煤自燃热失重特征规律及关键官能团研究

Study on thermogravimetric characteristics and key functional groups of coal spontaneous combustion

为了研究煤自燃过程中对失重起重要作用的关键官能团,以3种不同变质程度煤样为研究对象,根据TG热重实验和傅里叶变换红外实验,研究煤自燃热失重过程的特征温度和官能团变化规律,基于频率比模型法和灰色关联度分析煤自燃失重量与官能团间的相关性,并探讨不同变质程度煤自燃热失重过程的关键官能团。研究结果表明:随煤变质程度加深,热失重曲线后移,从褐煤到无烟煤,热失重特征温度分别增加22%,37%;随温度增加,官能团含量突变温度点与特征温度相近,羟基在150℃之前呈指数式下降后趋于稳定,脂肪烃、含氧官能团和芳香烃在燃点温度之后线性下降;影响不同变质程度煤自燃热失重的关键官能团不一致,C C是影响褐煤的热失重关键官能团,而甲基是影响烟煤、无烟煤的热失重关键官能团。研究结果可为煤自燃热失重过程关键官能团的确定提供重要参考。

To investigate the key functional groups that play a crucial role in the thermogravimetric process of coal spontaneous combustion,three types of coal samples with different metamorphic degrees were selected as the research object.According to the TG thermogravimetric experiment and Fourier transform infrared experiment,the characteristic temperature and functional groups variation law of the thermogravimetric process of coal spontaneous combustion were studied,then the correlation between the weight loss of coal spontaneous combustion and the functional groups was analyzed based on the frequency ratio model method and the grey correlation degree,and the key functional groups in the thermogravimetric process of coal spontaneous combustion with different metamorphic degrees were discussed.The results show that with the deepening metamorphic degree of coal,the thermogravimetric curve moves backward,and the thermogravimetric characteristic temperature from lignite to anthracite increases by 22%and 37%,respectively.With the increase of temperature,the temperature point of the mutation of functional groups content is close to the characteristic temperature,and the hydroxyl group decreases exponentially before 150℃and then tends to be stable,while the aliphatic hydrocarbon,oxygen-containing functional groups and aromatic hydrocarbon decrease linearly after the ignition temperature.The key functional groups affecting the thermogravimetric process of coal spontaneous combustion with different metamorphic degrees are inconsistent.C C is the key functional group affecting the thermogravimetric process of lignite,while methyl is the key functional group affecting the thermogravimetric process of bituminous coal and anthracite.The research results can provide important reference value for the determination of key functional groups in the thermogravimetric process of coal spontaneous combustion.