基于煤分子结构特性的炼焦煤热解动力学研究
Study on pyrolysis kinetics of coking coal based on structural characteristics of coal molecular
韩新杰 1李凯 1岳伟明 2崔贝贝 3申岩峰3
作者信息
- 1. 山西焦煤集团炼焦煤清洁利用实验室,太原 030023
- 2. 山西焦化股份有限公司,洪洞 041606
- 3. 太原理工大学 省部共建煤基能源清洁高效利用国家重点实验室,太原 030024
- 折叠
摘要
借助固体核磁(13C NMR)和红外光谱(FT-IR)对 4 种不同煤化程度炼焦煤的分子结构特性进行了分析,利用热重-质谱联用技术(TG-DSC-MS)解析了炼焦煤热分解行为并计算了热解动力学参数.结果表明:4 种炼焦煤的结构单元主体为 2～4 元苯环,其中,ZC煤中富含长链脂肪烃,LL煤中热稳定性较强的联苯结构较多.4 种煤的热解过程均可用 3 段一级反应动力学模型描述,初始热解阶段煤基体失重量与煤中脂肪醚和环烷醚含量有关;剧烈分解阶段的活化能显著高于初始分解阶段和半焦缩聚阶段;半焦缩聚阶段与煤芳构化程度有关,主要发生芳香团簇的交联缩聚反应,CZ煤在此阶段释放出更多热量.通过从煤分子化学结构稳定性的角度解析炼焦煤热分解机制,以期为炼焦煤资源分质利用及精细化煤焦化技术开发提供理论指导.
Abstract
The molecular structure properties of four types of coking coals with different ranks were evaluated by solid-state NMR(13C NMR)and Infrared spectroscopy(FT-IR).The thermal decomposition of coking coals was evaluated by Thermogravimetric-Mass spectrometry technique(TG-DSC-MS).In addition,the kinetic parameters of coal pyrolysis were calculated.The results indicate that the structural units of four types of coking coals consisting of 2-4 aromatic rings,especially,the ZC coal has a large number of long-chain aliphatic hydrocarbon while LL coal has more biphenyl with high thermal stability.The pyrolysis of four types of coals is described by three-stage first-order reaction kinetics model.The weight loss of the coal matrix in the initial pyrolysis stage is related to the content of aliphatic ether and naphthenic ether.The activation energy of the intensive decomposition stage is significantly higher than the initial decomposition stage and semi-coke condensation stage.The crosslinking and polycondensation reactions of aromatic clusters occur in the condensation stage of semi-coke,which is related to the aromatization degree of coal.The thermal decomposition mechanism of coking coal is analyzed from the stability of coal molecular chemical structure,it is expected to provide theoretical guidance for the utilization of coking coal resources and the development of refined coking technology.
关键词
炼焦煤/煤分子结构/热解特性/热解动力学Key words
Coking coal/Coal structure/Pyrolysis properties/Pyrolysis kinetics引用本文复制引用
基金项目
山西焦化股份有限公司技术开发项目(GFPMJS2022004)
出版年
2024
NETL
NSTL
万方数据