ENHANCED CONDENSED MODE OPERATION IN METHOD OF PRODUCING POLYOFEFINS WITH CHROMIUM BASED CATALYSTS

摘要

A gas phase polymerization process for producing a polyethylene polymer including polymerizing ethylene and optionally at least one a-olefin comonomer in a fluidized bed reactor under condensed mode operating conditions using a Cr+6-based supported catalyst and a catalyst initiation enhancing agent is provided. The catalyst initiation enhancing agent is an aluminum alkyl solution that is present in the fluidized bed reactor at effective Al/Cr ratios between 0.2 to 1.5. A catalyst initiation enhancing system including at least one aluminum alkyl and at least one hydrocarbon solvent wherein the aluminum alkyl is present in the solvent at concentrations of less than about 0.03 molar.