Extractive and Oxidative Desulfurization of Fuels Using Task-Specific Ionic Liquids

A series of different anion based N-methyl imidazolium ionic liquids(ILs) are synthesized in this paper.The ILs are applied as extractant,using 35% of H2O2 and CH3COOH as oxidant for the model oil and true oil(gasoline and diesel) desulfurization reactions.The results indicate that,the acidity of ILs and the carbon chain length of the imidazolium cation on the ILs are responsible for sulfur removal efficiency.The sulfur removal rate for strong acidic HSO-4 anion based long chain ILs can reach higher than 90% for model oil and 80% for true oil(gasoline and diesel) under IL∶Oil∶H2O2= 1∶25∶1 at 30 ℃.The sulfur content for gasoline is even decreased to about 10 mg·kg-1,which has reached the Euro Ⅴ standard.The ILs show pretty high industrial application prospect.