Thermodynamic insight on extractive distillation with entrainer forming new azeotropes

Abstract

This paper deals with the feasibility analysis of batch extractive distillation taking into account the effect of the univolatility lines ai,j = 1 and the shape of residue curves for ternary mixtures involving two binary azeotropes. A general feasibility criterion previously established for ternary mixtures only including one azeotrope is now extended to Serafimov’s classification diagrams: 2.0-1, 2.0-2a, 2.0-2b and 2.0-2c. Application of the feasibility criterion hints at which component goes up or down using a rectifying or stripping column. Preliminary feasibility results are verified by computing the map of extractive liquid profiles using a simplified modelling. Examples including batch rectifier are also corroborated by rigorous simulation using ProSim Batch.