and heated coolant is passed to at least one further cooling stage in order to cool it and is, after cooling, wholly or partly returned to the direct cooling apparatus and/or heated or cooled coolant is wholly or partly returned to the reactor.

Gas-phase polymerization with direct cooling

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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Schifferstadt, Germany

Kaspar Evertz