Energy, Exergy, Economic, and Environmental Analysis of the Vapor Recompression-Assisted Liquid-Only Transfer Extractive Dividing Wall Column for Separating Minimum-Boiling Point Azeotropes

The introduction of a dividing wall column into extractive distillation can help reduce energy consumption, while bringing about the difficulty in controlling the vapor split ratio below the vertical partition as well. A liquid-only transfer distillation wall column, which has nothing to do with the vapor split ratio, has been applied for the separation of a minimum-boiling point azeotrope in this work. Meanwhile, both vapor recompression (VRC) and intermediate reboiler (IR) technologies are applied in the liquid-only transfer extractive distillation wall column (LEDWC) for further decreasing energy consumption and the total annual cost. Consequently, four novel configurations are optimized for a minimum total annual cost. All of the processes are evaluated by energy consumption, lost work, economics, and gas emission. It shows that the (RE-)VRC-IR-LEDWC-CR exhibits the best performance. Moreover, it is economic if all the vapor overhead is used for VRC, which reduces the energy consumption, lost work, total annual cost, and gas emission by 39, 31, 25, and 39%, respectively, compared with conventional extractive distillation sequences.