Comparative evaluation of liquid–liquid equilibria for extraction of 2,2,3,3‐tetrafluoro‐1‐propanol from water by a ZIF‐8‐porous ionic liquid

Abstract

AbstractBACKGROUND2,2,3,3‐Tetrafluoro‐1‐propanol (TFP) is a benign solvent and widely used in the electronics industry as a cleaning agent. Because water and TFP can form an azeotropic mixture, it consumes energy to separate TFP from its aqueous mixtures using conventional distillation.RESULTSIn this work, the zeolitic imidazolate framework‐8 porous ionic liquid (ZIF‐8‐PIL) and the ionic liquid (IL) N‐butyl pyridinium bis(trifluoromethyl sulfonyl) imide ([Bpy][NTf2]) are used as extractants to extract TFP from its aqueous solution. ZIF‐8‐PIL was synthesized by ZIF‐8 and IL [Bpy][NTf2]. The liquid–liquid equilibrium (LLE) data for the two systems (water + TFP + ZIF‐8‐PIL/IL) were determined at 298.15, 308.15 and 318.15 K under 101.3 kPa. The selectivity (S) and distribution coefficient (D) were examined to assess the extractive performance of ZIF‐8‐PIL and IL. The non‐random two‐liquid (NRTL) model was applied to fit the tie‐line data of the investigated mixtures.CONCLUSIONThe results demonstrate that ZIF‐8‐PIL is a suitable extractant to separate TFP with values of S and D greater than unity. The NRTL model has better correlation performance for the ternary systems with root mean square deviation lower than 0.01. The obtained parameters satisfy the minimum state of the mixed Gibbs free energy, which indicated that the model parameters are reliable. © 2021 Society of Chemical Industry (SCI).