相转移催化氧化-萃取脱除直馏柴油中硫化物的研究

以四丁基溴化铵(TBAB)为相转移剂，采用H2O2-HCOOH催化氧化直馏柴油中含硫化合物，利用N, N-二甲基甲酰胺(DMF)萃取脱除氧化含硫化合物。通过考察TBAB用量、反应温度、反应时间、H2O2和HCOOH用量、剂油比、搅拌速率对柴油脱硫效果的影响，确定适宜的操作条件为：TBAB用量0.10%，反应温度60 ℃，反应时间2.0 h，V(H2O2)/V(柴油)为10%，V(H2O2)/V(HCOOH)=1:2，剂油体积比2∶5，搅拌速率150 r/min。在该反应条件下，直馏柴油的脱硫率达到82.03%，柴油收率为92.02%。模拟柴油脱硫反应动力学结果表明，H2O2-HCOOH相转移催化氧化脱除噻吩硫反应为表观一级反应，活化能为7.47 kJ/mol。

STUDY ON OXIDATION-EXTRACTION DESULFURIZATION OF STRAIGHT-RUN DIESEL BY PHASE TRANSFER CATALYSIS

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.