Efficiency Ranking through Exergy Analysis in Azeotropic Distillation Systems

This study employs and validates a methodology for the efficient selection of optimal energy-integrated distillation configurations for azeotropic separations of binary mixtures. The study focuses on minimum-boiling tetrahydrofuran/water and maximum-boiling acetone/chloroform azeotropes, utilizing exergy, economic, and controllability analyses to identify the most suitable rectification structures. The evaluated distillation structures include those based on extractive and pressure swing distillations for non-heat-integrated and fully heat-integrated configurations. The selection of the most appropriate configuration is contingent upon the process energy requirements, exergy efficiency, and controllability. The findings reveal that, while there are expected energy savings from heat integration, the economic viability is determined by the pressure sensitivity of the azeotrope. The non-heat-integrated sequences consistently outperform other configurations in controllability while heat-integrated systems perform better in terms of exergy efficiency and total annual costs. This underscores the pivotal role of heat integration in azeotropic distillation systems, showcasing significant benefits from energetic, exergetic, and economic standpoints and highlighting its potential for substantial savings. Conversely, the use of heat integration in the extractive distillation of acetone/chloroform exhibits less favorable properties and alternative separation technologies may be considered.