有机胺型铁基离子液体的H_2S吸收和再生性能

H2S Absorption Capacity and Regeneration Performance of Amine Fe-based Ionic Liquid

合成了有机胺型铁基离子液体1.6Et3 NHCl·FeCl3,研究了其热稳定性和对H2 S的吸收与再生性能.考察了H2 S浓度为832 mg/m3,温度为40-180℃,气体流速分别为100,300,400和500 mL/min条件下H2 S的去除率,结果表明当气体流速小于400 mL/min时,吸收率可达100%；随着温度升高,吸收效率提高并趋于恒定.在最优条件下测得1.6Et3 NHCl·FeCl3离子液体的硫容量为6.36 g/L,远高于[ Bmim] FeCl4离子液体.通过比较吸收H2 S前后的红外光谱图,进一步确定了氧化反应的发生.采用密度泛函理论从分子水平上研究了H2S与1.6Et3NHCl·FeCl3和[Bmim]FeCl4两种铁基离子液体以及Fe3＋水溶液的相互作用,从理论上比较了脱硫剂中的基质对H2 S吸收的影响,确定了胺基对H2 S吸收的促进作用.通过对脱硫产物的XRD分析,确定了斜方晶体（α-硫）的生成,与传统水相湿法氧化脱硫得到的产物相同.通入空气可快速有效地对1.6Et3 NHCl·FeCl3离子液体进行再生.

Amine Fe-based ionic liquid 1.6Et3NHCl·FeCl3 was synthesized with ideal H2S absorption ca-pacity and good thermostability. H2 S removal efficiency was tested under the condition with H2 S concentration of 832 mg/m3 , temperature ranging from 40 ℃ to 180 ℃, and gas flow of 100, 300, 400 or 500 mL/min. The results showed that when the gas flow was less than 400 mL/min, H2 S removal efficiency could reach 100%; H2 S removal efficiency increased with the increasing in temperature and tended to approach an asymp-totic value. Under the optimal conditions, the sulfur capacity of 1.6Et3NHCl·FeCl3 was 6.36 g/L, higher than that of [ Bmim] FeCl4 . Comparing the FTIR spectra before and after H2 S absorption, redox reaction be-tween 1.6Et3NHCl·FeCl3 and H2S was confirmed. The interaction between H2S and 1.6Et3NHCl·FeCl3/[ Bmim] FeCl4/H2 O has been studied at the molecular level using density functional theory, and the influence of the substrate on H2 S absorption was illustrated to be responsible for the enhancement of H2 S absorption by aminal group. The product after H2 S absorption was orthorhombic crystal sulfur（α） , which is the same as the product from traditional aqueous phase oxidation desulfurization. 1.6Et3NHCl·FeCl3ionic liquid can be re-used efficiently after quick regeneration by air flow.