Oh HW  Woo HC

Vol. 25,  No. 1, pp. 91-97, Mar.  2019
10.7464/ksct.2019.25.1.091

Oxidative desulfurization Marine diesel Heteropoly acid (HPA) Hydrogen peroxide Supported catalyst

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Oxidative desulfurization (ODS) has received much attention in recent years because refractory sulfur compounds such as dibenzothiophenes can be oxidized selectively to their corresponding sulfoxides and sulfones, and these products can be removed by extraction and adsorption. In this work, The oxidative desulfurization of marine diesel fuel was performed in a batch reactor with hydrogen peroxide (H2O2) in the presence of various supported heteropoly acid catalysts. The catalysts were characterized by XRD, XRF, XPS and nitrogen adsorption isotherm techniques. Based on the sulfur removal efficiency of promising silica supported heteropoly acid catalysts, the ranking of catalytic activity was: 30 H3PW12/SiO2 > 30 H3PMo12/SiO2 > 30 H4SiW12/SiO2, which appears to be related with their intrinsic acid strength. The 30 H3PW12/SiO2 catalyst showed the highest initial sulfur removal efficiency of about 66% under reaction conditions of 30 ℃, 0.025 g mL-1 (cat./oil), 1 h reaction time. However, through the recycle test of the H3PW12/SiO2 catalyst, significant deactivation was observed, which was attributed to the elution of the active component H3PW12. By introducing cesium cation (Cs+) into the H3PW12/SiO2 catalyst, the stability of the catalyst was improved with changing the solubility, and the Cs+ ion exchanged catalyst could be recycled for at least five times without severe elution.