酸性铁基离子液体催化氧化硫化氢的性能研究

Catalytic oxidation of H_2S by acidic iron(Ⅲ)-containing ionic liquids

为了获得催化氧化硫化氢性能最优的铁基离子液体体系,改变FeCl_3·6H_2O与[bmim]Cl的物质的量比(M值)合成不同的酸性的铁基离子液体,发现M值从0.1∶1增加至2∶1时,铁在离子液体中均以[bmim]FeCl_4的形式存在,且黏度和表面张力逐渐减小,但密度和稳定性逐渐增加。此外,升高温度均能急剧降低离子液体的黏度,合成的酸性离子液体在80℃下都能够稳定存在。在80℃下铁基离子液体催化氧化硫化氢的研究表明,随着M值的增加,硫磺的产量先增加后减小,在M值为0.3∶1时,硫磺产量最高,催化氧化性能最优。此外,铁基离子液体的酸性和低表面张力的特点使得硫磺颗粒较大,中位径达到22.42μm,可以有效避免硫堵。

In order to develop an optimal iron(III)-containing ionic liquid system for catalytic oxidation of H2S,the acidic iron(III)-containing ionic liquids were synthesized by using different molar ratio(M)of FeCl3·6H2O to 1-butyl-3-methy limidazolium chloride([bmim]Cl).It was found that with the increase of M from 0.1:1 to 2:1,1-butyl-3-methy limidazolium tetrach loroferrate([bmim]Fe(III)Cl4)was the dominating iron(III)species independent of the M value,however,the surface tension and viscosity of the iron(III)-containing ionic liquids decreased,and the density and thermostability of them increased.Moreover,the viscosity of the iron(III)-containing ionic liquids dramatically decreased with the increase of temperature and all of the synthesized iron(III)-containing ionic liquids possessed a good thermal stability under 80℃.The catalytic oxidation of H2S at 80℃by the acidic iron(III)-containing ionic liquids showed that the production of sulfur firstly increased and then decreased with the increase of M from 0.1:1 to 2:1,having a maximum value at the M value o f0.3:1,which indicated that the catalytic activity of the acidic iron(III)-containing ionic liquid synthesized at the M value of 0.3:1 was the best.The acidity and low surface tension of the iron(III)-containing ionic liquids make sulfur particles produced by them large,with a median diameter of 22.42um,which can effectively prevent sulfur plugging.