燃料与化工 ›› 2024, Vol. 55 ›› Issue (4): 1-6.

• 综述与专论 •    下一篇

基于煤分子结构特性的炼焦煤热解动力学研究

  

  1. (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;
  • 出版日期:2024-07-23 发布日期:2024-08-07

  • Online:2024-07-23 Published:2024-08-07

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。

关键词: 炼焦煤, 煤分子结构, 热解特性, 热解动力学

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.

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