Инд. авторы: | Li J., Yang Y.N., Li J.S., Mao Y.D., Saini V., Kokh S.V. |
Заглавие: | A TGA-DSC-based study on macroscopic behaviors of coal-oxygen reactions in context of underground coal fires |
Библ. ссылка: | Li J., Yang Y.N., Li J.S., Mao Y.D., Saini V., Kokh S.V. A TGA-DSC-based study on macroscopic behaviors of coal-oxygen reactions in context of underground coal fires // Journal of Thermal Analysis and Calorimetry. - 2022. - ISSN 1388-6150. - EISSN 1572-8943. |
Внешние системы: | DOI: 10.1007/s10973-021-10671-z; WoS: 000628486000002; |
Реферат: | eng: Underground coal fires (UCFs) cause remarkable loss of energy resources and significant environmental pollution. Due to the limited capacity of oxygen transport, the inception and development of UCFs represent a very unique mode of coal-oxygen reactions. Therefore, a high-volatile flammable coal sample is thermally analyzed with the combined TGA-DSC approach under four oxygen concentrations (21%, 15%, 9% and 3%) and three heating rates (1 degrees C min(-1), 2 degrees C min(-1) and 5 degrees C min(-1)). It is found that the oxygen concentration does not significantly influence the early (low-temperature) stage of coal-oxygen reactions. With the decrease in oxygen concentration, the intensity of the exothermic reactions is reduced and the duration of reactions is extended. Based on the experimental results, the apparent activation energy is calculated. The variation of the apparent activation energy reflects the different reaction stages: volatiles burning and char oxidation, which is verified by the TGA-DSC results. Under the extreme condition of 3% oxygen concentration, a very distinct macroscopic thermochemical behavior is observed, and the limited oxygen supply controls the reaction rate throughout the entire process, which qualitatively explains the persistency of the burning phenomena in most UCFs.
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Ключевые слова: | DSC; TGA–; Heating rate; Oxygen concentration; oxygen reactions; Coal–; Underground coal fires; Apparent activation energy; |
Издано: | 2022 |