Type III porous liquids for efficient separation of cyclohexene and cyclohexane

Abstract Liquid–liquid extraction is an important technique for the separation of olefins and alkanes. In this study, porous liquids (PLs) with permanent porosity and mobility were chosen as the extractants to investigate their separation for olefin‐alkane systems. Type III PLs were synthesized for cyclohexene/cyclohexane separation using ZU‐61 as the porous metal organic frame and [Emim][NTf 2 ] as the sterically hindered solvent. Under the optimized conditions, the distribution coefficient ( D ) and separation selectivity ( S ) of cyclohexene were determined to be 0.172 and 6.936, respectively, using 15 wt% PLs. The separation selectivity of PLs decreased by about 5% after four repetitions, demonstrating good stability. The separation mechanism of the cyclohexene/cyclohexane system was investigated by quantum chemical calculations and characterization, and an extraction‐adsorption coupled separation mechanism was proposed. The results showed that this method has good performance in separating olefinic alkanes.