Societe Chimique Des Charbonnages-cdf Chimie

Societe Chimique Des Charbonnages

Ethylene Plastique

Bernard Levresse

Jean-Pierre Machon

Pierre Gloriod

Robert Fonmartin

A device for separating a high pressure polyphase mixture consisting of a gas charged with liquid particles, and particularly a mixture of ethylene and polyethylene, which comprises a cylindrical vertical enclosure into which extends an inlet means for supplying the mixture thereto and which is provided at its lower end with an outlet for discharging separated liquids; a vertical cyclone in communication with the enclosure for receiving separated gases therefrom and having an outlet at its upper end for discharging gases separated in the cyclone and a liquid outlet at its lower end for discharging separated liquids therefrom; and an ejector comprising a nozzle, through which the polyphase mixture is fed, a mixing zone connected to the liquid outlet of the cyclone and a diffuser section for reducing the speed of the resultant mixture and being connected to the inlet means for supplying the polyphase mixture to the enclosure.

High pressure separation process

High pressure separation device

A process and apparatus for the polymerization of ethylene in at least one multizone reactor at a pressure of 300 to 2500 bars and at a temperature of 150 to 350.degree. C. The reaction mixture is passed from the reactor to a separator at a pressure of 50 to 500 bars in which the polymer separates from the gas. The polymer is then passed to a hopper at a pressure of 1 to 20 bars in which the major part of the gas remaining dissolved in the polymer is removed. The gas from the separator is recompressed and is returned only to the first zone of the reactor.

Process for polymerizing ethylene

The present invention relates to a process for the continuous polymerisation and copolymerisation of ethylene under a pressure higher than 500 bars and at temperatures higher than about 160.degree. C in the presence of a catalyst containing a derivative of a transition metal and an organic derivative of aluminium, wherein there is injected into the reaction mixture at the end of reaction at least one alkali metal salt or alkaline earth metal salt of a carboxylic acid, in an amount sufficient to bring about the deactivation of the catalyst, said salt being so chosen that its reaction products with the constituents of the catalyst remain in the polymer.

Deactivation of catalysts of the Ziegler type used for the preparation

A method for the polymerization or copolymerization of ethylene comprising polymerizing the ethylene at a pressure greater than 500 bars, at a temperature in the range 160.degree. to 280.degree.C and under conditions in which polymerization takes place in a single liquid phase, in the presence of a catalyst system comprising A. an alkylsiloxalane derivative of the formula, ##EQU1## and B. a halogenated titanium compound of the titanium trichloride type, the Al/Ti ratio between the constituents being between 1 and 10.

Growing community of inventors

Lillebonne, France

Bernard Levresse