Study On The Control Of CO 2 Subculture By Functionalized Ionic Liquids

Carbon dioxide (CO2) has recently been considered to be the main culprit for the "Global warming" issue. The topic on how to trap it attracted extensive attention. Ionic liquids are regarded as promising carbon dioxide absorbent because they exhibit some excellent properties such as negligible vapour pressure, wide liquid range, high thermal stabilities, and virtually limitless chemical tunabilities. Some functionalized ionic liquids with amino, amino acid, phenol have been used for the capture of CO2. However some problems such as low absorption capacity and high desorption energy consumption remained to be solved. Thus it is necessary to develop some new ionic liquids for improving the capture of CO2. Some functionalized ionic liquids with the carbonyl group were designed, synthesized and applied for the capture of CO2in this paper. The development of these novel ionic liquids provides a new method for improving the capture of gas.Firstly, It is known that there is an interaction between carbonyl group such as an aldehyde base and carbon dioxide. We hope it plays an important role in carbon dioxide capture. Therefore, the groups such as aldehyde were introduced into imidazole and phenolic anion to make the weak interaction stronger. Experimental results have shown that these ionic liquids exhibit a high absorption capacity for carbon dioxide up to1.24mol CO2/mol IL, which caused by Lewis acid-base and C-H…O weak hydrogen bonding between carbonyl group and CO2. In addition, carbonyl groups are a kind of electron-withdraw group, where the charge in N was dispersed resulting in the decrease of the enthalpy between carbon dioxide and ILs. Quantitative calculation and spectroscopic investigations showed that lewis acid-base and C-H…O weak hydrogen bonding existed between CO2and carbonyl-based ionic liquids. In addition, the ionic Liquid exhibited excellent cycling performance, which are the specific potential absorbents for carbon dioxide capture.Secondly, considering the perspective of industrial applications, the strategy that reducing the size of the cation will achieve high carbon dioxide adsorption capacity on the basis of weight (g CO2/g IL). Thus, two kinds of ionic liquids with different sizes of cations and the same anion such as [P4442][Triz] and [P66614][Triz] were designed, synthesized and applied for the capture of CO2. The experimental results showed that the cation with the smaller size exhibited improved performance for carbon capture process. The effect of the temperature on CO2capture was investigated, which shows that high CO2capacity up to14.3%achieved at35℃for [P4442][Triz]. This idea provides a method for designing a new ionic liquid for improving gas separation in industrial applications.In this paper, different types of ionic liquids were designed. They performed well in CO2capture. These methods developed in this work provide some new chances for developing highly efficient CO2capture processes.