Polymerization of olefines through heterogeneous catalysis IV. Modeling of heat and mass transfer resistance in the polymer particle boundary layer

Propylene and ethylene polymerization in liquid and gas media are described by a multigrain particle model. External boundary layer heat and mass transfer effects are investigated for various catalysts and operating conditions. For high‐activity catalysts used in slurry, external film mass transfer effects may be significant. For gas‐phase polymerization of propylene or ethylene, the model predicts significant particle overheating at short times, which may explain the particle sticking and agglomeration problems sometimes observed in industrial reactors.