Ultrasound assisted oxidative desulfurization of simulated diesel using flow cell and longitudinal bath in combination with different oxidants

Abstract

Ultrasound assisted oxidative desulfurization (UAOD) of simulated diesel containing dibenzothiophene (DBT) as a model sulfur compound has been investigated using ultrasonic flow cell (FC) and ultrasonic longitudinal bath operated individually and in combination with different oxidants. The influence of process parameters such as H2O2 loading (10 mL/L–40 mL/L), acetic acid (AA) loading (30 mL/L–90 mL/L), time (15 min–180 min), temperature (40 °C–70 °C), recirculation flow rate (45 mL/min– 85 mL/min) and potassium persulfate (KPS) loading (6 g/L to 14 g/L) on the progress of desulfurization has been studied using ultrasonic flow cell. Significant enhancement in the extent of desulfurization was observed with the use of optimum conditions and best approach for desulfurization of DBT was found to be FC + KPS + AA+H2O2 resulting in 100% desulfurization. A marginally better effect was demonstrated in a longitudinal bath at a working capacity of 4 L. The kinetic data revealed that the desulfurization process followed pseudo-first-order reaction kinetics. The thermodynamic parameters were also established for the desulfurization. Overall it was demonstrated that desulfurization was intensified using oxidants in combination with ultrasound and best results were shown at capacity of 4 L for the first time using a longitudinal bath.