Sono-desulfurization oxidation reactivities of FCC diesel fuel in metal ion/H2O2 systems

The objective of this work was to probe experimentally the characteristics of the use of Fe2+ or Cu2+ ions in the ultrasound-assisted oxidation desulfurization (UAODS) of diesel fuels and to develop a model that appropriately represented the mechanism. The influence of metal ions (Fe2+ or Cu2+) on aqueous phase pH values of the UAODS of diesel fuels was investigated. The UAODS proceeded rapidly only within a limited pH range from 1.9 to 2.1. It was observed that the UAODS of diesel fuels fitted pseudo-first-order kinetics under our experimental conditions. In UAODS of diesel fuels the apparent reaction rate constants can be greatly enhanced by addition of metal ions and/or using ultrasound. The combination of ultrasound and the metal ions can also reduce the apparent activation energy rapidly. The order of the apparent reaction rate constants in UAODS of diesel fuels is US–Fe2+–H2O2 system > US–Cu2+–H2O2 system > US–H2O2 system > H2O2 system.