Vapor phase reactor off-gas recycle system for use in the vapor state polymerization of monomers

Claim 1

An essentially isobaric, essentially total, reactor off-gas recycle process comprising: a. removing from a horizontal, vapor state reactor operating at polymerization conditions, off-gases containing at least quench liquid vapor and one or more polymerizable monomers from above a stirred, subfluidized bed of polymer distributed within the one or more polymerization sections of said reactor and removing entrained polymer from said off-gases to form a reactor off-gas stream; b. condensing quench liquid from and removing any remaining entrained polymer from said reactor off-gas stream to form liquid recycle which contains at least said quench liquid and said any remaining entrained polymer and gaseous recycle which contains a reduced amount of said quench liquid vapor; c. leading said gaseous recycle together with at least make-up of said one or more polymerizable monomers to one or more inlets spaced along said reactor and positioned largely underneath the surface of said bed and introducing said gaseous recycle and said at least make-up into said reactor; d. leading a first portion of said liquid recycle to a plurality of inlets spaced along said reactor and located above the surface of said bed and introducing said portion into said reactor; e. leading a second smaller portion of said liquid recycle together with make-up of at least one catalyst component to one or more inlets spaced along said reactor and introducing said portion into said reactor; and f. introducing make-up quench liquid into said reactor.