OPTIMAL-CONTROL AND ONLINE OPERATION OF REACTIVE BATCH DISTILLATION

While both the dynamic modelling, and to a lesser extent, the optimisa tion of reactive batch distillation have been studied in the past, iss ues related to control and on-line operation of such a process have no t been properly addressed. In this study, a priori optimal profiles of the operating variables are established for an industrial reactive di stillation process. The optimal profiles are found either by maximisin g the profitability or by minimising the operating time subject to con straints on the reactor temperature and the loss of volatile reactant in the distillate. The control properties at optimal and non-optimal c onditions are assessed. A one-point column control scheme with a PI-co ntroller is designed to implement the optimal profiles. The controller performance is tested using a simulation model including disturbances in the reaction model and in the reboiler heat duty. The fully automa tic operation of the process according to the optimal policies is demo nstrated in conjunction with both a continuous controller and a real t ime control system. Good performance is achieved in both cases. Copyri ght (C) 1996 Elsevier Science Ltd