A control scheme for packed bed reactors having a changing catalyst activity profile. II: On-line optimizing control

Abstract The on-line optimization of packed bed reactor performance is achieved via a comprehensive control system utilizing a two-dimensional partial differential equation reactor model, non-linear distributed parameters state estimation, sequential parameter estimation, control of the maximum estimated temperature and sequential optimization of economic criteria. Excellent performance has been demonstrated in both closed-loop simulation and real-time experiments with an exothermic wall-cooled reactor for the partial oxidation of methanol to formaldehyde. This scheme has shown robustness to both uncertain model parameters and catalyst decay. Rapid optimization was accomplished for reactor start-up, process disturbances and changes in the economic objective. Single-variable optimization of the maximum reactor temperature (as controlled by the wall temperature) as well as two-variable optimization manipulating both hotspot temperature and feed flow rate are demonstrated.