Combined extractive and oxidative desulfurization approach based on ultrasound and ultraviolet irradiation with additives for obtaining clean fuel

The combined extractive and oxidative desulfurization approach based on ultrasound (US) and ultraviolet (UV) irradiations with additives was investigated for treatment of simulated fuel comprising of thiophene as model sulfur component and toluene as representative fuel with an objective of obtaining a clean fuel. Experiments were performed at constant conditions of ultraviolet light and/or ultrasound with varied operating parameters as initial thiophene concentration (over the range 100-800 ppm), temperature (40 degrees C-80 degrees C), catalyst loading (0.25 to 1.5 g/L), and oxidant loading (5 mL/L to 15 mL/L) followed by the step of extraction under fixed conditions to establish the effect on desulfurization. Complete thiophene removal was achieved at best operating conditions of 1 g/L as catalyst loading, 12.5 mL/L as oxidant loading, 60 degrees C as temperature and 200 ppm as the initial concentration of thiophene within 50 min of treatment. The extent of desulfurization was significantly higher for the combination approach than achieved for individual approach of ultrasound and UV irradiation. The activation energy was found to be 25.86 kJ/mol. The gasoline desulfurization followed pseudo first order kinetics whereas the thermodynamic analysis demonstrated same spontaneity at varied temperature. The values of Delta G and Delta H were found to be 92.88 kJ/mol and 23.09 kJ/mol, respectively. The cavitational yield was significantly higher (8.82 x 10(-8) mg/J) for the combination approach. Overall, it was clearly demonstrated that the combined US/UV approach coupled with use of oxidants and catalyst at optimum conditions was the best treatment approach leading to effective removal of thiophene from the model fuel considered in the work. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

The study investigates a combined extractive and oxidative desulfurization approach using ultrasound and ultraviolet irradiation with additives for treatment of simulated fuel. Optimum conditions led to complete removal of thiophene, with significantly higher desulfurization achieved compared to individual ultrasound and UV methods.