Periodic operation of well mixed enzyme reactors with steady state multiplicities using relay feedback

Periodic operation of a well mixed enzyme reactor with input and output multiplicities is theoretically analyzed. The system is an isothermal continuously stirred tank enzyme reactor with a non ideal mixing represented by a Cholettes’ model and a reaction kinetics given by k ₁ c/(k ₁ c+1)². The system exhibits input multiplicities and output multiplicities. Some of the input steady-states correspond to unstable steady-states. The periodic operation in the inlet feed concentration cannot be done by open loop oscillation method. Relay feedback method is essential for the periodic operation of such systems. The improvement in the average conversion is calculated for the two unstable input steady-states. Higher average conversion is obtained at the largest value of the feed concentration. The limitation of relay feedback method for the stable input steady-state is also brought out.