Basell Polyolefine Gmbh

Reinhard Kuehl

Elke Damm

Rodrigo Carvajal

Phil Pyman

Gerhardus Meier

Harald Prang

Peter Kruempel

Volker Dolle

Giuseppe Penzo

Peter Rohrbach

Michael Aulbach

Michael Chatterjee

Alexander Seifert

A process for preparing an ethylene polymer in a suspension polymerization including the steps of separating the formed suspension of ethylene polymer particles in a solid-liquid separator into ethylene polymer particles and mother liquor, transferring a first part of the mother liquor into a work-up section including an evaporation unit for producing a wax-depleted portion of the mother liquor, wherein a protic agent is added to the part of the mother liquor which is transferred into the work-up section, and recycling a first part of the wax-depleted portion of the mother liquor to the polymerization reactor or the series of polymerization reactors.

Suspension process for preparing ethylene polymers comprising workup of the suspension medium

A process for preparing a multimodal ethylene copolymer in suspension in a reactor cascade including a first polymerization reactor and subsequent polymerization reactor(s) including polymerizing ethylene and C-C-1-alkenes and forming a suspension of multimodal ethylene copolymer particles in a suspension medium made from or containing a diluent, transferring the suspension into a separator, wherein the suspension is separated into multimodal ethylene copolymer particles and recovered suspension medium, purifying part of the recovered suspension medium for producing purified components of the recovered suspension medium, and recycling part of the purified components of the recovered suspension medium to the first polymerization reactor of the reactor cascade, wherein the purified components of the recovered suspension medium recycled to the first polymerization reactor and made from or containing the diluent, undergo catalytic hydrogenation before being introduced into the first polymerization reactor.

Suspension process for preparing ethylene copolymers in a reactor cascade

A process for continuously preparing a polyolefin composition made from or containing a polyolefin and carbon black in an extruder device. The process includes the steps of supplying polyolefin in form of a polyolefin powder and carbon black to a mixing device; alternatively, (a) measuring the flow rate of the polyolefin powder supplied to the mixing device or (b) measuring the flow rate of the polyolefin pellets prepared in the extruder device; adjusting the flow rate of the carbon black to the mixing device in response to the measured flow rate of the polyolefin powder or adjusting the flow rate of the polyolefin powder to the mixing device in response to the measured flow rate of the polyolefin pellets; melting and homogenizing the mixture within the extruder device; and pelletizing the polyolefin composition into the polyolefin pellets.

Process for preparing a polyolefin composition

A process for continuously preparing a polyolefin composition made from or containing a bimodal or multimodal polyolefin and one or more additives in an extruder device equipped with at least one hopper. The process includes the steps of supplying a bimodal or multimodal polyolefin in form of a polyolefin powder to the hopper; (a) measuring the flow rate of the polyolefin powder or (b) measuring the flow rate of the prepared polyolefin pellets; supplying one or more additives to the hopper; adjusting the flow rates of the additives supplied to the hopper in response to the measured flow rate of the polyolefin powder or adjusting the flow rate of the polyolefin powder in response to the measured flow rate of the polyolefin pellets; melting and homogenizing the polyolefin powder and additives within the extruder device; and pelletizing the molten polyolefin composition into the polyolefin pellets.

A method for preparing a dried powder is provided. The facility includes a first drying chamber having a heating element and a second drying chamber. A mixture of powder and diluent is introduced into the first drying chamber. A pre-dried powder is transferred from the first drying chamber into the second drying chamber. A dried powder, including a recirculated amount of powder and a discharge amount of powder, is formed in the second drying chamber. The recirculated amount of the dried powder is transferred by a conveyor device from the second drying chamber into the first drying chamber. The discharge amount of the dried powder is discharged from the second drying chamber.

Process for the preparation of a dried powder

A slurry polymerization process for the preparation of polyethylene in a reactor cascade of two or more polymerization reactors including the steps of feeding to a polymerization reactor amounts of ethylene, of a Ziegler catalyst, of fresh aluminum alkyl and of a diluent; feeding the slurry product withdrawn from the polymerization reactor to a second polymerization reactor; and feeding additional amounts of ethylene and of diluent wherein the ethylene is first passed through an ethylene purification unit, which reduces at least the concentration of carbon monoxide, carbon dioxide, oxygen, acetylene and water contained in the ethylene, before it is fed to the two or more polymerization reactors of the reactor cascade.

