Off-Line Tube-Based Robust Model Predictive Control for Uncertain and Highly Exothermic Polymerization Processes

Abstract

© 2015 Elsevier B.V. Polymerization processes usually contain some uncertain parameters such as those in kinetic rate constants and heat transfer coefficients. An inefficient handling of these uncertain parameters may lead to unexpected thermal runaway of the reaction. In this paper, off-line tube-based robust model predictive control (MPC) is developed. The trajectories of uncertain systems are restricted to lie in a sequence of tubes so robust stability and constraint satisfaction are guaranteed in the presence of both uncertain parameters and disturbances. All of the optimization problems are solved off-line so the proposed algorithm is applicable to fast dynamic polymerization processes. The proposed algorithm is applied to an illustrative example of continuous stirred tank reactor where highly exothermic polymerization reactions occur. The results show that robust stability and constraint satisfaction are guaranteed.