Abstract: FeCl3-based ionic liquids (ILs) with lower viscosity, prepared from the interaction of anhydrous FeCl3 and alkyl imidazolium bromide ([1-alkyl-3-methyl-imidazolium]Br, alkyl=ethyl, butyl, hexyl, octyl), were highly effective for denitrogenation of model oil containing quinoline or indole. The results showed that the chain length of the alkyl group on the imidazolium cation had no noticeable influence on the N-extraction efficiency. With the selected IL [Bmim]Br/FeCl3, up to 99.1% N-extraction efficiency of quinoline can be attained at extraction temperature of 30 ℃, IL/oil mass ratio of 1/7 and extraction time of 30 min, and indole extraction efficiency can also reach 98.9% by increasing the mass ratio of IL/oil to 1:1. Moreover, the extraction efficiency of quinoline can still reach 92.3% after four recycles of the IL.

Key words: FeCl3-based ionic liquid, denitrogenation, quinoline, indole