Tremendous attention has been paid to removal of N-/S-containing compounds from liquid fuel due to the necessity of reducing NO_x and SO_x emissions. In this work, the compatibility index (CI or PCI) was developed as a new criterion to evaluate the removal efficiency (R_e) of quinoline, carbazole and dibenzothiophene (DBT) in deep eutectic solvents (DESs). For alkaline quinoline, acid–base extraction was pronounced, and ChCl/mandelic acid was the optimal extractant to achieve a removal efficiency of 99.2 wt% (CI = 0.37). For near-neutral carbazole and DBT, polarity compatible extraction was the predominant mechanism. The highest R_e value of 94.9 wt% for carbazole removal was obtained in the ChCl/mandelic acid extractant (PCI = −0.044). DBT was difficult to remove directly because of its low molecular polarity. After adding H₂O₂, the desulfurization efficiency was found to increase to 99.1 wt% in the ChCl/p-toluenesulfonic acid extractant (PCI = 0.014). Furthermore, experiments with real diesel confirmed that the highest desulfurization and denitrification efficiency was 67.7 wt% and 63.7 wt%, respectively, in ChCl/p-toluenesulfonic acid. The compatibility index developed in this study has the potential to simplify the filtration operation of extractants and to intensify the removal efficiency of N-/S-containing compounds in the category of “green extraction”.

中文翻译：

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深入探讨低共熔溶剂对液体燃料的有效反硝化和脱硫：使用相容性指数对萃取剂进行过滤的创新评估标准

由于减少NO _x和SO _x排放的必要性，从液体燃料中去除含N / S的化合物已引起了极大的关注。在这项工作中，开发了相容性指数（CI或PCI）作为评估在深共熔溶剂（DES）中喹啉，咔唑和二苯并噻吩（DBT）的去除效率（R _e）的新标准。对于碱性喹啉，酸碱萃取非常明显，ChCl /扁桃酸是实现99.2 wt％（CI = 0.37）去除效率的最佳萃取剂。对于接近中性的咔唑和DBT，极性兼容萃取是主要机理。最高R _e在ChCl /扁桃酸萃取剂中获得的咔唑去除值为94.9 wt％（PCI = -0.044）。DBT由于其低分子极性而难以直接去除。加入H ₂ O _2后，发现在ChCl /对甲苯磺酸萃取剂中（PCI = 0.014），脱硫效率提高到99.1 wt％。此外，使用真实柴油的实验证实，在ChCl /对甲苯磺酸中，最高的脱硫和反硝化效率分别为67.7 wt％和63.7 wt％。在这项研究中开发的相容性指数具有简化萃取剂过滤操作并增强“绿色萃取”类别中含N / S的化合物的去除效率的潜力。