Geometric nonlinear analysis of multicomponent nonideal distillation: a simple computer-aided design procedure

Abstract

A simple noniterative design procedure for multicomponent distillation columns is developed. The procedure is based on the geometric theory of distillation presented in our previous work, and applies to constant relative volatility, ideal, nonideal, and azeotropic mixtures. The design technique provides an accurate and efficient method for determining the number of theoretical trays in the column, the optimum feed-plate location, and the exact product distribution, without the use of lengthy iterative schemes involving column simulations, as is the current practice. The procedure is easily extended to incorporate reactive distillation columns, as well as the retrofit design of distillation columns. The design procedure is illustrated using a number of multicomponent systems, including the mixture acetic acid—water—ethyl acetate—ethanol, which exhibits three binary azeotropes, one ternary azeotrope, and a nonideal vapor phase.