用于CO_2吸收的离子液体的合成、表征及吸收性能

以N-甲基咪唑和3-溴丙胺氢溴酸盐为起始原料,合成了一种含氨基的离子液体(ionic liquid,IL)——1-(1-氨基丙基)-3-甲基咪唑溴盐(简写为[NH2p-mim]Br),总产率为90.1%,溴含量为0.980 mol Br/mol IL,胺含量为0.948 mol NH2/mol IL。探讨了合成工艺,并通过1HNMR、13CNMR、IR和MS对产物结构进行了表征。吸收实验结果表明,该离子液体能够有效地吸收CO2,在40℃和106 kPa下,质量分数为45%的离子液体水溶液吸收CO2至饱和时,溶液中CO2的摩尔分数可达0.444 mol CO2/mol IL,接近理论吸收量0.5 mol CO2/mol IL;在90℃的真空状态下,吸收的CO2能够完全解吸,重复吸收实验表明,该离子液体吸收CO2的能力无明显下降。

Synthesis,Characterization and Absorption Efficiency of an Ionic Liquid for the Absorption of CO2

An ionic liquid(IL),1-(1-aminopropyl)-3-methylimidazolium bromide,was synthesized using N-methylimidazole and 3-bromopropylamine hydrobromide as raw materials,the final yield was 90.1%,the bromide content was 0.980 mol Br/mol IL and the amine content was 0.948 molNH2/mol IL.The product was characterized by 1HNMR,(13)CNMR,IR and MS.Experimental result indicated that the IL is an effective absorbent of CO2.The solubility of CO2 in mass fraction 45% aqueous solution of the IL was up to 0.444 mol CO2/mol IL at 40 ℃ and 106 kPa,very close to the theoretical maximum loading(0.5 mol CO2/mol IL).The absorption process could be reversed under vacuum at 90 ℃,and the absorption efficiency of the IL has little observable loss after repeated use.