Nonlinear Predictive Control of a Semi Batch Polymerization Reactor by an Extended DMC

In this paper a new nonlinear model predictive control law is applied to a semi-batch polymerization reactor. The particular model used in this study is the free radical polymerization of polymethylmethacrylate. The principal nonlinearities are due to the reaction rates and the gel effect. Two cases are considered: jacket temperature controlling the reaction temperature, and a MIMO structure where both the reaction temperature and the molecular weight are controlled by the jacket temperature and the initiator feed. The proposed control algorithm uses an explicit nonlinear process model and some of the elements of the classical DMC to solve the nonlinear input-output operator equation without computing the derivatives of the states and output equations. Constraints are not included in the present method.