Oxidative desulfurization utilizing activated carbon supported phosphotungstic acid in the frame of ultrasonication

Abstract

Desulfurization technology is essential to remove sulfur content in diesel oil to achieve clean fuel products. In this study, oxidative desulfurization via ultrasonic bath equipment was utilized in conjunction with a synthesized activated carbon supported phosphotungstic acid (HPW-AC) catalyst. This research focuses on the extent of desulfurization in a simulated diesel oil. This contains 2.3% sulfur from benzothiophene (BT) and dibenzothiophene (DBT) mixed in actual diesel oil. The effects of ultrasonication time (30 min to 90 min), reaction temperature (40 °C to 70 °C), and catalyst dosage (6 wt% to 18 wt%) were examined for the oxidation of the simulated diesel oil containing BT and DBT. A 2k full factorial design was implemented in the experimental runs to evaluate the parameters by the analysis of variance. Results showed that the curvature of the model was not significant (p-value = 0.3134). Thus, further optimization runs were no longer required to fully analyze the model. The best conditions for sulfur conversion can be attained at 30 min, 70 °C and 18 wt% HPW-AC catalyst. Furthermore, the basic diesel oil properties (density, viscosity, and calorific value) were compared before and after the desulfurization treatment process. Results indicated that the simulated diesel oil retained essentially the same properties prior to its treatment. This proves to show a promising result that can further be improved for its applicability in future industrial practice.