Ionic Liquids as Green Solvents for Reactive Separation of Glutaric Acid from Water

Abstract

In recent years, ionic liquids as green solvents have been received great attention owing to their remarkable properties. In this context, in the present study, the separation of glutaric acid from water was examined using green solvents instead of conventional organic solvents. As green solvents, four different types of imidazolium-based ionic liquids were utilized. Tributyl phosphate (TBP) was used as an extractant in ionic liquids. The effects of various factors like initial acid concentration (0.156-0.749 mol. L-1), TBP concentration in ionic liquids (0-3 mol. L-1), and type of ionic liquid were investigated. To evaluate the separation efficiency of glutaric acid from water, various parameters like extraction efficiencies (E), distribution coefficients (D), and loading factors (Z) were calculated. The values of these parameters changed in range of D (0.03-3.54), E (0.51-77.98%), and Z (0.040-0.177). The maximum D value of 3.54 and E value of 77.98% was obtained for reactive extraction of glutaric acid by using 3 mol. L-1 TBP in [BMIM][Tf2N] and 0.156 mol. L-1 initial glutaric acid concentration. Consequently, it was found that 77.98% of glutaric acid was separated from water at optimal conditions. This result indicated that imidazolium-based ionic liquids can be used for the reactive separation of glutaric acid from the water.