Abstract

Benzothiophene, Dibenzothiophene (DBT), 4-methyldibenzothiophene, and 4,6-dimethyldibenzothiophene are typical thiophenic compounds prevailing in diesel fuels. Using a hexadecane solution of these model compounds, experiments were carried out to compare the reactivity of the different benzothiophenes in oxidesulfurization (ODS) with several polar solvents. V2O5/Al2O3 catalyst, hydrogen peroxide as oxidant and the solvents: N,N-dimethylformamide (DMF), 2-ethoxyethanol (EEOH), acetonitrile (MeCN) and gamma-butyrolactone (BuL) were used. The experimental results showed that removal of benzothiophenes contained in diesel can be carried out efficiently in conditions here studied, with a yield to sulfones higher than 80%, depending on the reactivity of each S-compound and solvent used. DBT was completely removed but the yield to DBT sulfone with MeCN was only 95%. According to the solvent used, benzothiophenes reactivities decrease in the order: MeCN > BuL > EEOH > DMF. It was found that an important fraction of the eliminated compounds in the diesel phase, is not totally transformed to its corresponding sulfone, it is only removed as sulfur compound by extraction, without undergoing ODS reaction. Depending on the thiophenic compound, it was possible to remove about 70-85% of benzothiophenes by physical extraction process, using the best solvent (DMF) and only close to 30-60% with MeCN.

Recommended Citation

Gomez Bernal, Hilda and Cedeño Caero, Luis (2005) "Solvent Effects During Oxidation-Extraction Desulfurization Process of Aromatic Sulfur Compounds from Fuels," International Journal of Chemical Reactor Engineering: Vol. 3: A28.
Available at: http://www.bepress.com/ijcre/vol3/A28