Oxidative Desulfurization of Middle-Distillate Fuels Using Activated Carbon and Power Ultrasound

Abstract

The oxidative desulfurization (ODS) of jet and diesel fuels was studied using hydrogen peroxide plus formic acid as the oxidant, activated carbon as a reaction enhancer, and power ultrasound for phase dispersion. When the ODS treatment is followed by an activated alumina post-processing step, overall sulfur removal performance was 98% for JP-8 (at pH 1.4), 94% for diesel (at pH 1.5), and >88% for ultralow-sulfur diesel (at pH 1.5). The ODS treatment converts sulfur compounds to sulfones/sulfoxides, and activated alumina removes the oxidized sulfur compounds to yield a low-sulfur fuel. Control tests reveal that removal of any of the four reaction components (ultrasound, carbon, hydrogen peroxide, and formic acid) reduces the ODS removal performance, with hydrogen peroxide being the most crucial. The response of ODS removal performance to initial oxidant concentrations is consistent with performic acid, formed in situ from hydrogen peroxide and formic acid, being the active oxidizing species. Power ultrasou...