LAUSR

An extractive desulfurization method was developed with 1,8-diazabicyclo[5.4.0]undec-7-ene Im ([DBU][Im]) and 1,1,3,3-tetramethylguanidine Im ([TMG][Im]) as extractants. Effects of extraction time, ionic liquid (IL):model fuel mass ratio, ILs species, initial concentration of sulfur, and temperature on removal efficiency of sulfur compound were investigated. The removal efficiencies of dibenzothiophene, 4,6-dimethyldibenzothiophene, and benzothiophene with [DBU][Im]/[TMG][Im] as extractants were 79.2%/69.4%, 68.4%/57.7%, and 61.2%/54.4%, respectively. The interaction between [DBU][Im] and sulfur compounds could be enhanced by extra heterocyclic aromatic ring in DBU cation and imidazolium ring in Im anion. Both extraction processes with these two ILs as extractants were fast (extraction equilibrium was reached within 10 min). The reusability of prepared ILs was studied, and the multistage cross-current extraction experiments were performed. Moreover, the characterization methods of nuclear magnetic resonan...