CO2在非质子溶剂与铁基离子液体复合体系中的吸收

选用非质子型有机溶剂聚乙二醇二甲醚(NHD)与N, N-二甲基乙酰胺(DMAC), 分别与BmimFeCl₄复配, 构建了BmimFeCl₄/NHD和BmimFeCl₄/DMAC复合铁基离子液体体系. 考察了温度、 BmimFeCl₄/溶剂的质量 比以及压力对CO₂在复合铁基离子液体体系中溶解行为的影响. 结果表明, 高压低温的吸收条件更利于CO₂ 的溶解, 当BmimFeCl₄/DMAC质量比为7∶3时, CO₂在BmimFeCl₄/DMAC复合体系中的亨利系数为0.9181 MPa·L·mol^-1, 低于同等条件下BmimFeCl₄/NHD体系的亨利系数. 在常压、 363.2 K条件下进行再生, 经5次循环后, CO₂在BmimFeCl₄/NHD和BmimFeCl₄/DMAC中的溶解度分别为初次吸收量的92.53%和99.04%. 傅里叶变换红外光谱(FTIR)结果表明, 铁基离子液体复配体系吸收CO₂为物理吸收过程. 密度泛函理论(DFT)计算与IRI分析的结果表明, 在复配DMAC的体系中， CO₂更倾向与阳离子和溶剂分子作用, 而在复配NHD的体系中, CO₂则更容易与阴离子和溶剂分子作用.

CO2 Absorption in Composite of Aprotic Solvent and Iron-based Ionic Liquid

Two kinds of aprotic solvents， polyethylene glycol dimethyl ether（NHD） and N， N-dimethylacetamide （DMAC）， which have excellent desulphurization and decarbonization ability， were selected to construct composite of BmimFeCl₄ and solvent as novel decarbonization agents. The effects of temperature， mass ratio of BmimFeCl₄/solvent and pressure on CO₂ solubility were investigated. The results show that high pressure and low temperature are more conducive to the dissolution of CO₂. The Henry coefficient of BmimFeCl₄/DMAC（7∶3） with 0.9181 MPa·L·mol^-1 at 298.2 K， is lower than BmimFeCl₄/NHD under the same conditions， indicating that the former has a larger absorption capacity for carbon dioxide. Fourier transform infrared spectroscopy（FTIR） spectra show that the absorptions of carbon dioxide by the two composites depends on physical absorption between CO₂ molecule and the functional groups of BmimFeCl₄ before and after CO₂ absorption. After five absorption-regeneration cycles of CO₂ with the two kinds of the iron-based ionic liquid composites， the amounts of CO₂ absorption reached 92.53% and 99.04% of the first absorption for BmimFeCl₄/NHD and BmimFeCl₄/DMAC， respectively. density functional theory（DFT） calculations and IRI analyses show that CO₂ is more likely to interact with ［Bmim］⁺ cations and DMAC molecules in BmimFeCl₄/DMAC， nevertheless， in BmimFeCl₄/NHD， CO₂ is more likely to interact with ［FeCl₄］^- anions and NHD molecules.