Study on periodic feeding control for a semi-batch polymerization process

The relationships between period operation and Molecular Weight Distribution (MWD) of polymeric products were investigated firstly aiming at a semi-batch free-radical homo-polymerization process. Then, using the duty-cycle of the periodic feeding as a control variable, a novel method of controlling the quality of polymer was proposed. The objective function of maximum possible monomer conversion (X_M) with a specific value of polydispersity (PDI) of MWD was chosen as the control index. Particle Swarm Optimization (PSO) was utilized to solve the optimization problem. Simulation results indicated that under periodic operation of reactant feeding, the wider variation range for PDI of MWD can be obtained, and the PDI in a semi-batch polymerization reactor can reach the required goal in terms of adjusting the duty-cycle of periodic feeding.