On controlling an autothermal fixed-bed reactor at an unstanble state—IV: Model fitting and control of the laboratory reactor

Abstract

This study describes in detail model fitting and experimental control implementation for a tubular autothermal reactor running the water-gas shift reaction. The reactor is interfaced to a real-time computer for data logging and control purposes. Certain unknown reaction and heat transport parameters are either evaluated through indirect measurements or estimated from steady-state temperature and concentration data. The heat capacity of the catalyst bed is then adjusted so as to improve the agreement between simulated and measured transient responses. The control approach is purposely kept very simple: measurement of only a few bed temperatures, no state estimation scheme, and use of a single manipulated input. Operation of the reactor at an unstable steady state is clearly demonstrated by several independent tests. Finally, excellent agreement between experimental and simulation results are observed for various cases of pulse perturbation of the heat input at the catalyst bed entrance.