AIChE Journal, Vol.50, No.6, 1129-1149, 2004
Shortcut methods for nonideal multicomponent distillation: 3. Extractive distillation columns
Extractive distillation is a common process for the separation of homogeneous azeotropic mixtures with a minimum boiling azeotrope. In this process entrainer feed flow rate and reflux ratio of the extractive column represent the crucial design degrees of freedom that govern feasibility and operating cost. In this work feasibility and operational stability of the extractive column are related to the nonlinear analysis of the extractive section. A fully automated conceptual shortcut design method for the simultaneous determination of minimum entrainer feed flow rate and minimum reflux ratio is presented. The method is applicable to arbitrary multicomponent mixtures and allows direct screening of design alternatives and comparison of different entrainers. (C) 2004 American Institute of Chemical Engineers.
Keywords:multicomponent extractive distillation;minimum energy demand;rectification body method (RBM);economic screening;entrainer selection