不同溶剂预处理煤在ScCO<sub>2</sub>作用下的谱学差异及其机制

doi:10.3964/j.issn.1000-0593(2024)09-2657-10

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Abstract The purpose of this study is to study the effect of supercritical carbon dioxide (ScCO₂) on the chemical structure of coal after solvent pretreatment. The lean coal samples collected from Changzhi Huoerxinhe were adopted. Coal samples were pretreated with tetrahydrofuran (THF), hydrochloric acid (HCI), and hydrofluoric acid (HF), respectively. The Fourier transform infrared spectroscopy (FTIR), solid-state nuclear magnetic resonance (¹³C-NMR), and X-ray diffraction (XRD) were used to study the chemical composition and structure of coal samples. Results show that: ①The FITR peak-fitting spectra were basically consistent with the experimental curves, but the positions and intensities of the absorption peaks of each functional group still showed some deviations, and the aliphatic peaks disappeared in part of the bands after the pretreatment with acids (HCI and HF). The two types of acid pretreatment order are different, and the effect on the oxygenated functional group, fat structure, and aromatic structure of coal is not the same. The intensity of aromatic CC structure and oxygenated functional group peaks were enhanced after HF-HCI treatment. In contrast, the intensity of the aromatic CC structure was weakened after HCI-HF treatment, and the intensity of the structure of the oxygenated functional group was insignificant. The intensity of the aromatic CC structure of the coal samples was enhanced, and the intensity of the structure of the CC oxygenated functional group was reduced after THF pretreatment. After THF pretreatment, the intensity of the aromatic CC structure was enhanced, and the intensity of the CC oxygenated functional group was reduced. Overall, the intensity of aromatic CC structure is much larger than that of aliphatic structure and oxygenated functional group structure. ②In the ¹³C-NMR spectrum, the chemical shift of the main functional group peaks exhibits a certain degree of deviation. Aromatic carbon faB chemical shifts are overall shifted in the direction of increasing. The proportion of aromatic carbon is much greater than that of aliphatic carbon, indicating that aromatic carbon forms the bulk of the coal macromolecular structure. ③In the XRD pattern, the diffraction intensity of the 002 and 101 peaksk increases significantly, and the microcrystal structure parameter d₀₀₂ shows an increasing trend. It can be seen that THF, acidic treatment, and ScCO₂ all have a certain impact on the macromolecular structure of coal, causing the coal macromolecular network structure to become looser, which in turn increases the overall distance d₀₀₂ of the microcrystalline layer network. Research shows that changes in the spectral characteristics of the coal after solvent action were not only related to the nature of the solven, but also to the order of inorganic acid treatment, and consequently, the functional group composition and macromolecular structure were altered to varying degrees, which in turn affected the extraction effect of ScCO₂ on the pretreated coal.

Key words：ScCO₂;Solvent pretreatment;The Fourier transform infrared spectroscopy (FTIR);Nuclear magnetic resonance (¹³C-NMR);Chemical structure

Received: 2023-10-16 Accepted: 2024-03-27

ZTFLH:

TQ531

Corresponding Authors: ZHANG Shuo E-mail: zhangshuo_9112@163.com

Cite this article:

ZHANG Xiao-dong,KANG Hong-dong,LI Bing-hui, et al. Spectroscopic Differences in Different Solvent Pretreated Coals in the Presence of ScCO₂ and Their Mechanisms[J]. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2024, 44(09): 2657-2666.

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https://www.gpxygpfx.com/EN/10.3964/j.issn.1000-0593(2024)09-2657-10 OR https://www.gpxygpfx.com/EN/Y2024/V44/I09/2657

[1] SANG Shu-xun，YUAN Liang，LIU Shi-qi，et al(桑树勋，袁亮，刘世奇，等). Journal of China Coal Society(煤炭学报)，2022，47(4)：1430.
[2] ZHANG Shuo，ZHANG Xiao-dong，DING Zhe，et al(张硕，张小东，丁哲，等). Coal Conversion(煤炭转化)，2016，39(3)：1.
[3] YANG Wei，LUO Li-ming，WANG Yi-han，et al(杨威，罗黎明，王一涵，等). Journal of China Coal Society(煤炭学报)，2023，48(8)：3091.
[4] LIU Shi-qi，WANG Tian，DU Yi，et al(刘世奇，王恬，杜艺，等). Coal Geology & Exploration(煤田地质与勘探)，2018，46(5)：19.
[5] YUAN Mei，LI Zhao-ping，LI Bo-bo，et al(袁梅，李照平，李波波，等). Natural Gas Industry(天然气工业)，2022，42(6)：163.
[6] ZHAO Yun-gang，LI Mei-fen，ZENG Fan-gui，et al(赵云刚，李美芬，曾凡桂，等). Journal of China Coal Society(煤炭学报)，2018，43(2)：546.
[7] LI Sheng，LUO Ming-kun，FAN Chao-jun，et al(李胜，罗明坤，范超军，等). Journal of China Coal Society(煤炭学报)，2017，42(7)：1748.
[8] WANG Fang-fang，ZHANG Xiao-dong，PING Xiao-duo，et al(王芳芳，张小东，平晓朵，等). Spectroscopy and Spectral Analysis(光谱学与光谱分析)，2022，42(3)：896.
[9] Liu Shiqi，Ma Jingsheng，Sang Shuxun，et al. Fuel，2018，223：32.
[10] LIU Li-bao，YAO Hui-fang，JI Xin-qiang，et al(刘利宝，要惠芳，姬新强，等). Coal Conversion(煤炭转化)，2016，39(4)：10.
[11] SUN Ke-ming，WU Di，SU Ai-guo，et al(孙可明，吴迪，粟爱国，等). Chinese Journal of Rock Mechanics and Engineering(岩石力学与工程学报)，2013，32(S2)：3760.
[12] YUE Li-xin，SUN Ke-ming，ZHANG Feng-jia，et al(岳立新，孙可明，张风嘉，等). Journal of Liaoning Technical University(辽宁工程技术大学学报)，2013，32(9)：1157.
[13] XIE Ke-chang(谢克昌). Coal Structure and Its Reactivity(煤的结构与反应性). Beijing: Science Press(北京：科学出版社)，2002.
[14] Okolo G N，Neomagus H W J P，Everson R C，et al. Fuel，2015，158：779.
[15] GUO De-yong，YE Jian-wei，WANG Qi-bao，et al(郭德勇，叶建伟，王启宝，等). Journal of China Coal Society(煤炭学报)，2016，41(12)：3040.
[16] XIANG Jian-hua，ZENG Fan-gui，LIANG Hu-zhen，et al(相建华，曾凡桂，梁虎珍，等). Journal of China Coal Society(煤炭学报)，2016，41(6)：1498.
[17] CHANG Hai-zhou，CAI Xue-mei，LI Gai-xian，et al(常海洲，蔡雪梅，李改仙，等). Journal of Shanxi University(山西大学学报)，2008，(2)：223.