A STABLE CONTROL-STRUCTURE FOR BINARY DISTILLATION-COLUMNS

A Lyapunov-based controller for the composition control of binary dist illation columns has been developed. It takes into account physical co nstraints on the inputs and ensures the global asymptotic stability of the closed-loop system with robustness to modelling errors and with t he capability of performing set-point tracking and (approximate) distu rbance rejection. This controller requires the knowledge of the intern al state of the model and this leads to the design of an exponentially converging 'high-grain' observer. We arrive at the global asymptotic stability of the whole control structure (the controller + the observe r) by proving a somewhat general nonlinear separation principle.