Energy-saving process for manufacturing polyethylene and the related manufacturing device

摘要

Polyethylene is produced in at least one reactor under a pressure of 800 to 2500 bars and a temperature of 150 DEG to 350 DEG C., and the reaction mixture exiting the reactor through an expansion valve and supplied to a separator under a pressure of 50 to 400 bars is cooled by passing a flow Q of the mixture through a turbine. The turbine comprises at least one stage with a fixed nozzle and a bladed wheel having a rotation speed of between 12,000 and 40,000 r.p.m. Ethylene discharged from the separator is recycled to the inlet of a compressor, and the discharge from the compressor is supplied to the reactor.