Bringing the On-Line Control and Optimization of Semibatch Emulsion Copolymerization to the Pilot Plant

摘要

Due to hardening competition and increased focus on resource efficiency, efforts are made to develop advanced industrial optimization and control systems with the goal to shift the (semi-) batch production from recipe-based to a state-based approach. This study illustrates the steps needed for the implementation of optimization and on-line control of semibatch emulsion copolymerization involving the development of process model, its validation and connection with control software, and the realization at pilot plant scale. The process model must be fast and robust enough to provide estimation of the process trajectory reliably and quickly. Moreover, in connection with nonlinear model predictive control (NMPC), the model has to be able to learn from the process and to update parameter values in real time, e. g., due to change of reactor jacket heat transfer. The Cybernetica CENIT software is employed for NMPC. The industrial pilot-scale semibatch emulsion copolymerization of four comonomers (two of them water soluble) is used for the demonstration of NMPC functionality for: (i) reactor temperature control, (ii) minimization of batch time while preserving product quality, and (iii) minimization of batch duration with desired simultaneous shift in product quality.