Novel hybrid reactive-extractive distillation for separation of tetrahydrofuran, ethanol, and water azeotropic system with rigorous side reactions consideration

This study builds upon our previous research work (Ind. Eng. Chem. Res. 2023, 62, 27, 10,601-10,610), which investigated the impact of considering the side reactions in the hybrid reactive-extractive distillation (RED). Our prior investigation revealed a significant challenge, as the inclusion of side reactions led to staggering spikes in energy consumption and total annual cost (TAC), seemingly rendering the performance of RED impractical. In this study, we present another possible scenario for considering side reactions in RED and highlight that RED with side reactions can still be a superior alternative to conventional distillation methods, even when side reactions are considered. This work was exemplified by using the recovering tetrahydrofuran (THF) and ethanol (EtOH) from waste effluent. We explore two different cases: Case 1 involves a side-reaction-free RED configuration reproduced as the base case, while the introduction of side reactions resulted in an increase in TAC by about 79.2% and a rise in total energy consumption by about 69%. Implementing a vacuum system (Case 2) substantially reduced the TAC by about 39% and energy consumption by about 20.5%. Although Case 2 outperformed Case 1 economically, it fell short of the base case due to additional capital costs. In contrast, Case 2 exhibited a lower TAC by 58% relative to the conventional pressure swing distillation.