Bibliographic Details
| Title: |
低氧环境下煤自燃的CO₂钝化作用及官能团演化. |
| Alternate Title: |
CO₂ passivation and functional group evolution in coal spontaneous combustion under low oxygen environment. |
| Authors: |
刘伟1 liuwei7230@cumtb.edu.cn, 周禹军1 zhouyj1306@163.com, 卢亢亢1, 孔昊1, 李天男1 |
| Source: |
Coal Science & Technology (0253-2336). Feb2026, Vol. 54 Issue 2, p313-323. 11p. |
| Subject Terms: |
*Passivity (Chemistry), *Functional groups, *Atmospheric oxygen, *Fourier transform infrared spectroscopy, *Density functional theory, *Oxidation, *Coal combustion, *Bituminous coal |
| Abstract (English): |
To investigate the dynamic evolution of functional groups during coal spontaneous combustion under varying CO₂ concentrations and elucidate the chemical passivation mechanism of CO₂ on coal oxidation, this study selected a type I bituminous coal prone to spontaneous combustion from Liangdu Mine. Temperature-programmed oxidation experiments were conducted to compare the oxidative heat release characteristics of coal samples under four oxygen concentrations (5%, 10%, 15%, and 20%), determining the critical oxygen concentration for observing CO₂ passivation effects. Fourier transform infrared spectroscopy was applied to quantitatively analyze variations in major coal functional groups during temperature elevation under different CO₂ environments. Pearson correlation analysis was employed to investigate competitive and synergistic relationships among functional groups during low-temperature coal oxidation. Density functional theory calculations were performed to simulate reaction pathways between CO₂ and phenolic hydroxyl groups as well as phenylacetic acid. Results indicate that the critical oxygen concentration is 10%; below this threshold, the oxygen consumption rate de-creases by 49.2% and heat release intensity declines by 67.3%. Under 90% CO₂ conditions, coal aromaticity increases by 69.17%, aliphatic chain length parameter rises by 31.06%, ether bond content remains stable, and the temperature corresponding to maximum values shifts from 95 °C to 185 °C. Aromatic structures exhibit synergistic evolution with adjacent oxygen-containing groups during coal oxidation, while aliphatic chains compete with oxygen-containing groups for consumption. High CO₂ environments suppress coal oxidation chain re-actions, reducing competitive interactions while enhancing synergistic effects, significantly delaying aliphatic hydrocarbon thermal cleavage and inhibiting hydroxyl consumption and C=O decarboxylation. Reaction energy barriers between phenolic hydroxyl groups/phenylacetic acid and CO₂ are lower than those with oxygen, facilitating carboxylic compound formation with reduced heat release, thereby achieving chemical passivation of coal spontaneous combustion. [ABSTRACT FROM AUTHOR] |
| Abstract (Chinese): |
为研究不同 CO₂体积分数下煤自燃过程中官能团的动态演变, 揭示 CO₂对煤自燃的化学钝 化机制。以两渡矿的Ⅰ类容易自燃烟煤为研究对象, 利用程序升温氧化试验, 比较了 5%、10%、 15% 和 20% 4 种氧气体积分数下煤样的氧化放热特性, 确定了易于观测 CO₂钝化作用的临界氧气体 积分数; 利用傅里叶变换红外光谱, 量化分析了不同 CO₂ 气体环境下升温过程的煤主要官能团变化; 基于皮尔逊相关性分析, 探究煤低温氧化过程中各官能团之间的竞争和协同关系; 利用密度泛函理 论进行了量子化学模拟, 分别分析了酚羟基、苯乙酸与 CO₂的反应路径。结果表明: 煤样氧化所需 氧气放热临界体积分数为 10%, 氧气体积分数低于该数值时, 煤样的耗氧速率变化率降低 49.2%、 放热强度变化率降低 67.3% ;90% 体积分数 CO₂环境下煤样的芳香性提升 69.17%、脂肪链长度参数 提升 31.06%, 醚键相对含量无明显变化, 最大值对应温度由 95℃推移至 185℃;煤氧化过程中芳 香结构与邻近含氧官能团之间呈协同演化特性, 脂肪链与含氧官能团之间存在竞争性消耗关系, 高 CO₂环境抑制了煤氧化链式反应, 使官能团之间的竞争减弱、协同增强, 显著延缓了脂肪烃受热断 裂, 抑制了羟基的消耗和 C=O 基团的脫羧反应; 酚羟基和苯乙酸与 CO₂ 的反应能垒低于与氧气反 应时的能垒, 更易反应生成羧基化合物, 放热量更少, 从而达到煤自燃的化学钝化效果。 [ABSTRACT FROM AUTHOR] |
| Database: |
Energy & Power Source |
