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Thermal Properties and Key Groups Evolution of Low-Temperature Oxidation for Bituminous Coal under Lean-Oxygen Environment

[Image: see text] To deeply explore the spontaneous combustion disaster of coal caused by air leakage and oxygen supply, low-temperature coal oxidation experiments under different oxygen concentrations (DOC) were carried out. Within the coal spontaneous combustion characteristic measurement system,...

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Autores principales: Liu, Zejian, Xu, Yongliang, Wen, Xing-lin, Lv, Zhiguang, Wu, Jindong, Li, Minjie, Wang, Lanyun
Formato: Online Artículo Texto
Lenguaje:English
Publicado: American Chemical Society 2021
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8210409/
https://www.ncbi.nlm.nih.gov/pubmed/34151091
http://dx.doi.org/10.1021/acsomega.1c01338
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author Liu, Zejian
Xu, Yongliang
Wen, Xing-lin
Lv, Zhiguang
Wu, Jindong
Li, Minjie
Wang, Lanyun
author_facet Liu, Zejian
Xu, Yongliang
Wen, Xing-lin
Lv, Zhiguang
Wu, Jindong
Li, Minjie
Wang, Lanyun
author_sort Liu, Zejian
collection PubMed
description [Image: see text] To deeply explore the spontaneous combustion disaster of coal caused by air leakage and oxygen supply, low-temperature coal oxidation experiments under different oxygen concentrations (DOC) were carried out. Within the coal spontaneous combustion characteristic measurement system, a synchronous thermal analyzer (STA) and a Fourier transform infrared spectrometer (FTIR), the macro laws of gas and heat generation under DOC are analyzed, and the mechanism of the development of coal spontaneous combustion restricted by the lean-oxygen environment is also revealed. The results show that the change of oxygen concentration (OC) does not affect the critical temperature value and gas index change trend, but the lean-oxygen environment reduces the gas concentration and heat production rate very obviously. According to the temperature of the intersection, OC needs to be lowered to less than 5% when preventing spontaneous combustion of coal. The chain thermal reaction lags in the lean-oxygen environment, and the pyrolysis activity is significantly reduced. Meanwhile, the temperature points at T(6) and T(7) show significant differences. Furthermore, with increasing OC and temperature, the content of the aliphatic hydrocarbon presents an overall trend of first increasing, then decreasing, and continuously increasing after stage IV. It is concluded that (•)OH, aliphatic hydrocarbons, aromatic hydrocarbons, and carboxyl groups are the key groups for the coal spontaneous combustion evolution under DOC. To combine the spontaneous combustion reaction of coal in the DOC environment, the reaction path of the index gas in the macroscopic phenomenon and the reason for the concentration differences are revealed, the mechanism for exotherm varies caused by OC is clarified, and the microscopic inhibition affection on the chain reaction within the lean-oxygen environment is also explored. The results put forward the key groups evolution mechanism under the DOC for coal oxidation, which could provide the technical guidance for the fire prevention and control on coal mines.
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spelling pubmed-82104092021-06-17 Thermal Properties and Key Groups Evolution of Low-Temperature Oxidation for Bituminous Coal under Lean-Oxygen Environment Liu, Zejian Xu, Yongliang Wen, Xing-lin Lv, Zhiguang Wu, Jindong Li, Minjie Wang, Lanyun ACS Omega [Image: see text] To deeply explore the spontaneous combustion disaster of coal caused by air leakage and oxygen supply, low-temperature coal oxidation experiments under different oxygen concentrations (DOC) were carried out. Within the coal spontaneous combustion characteristic measurement system, a synchronous thermal analyzer (STA) and a Fourier transform infrared spectrometer (FTIR), the macro laws of gas and heat generation under DOC are analyzed, and the mechanism of the development of coal spontaneous combustion restricted by the lean-oxygen environment is also revealed. The results show that the change of oxygen concentration (OC) does not affect the critical temperature value and gas index change trend, but the lean-oxygen environment reduces the gas concentration and heat production rate very obviously. According to the temperature of the intersection, OC needs to be lowered to less than 5% when preventing spontaneous combustion of coal. The chain thermal reaction lags in the lean-oxygen environment, and the pyrolysis activity is significantly reduced. Meanwhile, the temperature points at T(6) and T(7) show significant differences. Furthermore, with increasing OC and temperature, the content of the aliphatic hydrocarbon presents an overall trend of first increasing, then decreasing, and continuously increasing after stage IV. It is concluded that (•)OH, aliphatic hydrocarbons, aromatic hydrocarbons, and carboxyl groups are the key groups for the coal spontaneous combustion evolution under DOC. To combine the spontaneous combustion reaction of coal in the DOC environment, the reaction path of the index gas in the macroscopic phenomenon and the reason for the concentration differences are revealed, the mechanism for exotherm varies caused by OC is clarified, and the microscopic inhibition affection on the chain reaction within the lean-oxygen environment is also explored. The results put forward the key groups evolution mechanism under the DOC for coal oxidation, which could provide the technical guidance for the fire prevention and control on coal mines. American Chemical Society 2021-06-02 /pmc/articles/PMC8210409/ /pubmed/34151091 http://dx.doi.org/10.1021/acsomega.1c01338 Text en © 2021 The Authors. Published by American Chemical Society Permits non-commercial access and re-use, provided that author attribution and integrity are maintained; but does not permit creation of adaptations or other derivative works (https://creativecommons.org/licenses/by-nc-nd/4.0/).
spellingShingle Liu, Zejian
Xu, Yongliang
Wen, Xing-lin
Lv, Zhiguang
Wu, Jindong
Li, Minjie
Wang, Lanyun
Thermal Properties and Key Groups Evolution of Low-Temperature Oxidation for Bituminous Coal under Lean-Oxygen Environment
title Thermal Properties and Key Groups Evolution of Low-Temperature Oxidation for Bituminous Coal under Lean-Oxygen Environment
title_full Thermal Properties and Key Groups Evolution of Low-Temperature Oxidation for Bituminous Coal under Lean-Oxygen Environment
title_fullStr Thermal Properties and Key Groups Evolution of Low-Temperature Oxidation for Bituminous Coal under Lean-Oxygen Environment
title_full_unstemmed Thermal Properties and Key Groups Evolution of Low-Temperature Oxidation for Bituminous Coal under Lean-Oxygen Environment
title_short Thermal Properties and Key Groups Evolution of Low-Temperature Oxidation for Bituminous Coal under Lean-Oxygen Environment
title_sort thermal properties and key groups evolution of low-temperature oxidation for bituminous coal under lean-oxygen environment
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8210409/
https://www.ncbi.nlm.nih.gov/pubmed/34151091
http://dx.doi.org/10.1021/acsomega.1c01338
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