Model predictive control of a non-isothermal axial dispersion tubular reactor with recycle

Abstract

This paper addresses the model predictive output controller design for a non-isothermal axial dispersion tubular reactor accounting for energy and mass transport in a recycle stream. The underlying transport-reaction process is characterized by different mass and energy Peclet numbers. Open-loop analysis reveals unstable operating conditions based on the reactor’s parameters. The discrete model of the system is obtained by considering a Crank-Nicolson type of discretization method without any model reduction and/or spatial approximation for the system of coupled parabolic PDEs. The proposed predictive controller accounts for asymptotic close-loop system stabilization and/or naturally present input and state constraints with the rejection of possible disturbances arising from reactor operations. To account for the output controller design, a discrete observer is developed to reconstruct the infinite dimensional states in the predictive control realization. Finally, the controller’s performance is assessed via simulation studies, implying proper state stabilization and constraints satisfaction with input disturbance rejection.