相变离子液体体系吸收分离CO_(2)的研究现状及展望

Research status and prospect of CO_(2)absorption and separation by phase-change ionic liquid systems

全球工业化的迅速发展及人口增长使得化石燃料消耗不断增加,导致二氧化碳(CO_(2))排放量逐年递增,引发全球化气候问题。醇胺吸收法目前在工业CO_(2)捕集应用最广泛,主要以单乙醇胺、甲基二乙醇胺等水溶液为吸收剂,存在溶剂损耗大、再生能耗高等问题,开发高效低能耗的新型吸收剂是实现CO_(2)大规模捕集的关键。离子液体具有气体亲和性好、蒸气压低、结构性质可调等特点,其中相变离子液体体系因节能潜力大被认为是新一代CO_(2)吸收剂,其吸收CO_(2)后由均相变为互不相溶的液-液或液-固两相,再生时仅需对CO_(2)富相加热处理,可有效减少吸收剂再生体积,降低再生能耗。重点总结近五年相变离子液体体系在CO_(2)分离的研究现状和进展,对不同相变行为的液-液和液-固相变离子液体体系分类阐述和讨论,并对其发展趋势进行展望。

The rapid development of global industrialization and population growth have led to increasing consumption of fossil fuels,resulting in increasing carbon dioxide(CO_(2))emissions year by year,triggering global climate issues.Presently,the alkanolamine absorption method is the most widely used for CO_(2)capture in industries,mainly using aqueous solutions as monoethanolamine and methyl diethanolamine as absorbent,which results in large solvent loss and high energy consumption for regeneration.The development of new absorbent with high efficiency and low energy consumption is the key to achieve large-scale CO_(2)capture.Ionic liquids have the characteristics of great gas affinity,low vapor pressures and tunable structures properties.Phase-change ionic liquid systems are considered as the new generation solvents for CO_(2)capture with low energy consumption.During CO_(2)absorption,homogeneous ionic liquid-based solvents can undergo phase transition into liquid-liquid or liquidsolid immiscible systems.For regeneration,only the CO_(2)-riched phase needs to be heated,which reduces the regeneration volume of absorbent and energy consumption.This review summarized the progresses of the phasechange ionic liquid systems for CO_(2)capture in recent five years,different liquid-liquid and liquid-solid phasechange behaviors of phase-change ionic liquid systems were discussed.The development trends of CO_(2)capture in phase-change ionic liquid systems were also prospected.