Dynamic characteristics of a periodically forced fluidized bed catalytic reactor under conventional PI control

Abstract

A two-phase model of a non-isothermal fluidized bed catalytic reactor with consecutive exothermic reactions A—» b —> C is used to investigate the dynamic characteristics of this industrially important unit when it is periodically forced. The investigation concentrates on forcing a periodic regime of the autonomous system with a relatively high forcing frequency. It is shown that by periodic forcing of the feed temperature, chaotic legimes occur for small amplitudes of forcing. For constant frequency and with the change in the forcing amplitude the behavior of the unit alternates between periodic and chaotic regimes via period doubling and period adding mechanisms. When on the other hand the amplitude is fixed chaotic regimes also appear for small changes in the forcing frequency. The effects of these parametric perturbation ! on the yield of the desired intermedials product B is also investigated. It is shown that the yield can be improved by an appropriate selection of the forcing frequency.