A vapor phase side stream intensified extractive distillation process for separation of azeotropic mixture 2, 2, 2-trifluoroethanol and water

Abstract

2,2,2-Trifluoroethanol (TFE) is an important organic fluoride with various commercial applications. During the production of TFE through hydrolysis, an azeotrope of TFE and water can form, making it challenging to separate using conventional distillation. This study proposes a novel approach employing vapor phase side stream intensified extractive distillation separation (VSED) with glycerol serving as an entrainer to address this challenge. Additionally, a dividing wall column process (DWC) is established. The total annual cost (TAC), CO2 emissions and total energy cost (TEC) of the proposed separation processes are calculated and compared. The results indicate that VSED process can recover TFE with a purity of 0.9995 (mole fraction). VSED exhibits a TAC reduction of 34.2 % and a CO2 emissions reduction of 33.9 % compared to the CED process. In addition, a dual-composition control strategy is proposed for the VSED process. The results show that control strategy can effectively cope with the feed flow perturbation of ±20 % and the feed composition perturbation of ±5 %.