Method and apparatus for reducing fouling

摘要

Provided herein is a method for operating a slurry polymerization reaction system to reduce, inhibit, and/or prevent fouling in the polymer recovery and separation apparatus, including one or more portions of a high pressure flash tank. The method generally comprises polymerizing a monomer feed in a slurry polymerization reactor in the presence of catalyst and diluent to produce a polymerization effluent; continuously discharging at least a portion of said polymerization effluent from the reactor through a discharge valve; combining a catalyst poison stream with the polymerization effluent downstream of said discharge valve, wherein the catalyst poison stream comprises a catalyst poison that is a gas at standard conditions; and flashing the combination of polymerization effluent and catalyst poison stream in a first flash tank.

主权项

1. A process for producing polymer comprising:
a. polymerizing a monomer feed in a slurry polymerization reactor in the presence of a chromium oxide-based catalyst and diluent to produce a polymerization effluent comprising a slurry of polymer solids, unreacted monomer, and diluent; b. continuously discharging at least a portion of said polymerization effluent from the reactor through a discharge valve; c. continuously combining a catalyst poison stream selected from the group consisting of O2, O3, CO, CO2, NH3, SO, SO2, SO3, or mixtures thereof with the polymerization effluent downstream of said discharge valve, wherein the catalyst poison stream comprises a catalyst poison that is a gas at standard conditions and has a molar ratio of catalyst poison to chromium that is less than 0.1, and wherein the catalyst poison stream comprises at least 70 mol % of a carrier gas; d. flashing the combination of polymerization effluent and the catalyst poison stream in a first flash tank at a pressure greater than or equal to 0.17 MPa to produce a concentrated polymer effluent and a first gas stream comprising vaporized diluent, unreacted monomer, and catalyst poison; and e. condensing the vaporized diluent and unreacted monomer, and removing the catalyst poison from said condensed diluent and monomer as a gas by venting.