Simultaneous Design and Control of Polymerization Reactors

Abstract: Chemical engineering science has recognized the necessity of integrating process design and control; however, few steps have been taken in this direction in polymer science. In this work, a Mixed-Integer Dynamic Optimization approach is used for the simultaneous design and control of a styrene polymerization reactor. Our goal is to design the process and its control system in order to produce two polymer grades, which are defined in terms of the number average molecular weight (Mn). The process design involves reactor and initiator selection, and the two steady state operating points. The control system consists of a feedforward-feedback control scheme, which is designed to achieve optimal grade transition operation. The control system design includes optimal pairings between controlled and manipulated variables and controller’s tuning parameters for PI feedback controllers, and the best trajectories of the feedforward controllers.