负载[APMIm][Br]离子液体吸收CO_2的性能

CO_2 absorption properties of supported [APMIm][Br]

1-氨丙基-3-甲基咪唑溴盐（[APMIm][Br]）离子液体通过化学反应捕集CO2。采用浸渍-蒸发将[APMIm][Br]离子液体负载在硅胶表面，通过比表面孔隙吸附测定仪、热重分析仪（TGA）对吸收剂的结构与性能进行研究，负载量为10%～50%，温度为303.15～323.15 K，CO2浓度分别为10%、30%、50%。结果表明：硅胶表面的离子液体薄膜厚度达到86 nm（负载40%）时，具有最快的吸收速率，且受CO2浓度和温度变化的影响较小，平衡吸收量在50% CO2体系中达到理论吸收量的80%，随着温度的升高而降低，当负载量为50%时，膜厚增加到230 nm，导致吸收速率和平衡吸收量大幅度下降。值得注意的是：负载离子液体吸收剂在循环使用3次之后，结构与性能均保持不变，表现出一定的工业运用前景。

CO2 was absorbed by 1-aminopropyl-3-methylimidazolium bromine（[APMIm][Br]）as chemical reaction. The absorbents were prepared by supporting ionic liquids on porous silica gel through the impregnation-evaporation method, and pore structure and absorption capacity were characterized with specific surface pore adsorption apparatus and thermogravimetric analysis, respectively. CO2 absorption was conducted under the following conditions： 10% to 50% of ionic liquids loading, 303.15 K to 323.15 K of temperature, and 10%, 30%, 50% of CO2 in mixed gas. The results suggested that absorption rate was fastest when film thickness of ionic liquids on the silica gel was 86 nm, and was little affected by the change of CO2 concentration and temperature. Equilibrium absorption amount reached 80% of the theoretical uptake in 50% CO2 system, and was reducing with increasing temperature. However, absorption rate and capacity decreased obviously as film thickness of ionic liquid exceeded 230 nm. The properties of supported ionic liquid absorbent remained unchanged after recycling three times, showing the prospect of industrial use.