SHORTCUT METHODS FOR NONIDEAL MULTICOMPONENT DISTILLATION - 1 - SIMPLE COLUMNS

Shortcut methods are a prerequisite for the fast evaluation of alterna tives in process design. The rectification body method (RBM) for calcu lating the minimum energy demand of homogeneous, azeotropic multicompo nent distillation processes is presented. The new method incorporates both the classical Underwood technique and certain previously proposed techniques as special cases. It employs all pinch point branches of b oth column sections and thus requires no a priori selection of active pinch points. It is entirely general and can be applied to any type of split of nonideal and azeotropic mixtures irrespective of the number of components. Hence, it significantly extends previous results and pr actical applicability Its features are highlighted through examples of nonideal separations with three, four, and five components.