双功能离子液体的合成及二氧化碳捕集性能

采用两步法合成了新型功能化离子液体1-甲氧基乙基-3-甲基咪唑甘氨酸(C_3O_1mim]Gly]),并研究了其对CO_2的吸收性能.利用核磁共振、红外光谱及热重分析等手段进行表征,验证了该离子液体的结构,且发现其具有较高的热稳定性.对比单乙醇胺(MEA),考察了C_3O_1mim]Gly]在不同温度下对CO_2的捕集能力,结果表明,C_3O_1mim]Gly]在40℃下的吸收容量可达1.26 mol CO_2/mol IL,远高于MEA,这表明C_3O_1mim]Gly]对CO_2具有良好的吸收能力,吸收容量随着温度升高而降低.该离子液体同时具有良好的循环稳定性,进行5次吸收解吸操作后仍可保持较高的CO_2吸收量.对该离子液体吸收CO_2进行了动力学研究,结果表明,Pseudo-second-order模型能够较好地描述该吸收过程.

Synthesis of Dual-functionalized Ionic Liquid and Application in CO2 Absorption

A new bifunctional ionic liquid was prepared, characterized and applied in the absorption and de-sorption of CO2. First, 1-methoxyethyl-3-methyl imidazolium glycinate(C3O1mim]Gly]) was synthesized by two-step method. The molecular structure was characterized and confirmed by 1 H, 13 C nuclear magnetic resonance(NMR) and Fourier transform infrared(FTIR) spectroscopy. And thermogravimetric(TG) analysis suggested that C3O1mim]Gly] had good thermal stability. Then, compared to monoethanolamine(MEA), the CO2 absorption capacity of C3O1mim]Gly] was studied in the range of 25—100℃ at normal pressure. By computation, the CO2 absorption capacity can reach 1. 26 mol CO2/mol IL at 40 ℃, which is greatly higher than that of monoethanolamine ( 0. 54 mol CO2/mol MEA ) . And absorption capacity of CO2 in C3O1mim]Gly] would decrease with the increase of temperature from 40 ℃ to 100 ℃. Furthermore, the ionic liquid exhibited excellent reversibility and CO2 absorption capacity can be maintained after 5 times of absorption-desorption circulation. Finally, the absorption kinetics of CO2 in C3 O1 mim] Gly] was studied at 40 ℃. And Pseudo-second-order model is good to describe CO2 absorption in C3O1mim]Gly].