摘要
研究了微波辐射下磷钼酸镧盐催化模型油和直馏柴油的氧化脱硫反应,并比较了不同萃取条件下柴油的脱硫率和回收率.结果表明,在相同的反应条件下,微波辐射加热时DBT,BT的脱除率比普通加热分别提高了7.5倍和3.9倍.二苯并噻吩和苯并噻吩的氧化反应都符合表观一级反应动力学规律.在70℃和400 W微波功率下,DBT,BT的脱除率可分别达到94.0%和91.2%.直馏柴油氧化脱硫的最佳反应条件为:剂油质量比为7.1 mg/g,H2O2初始浓度为0.44 mol/L,微波功率为400 W,反应温度为70℃和反应时间为120 m in.当V(DMF)/V(柴油)为1/4和萃取1次时,柴油脱硫率为64.5%,回收率为97.6%,当提高V(DMF)/V(柴油)或萃取次数,柴油的脱硫率提高了,但回收率却明显下降.在氧化脱硫过程中,首先过氧化氢亲核进攻催化剂的活性中心Mo(Ⅵ),然后氧化噻吩类形成亚砜,最后亚砜进一步被氧化生成砜.
The oxidative desulfurization of model oil and straight - run diesel catalyzed by lanthanum phosphomolybdate under microwave radiation was studied. And the desulfurization rates and recovery rates of diesel with different extraction conditions were investigated. Under the same reaction conditions,the conversion rates of DBT and BT were 7.5 times and 3.9 times higher under microwave radiation heating than that of traditional heat- ing, respectively. Both of the oxidative reactions of DBT and BT were in eonforInity with apparent - first order kinetics. The conversion rates of DBT and BT could be up to 94.0% and 91.2% under 400 W mierowave radiation and 70 ℃ , respectively. The best reaction conditions for oxidative desulfurization of straight diesel are ： m （ cata- lyst）/m（diesel） is 7.1 mg/g,the initial concentration of H202 is 0.44 mol/L,mierowave power is 400 W,reaetion temperature is 70℃ and reaction time is 120 rain. When extracted once with V（ DMF）/V（diesel） of 1/4 ,the desulfurization rate of diesel was 64.5% with the recovery rate of 97.6%. And with higher V（ DMF）/V（diesel） or extraction times,the desulfurization rates increased,but the reeovery rates of diesel declined obviously. During the oxidative process of diesel,it was first that hydrogen peroxide attaeked the active center Mo（VI） of the catalyst, then thiophenes were oxidized to sulfoxides,and further being oxidized to sulfones.
出处
《云南大学学报（自然科学版）》
CAS
CSCD
北大核心
2009年第5期499-504,共6页
Journal of Yunnan University(Natural Sciences Edition)
基金
高等学校博士学科点专项科研基金项目资助(200804880003)
湖北省自然科学基金项目资助(2008CDB376,2008CDB025)
关键词
微波辐射
磷钼酸镧盐
柴油
氧化脱硫
反应机理
microwave radiation
lanthanum phosphomolybdate
diesel
oxidative desulfurization
reactionmechanism
