Computer aided design of styrene batch suspension polymerization reactors

The present paper deals with the development of a comprehensive CAD tool for a styrene free-radical batch suspension polymerization reactor. The gPROMS(C) simulation platform is employed for describing the dynamic behavior of the batch polymerization system. The kinetic model accounts for both thermal and chemical initiation mechanisms, thus, the model can be employed over an extended range of polymerization temperatures. A generalized free-volume model is derived to account for diffusion-controlled reactions (e.g., termination, propagation and chemical initiation). The overall reactor model includes also appropriate dynamic energy balances for the reaction medium and the coolant in the reactor jacket. An equation of state model is employed to calculate the concentration of the various species (e.g., monomer, solvent, H2O) in the various phases present in the reactor. A Windows(TM) user-friendly interface, based on DELPHI programming language, has been developed to link the gPROMS model with the input file containing the necessary design and reactor operating data. It is shown that the model can successfully simulate the operation of batch styrene suspension polymerization reactors, and predict the polymerization rate, temperature, pressure and molecular weight distribution of polystyrene.