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An effective process to remove nitrogen-based compounds from fossil fuels without harming the process of sulfur removal is an actual gap in refineries. A success combination of desulfurization and denitrogenation processes capable of completely removing the most environmental contaminates in diesel under sustainable conditions was achieved in this work, applying polyoxometalates as catalysts, hydrogen peroxide as oxidant, and an immiscible ionic liquid as an extraction solvent. The developed process based in simultaneous oxidative desulfurization (ODS) and oxidative denitrogenation (ODN) involved initial extraction of sulfur and nitrogen compounds followed by catalytic oxidation. Keggin-type polyoxomolybdates revealed much higher reusing capacity than the related polyoxotungstate. Effectively, the first catalysts practically allowed complete sulfur and nitrogen removal only in 1 h of reaction and for ten consecutive cycles, maintaining the original catalyst and ionic liquid samples.
Dinis Silva; Alexandre Viana; Fátima Mirante; Baltazar de Castro; Luís Cunha-Silva; Salete Balula. Removing Simultaneously Sulfur and Nitrogen from Fuel under a Sustainable Oxidative Catalytic System. Sustainable Chemistry 2021, 2, 382 -391.
AMA StyleDinis Silva, Alexandre Viana, Fátima Mirante, Baltazar de Castro, Luís Cunha-Silva, Salete Balula. Removing Simultaneously Sulfur and Nitrogen from Fuel under a Sustainable Oxidative Catalytic System. Sustainable Chemistry. 2021; 2 (2):382-391.
Chicago/Turabian StyleDinis Silva; Alexandre Viana; Fátima Mirante; Baltazar de Castro; Luís Cunha-Silva; Salete Balula. 2021. "Removing Simultaneously Sulfur and Nitrogen from Fuel under a Sustainable Oxidative Catalytic System." Sustainable Chemistry 2, no. 2: 382-391.
Two quaternary ammonium catalysts based on the monovacant polyoxotungstate ([PW11O39]7−, abbreviated as PW11) were prepared and characterized. The desulfurization performances of the PW11-based hybrids (of tetrabutylammonium and trimethyloctadecylammonium, abbreviated as TBA[PW11] and ODA[PW11], respectively), the corresponding potassium salt (K7PW11O39, abbreviated as KPW11) and the peroxo-compound (TBA-PO4[WO(O2)2], abbreviated as TBA[PW4]) were compared as catalysts for the oxidative desulfurization of a multicomponent model diesel (2000 ppm S). The oxidative desulfurization studies (ODS) were performed using solvent-free systems and aqueous H2O2 as oxidant. The nature of the cation in the PW11 catalyst showed to have an important influence on the catalytic performance. In fact, the PW11-hybrid catalysts showed higher catalytic efficiency than the peroxo-compound TBA[PW4], known as Venturello compound. TBA[PW11] revealed a remarkable desulfurization performance with 96.5% of sulfur compounds removed in the first 130 min. The reusability and stability of the catalyst were also investigated for ten consecutive ODS cycles without loss of activity. A treated clean diesel could be recovered without sulfur compounds by performing a final liquid/liquid extraction diesel/EtOH:H2O mixture (1:1) after the catalytic oxidative step.
Fátima Mirante; Baltazar De Castro; Carlos M. Granadeiro; Salete S. Balula. Solvent-Free Desulfurization System to Produce Low-Sulfur Diesel Using Hybrid Monovacant Keggin-Type Catalyst. Molecules 2020, 25, 4961 .
AMA StyleFátima Mirante, Baltazar De Castro, Carlos M. Granadeiro, Salete S. Balula. Solvent-Free Desulfurization System to Produce Low-Sulfur Diesel Using Hybrid Monovacant Keggin-Type Catalyst. Molecules. 2020; 25 (21):4961.
Chicago/Turabian StyleFátima Mirante; Baltazar De Castro; Carlos M. Granadeiro; Salete S. Balula. 2020. "Solvent-Free Desulfurization System to Produce Low-Sulfur Diesel Using Hybrid Monovacant Keggin-Type Catalyst." Molecules 25, no. 21: 4961.