The melting-type of caprolactam-tetrabutylammonium bromide acidic quaternary ammonium ionic liquids (ILs) were synthesized as catalysts for the olefin alkylation thiophenic sulfur (OATS) in FCC gasoline. [CPL-TBAB]2HSO₄ with high acid strength showed the best desulfurization performance. GC–MS analysis suggested that the alkylation products of model oil were mainly mono-alkyl or di-alkyl thiophenic sulfides. The decrease of acid strength made the activity of IL degraded. Re-cation regeneration of cationic ligands with higher price recovered from the used IL was proposed to restore the acid strength by adding new anionic groups, and it showed a similar desulfurization activity as the fresh IL.

合成了己内酰胺-四丁基溴化铵酸性季铵离子液体（ILs）的熔融类型，作为FCC汽油中烯烃烷基化噻吩硫（OATS）的催化剂。高酸强度的[CPL-TBAB] 2HSO ₄表现出最好的脱硫性能。GC-MS分析表明，模型油的烷基化产物主要是单烷基或二烷基噻吩硫化物。酸强度的降低使IL的活性降低。再-阳离子阳离子配体的再生用更高的价格回收从所使用的IL提出通过添加新的阴离子基团以恢复酸强度，并且它显示了类似的脱硫活性作为新鲜IL。