(216c) Using Distillation Column Profile Maps to Identify Suitable Thermodynamic Model for Complex Systems

Authors: 
Modise, T. S. D. - Presenter, Wits University


In this paper we will show that column profile maps can be used to identify suitable thermodynamic models for complex systems. The ethanol, water and ethyl acetate system is one of the most complicate systems because it has a ternary azeotrope and liquid-liquid equilibrium envelope. This ternary azeotrope is very difficult to predict since it is very close to the liquid-liquid envelope. Furzer (2001) required new Unifac vapour-liquid equilibrium parameters because with the known parameters, he failed to calculate the ternary azeotrope correctly. In this paper we will show the contradiction between two thermodynamic models, Uniquac and NRTL models, do not predict the same composition of the ternary azeotrope suing the residue curve map even though the prediction is quiet close. We will show that when using the column profile maps which are linear transforms of the residue curve maps, the topology of the column profiles are quiet different when using the two thermodynamic models. The experimental simulations are conducted on the column profile map to identify which one of the two topology agrees with the experimental simulation.