MODELING AND SIMULATION OF REACTIVE DIVIDED WALL DISTILLATION COLUMN

Abstract

Distillation is an operation which is best governed by the concept of vapor-liquid equilibrium. For simulation purposes the minor change in pressure does not affect the equilibrium significantly. So the change in pressure (plate by plate) is usually neglected and it is assumed to be constant or having constant pressure drop. Pressure difference is more or less act as a deciding factor for total molar vapor or liquid flow across the trays, especially in the case of divided wall distillation column (DWC) or reactive DWC. In the present work the analysis is done for reactive DWC, for the feasible operation the process parameters vapor split ratio, liquid split ratio and reflux rate are adjusted in such a way that the difference in pressure drops at both sides of the wall is zero. Several simulations are performed using two thermally coupled RADFRAC columns of Aspen Plus followed by optimization using Box behnken design operated under multiple response surface methodology. The results show that the pressure drop difference is the key factor for the product purity and energy efficiency of the column; it plays a major role for the control and operation of reactive DWC through optimized liquid split and vapor split.