季铵盐离子液体改性活性炭及其热安全性研究

Study on modified activated carbon with quaternary ammonium salt ionic liquid and its thermal safety

为进一步提高活性炭对VOCs的吸附性能和热安全性,采用铵盐类离子液体改性原始活性炭,优化其理化性质。结果表明:改性活性炭表面生成新的无机盐化合物,C=O、-OH、C-O、-COOH和C-S基团增加;孔隙结构增多且分布均匀,比表面积及微孔体积增大;改性后活性炭对甲苯的吸附量提高3.14倍,吸附效率明显提升;在固定碳的燃烧阶段,改性活性炭活化能为54.44 kJ·mol^(-1),是改性前活性炭的1.38倍,活化能增大,物质稳定性增强;当粒径为120~150目及200目以上时,改性前后活性炭的自燃温度分别从328.4℃、319.3℃增长至355.1℃、345.7℃。因此,负载季铵盐离子液体可有效提高活性炭吸附性能和热安全性,研究结果可为优化VOCs处理工艺提供参考。

In order to further improve the adsorption performance and thermal safety of activated carbon on VOCs,the ammonium salt ionic liquid was used to modify the original activated carbon so as to optimize its physicochemical properties.The results showed that new inorganic salt compounds were formed on the surface of modified activated carbon,and the groups such as C=O,-OH,C-O,-COOH and C-S increased.The pore structure increased and distributed evenly,and the specific surface area and micropore volume increased.The adsorption capacity of toluene by modified activated carbon increased by 3.14 times,and the adsorption efficiency was significantly improved.In the combustion stage of fixed carbon,the activation energy of the modified activated carbon was 54.44 kJ·mol^(-1),which was 1.38 times that of the activated carbon before modification.The activation energy increased and the substance stability strengthened.When the particle size was 120~150 mesh and more than 200 mesh,the spontaneous combustion temperature of activated carbon before and after modification increased from 319.3℃and 328.4℃to 345.7℃and 355.1℃,respectively.Therefore,the loaded quaternary ammonium salt ionic liquid could improve the adsorption performance and thermal safety of activated carbon,and the research results are of positive significance for the optimization of VOCs treatment process.