A sustainable peroxophosphomolybdate/H2O2 system for the oxidative removal of organosulfur compounds from simulated and real high-sulfur diesels

• Published in: Applied catalysis. A, General Vol. 589; p. 117154
• Main Authors: Julião, Diana, Gomes, Ana C., Cunha-Silva, Luís, Valença, Rita, Ribeiro, Jorge C., Pillinger, Martyn, de Castro, Baltazar, Gonçalves, Isabel S., Balula, Salete S.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 05.01.2020; Elsevier Science SA
• Subjects: Benzothiophene; Catalysts; Computer simulation; Desulfurizing; Dibenzothiophene; Diesel; Hydrogen peroxide; Organosulfur compounds; Oxidation; Oxidative desulfurization; Oxidizing agents; Peroxophosphomolybdate; Sulfones; Sulfur; Sulfur compounds; Sulfur content; Sulfur removal; Oxidative desulfurization; Peroxophosphomolybdate; Diesel; Hydrogen peroxide; Dibenzothiophene
• ISSN: 0926-860X; 1873-3875
• DOI: 10.1016/j.apcata.2019.117154

[Display omitted] •Crystal structure of the peroxophosphomolybdate [(n-C4H9)4N]3{PO4[MoO(O2)2]4}.•Complete desulfurization of a multicomponent model diesel (3 h, 70 °C).•Catalyst pluses include high stability, low H2O2/S ratios, and no leaching effects.•Easy catalyst separation promotes its efficient reuse in many desulfurization cycles.•Desulfurization efficiency of 78% achieved with a high-sulfur untreated real diesel. Highly efficient, deep desulfurization of a multi-component model diesel containing benzothiophene (BT), dibenzothiophene (DBT) and 4,6-dimethyldibenzothiophene (4,6-DMDBT) has been achieved by using the peroxophosphomolybdate [(n-C4H9)4N]3{PO4[MoO(O2)2]4} (Q3PMo4) directly as catalyst, and aqueous H2O2 as oxidant. Q3PMo4 behaves as a heterogeneous catalyst in the complete oxidation of the various sulfur compounds to the corresponding sulfones within 3 h at 70 °C, using a relatively low H2O2/S molar ratio of 3.7, and could be recycled for ten times with only a minimal decrease in activity. A study was performed to adapt the catalyst Q3PMo4 for the removal of sulfur from a real untreated diesel while maintaining a low, economically desirable, H2O2/S molar ratio of 3.7. The highest desulfurization performance was achieved in the presence of an extraction solvent during the catalytic oxidative stage, reinforced by two extraction steps before and after sulfur oxidation. Under these conditions, the sulfur content of the real diesel was reduced from 2300 to 500 ppm (78% desulfurization efficiency) after 3 h.