关键词: 直馏柴油, 脱硫, 氧化, 相转移催化, 动力学

Abstract: The desulfurization of straight-run diesel fuel was carried out in a hydroperoxide-formic acid catalytic oxidation system using tetrabutylammonium bromide (TBAB) as phase transfer catalyst, and later the oxidized organic sulfur compounds were separated by N,N-Dimethylformamide (DMF) extraction. The influences of the amount of TBAB, reaction temperature, reaction time, dosages of hydroperoxide and formic acid, the volume ratio of solvent-to-oil and mixing speed on the desulfurization of straight-run diesel fuel were investigated. The optimum operation conditions were obtained as follows: a TBAB content of 0.1%, a reaction temperature of 60℃, a reaction time of 2 h, a volume ratio of hydroperoxide-to-diesel of 0.1, a volume ratio of hydroperoxide-to-formic acid of 0.5, a volume ratio of extractant to diesel of 0.4 and a mixing speed of 150 r·min-1. Under such conditions the removal rate of sulfur and the recovered yield of diesel oil were 82.03% and 92.02%, respectively. The results of kinetics study by model fuel showed that the reaction of thiophene removal by H2O2-HCOOH phase transfer catalytic oxidation system was a pseudo first-order reaction with an activation energy of 7.47 kJ·mol-1.

Key words: straight-run diesel oil, desulfurization, oxidation, phase transfer catalysis, kinetics