Catalyst Requirements for Gas-Phase Fluid-bed Reactor

Activity Catalyst productivity can range significantly between catalyst families and polymerization conditions within a catalyst family from about 2,000-8,000 g polyethylene/g of catalyst. Residual transition metal in the 

1-Hexene reactivity Catalyst reactivity with 1-hexene is important in order to reduce the amount of 1-hexene needed in the reactor. Ziegler-type catalysts based on Ti/Mg compounds exhibit relatively poor reactivity with 1-hexene compared with many other catalysts. Such catalysts can require a 1-hexene/ethylene vapor phase ratio of about 0.12 and higher in a commercial reactor, thus limiting the ethylene partial pressure in the reactor and leading to lower production rates and/or lower catalyst productivity. However, with the super-condensing mode of operation, comonomer fed concerns are rare. Most other catalysts used in a fluid-bed reactor exhibit higher 1 -hexene reactivity and, therefore, require lower 1 -hexene feed rates and fewer operational problems 

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