超临界流体萃取分离离子液体与有机物及其相平衡的研究

离子液体具有一些优良的物理和化学性质,非常有希望成为传统有机溶剂的替代溶剂.但是如何从过程物流中分离和回收离子液体将是其工业化应用的一个很大挑战.蒸馏、液液萃取和超临界萃取是目前已知的三个可行的方法.其中超临界萃取可应用于离子液体与挥发的或相对不挥发的有机物的分离,而且不存在相间交叉污染.本文从二元体系相平衡、三元体系相平衡、模型化研究和萃取实验结果方面介绍了超临界萃取方法的最新研究进展,在此基础上提出了用超临界丙烷替代超临界二氧化碳作为萃取溶剂的新思路,并探讨了该领域今后的研究方向和工业化前景.

Separation of Organics from Ionic Liquids Using Supercritical Fluids and Phase Behaviors of These Systems

Ionic liquids hold great potential as replacements for traditional volatile organic solvents due to their unique characteristics. However, the separation and recovery of ionic liquids from process streams is a major challenge for the development of industrial processes that will use these interesting new solvents. Distillation, liquid-liquid extraction and supercritical fluid extraction are known feasible separation methods. Among the rest, supercritical fluid extraction can be used to separate both volatile and relatively non-volatile organic compounds from ionic liquids without cross-contamination between phases. The latest progress in the separation methods is reviewed from the aspects of phase behavior of binary system, phase behavior of ternary system, modeling and experimental results of supercritical fluid extraction. A new idea is put forward that supercritical propane could be an alternative for supercritical carbon dioxide. The future research and the industrialization prospect of the technology are also approached.