Multi-reactor slurry polymerization processes with high ethylene purity

The present disclosure generally relates to a slurry polymerization process for the preparation of polyethylene in the presence of a Ziegler catalyst and aluminum alkyl co-catalyst in at least one polymerization reactor, in which process suspension medium comprising a concentration of aluminum alkyl co-catalyst is recycled to the polymerization, the concentration of aluminum alkyl co-catalyst in the recycled suspension medium is determined; and the amount of fresh aluminum alkyl co-catalyst fed to the polymerization is adjusted to maintain a targeted aluminum alkyl co-catalyst concentration in the recycled suspension medium.

Methods for controlling aluminum alkyl feed to a slurry polymerization process

A process for the preparation of polyethylene by polymerizing in a slurry ethylene and optionally one or more Cto Calpha-olefins in a reactor system comprising a polymerization reactor and one or more first heat exchangers located outside the polymerization reactor where the slurry in the polymerization reactor is cooled by withdrawing slurry from the polymerization reactor, cooling the slurry in the one or more first heat exchangers and returning the cooled slurry to the polymerization reactor, wherein the one or more first heat exchangers are cooled by a first coolant having a temperature of 29&#xb0; C. or higher.

Ethylene polymerization process having improved heat exchanger performance

A method for controlling a slurry polymerization for the preparation of polyethylene, where the polyethylene is formed in a polymerization reactor comprising a vapor section by contacting a Ziegler-type catalyst, ethylene, and either hydrogen or, as comonomer(s), one or more Cto Calpha-olefins or hydrogen and one or more Cto Calpha-olefins, wherein the ethylene partial pressure is maintained by adjusting the flow rate of the catalyst to the polymerization reactor and the hydrogen/ethylene and comonomer/ethylene partial pressure ratios are maintained by adjusting the flow rates of hydrogen and/or of the one or more comonomers to the polymerization reactor.

Process for controlling an ethylene polymerization process

The present disclosure relates to a process for the preparation of polyethylene by polymerizing in a slurry ethylene and optionally one or more Cto Calpha-olefins. In some embodiments, the polymerization is carried out in a cylindrical polymerization reactor equipped with an agitator for mixing the contents of the reactor and inducing a flow of the slurry, the ethylene is fed into the reactor by an ethylene injection system comprising one or more injection nozzles which project through the bottom reactor head or through the reactor wall and extend from 0.02-0.5 times the inner diameter D into the reactor, and the ethylene exits the injection nozzle with an exit velocity from 10-200 m/s.

Process for ethylene polymerization with improved ethylene feed system

Process for the preparation of a polyolefin polymer by continuously polymerizing one or more olefin monomers in suspension at temperatures of from 40&#xb0; C. to 120&#xb0; C. and pressures of from 0.1 to 10 MPa in the presence of a polymerization catalyst in at least one polymerization reactor, comprising a) withdrawing a suspension of solid polyolefin particles in a suspension medium from the polymerization reactor, wherein the suspension has a temperature of from&#xb0; C. to 120&#xb0; C.; b) feeding the suspension withdrawn from the polymerization reactor to a moderating vessel; c) keeping the suspension in the moderating vessel at a temperature of from 60&#xb0; C. to 85&#xb0; C. for a time sufficiently long that the mean residence time of the suspension in the moderating vessel is at least 5 min; d) withdrawing suspension from the moderating vessel; e) cooling the suspension withdrawn from the moderating vessel to a temperature of from 20&#xb0; C. to 55&#xb0; C.; and f) mechanically separating the solid polyolefin particles from the liquid suspension medium, and method for controlling the content of hydrocarbons with from 14 to 300 carbon atoms in a polyolefin polymer prepared by polymerizing one or more olefin monomers in suspension.

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Bornheim, Germany

Reinhard Kuehl