EMIES/nC_9H_(10)O_2基低共熔溶剂的制备及其氧化脱硫活性的研究

Preparation of EMIES/nC_9H_(10)O_2-based deep eutectic solvents and its oxidative desulfurization activity

通过简单加热1-乙基-3-甲基咪唑硫酸乙酯(EMIES)离子液体和3-苯丙酸(C_9H_(10)O_2)的混合物,制备了一系列酸性低共熔溶剂EMIES/nC_9H_(10)O_2(n=0.25,0.5,1,2,4)。通过FTIR,~1H NMR和TGA的表征,确定EMIES/nC_9H_(10)O_2的结构。以该低共熔溶剂为催化剂和萃取剂,H_2O_2为氧化剂,组成氧化-萃取脱硫体系,用于脱除模拟油中的硫化物。考察了原料配比、反应温度、氧硫比(O/S)、低共熔溶剂加入量和不同硫化物对脱硫性能的影响。结果表明,在EMIES和C_9H_(10)O_2摩尔比为1∶1,反应温度为50℃,O/S比为8,低共熔溶剂加入量为1.5 g和模拟油5 ml的反应条件下,二苯并噻吩、4,6-二甲基二苯并噻吩和苯并噻吩的脱除率分别为94.8%、91.6%和46.4%。低共熔溶剂可循环使用6次,活性无明显下降。此外,对该氧化-萃取脱硫体系的脱硫机理进行了探讨。

A series of acidic deep eutectic solvents(DESs)EMIES/nC9H10O2(n=0.25,0.5,1,2,4)were synthesized by simply heating the mixture of 1-ethyl-3-methylimidazolium ethylsulfate(EMIES)and 3-phenylpropionic acid(C9H10O2).The structure of EMIES/nC9H10O2 was determined by FTIR,1H NMR and TGA characterization.The extraction-oxidation desulfurization system was developed to remove sulfides from model oil using EMIES/nC9H10O2 as the extractant and catalyst,H2O2 as the oxidation.The influences of raw material ratio,reaction temperature,O/S ratio,amount of DESs and different sulfide on the desulfurization performance were investigated.The experimental results demonstrated the optimal reaction conditions were molar ratio of EMIES to C9H10O2 of 1∶1,temperature of 50℃,O/S ratio of 8,the amount of DESs of 1.5 g and 5 ml model oil.Removal rate of DBT,4,6-DMDBT and BT reached 94.8%,91.6%and 46.4%,respectively,under the optimal condition.The DESs can be reused for 6 times without significant decrease in activity.In addition,the desulfurization mechanism of the oxidation-extraction desulfurization system was discussed.