Model-based control of catalytic reactors with reverse flow operation

Dynamic operation of catalytic reactors has attracted increasing attention in recent years. The most successful application of this type of reactors is based on a reverse flow operation, where the dynamic operation improves the overall thermal efficiency of the system. The design and modeling of catalytic reactors with reverse flow operation has been thoroughly investigated; however, control of such systems is an area that has not received much attention. Issues such as the distributed nature of the state variables, the nonlinear dynamics and the unsteady-state operation make the formulation of a controller for this type of systems a challenging but interesting problem.;The goal of this thesis is twofold: firstly, the development of control strategies for catalytic reverse flow reactors is studied. Particular emphasis is put on the application of the reactor for mitigation of lean methane emissions. Secondly, the development of measures to quantify the nonlinearity in distributed parameter systems and, in particular, quasi-linear hyperbolic partial differential equations models. Such nonlinearity measures are intended for assessment of the suitability of linear control for such systems.;To formulate control strategies for catalytic flow reversal reactors (CFRR), optimal control techniques were used. On a practical side, a Model Predictive Control (MPC) scheme was employed. On a theoretical side, LQ-feedback control for infinite dimensional systems was used.;The control strategies were applied to a CFRR for the combustion of fugitive methane emissions. The CFRR technology has been successfully tested in underground coal mine applications, and its use in the oil and gas sector in Canada and around the world shows great promise. Outstanding issues to resolve include optimization of reactor design and development of suitable control strategies. It is expected that with the tools developed in this research, we will get closer to a successful control technique that can be used for a safe, stable and efficient operation of CFRR units.;One of the main issues in developing a control scheme for a catalytic reactor or any other distributed parameter system is the nonlinear dynamics. While published results in this area of quantification of process nonlinearity are limited to lumped parameter systems, this thesis focus on distributed parameter systems. Specifically, we look at means of open- and closed-loop nonlinearity quantification for systems modeled by quasi-linear hyperbolic partial differential equations.