Control of particle size distribution described by a population balance model of semibatch emulsion polymerization

This work addresses the computation of surfactant feed pro®les for shaping a particle size distribution to a bimodal target dis- tribution. A fundamental population balance model of styrene semibatch emulsion polymerization is used in this control study. Both surfactant feed rate and free surfactant concentration are considered as alternative control variables and a comparison is made of the two approaches. A comparison is also made of several di€erent objective function norms in the optimization. Results suggest that a min±max norm, tied to the distribution modes, is the most appropriate metric.