Multiplicity and Stability of Olefin Polymerization Particles and Reactors

Roger Schmitz was a pioneer in providing an understanding of chemical reactor multiplicity and stability problems. His work stimulated others in the field to explore a broader range of practical problems and solutions. Polyolefins such as polyethylenes are the largest volume and least expensive polymer products available. Many of these products are produced in multiphase fluidized bed or stirred bed reactors where growing polymer particles containing catalyst and reactants generate an extremely large amount of heat from the highly exothermic polymerization. These reactors and even individual particles are subject to multiple steady states and stability problems. This paper reviews this issue and presents some solutions through operation at supercritical and near supercritical conditions. Both modeling and experimental results will be presented.