| CPC C08F 10/06 (2013.01) | 20 Claims |
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1. A process for pre-polymerizing propylene, comprising:
adding a catalyst and propylene to a first mixer;
mixing the catalyst and propylene in the first mixer to form a first catalyst suspension comprising the catalyst and propylene;
flowing the first catalyst suspension from the first mixer to a second mixer, wherein the second mixer is a stirred tank;
adding a co-catalyst and an electron donor agent to the first catalyst suspension;
pre-polymerizing propylene in the second mixer to form a second catalyst suspension comprising propylene, catalyst particles coated with polypropylene, the co-catalyst, and the electron donor agent;
feeding the second catalyst suspension to a polymerization reactor; and
introducing additional co-catalyst and electron donor agent to the polymerization reactor,
wherein the co-catalyst is added to the first catalyst suspension at a location in a transfer line that is upstream of the location where the electron donor agent is added.
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