一种低共熔溶剂在深度萃取模拟油脱硫中的应用

Deep Extractive Desulfrization from Model Oil by Novel Deep Eutectic Solvents

以咪唑及其衍生物和Bu4NBr为原料,按不同原料配比,通过低温共熔得到了一系列新型低共熔溶剂（DESs）,用于萃取脱除模拟油品中的二苯并噻吩（DBT）,并对其最佳脱硫条件进行了考察。结果表明：当n（Bu4NBr）/n（咪唑）=0.6时,该类DESs对二苯并噻吩表现出最佳萃取效果。针对DESs考察了剂油体积比与反应温度对脱硫效果的影响,测定了DESs的选择性能与重复使用性能。结果表明：在V（DES）∶V（Oil）=1∶6、萃取温度为20℃、萃取时间为30 min时,咪唑与Bu4NBr共熔物（DESⅠ）对二苯并噻吩的脱硫率达到89.2%;经4次萃取后,其脱硫率达到95.0%;相同条件下该类DESs对于不同噻吩类衍生物的脱除能力的顺序为：二苯并噻吩（DBT）〉苯并噻吩（BT）〉4,6-二甲基二苯并噻吩（4,6-DMDBT）〉噻吩（T）;再生后脱硫效果良好;经7次重复萃取过程后,DESs对DBT的脱硫率仍高达86.8%。

A series of novel deep eutectic solvents（DESs） were synthesized with imidazole, its derivatives and Bu4 NBr as raw materials by low temperature eutectic method. The extraction removal of dibenzothiophene（DBT） in model oil was carried out with DESs as extraction agent and the optimum desulfurization conditions were determined. The results showed that the deep eutectic solvent with a molar ratio of Bu4 NBr to imidazole of 0.6 exhibited the best extraction effect on dibenzothiophene. In addition, the effect of volume ratio of extraction agent to oil and temperature on the desulfurization rate was investigated. The selectivity and recycling performance of DESs were also investigated. The results showed that the desulfurization rate of DBT was 89.2% under the conditions of extraction agent/oil volume ratio of 1： 6, extraction temperature of 20 ℃. And the desulfurization rate could reach up to 95.0% after four times extractions. Under the same conditions, the order of removal ability of different thiophene derivatives was：DBT〉benzothiophene（BT）〉4,6-dimethyldibenzothiophene（4,6-DMDBT）thiophene（T）. The deep eutectic solvent still exhibited excellent desulfurization effect for DBT after regeneration. The desulfurization rate of DBT could reach 86.8% after seven times repeated extractions.