用[BMIM][Cu2Cl3]离子液体萃取脱除汽油中的硫化物

以不同的IL（ionic liquid）/油质量比，采用BMIM]Cu2Cl3]（BMIM]=1-butyl-3-methylimidazolium）对模型汽油和商品汽油进行单步和多步萃取脱硫实验；并合成几种具有不同阴离子和阳离子结构的离子液体，评价和比较了离子液体对商品汽油的萃取脱硫性能的影响。实验结果表明，具有较好的水稳定性和常温流动性的BMIM] Cu2Cl3]离子液体硫容较高，在IL/油质量比为1∶3时，经多步萃取后，油品中的硫质量分数降至20×10-6～30×10-6，累计脱硫率超过95%。汽油中其他组分对脱硫效果影响很小。BMIM]Cu2Cl3]与汽油形成稳定的两相系统，分离方便。离子液体脱硫能力可以通过四氯化碳反萃取完全恢复。

Extractive desulfurization from gasoline by [BMIM][Cu2Cl3]

A moisture stable ionic liquid that contains Cu(Ⅰ) was used as solvent for desulfurization from gasoline in this paper. CuC1 was mixed with 1-butyl-3-methylimidazolium (BMIM) chloride according to the molar ratio of 2∶1 to synthesize BMIM]Cu2Cl3] ionic liquid. BMIM]Zn2Cl5] and Et3NH]Cu2Cl3](Et=ethyl) were prepared in the same process. Model oil (dissolving thiophene in the mixture of heptane and toluene) and commercial gasoline were treated by BMIM]Cu2Cl3] at room temperature. It is found that BMIM]Cu2Cl3] could remarkably remove sulfur from oil. After six-stage extraction, the S content in the model oil reduces from 650×10-6 to 20×10-6 when the mass ratio of IL/oil is 1∶3. The single stage desulfurization decreases from 37% to 23% with the IL/oil ratio decrease from 1∶2 to 1∶5. It is also shown that the desulfurization ability of BMIM]Cu2Cl3] from real gasoline is similar to that from model oil. Other components in gasoline have little influence on the desulfurization ability of BMIM]Cu2Cl3]. BMIM]Cu2Cl3] can be easily separated because of the biphasic systems of IL/oil formation. The polymerization products of olefin in gasoline are not detected in desulfurization. Desulfurization abilities of BMIM]Zn2Cl5] or Et3NH]Cu2Cl3] are lower than that of BMIM]Cu2Cl3]. Carbon tetrachloride and toluene were used to regenerate the ionic liquid prepared. The regeneration was conducted at mass ratio IL/solvent of 1∶3 and temperature of 75 ℃ with stirring for 30 min. The regeneration results indicate that the sulfur removal capacity of IL is recovered completely by carbon tetrachloride treatment, but toluene shows poor ability to regenerate BMIM]Cu2Cl3]. CCl4 might be easily seperated from the high boiling point thiophene derivatives absorbed by evaporation or rectification .