Process for controlling the MWD of a broad or bimodal resin in a single reactor

摘要

A process for controlling the MWD of a broad or bimodal resin in a single fluid bed reactor using a mixed catalyst composition containing a bimetallic catalyst and a make-up catalyst of at least one metallic component of the bimetallic catalyst. The bimetallic catalyst, which is formed with at least one metallocene of a transition metal, produces broad or bimodal molecular weight distribution polyolefin resin whose composition depends on the ratio of the concentration of the two catalyst components producing the HMW/LMW components. The make-up catalyst consisting of a single metal component is added in proportion necessary to make-up the deficiencies in the amount of the HMW/LMW component. The type of make-up catalyst added depends on whether increase of the HMW or LMW component produced by the bimetallic catalyst is sought. The mixed catalyst compostion may be fed into the reactor as a mixture or through separate catalyst ports of the reactor.