负载型离子液体吸附分离CO2的研究现状及展望

Abstract

人口增长与全球工业化的加速发展促使化石能源需求量逐年递增，由此导致大气中二氧化碳（CO2）含量快速上升并引发了全球系列气候问题，“碳达峰·碳中和”背景下的CO2减排刻不容缓。传统工业捕集CO2方法由于能耗高、选择性较差、溶剂损耗大等问题限制了其大规模推广应用，离子液体因其极低挥发性、强的气体亲和性、可调的结构性质等特点在CO2捕集分离领域逐渐显示出独特优势，但离子液体特别是功能化后通常黏度较高或室温呈固态，导致气液传质效果差或无法直接应用于吸收分离过程。负载型离子液体兼具离子液体和多孔材料的共同优势，不仅能提升选择性分离效果，有效避免离子液体直接吸收造成的高黏度，还可拓展离子液体应用范围，具有广阔的发展前景。重点总结了近些年物理和化学负载型离子液体在CO2吸附分离方面的研究现状和进展，并对负载型离子液体捕集分离CO2研究的发展趋势进行了展望。

Population growth and accelerated global industrialization have led to a yearly increase in fossil energy demand, resulting in a rapid increase of carbon dioxide (CO2) emission in the atmosphere, which has led to a series of global climate problems, and CO2 reduction in the context of “carbon peak and carbon neutralization” is imperative. Traditional industrial technologies for CO2 separation are limited by high energy consumption, low selectivity and large solvent loss. Ionic liquids (ILs) have showed unique advantages in the field of CO2 capture and separation due to their extremely low volatility, strong gas affinity and tunable structures. However, ILs, especially after functionalization, usually are highly viscous or solid at room temperature, resulting in poor gas-liquid mass transfer limiting their applications on CO2 absorption and separation. Supported ionic liquids combine the advantages of ILs and porous materials, not only can enhance selective separation and effectively avoid high viscosity caused by direct absorption of ILs, but also can expand the application range of ILs, which have broad development prospect. This work comprehensively summarized the status and progress on physically and chemically supported ILs for CO2 adsorption and separation in recent years, and provided an outlook on the development trend in future.