摘要
针对利用DSC曲线研究煤氧复合反应的阶段划分、热量变化及产物生成路径等方面存在定义表述不够系统,TG和DSC耦合分析不够深入等问题,利用TG/DSC/MS联用技术,开展惰气和空气氛围下不同升温速率煤氧复合全过程的测试与分析。实验表明:基于DSC划分法可将煤氧复合全过程划分为水分蒸发及气体脱附吸热阶段、化学吸附和缓慢反应放热阶段、煤热解生成活性基团放热阶段和挥发分与固定碳燃烧放热阶段。通过特征温度的作图比较,发现TG划分法和DSC划分法的煤氧复合全过程的划分具有高度的重合性和一致性,这证明了DSC划分法的可行性和正确性。利用矿井火灾学、热分析动力学和煤化学理论,阐述了煤氧复合全过程相应阶段的温度范围、生成产物。通过气相产物的质谱分析和Chem 3D软件的建模分析,在构建煤结构单元局部片段的基础上阐明了甲烷、乙烯、一氧化碳和二氧化碳等气体生成的反应历程及生成机理。获得了煤氧复合过程中CH_(4)和C_(2) H_(4)的生成趋势具有相似性规律,且离子流强度曲线出现的峰值温度基本相同。CO_(2)的逸出曲线呈抛物线,在560℃时出现逸出峰。发现了CO的离子流强度曲线具有双峰特征,双峰对应的特征温度分别为530,609℃。研究成果可为厘清煤氧复合的全过程和煤自燃分级预警提供理论支撑。
In response to study the stage division,heat change and product formation path of coal-oxygen complex reaction by DSC curve,there are some scientific problems,such as lack of systematic definition and description,and insufficient in-depth TG and DSC coupling relationship,etc.,the combined technology of TG/DSC/MS was used to test and analyze the whole process of coal-oxygen complex reaction at different heating rates in inert gas and air atmosphere.The experimental results show that the coal-oxygen complex reaction process can be divided into the heat absorption stage of water evaporation and gas desorption,the exothermic stage of chemical adsorption and slow reaction,the exothermic stage of coal pyrolysis to generate reaction groups,and the exothermic stage of volatile matter and fixed carbon combustion based on DSC curve.By drawing and comparing the characteristic temperature,it was found that the division of coal-oxygen compound stage based on TG division method and DSC division method has a high degree of overlap and consistency,which proves the feasibility and correctness of DSC division method.The temperature range,products,reaction course and reaction mechanism of the corresponding stages were defined by using the theory of coalmine fire science,thermal analysis dynamics and coal chemistry theory.The multi-channel,reaction path and formation mechanism of methane,ethylene,carbon monoxide and carbon dioxide were clarified by the mass spectrometry analysis of ionic flow intensity of gas products and the modeling analysis of Chem 3D software on the basis of the fragment unit of coal molecular structure.It was obtained that the generation trends of CH_(4) and C_(2)H_(4) are similar in the process of coal-oxygen complex reaction.And the peak temperature of ion current intensity curve is basically the same(135℃).The escape curve of CO_(2) is parabola,and the escape peak appears at 560℃.It was found that the ionic current intensity curve of CO gas has bimodal characteristic,and the characteristic temperatures c
作者
贾海林
崔博
焦振营
赵万里
徐倩倩
孙沣楠
JIA Hailin;CUI Bo;JIAO Zhenying;ZHAO Wanli;XU Qianqian;SUN Fengnan(Collaborative Innovation Center of Coal Work Safety and Clean High Efficiency Utilization,Henan Polytechnic University,Jiaozuo 454000,China;State Key Laboratory Cultivation Base for Gas Geology and Gas Control,Henan Polytechnic University,Jiaozuo 454000,China;State Key Laboratory of Coking Coal Resources Development and Comprehensive Utilization of China Pingmei Shenma Group,Pingdingshan 467099,China)
出处
《煤炭学报》
EI
CAS
CSCD
北大核心
2022年第10期3704-3714,共11页
Journal of China Coal Society
基金
国家重点研发计划资助项目(2018YFC0807900)
国家自然科学基金资助项目(51304069)
教育部创新团队发展支持计划资助项目(IRT-16R22)。
关键词
煤氧复合全过程
吸放热效应
TG与DSC耦合关系
DSC划分法
离子流强度
whole process of coal-oxygen complex reaction
heat absorption and release effect
coupling relationship of TG and DSC
classification method based DSC
ion current intensity
