咪唑类离子液体分离回收焦化粗苯中的噻吩

Separation and Recovery of Thiophene in Coking Crude Benzol by Imidazolium-Based Ionic Liquids

采用金属氯化物(MCly)与1-丁基-3-甲基咪唑氯化盐([BMIM]Cl)按不同摩尔比合成了一系列咪唑类离子液体,研究了离子液体用于分离回收焦化粗苯模拟液中噻吩的性能。实验结果表明,当MCly(AlCl3和FeCl3)与[BMIM]Cl的摩尔比为2时,合成的离子液体[BMIM]Cl-2AlCl3和[BMIM]Cl-2FeCl3的分离率最大,且这两种离子液体的分离效果明显优于其他离子液体;离子液体萃取分离的优化条件为:萃取时间40～60 min、萃取温度50～60℃、离子液体与苯馏分的体积比1∶20([BMIM].Cl-2AlCl3与苯馏分的体积比1∶30);[BMIM]Cl-2AlCl3和[BMIM]Cl-2FeCl3离子液体作为萃取剂可分别重复使用6次和5次,且它们具有深度萃取分离效果。[BMIM]Cl-2AlCl3和[BMIM]Cl-2FeCl3离子液体的萃取分离性能通过再生基本可以得到恢复,且通过减压蒸馏(0.05 MPa)再生可分别回收57.33%和53.21%的噻吩。

A series of imidazolium-based ionic liquids were synthesized with various molar ratios of metal chlorides（MCly） to 1-butyl-3-methylimidazolium chloride（Cl）.The separation and recovery of thiophene in simulative coking crude benzol with ionic liquids as the extractants were researched.The results showed that the separation effects of the synthesized ionic liquids,Cl-2AlCl3 and Cl-2FeCl3,were better than those of the other synthesized ionic liquids,and the best molar ratio of MCly（AlCl3 and FeCl3） to Cl was 2.The optimal desulfurization conditions for the ionic liquids were as follows：extraction time 40-60 min,extraction temperature 50-60 ℃ and V（ionic liquid）∶V（benzene fraction） 1∶20（V（Cl-2AlCl3）∶V（benzene fraction） 1∶30）.Cl-2AlCl3 and Cl-2FeCl3 could be reused for 6 and 5 times at least,respectively,and could be used in deep extractive separation.The regeneration results indicated that the sulfur removal capacities of the two ionic liquids could be recovered basically by carbon tetrachloride treatment or vacuum distillation.The thiophene recovery rates were 57.33% for Cl-2AlCl3 and 53.21% for Cl-2FeCl3 after the vacuum distillation regeneration under 0.05 MPa.