Complex Dynamic Behavior during Polyol Preparation in Continuous Processes Using Heterogeneous Double Metal Cyanide Catalysts

The transition from batch to continuous processes for polyol production presents interesting challenges because of the unusual behavior of double metal cyanide (DMC) catalysts. One feature that is often observed in these catalysts is the need for an activation period whose length changes from one catalyst formulation to another. When this activation occurs in the same reactor where the chain growth reaction is going to take place, the length of the activation period plays an important role in deciding the reactor residence time. Another feature that has been observed is the deactivation of the catalyst under some reactor conditions.