Optimal temperature control in a batch polymerization reactor using nonlinear generalized predictive control

The application of Non-Linear Generalized Predictive Control (NLGPC) to the Free radical solution polymerization of styrene in a jacketed batch reacto r has been realized. The dynamic behavior of polymerization reactor is mode lled and simulated for control purposes. The optimal temperature policies f or minimum time, desired conversion and molecular chain length were obtaine d at different initiator concentrations by applying the optimal control the ory which is based on the Hamiltonian principle. The polynomial Nonlinear a uto Regressive Integrated Moving Average with eXternal input (NARIMAX) mode l is used to relate the reactor temperature with heat input for nonlinear c ontrol algorithm. The linear (ARIMAX) and nonlinear (NARIMAX) models are ut ilized in the GPC algorithm for comparison. A Pseudo Random Binary Sequence (PRBS) signal was employed to operate the system. The model parameters are evaluated by using Levenberg Marquart Method. The NLGPC, Linear Generalize d Predictive Control (LGPC) and standard PID controllers are applied experi mentally to the polymerization reactor by using on-line computer control sy stem. The performance of NLGPC control system was compared with LGPC and st andard PID controller. it is concluded that the NLGPC control gives much be tter performance than the other.