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.
