Dynamic behavior of oxidative heat release of key active groups for different Jurassic coal seams in northern Shaanxi

• Published in: Journal of thermal analysis and calorimetry 2023-06, Vol.148 (11), p.4853-4865
• Main Authors: Ma, Teng, Ren, Shuai-jing, Zhai, Xiao-wei, Bai, Ya-E., Song, Bo-Bo, Hao, Le, Ren, Li-Feng, Chen, Xiao-Kun
• Format: Article
• Language: English
• Subjects: Absorption spectra; Aliphatic hydrocarbons; Analysis; Analytical Chemistry; Aromatic hydrocarbons; Bituminous coal; Chemistry; Chemistry and Materials Science; Coal; Combustion; Correlation; Correlation analysis; Functional groups; Heat; Heat flux; Heat transfer; Heat transmission; Hydrocarbons; Infrared analysis; Infrared spectroscopy; Inorganic Chemistry; Laws, regulations and rules; Measurement; Measurement Science and Instrumentation; Oxidation; Oxygen; Physical Chemistry; Polymer Sciences; Radiation; Spontaneous combustion; Temperature effects
• ISSN: 1388-6150; 1588-2926
• DOI: 10.1007/s10973-023-12027-1

In order to explore the characteristics of spontaneous combustion of Jurassic coal in northern Shaanxi with low metamorphic degree and high coke content, DSC differential scanning calorimeter and diffuse in situ infrared spectroscopy experiment were used to study and analyze the dynamic evolution law and interaction relationship between macroscopic thermal effect and microstructure in the spontaneous combustion process of different coal seams in northern Shaanxi. The results show that there are three characteristic temperature points in the heat flow curve during the spontaneous combustion of Jurassic coal in northern Shaanxi, which can be divided into four stages according to the characteristic temperature points. It was found that the consumption and production of functional groups in Jurassic coal oxidation process were mainly in the absorption bands of aliphatic hydrocarbon, aromatic hydrocarbon and oxygen-containing functional groups, and CH 3 , CH 2 , C–H, OH and C=O were the most active key functional groups in the process of coal oxidation. The dynamic correlation degree between heat flux intensity and key active groups is established by using dynamic grey correlation mathematics method. It is concluded that C=O bond has the highest correlation with heat flow intensity during coal oxidation, and has the greatest influence on heat flow intensity. The correlation values of the active groups CH 3 and CH 2 are second only to the C=O bond, and they are easy to react with oxygen, accompanied by the reaction heat. Although the correlation degree between C–H and OH bond is lower than that of C=O, CH 3 and CH 2 bond, the correlation degree value is also high, and has certain contribution to the coal reaction heat. These research results have important guiding significance for the development of targeted inhibitors for Jurassic coal spontaneous combustion disaster in northern Shaanxi.