摘要
微生物对煤自燃的阻化抑制是有效降低矿井煤氧化速率、延缓自然发火的绿色途径。该文采用X射线衍射实验、Fourier变换红外光谱实验以及热重实验,从微观结构和宏观氧化特性分析了微生物对煤自燃的抑制作用。结果表明:微生物对煤的微晶结构有序化和石墨化有促进作用,减少了煤中分子官能团数量,破坏了脂肪烃和含氧官能团结构;处理煤样的平均微晶直径和有效堆砌芳香片层数分别降低了32.04%和27.22%,脂肪烃峰总面积下降55.80%;处理煤样的特征温度点均向较高温度区移动,其中以最大热失重速率温度以及燃尽温度升幅最为显著,偏移温度分别为67.87℃和138.67℃。该研究为今后通过微生物作用抑制煤自燃提供了依据。
[Objective]Traditional methods for the prevention of spontaneous coal combustion rely on chemical additives.However,these methods are often costly and potentially polluting.Microbial technology has been gradually applied to the prevention and control of spontaneous coal combustion due to its environmental protection and high efficiency.This study aimed to explore a green and efficient method for inhibiting spontaneous coal combustion through the influence of microorganisms on the microcrystalline structure and oxidation characteristics of lignite and provide new ideas for the diversification and greening of spontaneous coal combustion prevention strategies.[Methods]The inhibitory effect of microorganisms on spontaneous coal combustion was analyzed from two aspects:microstructure and macroscopic oxidation characteristics.In the experiment,lignite samples from a coal mine in Inner Mongolia were used,and Sphingomonas polyaromaticivorans was selected for the bacterium-coal mixing experiment.X-ray diffractometer and Fourier transform infrared spectroscopy experiments were used to analyze the microstructural changes in lignite after microbial treatment.Moreover,alterations in the minerals and functional groups in the coal were revealed to gain insights into the effects of microbial treatment on coal microstructure.In addition,the key thermodynamic parameters,such as characteristic temperature,thermal weight loss,and thermal loss rate of coal samples in the oxidation and spontaneous combustion process,were analyzed through macroscopic thermal analysis techniques,such as thermogravimetric analysis(TGA)and differential scanning calorimetry.[Results]The experimental results show the following:(1)The microcrystalline structure of the coal sample tended to be orderly and graphitized after microbial treatment,and the average crystallite diameter and the number of effective stacked aromatic flakes were considerably reduced by 32.04%and 27.22%,respectively.These results indicate that microorganisms can reduce the unstable aliphatic hydrocarbon side-chain structure in coal through oxidation,decarboxylation,and enzyme catalysis and promote coal graphitization.(2)After microbial treatment,the fitting peak areas of hydroxyl groups,oxygen-containing functional groups,and aromatic hydrocarbons in the coal samples decreased substantially,with the fitting peak areas of hydroxyl groups and aliphatic hydrocarbons decreasing by 43.21%and 55.56%.This finding indicates that microorganisms tremendously affect the mechanism of oxidative spontaneous combustion of coal by reducing the number of functional groups and the generation of free radicals.(3)After microbial treatment,the characteristic temperature points of the coal samples shifted to the higher-temperature region in the TGA curve,and changes in the maximum thermogravimetric rate temperature and burnout temperature were the most significant,which were increased by 67.87°C and 138.67°C,respectively.These results indicate that microorganisms greatly improve coal's thermal stability and resistance to oxidation and effectively inhibit its low-temperature oxidation process.[Conclusions]Microbial treatment of coal samples changes their microcrystalline structures and promotes their orderliness and graphitization.The number of functional groups in coal and the coal's oxidation activity are considerably reduced.In addition,microorganisms improve the thermal stability and oxidation resistance of coal,slow its oxidation rate,and effectively inhibit its low-temperature oxidation process.These results provide a scientific basis for inhibiting spontaneous coal combustion through microbial action and provide a reference for the greening and diversification of the corresponding prevention strategies.
作者
易欣
强金波
郭行
YI Xin;QIANG Jinbo;GUO Hang(College of Safety Science and Engineering,Xi'an University of Science and Technology,Xi'an 710054,China;Shaanxi Key Laboratory of Prevention and Control of Coal Fire,Xi'an University of Science and Technology,Xi'an 710054,China)
出处
《清华大学学报(自然科学版)》
北大核心
2025年第6期1102-1111,共10页
Journal of Tsinghua University(Science and Technology)
基金
国家自然科学基金面上项目(52274225)
陕西省科技厅创新团队建设资助项目(2024RS-CXTD-52)
陕西省国际科技合作计划项目(2023-GHZD-31)。
关键词
微生物
煤自燃
微晶结构
官能团
表观活化能
microbial
spontaneous coal combustion
microcrystalline structure
functional group
apparent activation energy
