Analyzing the sustainability of intensified side‐stream extractive distillation for binary azeotropic separation: a comparative study

Abstract

AbstractBACKGROUNDThe sustainability performance of extractive distillation (ED) that collectively considers energy efficiency, process safety, economic profitability, process control, and environmental emission has not been widely reported. Motivated by this lack of research, we analyzed and compared the sustainability performance of the intensified side‐stream ED (SSED) with that of the conventional extractive distillation (CED) for the separation of binary azeotropic mixtures. Two different design approaches were analyzed; the first approach involves designing the intensified SSED by preserving the original CED column configuration, while the second approach involves optimizing the original column configuration to become a new intensified SSED configuration.RESULTSWe found that preserving the original configuration usually provides energy‐savings, but this advantage is not guaranteed unless the process is optimized. Generally, the reduction in energy consumption improves economic and environmental performance. However, the optimized design has a higher risk index because it is usually larger in size, for the sake of lowering the energy consumption. In addition, the optimized design usually has a higher condition number, which signifies that a more complex control structure is required.CONCLUSIONAltogether, designing the intensified process via process optimization does not always guarantee significant improvement in all sustainability indicators. © 2023 Society of Chemical Industry (SCI).