咪唑类离子液体的二氧化硫吸附性能

Adsorption Performances for Sulfur Dioxide Using Imidazole Ionic Liquids

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]Cl>[Bmim]Cl>[Bmim]NO3>[Bmim]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.

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 [C5mim]Cl [Bmim]Cl [Bmim]NO3 [Bmim]BF4.The total SO2 adsorption amount of [C5mim]Cl was 200.8 mg/g,and the optimal adsorption temperature of [Bmim]Cl was 40℃.The order of anions impacting adsorption performances of ionic liquids was Cl NO 3- BF 4-.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℃）,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.