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Comparative Analyses between Raw and Preoxidized Pulverized Coals: Combustion Behaviors and Thermokinetic and Microcharacteristics

[Image: see text] Investigating the difference in the combustion performance and microcharacteristics of oxidized and raw pulverized coal (PC) can contribute to effectively prevent and control the spontaneous combustion of deposited coal dust in high-temperature environment and further help guarante...

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Autores principales: Zou, Li, Wang, Yungang, Bai, Yanyuan, Liu, Yang, Zhao, Qinxin
Formato: Online Artículo Texto
Lenguaje:English
Publicado: American Chemical Society 2021
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8757352/
https://www.ncbi.nlm.nih.gov/pubmed/35036775
http://dx.doi.org/10.1021/acsomega.1c05694
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author Zou, Li
Wang, Yungang
Bai, Yanyuan
Liu, Yang
Zhao, Qinxin
author_facet Zou, Li
Wang, Yungang
Bai, Yanyuan
Liu, Yang
Zhao, Qinxin
author_sort Zou, Li
collection PubMed
description [Image: see text] Investigating the difference in the combustion performance and microcharacteristics of oxidized and raw pulverized coal (PC) can contribute to effectively prevent and control the spontaneous combustion of deposited coal dust in high-temperature environment and further help guarantee the safe operation of coal-fired boiler. In this study, the combustion performance and thermokinetic and microcharacteristics of three raw coal samples and their preoxidized forms were explored by a thermogravimetric analyzer (TGA) and Fourier transform infrared spectroscopy (FTIR). According to the characteristic temperatures and variations of the mass loss rate during heating, the entire combustion process of PC was divided into four periods. For each type of coal, the preoxidized PC had relatively lower characteristic temperatures than the corresponding raw PC. The preoxidized samples had larger values of ignition index (C(ig)) and comprehensive combustibility index (S), but lower values of burnout index (C(b)) than raw samples. The values of apparent activation energy (E) for the preoxidized PC were below that of the corresponding raw PC at the same conversion rate (α), which suggested the preoxidized PC required relatively less energy to react and was more prone to spontaneous combustion. In addition, although parts of −OH, C=O, and aliphatic hydrocarbon groups were consumed after the preoxidation treatment, the increase in C–O and −COO– bonds compensated for the adverse effect of the reduction of the aforementioned groups on coal combustion.
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spelling pubmed-87573522022-01-13 Comparative Analyses between Raw and Preoxidized Pulverized Coals: Combustion Behaviors and Thermokinetic and Microcharacteristics Zou, Li Wang, Yungang Bai, Yanyuan Liu, Yang Zhao, Qinxin ACS Omega [Image: see text] Investigating the difference in the combustion performance and microcharacteristics of oxidized and raw pulverized coal (PC) can contribute to effectively prevent and control the spontaneous combustion of deposited coal dust in high-temperature environment and further help guarantee the safe operation of coal-fired boiler. In this study, the combustion performance and thermokinetic and microcharacteristics of three raw coal samples and their preoxidized forms were explored by a thermogravimetric analyzer (TGA) and Fourier transform infrared spectroscopy (FTIR). According to the characteristic temperatures and variations of the mass loss rate during heating, the entire combustion process of PC was divided into four periods. For each type of coal, the preoxidized PC had relatively lower characteristic temperatures than the corresponding raw PC. The preoxidized samples had larger values of ignition index (C(ig)) and comprehensive combustibility index (S), but lower values of burnout index (C(b)) than raw samples. The values of apparent activation energy (E) for the preoxidized PC were below that of the corresponding raw PC at the same conversion rate (α), which suggested the preoxidized PC required relatively less energy to react and was more prone to spontaneous combustion. In addition, although parts of −OH, C=O, and aliphatic hydrocarbon groups were consumed after the preoxidation treatment, the increase in C–O and −COO– bonds compensated for the adverse effect of the reduction of the aforementioned groups on coal combustion. American Chemical Society 2021-12-20 /pmc/articles/PMC8757352/ /pubmed/35036775 http://dx.doi.org/10.1021/acsomega.1c05694 Text en © 2021 The Authors. Published by American Chemical Society https://creativecommons.org/licenses/by-nc-nd/4.0/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 Zou, Li
Wang, Yungang
Bai, Yanyuan
Liu, Yang
Zhao, Qinxin
Comparative Analyses between Raw and Preoxidized Pulverized Coals: Combustion Behaviors and Thermokinetic and Microcharacteristics
title Comparative Analyses between Raw and Preoxidized Pulverized Coals: Combustion Behaviors and Thermokinetic and Microcharacteristics
title_full Comparative Analyses between Raw and Preoxidized Pulverized Coals: Combustion Behaviors and Thermokinetic and Microcharacteristics
title_fullStr Comparative Analyses between Raw and Preoxidized Pulverized Coals: Combustion Behaviors and Thermokinetic and Microcharacteristics
title_full_unstemmed Comparative Analyses between Raw and Preoxidized Pulverized Coals: Combustion Behaviors and Thermokinetic and Microcharacteristics
title_short Comparative Analyses between Raw and Preoxidized Pulverized Coals: Combustion Behaviors and Thermokinetic and Microcharacteristics
title_sort comparative analyses between raw and preoxidized pulverized coals: combustion behaviors and thermokinetic and microcharacteristics
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8757352/
https://www.ncbi.nlm.nih.gov/pubmed/35036775
http://dx.doi.org/10.1021/acsomega.1c05694
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