| Styrene and methacrylates are principal components of many automotive coatings resins. Acrylic resins for coatings production are produced using a "starved feed" strategy in which the monomer and initiator are fed at a fixed rate over a period of several hours to produce polymer with relatively constant composition and molecular weight with minimal on-line measurement. The resulting robust reactor operation comes at a price in terms of long batch time, and drift in both polymer molecular weight and composition still occurs in the early and late stages of the batch. Improved operation requires a combination of an optimal recipe with an effective on-line control strategy based on a mathematical model that capture the underlying physics of the process.;In this work, a real-time optimization scheme for nonlinear processes is implemented for this system. The system input and state trajectories are determined on-line to minimize a cost function defined in terms of deviation from target molecular weight and composition, and batch time. The performance of the proposed strategy is examined through numerical simulation for several study cases for the Butyl Methacrylate and Styrene (BMA/STY) free radical polymerization system which has been extensively studied in the past few years. [42,43] Results show that polymer quality can be assured in minimum batch time while achieving constraint satisfaction over the entire run. |
