离子液体用于四氢呋喃-乙醇-水三元共沸物系分离的研究

以离子液体1-丁基-3-甲基咪唑二氰胺（BMIM] DCA]）为萃取剂，采用流程模拟和机理分析两种方法，对离子液体用于四氢呋喃（THF）-乙醇-水三元共沸物的分离进行了研究。通过COSMO-RS理论，以选择性为性能指标筛选出合适的离子液体BMIM]DCA]，并且以BMIM]DCA]为萃取剂，在适合的操作条件下建立了萃取精馏过程，模拟结果表明THF、乙醇和水的质量分数都接近1。通过对BMIM]DCA]和三种溶质的σ-谱图分析，发现BMIM]DCA]可分别与三种溶质形成更强的氢键，从而打破三种溶质间的固有氢键，进而消除它们的共沸现象。

Study on separation of tetrahydrofuran-ethanol-water ternary azeotrope system by ionic liquid

Using ionic liquid 1-butyl-3-methylimidazolium dicyandiamide (BMIM]DCA]) as extractant, the separation of tetrahydrofuran (THF)-ethanol-water ternary azeotrope was studied by process simulation and mechanism analysis. Based on COSMO-RS theory, suitable ionic liquid BMIM] DCA] was selected with selectivity as performance index, and the extractive distillation process was established with BMIM] DCA] as extractant and suitable operating conditions. The simulation results showed that the mass fraction of THF, ethanol and water was close to 1. Through the analysis of σ-profiles of BMIM] DCA] and three solutes, it is found that BMIM] DCA] can form stronger hydrogen bonds with three solutes respectively, thus breaking the inherent hydrogen bonds between the three solutes and eliminating their azeotropy.