Xu Yongliang, Liu Yang, Xie Huilong, Chen Menglei, Wang Lanyun
College of Safety Science and Engineering, Henan Polytechnic University, 2001, Century Avenue, Jiaozuo, Henan CN 454000, China.
Collaborative Innovation Center for Coal Safety Production & High-Efficient-Clean Utilization By Provincial and Ministerial Co-Construction, 2001, Century Avenue, Jiaozuo, Henan CN 454000, China.
ACS Omega. 2020 Aug 12;5(33):21127-21136. doi: 10.1021/acsomega.0c02795. eCollection 2020 Aug 25.
In order to improve the total sulfur removal rate in coal combustion, an acidic ionic liquid (IL) 1-carboxymethyl-3-methylimidazolium hydrogen sulfate ([HOOCCHmim][HSO]) as the extractant combined with the oxidant 30% hydrogen peroxide (HO) was applied to reduce the total sulfur content, and its microscopic mechanism of desulfurization was analyzed. The experimental results show that the desulfurization rate of the [HOOCCHmim][HSO]-HO (1:10) solution was 45.12% and the organic sulfur removal rate was 16.26%, which were significantly higher than those of only HO or pure [HOOCCHmim][HSO]. Fourier-transform infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy analyses showed that the mercaptan -SH and disulfide -S-S- in coal decreased after being treated with IL-HO. In particular, the results of FTIR spectroscopy indicated that the relative proportion of -S-S-and -SH treated with IL-HO (1:10) decreased by 31.9 and 27.2%, respectively, compared with that of a pure IL. This is due to HO oxidation; -SH and -S-S- were oxidized to sulfoxide and then the sulfoxide transferred from the coal phase to the IL phase, which improved organic sulfur removal from coal. Therefore, the combination of an ionic liquid and HO could increase the total desulfurization rate. In addition, the thermogravimetric analysis of coal is divided into four different stages; the weight loss during the combustion stage and the residues show that the IL-HO could improve the coal combustion because of good previous swelling and destruction of bridge bonds and hydrogen bonding of coal. Besides, the fewer residues in IL-HO-treated coals also indicate that a less amount of inorganic substance is left in coal after IL-HO desulfurization, which is consistent with the desulfurization results.
为提高煤炭燃烧中的总脱硫率，采用酸性离子液体（IL）1-羧甲基-3-甲基咪唑硫酸氢盐（[HOOCCH₂mim][HSO₄]）作为萃取剂，并与氧化剂30%过氧化氢（H₂O₂）结合用于降低总硫含量，同时分析了其微观脱硫机理。实验结果表明，[HOOCCH₂mim][HSO₄]-H₂O₂（1:10）溶液的脱硫率为45.12%，有机硫脱除率为16.26%，显著高于单独使用H₂O₂或纯[HOOCCH₂mim][HSO₄]的情况。傅里叶变换红外（FTIR）光谱和X射线光电子能谱分析表明，煤中的硫醇-SH和二硫化物-S-S-经IL-H₂O₂处理后减少。特别是，FTIR光谱结果表明，与纯IL相比，经IL-H₂O₂（1:10）处理的-S-S-和-SH的相对比例分别降低了31.9%和27.2%。这是由于H₂O₂氧化作用；-SH和-S-S-被氧化为亚砜，然后亚砜从煤相转移到IL相，从而提高了煤中有机硫的脱除率。因此，离子液体与H₂O₂的结合可提高总脱硫率。此外，煤的热重分析分为四个不同阶段；燃烧阶段的失重和残渣表明，IL-H₂O₂由于对煤先前的良好溶胀以及桥键和氢键的破坏而能够改善煤的燃烧。此外，经IL-H₂O₂处理的煤中残渣较少也表明，IL-H₂O₂脱硫后煤中残留的无机物较少，这与脱硫结果一致。
