DYNAMIC OPTIMIZATION OF MOLECULAR WEIGHT DISTRIBUTION IN BATCH POLYMERIZATION REACTORS

This paper applies the orthogonal collocation on finite elements (OCFE) method and the fixed pivot (FP) technique for the prediction of the molecular weight distribution (MWD) for linear free-radical polymerization systems. It is shown that for linear polymers, the two methods result in similar molecular weight distributions for a bimodal MWD. An optimal operating policy that ensures the satisfaction of desired polymer quality specifications and process economics regulations is derived employing a performance index which penalizes the deviations of the MWD from specific desired values. Finally, the optimal trajectories were applied to a free-radical MMA batch pilot-scale polymerization reactor.