微波辐射下柴油的催化氧化脱硫效果研究

Catalytic oxidative desulfurization of diesel under microwave radiation

将苯并噻吩(BT)和二苯并噻吩(DBT)分别溶于正辛烷配成模型油,以H2O2为氧化剂,研究普通加热和微波辐射加热下磷钼酸催化模型油和直馏柴油的氧化脱硫效果。分析了催化剂用量、H2O2初始浓度、反应温度和反应时间等对DBT、BT脱除率的影响,分析了不同萃取条件下的柴油脱硫率和回收率。结果表明,微波辐射加热下,DBT、BT的脱除率比普通加热分别提高了7.7倍和3.7倍;在70℃和400 W微波功率下,DBT、BT的脱除率分别为95.4%和62.3%;催化剂用量、H2O2初始浓度、反应温度和反应时间等对DBT、BT的氧化脱除率均有影响;v(萃取剂)/v(柴油)为1/4时,采用DMF萃取1次,柴油的脱硫率为61.8%,回收率为98.4%,萃取次数增加,柴油脱硫率提高,而回收率明显下降。

The oxidative desulfurization of model oil and straight-run diesel catalyzed by phosphomolybdic acid under traditional heating and microwave radiation was studied, with benzothiophene （BT） and dibenzothiophene （DBT） dissolved respectively in n-octane as the model oil and the aqueous solution of H2O2 as the oxidant. The effects of catalyst dosage, initial concentration of H2O2, reaction temperature and reaction time on conversions of DBT and BT, desulfurization rate and recovery rate of diesel with different extraction conditions were investigated. Under the same reaction conditions, the con- version rates of DBT and BT are 7. 7 and 3.7 times higher under microwave radiation than those under traditional heating, respectively. And the conversion rates of DBT and BT can be up to 95. 4% and 62.3% under 400 W microwave and 70 ℃, respectively. It is also shown that the catalyst dosage, initial concentration of H2O2, reaction temperature and reaction time affect the conversions of DBT and BT. When extracted once under the condition of v（DMF）/v（diesel） at 1/4, the desulfurization rate of diesel is 61.8% and the recovery rate is 98.4%. And with higher extraction times, the desulfurization rates increase, but the recovery rate of diesel declines obviously.