抄録
This paper describes the study of gain-maximizing (GMAX) control in redox processes. A redox process is characterized by the sigmoid curve that relates the redox potential to the oxidizing- or a reducing-agent injection rate, and the inflection point (IP) of the sigmoid corresponds to the equivalence point. Since the gain of the redox potential with respect to the agent-injection rate becomes maximum at the IP, controlling the redox potential by the GMAX method can optimize the process conditions where just enough of agent is supplied. Experiments were performed in a reaction process in which CIO– in tap water is reduced by S2O32–. The response of the redox potential to the agent-injection rate exhibited high-order dynamic behavior which is well described by a dead-time-plus-first-order (DPF) model. Accordingly, a GMAX algorithm based on the DPF model has been developed. Control experiments show that the GMAX method can satisfactorily control the redox reaction. Its application to other processes is also discussed.
