An inexpensive N-methyl-2-pyrrolidone-based ionic liquid as efficient extractant and catalyst for desulfurization of dibenzothiophene

作者：Li Fa tang^*; Wu Biao; Liu Rui hong; Wang Xiao jing; Chen Lan ju; Zhao Di shun

来源：Chemical Engineering Journal, 2015, 274: 192-199.

DOI：10.1016/j.cej.2015.04.027

• Oxidative desulfurization
• Dibenzothiophene
• Extraction
• Metal chlorides
• N-methyl-pyrrolidone
• Ionic liquid

Inexpensive N-methyl-pyrrolidone (NMP)-based ionic liquids (ILs) are synthesized by coordinating N-methyl-pyrrolidone with anhydrous FeCl3 or ZnCl2. The introduction of metal chlorides lowers the solubility of NMP for actual diesel. The obtained C5H9NO center dot 0.3FeCl(3) IL shows remarkable extraction ability for dibenzothiophene (DBT) with Nernst partition coefficients (k(N)) above 7.5, which can be attributed to its low viscosity and bifunctional extractive groups of five-membered ring of NMP and unoccupied orbitals of Fe ion. The oxidative desulfurization of DBT using H2O2 as oxidant and ILs as extractants are investigated. The scavenger experiments and electron paramagnetic resonance (EPR) measurement verify the active species is hydroxyl radical ((OH)-O-center dot) responsible for the oxidation of DBT. FeCl3-based ILs show much better effects in catalyzing H2O2 to generate (OH)-O-center dot than ZnCl2-based ILs. The process and mechanism for extraction and catalytic oxidation of DBT in an oil-ionic liquid-H2O2 system are proposed. The C5H9NO center dot 0.3FeCl(3) IL shows excellent recycling performance. After six-run experiment, there is only little loss in activity, which can be ascribed to the high solubility (18,190 ppm) of dibenzothiophene-sulfone (DBTO2), the main oxidation product of DBT, in the IL.

• 出版日期2015-8-15
• 单位河北大学