Nonlinear Switching Control of the CO Oxidation Reaction Rate in Hydrogen Production

Catalytic CO oxidation on platinum group metals can exhibit nonlinear behaviors like catastrophe, bistability, and hysteresis, which are indicative of self-organizing processes occurring in the course of the oxidation reaction. As a result, the system demonstrates a multi-branch nonlinear input/output relationship for which the output value depends not only on the instantaneous input values, but also on the history of operations. Traditional linear control approaches may cause unstable operation in the CO oxidation reaction. In this paper, a nonlinear control strategy is proposed to solve the control problem. The control strategy incorporates a PI controller and a switching control strategy by which the control system can maintain a high regulating performance while preventing unstable operation. It may be applied to control operations in industrial processes of catalytic CO oxidation.