C6H11NO/nCF3SO3H型低共熔溶剂氧化脱除模拟油中的二苯并噻吩

Oxidative removal of dibenzothiophene from model oil by C6H11NO/nCF3SO3H deep eutectic solvents

通过简单加热并搅拌己内酰胺(C6H11NO)和三氟甲磺酸(CF3SO3H)的混合物合成了C6H11NO/nCF3SO3H(n=0.25,0.5,1)型酸性低共熔溶剂。利用红外光谱(FTIR)和氢谱(1HNMR)确定了C6H11NO/nCF3SO3H的结构特征。以C6H11NO/0.5CF3SO3H低共熔溶剂和H2O2组成萃取-氧化脱硫系统,并将其应用于脱除模拟油中的二苯并噻吩(DBT)。研究n(CF3SO3H)∶n(C6H11NO)、反应温度、O/S、C6H11NO/0.5CF3SO3H的加入量和不同类型的硫化物对脱硫效果的影响。实验结果表明,在模拟油体积为5mL、n(CF3SO3H)∶n(C6H11NO)=0.5、反应温度为60℃、O/S=6、C6H11NO/0.5CF3SO3H的加入量为1.0mL的最佳反应条件下,C6H11NO/0.5CF3SO3H对DBT、4,6-DMDBT、BT和真实油的脱硫率分别达99.4%、98.6%、83.6%和61.6%。红外表征分析了DBT与DESs之间存在相互作用,这种作用促进了氧化脱硫的进程。催化剂5次循环反应以后,其脱硫率仍高达91.9%,表明C6H11NO/0.5CF3SO3H低共熔溶剂具有较高的脱硫性能和稳定性。

Deep eutectic solvents C6H11NO/nCF3SO3H(n=0.25,0.5,1)were synthesized by simply heating and stirring the mixture of caprolactam(C6H11NO)and trifluoromethanesulfonic acid(CF3SO3H).The structural characteristics of C6H11NO/nCF3SO3H were determined by infrared spectroscopy(FTIR)and hydrogen spectroscopy(1HNMR).An extraction-oxidation desulfurization system was composed of C6H11NO/0.5CF3SO3H deep eutectic solvent and H2O2,and it was applied to remove dibenzothiophene(DBT)in model oil.The effects of n(CF3SO3H)∶n(C6H11NO),reaction temperature,O/S,dosage of C6H11NO/0.5CF3SO3H and different types of sulfides on desulfurization rate were studied.The experimental results indicated that under the optimum conditions of V(oil)5mL,n(CF3SO3H)∶n(C6H11NO)=0.5,reaction temperature 60℃,O/S=6 and V(DESs)1.0mL,the desulfurization rates of DBT,4,6-DMDBT,BT and real oil were 99.4%,98.6%,83.6%and 61.6%,respectively.The stability of deep eutectic solvent was studied by infrared spectroscopy of recovered C6H11NO/0.5CF3SO3H.The interaction between DBT and DESs was analyzed by infrared spectroscopy of DBT,DESs and DBT-DESs.This interaction promoted the process of oxidative desulfurization.After five recycling runs,its desulfurization rate was still as high as 91.9%,indicating that C6H11NO/0.5CF3SO3H had high catalytic desulfurization activity and stability.