Absorption Performance and Mechanism of CO2 in Aqueous Solutions of Amine-Based Ionic Liquids

详细信息    查看全文

• 作者：Pengcheng Hu ; Rui Zhang ; Zhichang Liu ; Haiyan Liu ; Chunming Xu ; Xianghai Meng ; Meng Liang ; Shuangshuang Liang
• 刊名：Energy & Fuels
• 出版年：2015
• 出版时间：September 17, 2015
• 年：2015
• 卷：29
• 期：9
• 页码：6019-6024
• 全文大小：469K
• ISSN：1520-5029

文摘

Several amine-based ionic liquids (ILs) were synthesized via a one-step method using low-priced organic amines and inorganic acids, and they were mixed with water to form new CO₂ absorbents. The effects of the ionic structure, IL concentration, temperature, and pressure on the CO₂ absorption performance were investigated. The absorption performance of ILs was closely related to the ionic structure, and the CO₂ molar absorption capacity in ILs with the same cation followed the order of [NO₃] > [BF₄] > [SO₄] or [HSO₄], whereas that with the same anion ranked in the following order: multiple amine > diamine > monoamine. The IL [TETA][NO₃] with 40 wt % concentration showed the best capacity for CO₂ absorption. Moreover, low temperature and high pressure favored CO₂ absorption. The reaction mechanism of the amine group with CO₂ in aqueous solutions of [TETA][NO₃], primary amine, and secondary amine was studied via in situ infrared (IR) spectrophotometry. The results showed that the primary and secondary amines first reacted with CO₂ to form carbamate, which decomposed further into bicarbonate with the continuous addition of CO₂. However, carbamate generated from the reaction of [TETA][NO₃] with CO₂ did not decompose further.