Ultrasound-assisted oxidative desulfurization of bunker-C oil using tert-butyl hydroperoxide

This work investigated the ultrasonic assisted oxidative desulfurization of bunker-C oil with TBHP/MoO3 system. The operational parameters for the desulfurization procedure such as ultrasonic irradiation time, ultrasonic wave amplitude, catalyst initial concentration and oxidation agent initial concentration were studied. The experimental results show that the present oxidation system was very efficient for the desulfurization of bunker-C oil and ∼35% sulfur was removed which was dependent on operational parameters. The application of ultrasonic irradiation allowed sulfur removal in a shorter time. The stronger the solvent polarity is, the higher the sulfur removal rate, but the recovery rate of oil is lower. The sulfur compounds in bunker-C oil reacted with TBHP to produce corresponding sulfoxide, and further oxidation produced the corresponding sulfone.

► About 35% sulfur was removed by using TBHP/MoO3 system in presence of ultrasound.
► The application of ultrasonic irradiation allowed sulfur removal in a shorter time.
► The sulfur removal increased and the recovery of oil declined with higher polarity of the solvent.
► The sulfur compounds reacted with TBHP to produce sulfoxide, and further produced the sulfone.