Design and optimisation of novel hybrid side-stream reactive-extractive distillation for recovery of isopropyl alcohol and ethyl acetate from wastewater

For the first time, we developed a novel side-stream double-column reactive-extractive distillation (SS-DCRED) for the recovery of isopropanol (IPA) and ethyl acetate (EA) from wastewater. Starting with the conceptual design and optimisation of a double-column reactive-extractive distillation (DCRED) using particle swarm optimisation (PSO), we designed and optimised next the SS-DCRED, which is the main contribution of this work. In addition, a reactive-extractive dividing wall column (REDWC) was also developed as we intend to benchmark the SS-DCRED with the REDWC, which is available in literature. The performance of the SS-DCRED was also compared against the DCRED and the best heat-integrated conventional extractive distillation (HI-CED) using ionic liquid (ILs) and ethylene glycol (EG) from previous work based on total energy consumption, TAC, envi-ronmental performance, and thermodynamic efficiency. Overall, the total energy consumption, TAC, and envi-ronmental performance of the SS-DCRED are 51%, 40%, and 51% lower with respect to the HI-CED using ILs and are 63%, 56%, and 63% lower than the HI-CED using EG from previous work. Likewise, it is also better than the REDWC by about 8%, 4%, and 9% in terms of total energy consumption, TAC, and environmental emissions with respect to the REDWC. These significant enhancement highlights the superiority of our proposed SS-DCRED.

Automated summary

In this study, a novel side-stream double-column reactive-extractive distillation (SS-DCRED) was developed for the recovery of isopropanol (IPA) and ethyl acetate (EA) from wastewater. Compared to previous methods, the SS-DCRED achieved significant improvements in total energy consumption, total cost, and environmental performance.