Dibenzothiophene removal using organic peroxide coupling ionic liquid

Taking tungstophosphoric acid as the catalyst, the removal of dibenzothiophene(DBT) remained in n-heptane using organic peroxide coupling ionic liquid was studied. The results indicate that the removal of sulfur is only about 27.78%~38.76% by using \bmim\BF₄ or \bmim\PF₆ ionic liquid (IL) as an extractant alone for the DBT-containing model oil. While 76.6% of DBT can be oxidized to dibenzothiophene sulfone by using the organic peroxide made from organic formic acid and H₂O₂ in equal volume as oxidants at 70℃ and the reaction time of 6h without catalyst and ionic liquids. As the system contains tungstophosphoric acid, organic peroxide and \bmim\PF₆ ionic liquid, the catalytic oxidation and sulfur removal are improved apparently. The DBT removal reaches 98.60% at 70℃ and the reaction time of 6h when the molar ratio of catalyst to DBT, the volume ratio of oxidant to DBT and the volume ratio of \bmim\PF₆ ionic liquid to DBT are 0.20∶1, 10∶1, 1∶1, respectively. The coupling system could be recycled five times without significant decrease in activity.