离子液体在氨气分离回收中的应用及展望

摘要

氨(NH3)是典型有毒有害工业气态污染物,也是形成PM2.5中二次颗粒物的根本原因之一,大量含氨气体的排放严重威胁人类的生活环境和健康.采用传统的酸法或水法,通常存在腐蚀性强、污染重、能耗高等问题,且难以回收利用氨资源.离子液体因其极低的挥发性、较好的化学/热稳定性、酸碱可调及高的氨溶解度等特点,为高效低能耗NH3分离提供了新途径.综述了近年来国内外离子液体在NH3分离中的研究进展,重点总结了常规离子液体、功能离子液体及离子液体溶剂/材料对NH3的吸收/吸附性能,阐明了阴阳离子、功能基团对NH3吸收性能的影响规律及其吸收机理,并探讨了该方向的研究和发展趋势.%As one of the typical alkaline and poisonous pollutants, ammonia (NH3) is widely considered as a primary factor for the formation of fog and haze, which has caused a wide range of environmental problems and serious harm to human health. The traditional technologies for NH3 separation, like water scrubbing and acid scrubbing, have been applied in industries. However, some inherent drawbacks, such as severe corrosion, heavy pollution, high energy consumption, and hard to recover NH3 resources come with yet. Ionic liquids (ILs) provide a novel way for efficient and energy-saving separation of NH3 owing to their extremely low vapour pressure, good chemical/thermal stability and tuneable acidity and alkalinity. In this review, the recent advances on conventional ILs, functionalized ILs and IL-based solvents and materials for NH3 absorption/adsorption have been overviewed. The NH3 absorption capacities in different ILs were summarized and the effect of cations, anions and functional groups on NH3 absorption and the mechanisms have been discussed, and the research and development trend of this direction are discussed.