Solubilities and Thermodynamic Properties of SO2 in Ionic Liquids

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• 作者：Meijin Jin ; Yucui Hou ; Weize Wu ; Shuhang Ren ; Shidong Tian ; Li Xiao ; Zhigang Lei
• 刊名：Journal of Physical Chemistry B
• 出版年：2011
• 出版时间：May 26, 2011
• 年：2011
• 卷：115
• 期：20
• 页码：6585-6591
• 全文大小：820K
• 年卷期：v.115,no.20(May 26, 2011)
• ISSN：1520-5207

文摘

Task-specific ionic liquids (TSILs) have been experimentally demonstrated to absorb more sulfur dioxide (SO<sub>2sub>) than normal ILs from gas mixtures with low SO<sub>2sub> concentrations; however, the differences of SO<sub>2sub> solubilities in the two kinds of ILs at given temperatures and pressures have not been studied systematically. Moreover, the mechanism of the interaction between SO<sub>2sub> and ILs still remains unclear. In this work, the solubilities of SO<sub>2sub> in TSILs (1,1,3,3-tetramethylguanidinium lactate and monoethanolaminium lactate) and normal ILs (1-butyl-3-methylimidazolium tetrafluoroborate and 1-butyl-3-methylimidazolium hexafluorophosphate) were determined. The solubilities of SO<sub>2sub> are correlated by a modified Redlich鈭扠wong equation of state (RK EoS). The chemical absorption and physical absorption are differentiated, and the absorption mechanism has been proposed with the aid of the modified RK EoS. SO<sub>2sub> absorption capacity in TSILs is contributed from both chemical interaction and physical interaction. Two TSIL molecules chemically absorb one SO<sub>2sub> molecule, and the chemical absorption amount follows the chemical equilibrium. Normal ILs only physically absorb SO<sub>2sub> following Henry鈥檚 law. The chemical equilibrium constant, reaction enthalpy, Gibbs energy of reaction, reaction entropy, and Henry鈥檚 law constant of SO<sub>2sub> absorbed in ILs have been calculated. The present model can predict SO<sub>2sub> absorption capacity for capture and SO<sub>2sub> equilibrium concentration in IL for recovery.