Modified basic distillation configurations with intermediate sections for energy savings

Abstract

Basic distillation configurations have been well studied, comprising of energy efficient (n − 1)‐column configurations that can be used to separate an n‐component nonazeotropic feed mixture into its components. In this article, we present new (n − 1)‐column configurations which differ from the conventional basic configurations due to the introduction of extra intermediate sections and the additional transfer‐streams associated with submixtures of these sections. We demonstrate using four‐component examples that these small differences lead to some interesting nonintuitive physical effects in the new configurations, resulting in large energy savings compared to the basic configurations. The proposed configurations offer more operable and energy efficient options for onsite implementation than the corresponding optimally operated basic configurations. © 2014 American Institute of Chemical Engineers AIChE J, 60: 1091–1097, 2014