脱芳烃萃取剂的研究进展

Research Advances in Solvents for Aromatics Extraction Separation

综述了国内外脱芳烃萃取剂的研究新进展,包括离子液体、单一萃取剂和复合萃取剂。离子液体萃取剂通过阴、阳离子类型及取代基的调变,可提高芳烃选择性和分配系数,甚至实现深度脱芳烃;单一萃取剂中糠醛、1,3-二氰基丁烷、碳酸乙烯酯、羟丙基α-环糊精等可用于萃取脱芳烃;脱重芳烃除了常用的邻苯二甲酸二甲酯萃取剂外,邻苯二甲酸二辛酯和甘油也有较好的效果;复合萃取剂通过将常用萃取剂与醇、胺等极性溶剂复配或是加盐的方式可提高分配系数。指出离子液体萃取剂最具发展前景,但目前存在成本高,重复利用率低等问题;复合萃取剂由于简单有效、成本低廉,在离子液体萃取剂的应用没有重大突破前,更具实用价值。

Recent progresses in the extractants for aromatics extraction separation,including ionic liquids,single and composite extractants,were discussed.Using ionic liquid extratants can improve the selectivity to aromatic hydrocarbons and the distribution coefficients through changing the types and substituents of the anions or cations,even achieve deep dearomatization.The single extrctants,namely furfural,1,3-dicyano butane,ethylene carbonate and hydroxypropyl α-cyclodextrin,can be used in the aromatics extraction.For heavy aromatics extraction,dimethyl phthalate is commonly used,and dioctyl phthalate and glycerol were also found as good extractants.By mixing common extrctants with polar solvents such as alcohols and amines or adding salts,the distribution coefficients of composite extractants were improved.It was pointed out that ionic liquids were the most promising extractants,but their weaknesses were high cost and low recycling rate.Before the application of ionic liquids has major breakthrough,the composite extractants has high practical value due to their simplicity,high efficiency and low-cost.