Patent ID: 7902325

Claim:
A polymerization process comprising: introducing a catalyst system to a reaction zone comprising a loop reactor; contacting the catalyst system with a cocatalyst at a catalyst system to cocatalyst ratio of from about 0.3:1 to about 0.7:1; introducing propylene to the reaction zone; contacting the propylene with the catalyst system to form polypropylene via a polymerization reaction, wherein the polypropylene comprises a first aggregate residual metal level that is at least 60 ppm; contacting the polypropylene with a quench agent to terminate the polymerization reaction, wherein the quench agent is at least partially soluble in the propylene; and contacting the polypropylene with a wash agent comprising propylene to form a polypropylene having a second level of residual metals that is about 40 ppm or less.