摘要
为了研究烟煤的自燃特性,利用热重-差热-傅里叶变换红外光谱(TGA-DTA-FTIR)测试了不同烟煤在变升温速率下重量变化、热量变化、气体释放过程。研究表明:烟煤的挥发分越大,其各特征温度越低、放热峰高度越大。采用Coats-Redfern法计算的活化能显示在自燃过程中活化能依次为正值、负值、正值。100℃前活化能为正,而后变为负,当活化能为负时反应不存在能垒,因此应努力在100℃前控制煤自燃。烟煤活化能大小排序与挥发分大小排序相同。由红外光谱分析得到:实验开始便有少量CO2、H2O、CO、CH4放出,随温度升高H2O浓度逐渐增大在100℃前后形成小高峰。300℃左右各气体开始大量生成,500℃前后CO、CO2、CH4浓度达到顶峰。生成气体的浓度:CO2>H2O>CO>CH4,CO2约占生成气体的90%。烟煤生成各气体的浓度排序与挥发分大小排序相同。
In order to study the spontaneous combustion characteristics of bituminous coal,the weight change,heat change and gas release process of dif ferent bituminous coals under variable heating rate are measured by Thermo gravimetr ic Analysis-Dif ferential Thermal Analysis-Four ier Transfor m inf rared spectroscopy(TGA-DTA-FTIR).The result shows that the higher the volatile content of bituminous coal is,the lower the characteristic temperatures are and the higher the exothermic peak heights are.The activation energy calculated by coats-Redfern method shows that the activation energy is positive,negative and positive in the process of spontaneous combustion.The activation energy is positive before 100℃and then becomes negative.When the activation energy is negative,there is no energy barrier in the reaction.Therefore,efforts should be made to control coal spontaneous combustion before 100℃.The order of activation energy of bituminous coal is the same as that of volatile matter.According to the infrared spectrum,a small amount of CO2,H2O,CO and CH4 are released at the beginning of the experiment.With the increase of temperature,the concentration of H2O increases gradually,and a small peak is formed around 100℃.A large number of gases begin to generate at about 300℃.The concentrations of CO,CO2 and CH4 reach the peak at about 500℃.The concentration of the generated gas is:CO2>H2O>CO>CH4,and CO2 accounts for about 90%of the generated gas.The order of the concentration of each gas generated by bituminous coal is the same as that of volatile matter.
作者
张红芬
王宝夫
曹伟
易海洋
高尔新
ZHANG Hongfen;WANG Baofu;CAO Wei;YI Haiyang;GAO Erxin(Architectural Engineering College,North China Institute of Science and Technology,Langfang,Hebei Province,065201 China;School of Mechanics and Civil Engineering,China University of Mining and Technology(Beijing),Beijing,100083 China)
出处
《科技创新导报》
2021年第2期77-82,共6页
Science and Technology Innovation Herald
基金
中央高校基本科研业务费资助项目(项目名称:煤耗氧升温过程THMC耦合作用本构规律及模型构建
项目编号:3142018014)
廊坊市科学技术研究与发展计划项目(项目名称:煤自燃过程流-固-热-化耦合机制及灾害预测
项目编号:2018013022)
廊坊市科学技术研究与发展计划项目(项目名称:考虑参数空间变异性的多层边坡可靠度研究
项目编号:2019013129)。
关键词
TGA-DTA-FTIR
特征温度
活化能
气体释放
Coal spontaneous combustion
TGA-DTA-FTIR
Character istic temperature
Activation energy
Gas release
