Numerical study on increasing PVC suspension polymerization productivity by using PSO optimization algorithm

Abstract

Despite the high application of poly (vinyl chloride) (PVC), it is still produced by batch wise rectors via suspension polymerization. Therefore, it is essential to improve the productivity of these processes by decreasing in the time of each batch maintaining desired polymer quality. The industrial batch reactors are restricted by a maximum reactor cooling capacity limiting the extent of rate of heat release over the exothermic polymerization. The reactor cooling system was fixed at maximum cooling capacity to satisfy an isothermal process. In order to reduce the polymerization time, the polymerization rate at any time of the batch should be in its possible maximum value. An operation approach is to run the industrial process isothermally using a mixture (cocktail) of initiators with different half-life. The aim of this study is to apply a mathematical model for PVC polymerization process for a choosing the optimal amounts of initiators in the cocktail by using particle swarm optimization algorithm. Results show that if an optimal amount of different initiators in the mixture was chosen, a significant reduction of the total processing time for a prescribed polymer specification can be obtained, as compared to the case in which only one initiator is optimally chosen.