Inferential control of high-purity multicomponent batch distillation columns using an extended Kalman filter

To control the sequencing of the batch distillation steps and to guarantee that all products will meet their purity specifications, this work has prop osed an inferential control system for high-purity multicomponent batch dis tillation columns, that is able to cope with difficulties commonly encounte red in practice, including lack of on-line composition analyzers, plant/mod el mismatch, uncertainty in the initial system state, and measurement noise . An extended Kalman filter has been implemented to provide updated composi tion estimates from temperature measurements, and globally linearizing cont rollers have been designed to control the distillate composition, The choic e of the number and location of temperature sensors, as well as the sensiti vity of the controller settings to changes in the operating conditions, has also been discussed. Tight composition control was achieved, and the propo sed inferential control scheme was shown to be robust and suitable for prac tical implementation.