SO2 Absorption by Carboxylate Anion-Based Task-Specific Ionic Liquids: Effect of Solvents and Mechanism

详细信息    查看全文

• 作者：Junhai Zhao ; Shuhang Ren ; Yucui Hou ; Kai Zhang ; Weize Wu
• 刊名：Industrial & Engineering Chemistry Research
• 出版年：2016
• 出版时间：December 21, 2016
• 年：2016
• 卷：55
• 期：50
• 页码：12919-12928
• 全文大小：579K
• ISSN：1520-5045

文摘

Task-specific ionic liquids (TSILs) have been widely observed to effectively absorb low-concentration SO₂ from flue gas by chemical interaction. However, the interaction between SO₂ and TSILs is still unclear. The addition of solvents can decrease the viscosity of TSILs and promote mass transfer, but whether the solvents have an impact on absorption is unknown, as is the effect on absorption mechanism. To solve these issues, we synthesized several types of TSILs containing carboxylate anion to capture SO₂ from simulated flue gas. The mechanism of absorption of SO₂ by the TSILs was investigated in detail using Fourier transform infrared (FT-IR), ¹H nuclear magnetic resonance (NMR), and ¹³C NMR. The results show that chemical interactions can be found between the carboxylate anions of TSILs and SO₂. Simultaneously, the effect of several solvents on SO₂ absorption capacity of TSILs was studied. The results indicate that ethylene glycol (EG) in TSILs has a strong influence on SO₂ absorption by guanidinium- and alkanolaminium-based TSILs, but for quaternary ammonium-based TSILs, EG has no effect. Finally, the interaction between EG and TSILs was investigated by FT-IR, and the absorption mechanism was studied. It has been found that the addition of EG can improve the basicity of guanidinium- and alkanolaminium-based TSILs to increase the absorption capacity.