Time scale multiplicity and nonlinear control of an ethyl acetate reactive distillation column

In this paper, the dynamics and control of a reactive distillation column for the production of ethyl acetate are studied. Initially, the existence of fast and slow dynamics corresponding to the liquid flow rates, and the liquid compositions and hold-ups, respectively, is documented and analyzed. A description of the slow dynamics of the column is derived using singular perturbation arguments, and is used for the synthesis of a nonlinear feedback controller. The performance and robustness of this controller are evaluated and compared with those of a controller based on the exact two time scale model.