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To obtain the basic data for the recovery of 1-methylimidazole from wastewater by extraction, the ternary liquid−liquid phase equilibrium data of the water (1) + 1-methylimidazole (2) + 1-butyl-3-methylimidazolium hexafluorophosphate ([Bmim][PF 6 ]) (3) system were determined using an equilibrium autoclave at the temperatures of 303.15 to 323.15 K and 101.32 kPa. The solute distribution coefficient (D) and the selectivity (S) of the ternary system were calculated in accordance with the experimental data. Their values were up to 1.39 and 41.17, respectively, which showed that the ionic liquid can extract 1-methylimidazole effectively. The experimental results showed that the temperature had a slight effect on the liquid−liquid equilibrium behavior. Meanwhile, the calculated results revealed that the selectivity coefficient decreased with the enhancing concentration of 1-methylimidazole in the ternary system and the increasing temperature. In addition, the nonrandom two liquid (NRTL) model was used for correlation of the ternary systems. The root-mean-square deviation value of 0.0218 indicated that the calculated results using the model were in good agreement with the experimental data and were reliable to apply to practice.

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The supercritical technology is a promising green process in the fields of medicine, cosmetics, food, and feed industries. However, the poor solubility of phospholipid in supercritical carbon dioxide (ScCO2) limits its application in some processes. In order to enhance the solubility, a modified phospholipid with ScCO2‐philic group (eg, polyvinyl acetate), is designed and successfully synthesized. The solubility of the ScCO2‐philic phospholipids in ScCO2 with ethanol as cosolvent (0.5, 1.0, 2.0 mol%) is determined at the temperatures of 313.15, 318.15, 323.15, 328.15 K, and the pressure range of 9 to 15 MPa. The determination results indicate that the solubility of the modified phospholipid in ScCO2 is much higher than that of the soybean phospholipids. Furthermore, five semiempirical equations, namely, Chrastil‐G, MST‐S, Sodeifian‐Sajadian, Pérez, and Reddy, are used to correlate and predict the experimental results. The average absolute relative deviations of the correlation equations are 6.91%, 7.08%, 6.06%, 2.62%, and 6.15%, respectively, indicating that the solubility data can be well predicted.

To evaluate the feasibility of extraction of 1-methylimidazole from its low-concentration aqueous solution by ionic liquids, the liquid–liquid equilibrium of the ternary system of water + 1-methylimidazole + ionic liquid ([Hmim]­[PF6], [Omim]­[PF6], or [Omim]­[BF4]) was determined at 303.15 K and atmospheric pressure. The distribution coefficient and selectivity were calculated in accordance with the experimental results. The effects of the anion and cation of ionic liquids on the separation ability were discussed. The results indicated that the extraction capacity increased with increasing cationic carbon chain length, and the change of anions significantly affected the distribution coefficient and selectivity. As expected, the three ionic liquids were feasible as extractants for separating 1-methylimidazole from water. It also indicated that [Omim]­[PF6] was a more suitable extractant than [Hmim]­[PF6] and [Omim]­[BF4] for the extraction. The highest distribution coefficient and selectivity of [Omim]­[PF6] could reach 1.71 and 111.92, respectively, indicating [Omim]­[PF6] as a good choice for extracting 1-methylimidazole from water. In addition, the non-random two-liquid model was employed to successfully correlate the experimental data with a root-mean-square deviation of less than 0.0188. Moreover, a GUI-MATLAB tool was used to verify the consistency of the correlated parameters.