Modern and Classical Control Techniques Applied to an Anionic Polystyrene Reactor

Modern and classical control techniques are developed for the continuous polymerization of polystyrene initiated with n-butyl lithium. State variable techniques are utilized via pole placement to decrease substantially the transient response time. A steady state decoupling algorithm is designed to control separately the production rate of polymer and its number average molecular weight. Standard proportional/integral controllers then regulate the system against load changes. Simulations include load and setpoint disturbances and demonstrate that the design efficiently regulates the controlled variables in such a way that the cost of raw materials is minimized in the steady state. Furthermore, the controller is effective in changing resin molecular weight at a constant production rate.