Process and Apparatus for Continuous Solution Polymerization

Abstract

Provided are processes and apparatuses for continuous solution polymerization which can mitigate fouling during the production of propylene-based polymers.

What is claimed is: 
     
         1 . A plant for continuous solution polymerization of a feed comprising one or more olefin monomers and a solvent, the plant comprising:
 a reactor;   blending means to blend one or more olefin monomers and a solvent to produce a feed for the reactor;   a pump for pressurizing the feed; and   one or more heat exchangers for cooling the feed prior to entry into the reactor;   wherein at least one heat exchanger is located downstream of the pump,   wherein the feed enters the pump at a temperature above the cloud point of the polymer produced in the reactor, and   wherein the polymer produced in the reactor is a propylene-based polymer.   
     
     
         2 . The plant of  claim 1 , wherein the total differential head of the pump stays substantially the same during the continuous solution polymerization. 
     
     
         3 . The plant of  claim 1 , wherein the propylene-based polymer comprises at least about 60 wt % propylene-derived units and about 5 to about 25 wt % ethylene-derived units, based on total weight of the propylene-based polymer, and wherein the propylene-based polymer has a heat of fusion of less than about 80 J/g. 
     
     
         4 . The plant of  claim 1 , wherein the feed is pressurized by the pump to a pressure of at least 75 bar. 
     
     
         5 . The plant of  claim 1 , wherein the feed is cooled in the at least one heat exchanger to a temperature of from 40° C. to −42° C. 
     
     
         6 - 10 . (canceled) 
     
     
         11 . A plant for continuous solution polymerization of a feed comprising one or more olefin monomers and a solvent, the plant comprising:
 a reactor;   feed blending means to prepare a feed comprising one or more olefin monomers in a solvent and means to supply to the reactor the feed and a catalyst to form therein a polymer-containing reactor mixture;   downstream of the reactor, separation means for separating the polymer from the unreacted monomer and the solvent to form a lean phase; and   an apparatus for recycling the lean phase back through the feed blending means and to the reactor including a pump for pressurizing the lean phase and one or more heat exchangers for cooling the solvent prior to re-use;   wherein at least one heat exchanger is located downstream of the pump,   wherein the lean phase enters the pump at a temperature above the cloud point of the polymer produced in the reactor, and   wherein the polymer produced in the reactor is a propylene-based polymer.   
     
     
         12 . The plant of  claim 11 , wherein the total differential head of the pump stays substantially the same during the continuous solution polymerization. 
     
     
         13 . The plant of  claim 11 , wherein the propylene-based polymer comprises at least about 60 wt % propylene-derived units and about 5 to about 25 wt % ethylene-derived units, based on total weight of the propylene-based polymer, and wherein the propylene-based polymer has a heat of fusion of less than about 80 J/g. 
     
     
         14 . The plant of  claim 11 , wherein the lean phase is pressurized by the pump to a pressure of at least 75 bar. 
     
     
         15 . The plant of  claim 11 , wherein the lean phase is cooled in the at least one heat exchanger to a temperature of from 40° C. to −42° C. 
     
     
         16 - 19 . (canceled)