Heteropolyacids as effective catalysts to obtain zero sulfur diesel

de Angelis, Alberto; Pollesel, Paolo; Molinari, Daniele; O'Neal Parker, Wallace; Frattini, Alessandra; Cavani, Fabrizio; Martins, Susie; Perego, Carlo

doi:10.1351/pac200779111887

Pure Appl. Chem., 2007, Vol. 79, No. 11, pp. 1887-1894

http://dx.doi.org/10.1351/pac200779111887

Heteropolyacids as effective catalysts to obtain zero sulfur diesel

Alberto de Angelis¹, Paolo Pollesel¹, Daniele Molinari¹, Wallace O'Neal Parker, Jr.¹, Alessandra Frattini², Fabrizio Cavani², Susie Martins³ and Carlo Perego¹

¹ Eni, Refining and Marketing Division, via F. Maritano 26, San Donato Milanese, Italy
² University of Bologna, viale Risorgimento 4, Bologna, Italy
³ UOP, 25 East Algonquin Road, Des Plaines, IL 60017, USA

Abstract: This paper deals with the catalytic properties of different supported heteropolyacids (HPAs), both molybdenum- and tungsten-based, in the oxidative desulfurization process of diesel. We are jointly developing a new oxidative desulfurization process, aimed at reducing the sulfur content in diesel to less than 10 ppm (parts per million) using in situ produced peroxides. In this new process, high-molecular-weight organosulfur compounds, such as 4,6-dimethyl-dibenzothiophene (DMDBT), difficult to be eliminated by conventional hydrodesulfurization, are oxidized to the corresponding sulfones and subsequently removed by adsorption. Molybdenum-based HPAs, with Keggin structure, proved to be the most active and selective catalysts for oxidizing DMDBT with on-stream lifetimes exceeding 1500 h time on stream (t.o.s.).