咪唑类离子液体的二氧化硫吸附性能

为研究咪唑类离子液体脱除烟道气中SO2的规律,以1-丁基,3-甲基氯代咪唑(Bmim]Cl)、1-丁基,3-甲基硝酸咪唑(Bmim]NO3)、1-丁基,3-甲基氟硼酸咪唑(Bmim]BF4)和1-戊基,3-甲基氯代咪唑(C5mim]Cl)4种离子液体作为SO2吸附剂,研究了不同条件下4种离子液体对模拟烟道气中SO2的吸附性能,并初步进行了离子液体再生脱硫试验.利用傅立叶变换红外光谱(FTIR)对吸附前、后和再生后的Bmim]Cl结构变化进行了研究.结果表明,4种离子液体对SO2均有吸附能力,且吸附能力为:C5mim]ClBmim]ClBmim]NO3Bmim]BF4,其中C5mim]Cl的累积脱硫量达到200.8mg/g,Bmim]Cl的最佳脱硫温度为40.0℃;3种阴离子对脱硫性能的影响顺序为:Cl-NO3-BF4-.在温度为90.0℃、压强为0.09MPa、再生4.0h后,Bmim]Cl的硫容从再生前的65.9mg/g下降到26.5mg/g.脱硫过程中离子液体的结构发生了变化,它对SO2分子同时存在物理吸附和化学吸附.

Adsorption Performances for Sulfur Dioxide Using Imidazole Ionic Liquids

To discover the SO2 adsorption laws of ionic liquids in simulating flue gas, the SO2 adsorbents 1-butyl-3-methylimidazolium chloride (Bmim] Cl), 1-butyl-3-methylimidazolium nitrate (Bmim] NO3), 1-butyl-3-methylimidazolium tetrafluoroborate (Bmim] BF4) and 1-amyl-3-methylimidazolium chloride C5 mim] Cl ionic liquids were synthesized. The performances were studied under different conditions and the general rules of regeneration were explored. And the diversification of Bmim] Cl chemical structures, which were pre-desulfated, post-desulfated and post-regenerated, were characterized by Fourier Transform Infrared Spectroscopy. The results illustrated that these ionic liquids all had the ability of SO2 adsorption, and the order of SO2 adsorption performances was C5 mim] C1 > Bmim] Cl > Bmim] NO3 > Bmim] BF4. The total SO2 adsorption amount of C5 mim] Cl was 200. 8 mg/g, and the optimal adsorption temperature of Bmim] Cl was 40 degrees C. The order of anions impacting adsorption performances of ionic liquids was Cl- > NO3- > BF4-. The sulfur capacity of ionic liquids decreased to 26.5 mg/g from 65.9 mg/g after desorption under the condition of heating (90 degrees C), vacuum (0.09 MPa) and 4.0 h. In addition, the chemical structures of ionic liquid had changed, and the forms of SO2 adsorbed by Bmim] Cl were physico-chemical processes.