SUSPENSION PROCESS FOR PREPARING ETHYLENE COPOLYMERS IN A REACTOR CASCADE

A process for preparing a multimodal ethylene copolymer in suspension in a reactor cascade comprising a first polymerization reactor and one or more subsequent polymerization reactors comprising separating the suspension formed in the reactor cascade into multimodal ethylene copolymer particles and recovered suspension medium, purifying a part of the recovered suspension medium in a purification section for producing purified components of the recovered suspension medium, and recycling at least some or a 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, which comprise the diluent, undergo a catalytic hydrogenation be-fore being introduced into the first polymerization reactor, and an apparatus for polymerizing olefinic monomers in suspension in a reactor cascade.