丁二烯抽提工艺中离子液体添加剂的筛选及分离性能

提出以离子液体为第三组分的丁二烯抽提新工艺，通过考察不同结构的离子液体对C₄组分在复合萃取剂中相对挥发度的影响，并结合量化计算的方法，研究了该工艺中萃取剂和第三组分与C₄组分的相互作用机理，从而优选出适用于该工艺的离子液体添加剂Emim]PF₆]。另外研究了该离子液体在工业条件下对C₄组分分离性能的影响，并对改进前后的工艺进行全流程模拟计算。结果表明：与现有乙腈法相比，离子液体的加入有利于提高C₄在新型萃取剂中的相对挥发度，具有很好的分离效果。含离子液体的新工艺可使能耗降低约6.62%，乙腈消耗量降低约24%，而且离子液体能够回收利用，回收率高达98%（质量分数）以上，因此基于离子液体的乙腈法抽提丁二烯新技术具有很好的工业应用前景。

Selection and separation performance of ionic liquid as additive in butadiene extraction with ACN

A new separation process of C₄ mixture with ionic liquid as additive was proposed. The influence of ionic liquid on the relative volatility of C₄ mixtures in acetonitrile (ACN) solvent system was investigated. The interaction mechanisms between ACN, ionic liquid and C₄ were analyzed by quantum chemistry calculations. In addition, two flowsheets of ACN butadiene extraction process with or without ionic liquid were simulated. Ionic liquids were proved to be effective additives for C₄ separation, and the appropriate ionic liquid Emim]PF₆] for ACN butadiene extraction process was chosen and confirmed by the simulation results. In the practical process, the mixed solvent of ACN with ionic liquids showed better separation performance than that of ACN solvent, and the new technology could recover more than 98%(mass) ionic liquids after the distillation process. Moreover, separating C₄ with ionic liquid could decrease energy consumption by about 24%. Therefore, the proposed new process technology with ionic liquid as additive is a perspective C₄ mixture separation process.