EXPERIMENTAL EVALUATION OF COMPARTMENTAL AND BILINEAR MODELS OF AN EXTRACTIVE DISTILLATION COLUMN.

The system under study is the separation of an azeotrope of acetone and methanol using water as a solvent. This is a multicomponent, nonlinear distillation which poses many difficult process control problems. The grouping of several trays together as a compartment has a thermodynamic basis and reduces the total number of model equations to be solved. The steady state behavior of an experimental column has been modeled using 5, 4, and 3 compartments. The compartmental simulation results agree with a complete tray to tray simulation and with the experimental data. The nonlinear behavior of the system has been modeled as a bilinear system. The reduced order bilinear system has been developed mechanistically using a compartmental technique. This model has been tested against the dynamic behavior of the experimental column and with a complete mass and energy balance model.