Deep desulfurization of diesel fuels by catalytic oxidation

Abstract

Reaction feed was prepared by dissolving dibenzothiophene (DBT), which was selected as a model organosulfur compound in diesel fuels, in n-octane. The oxidant was a 30 wt-% aqueous solution of hydrogen peroxide. Catalytic performance of the activated carbons with saturation adsorption of DBT was investigated in the presence of formic acid. In addition, the effects of activated carbon dosage, formic acid concentration, initial concentration of hydrogen peroxide, initial concentration of DBT and reaction temperature on the oxidation of DBT were investigated. Experimental results indicated that performic acid and the hydroxyl radicals produced are coupled to oxidize DBT with a conversion ratio of 100%. Catalytic performance of the combination of activated carbon and formic acid is higher than that of only formic acid. The concentration of formic acid, activated carbon dosage, initial concentration of hydrogen peroxide and reaction temperature affect the oxidative removal of DBT. The higher the initial concentration of DBT in the n-octane solution, the more difficult the deep desulfurization by oxidation is.