Ionic liquids (ILs) were selected and applied to investigate the best coal desulfurization through orthogonal tests. FTIR, XPS, SEM and contact angle tests were used to characterize the effect on the physical and chemical structures in coal for revealing the coal desulfurization mechanism by ILs-HO system. The orthogonal test results showed that reaction temperature and reaction time were the main influencing factors for the desulfurization rates of coal in the ILs-HO system, and the ILs synergy could effectively improve the desulfurization rates of HO. The maximum coal desulfurization rates of [BMIM][HSO], [BMIM][OTF], and [BMIM][BF] ionic liquids were 30.7%, 30%, and 33.2%, respectively. The results indicated that the alkyl groups in coal were oxidized and the contents of oxygen-containing functional groups such as hydroxyl and carbonyl increased. Coal surface underwent swelling, the internal pores increased and new pores and cracks were generated. The wettability of coal improved substantially. In addition, the physical structures changes in coal facilitated the contact between the extractant and the sulfur-containing structures. The contents of thiols and sulfides in coal significantly decreased and were oxidized to sulfoxides and sulfones, with some further oxidized to soluble sulfites or sulfates. Thus achieving removal from coal.

中文翻译：

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ILs-H2O2体系脱硫机理及其对煤结构的影响研究


选择离子液体（IL）并通过正交试验研究最佳的煤脱硫效果。采用FTIR、XPS、SEM和接触角测试表征ILs-HO体系对煤中物理和化学结构的影响，揭示ILs-HO体系的煤脱硫机理。正交试验结果表明，反应温度和反应时间是ILs-H2O体系中煤脱硫率的主要影响因素，ILs协同作用可有效提高H2O脱硫率。 [BMIM][HSO]、[BMIM][OTF]和[BMIM][BF]离子液体的最大煤脱硫率分别为30.7%、30%和33.2%。结果表明，煤中的烷基被氧化，羟基、羰基等含氧官能团含量增加。煤表面发生膨胀，内部孔隙增多，并产生新的孔隙和裂缝。煤的润湿性明显改善。此外，煤的物理结构变化促进了萃取剂与含硫结构之间的接触。煤中硫醇和硫化物含量显着下降，并被氧化成亚砜和砜，有的进一步氧化成可溶性亚硫酸盐或硫酸盐。从而实现从煤中的去除。