Multiplicity of the steady in the fluidized bed reactors—III: Yield of the consecutive reaction A → B → C

Abstract

The simplified non-isothermal model for fluidized bed reactors developed earlier (Parts I, II) is extended here to the case of exothermic consecutive reaction, A → B → C. It is shown that simple adiabatic operation is not possible when the second reaction, B →- C is relatively fast because the desired operating temperature corresponds to an unstable steady state. A simple control scheme is suggested to stabilize the unstable steady state. Conditions for the existence of unstable steady state giving rise to limit cycle behaviour are discussed using local stabdity analysis. Limit cycles are shown on the phase plane and the effect of controller gain is investigated.