N-butyl-pyridinium tetrafluoroborate as a highly efficient ionic liquid for removal of dibenzothiophene from organic solutions

In this research, 1-butyl-pyridinium tetrafluoroborate (C₄PyBF₄^-) was prepared by ion exchange method and was characterized by ¹H-NMR, ¹³C-NMR, and FT-IR techniques. The synthesized ionic liquid was used for removal of dibenzothiophene as a typical organosulfur pollutant from organic medium. The effect of different parameters on the extraction efficiency was studied and optimized. At the optimized conditions, 97.68% of dibenzothiophene was extracted from 1 000 mg/L n-hexane solution. The extraction efficiency obtained in this work was higher than the previous reported values. The desulfurization reaction was kinetically followed the second order mechanism. The ionic liquid was reusable and after four regeneration cycles 97% of its original extraction efficiency was retained.