Technology Unit

The reaction mixture leaving the hyper-compressor is fed to a tubular reactor. High pressure tubular reactors are offered in two generally different forms, TS and TM with different reaction zones. In the reaction zones, the polymerisation is initiated by adding the polymerisation initiator (oxygen or peroxide). Due to the exothermic nature of the ethylene polymerisation, the reaction mixture heats up, and the resulting polyethylene product is in a molten state. Temperature is controlled by the concentration and type of added initiators as well as by the hot water circuit. Side streams of cooled fresh ethylene can be used for a fast cool down of the reaction mixture and restart of the initiation. The conversion of more than 35% per pass can be achieved by this procedure.