Dissect the capacity of low-temperature oxidation of coal with different metamorphic degrees. (15th May 2021)

• Record Type: Journal Article
• Authors: Cai, Jiawen; Yang, Shengqiang; Zheng, Wancheng; Song, Wanxin; Gupta, Rajender
• Is Part Of: Fuel. Volume 292(2021)
• Publication Date: 2021-05-15
• Subjects: Low-temperature oxidation -- Radical -- Relative growth rate -- Oxidizability; Fuel -- Periodicals; Coal -- Periodicals; Coal; Fuel; Periodicals; 662.6
• DOI: 10.1016/j.fuel.2021.120256
• Languages: English
• ISSNs: 0016-2361

Abstract

Highlights: The initial temperature of CO evolution and its increment and CPTs were obtained. The spectra of coal low-temperature oxidation were investigated by in-situ EPR spectroscopy. An approach to quantify the oxidizability of coal using the relative growth rate R was provided. Abstract: Radical chemistry is a major factor affecting the low-temperature oxidation of coal, which plays a critical role in the coal oxygen complex reaction. However, the characteristics of radical for judging its ability to oxidize are still poorly understood. The electron paramagnetic resonance (EPR) spectroscopy has emerged as a powerful approach in studying the behavior of radicals. So the EPR spectra of coal low-temperature oxidation were investigated by in-situ EPR spectroscopy. Analysis of the initial temperature of CO evolution and its increment and crossing-point temperatures (CPTs) of coal reveal that the oxidizability of low-rank coal is more prominent than others. The EPR linear profile of low-rank coal has a well temperature dependence and a large g factor, an indicator of oxidizability. However, it is not consistent with the increasing trend of the absolute content of radical concentration. This study provides a novel approach to quantify the oxidizability of coal using the relative growth rate R of radials, and the results are consistent with the coal spontaneous combustion tendency. The main objective of the current study is to obtain a comprehensive understanding of low-temperature oxidation of coal with different ranks.