A total of 10 new N-alkyl piperazinium-based ionic liquids (ILs) have been prepared, and they are used as extractants for removing aromatics from three kinds of hydrocarbon fuels. A total of 3 ILs, N-methyl piperazinium lactate (MPL), N-ethyl piperazinium lactate (EPL), and N-ethyl piperazinium propionate (EPP), in the liquid state at room temperature are used directly for extraction, while the other 7 ILs in the solid state at room temperature are used with methanol as the co-solvent. Effects on the extraction efficiency of the temperature and the amounts of IL and co-solvent are investigated. The results indicate that the amounts of IL and co-solvent play very important roles in the extraction process and the efficiency is greatly influenced by the cation and anion structures in the N-alkyl piperazinium-based ILs. In comparison to 1,1,3,3-tetramethylguanidinium lactate (TMGL), the extraction capability order is EPP > EPL > MPL > TMGL. The ILs with aromatic anions are found to have better extraction capability than the others. Furthermore, recycling of ILs reflects that these ILs can be recovered simply by vacuum distillation without a significant decrease in the activity of dearomatization.

A novel ionic liquid N-ethyl piperazinium propionate, [NEPP], was prepared, and the densities and viscosities for the binary mixtures of [NEPP] with methanol, ethanol, n-propanol, and n-butanol were measured over the whole concentration range at (298.15, 303.15, 308.15, and 313.15) K and 0.1 MPa. The data of the excess molar volume, V m E, were calculated and fitted with the Redlich–Kister type polynomial equation. The values of V m E of the investigated systems are all negative, indicating that the ion–dipole interactions play important roles between the molecules of the ionic liquid and the alcohols.

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To cultivate students' innovative ability and practical ability, as well as to help them comprehensively master the theoretical knowledge and experimental skills of organic synthesis experiments, teaching exploration and practice of combining research and systematicness in organic synthesis laboratories have been carried out. In the process of designing the curriculum and teaching, we should implement ideas, methods, and teaching reforms that are student-centric. From the viewpoint of enhancing teaching reforms, teaching methods, assessment methods, and other teaching links that explore research, science, and education integration should be combined with the actual classroom teaching, advocate heuristic, and inquiry teaching methods. The implementation of a research-oriented teaching mode effectively stimulated the enthusiasm of students' independent research-oriented learning, improved their comprehensive practical ability, and established a clear correlation between laboratory teaching and scientific research.