摘要
利用热重分析技术(TGA)研究了黑山煤的热失重行为。结果表明:黑山煤的热解反应主要发生在320~620℃,其中446℃时失重率达到最大,热解反应最剧烈,620℃以后热失重较缓慢。利用裂解-气相-质谱联用仪(Py-GC/MS)考察了不同特征温度下煤热裂解行为和产物。结果显示,320℃之前主要是一些以游离形式存在于煤结构中的小分子和脂肪酸受热分解挥发;320℃之后发生热裂解反应,连接煤中各单元的不同化学键按照键能大小依次断裂,对应生成不同类型的热解产物,首先生成长链烷烃、多环芳烃,随着温度升高,又先后生成三环、二环、单环芳烃和酚类等物质,550℃以后,热裂解产物会发生二次裂解反应,生成更低分子量的脂肪烃,同时随着温度的升高,芳环之间脱氢缩聚,导致芳香层面不断增大。
For a more detailed understanding of the coal pyrolysis process, Thermo-gravimetric behavior of Heishan coal was studied by Thermogravimetry （TGA） to judge the pyrolysis reaction occurred in the different temperature range, and introduce some characteristics of coal pyrolysis temperature. It showed that the thermal pyrolysis reaction of Heishan coal mainly occurred between 320 - 620 ℃, and weightlessness rate reached maximum at 446℃, the strongest pyrolysis reactions occurred at this moment. The pyrolysis-gas-phase-mass spectrometry（Py-GC/MS） was also used to investigate the products of coal pyrolysis under the different characteristics of the temperature. The results showed that the products were mainly volatiles which were some small molecular material and some fatty acid substances in the form of free existing in coal medium before 320 ℃. Above 320 ℃, the thermal pyrolysis reaction was taken place, according to the intensity of bond energy, long chain alkane, polycyclic aromatic hydrocarbons was generated and then three-ring, bicyclic and monocylic aromatics and phenols. After 550 ℃, the secondary cracking reaction of the pyrolysis product occurred to generate lower molecular weight fatty hydrocarbon, meanwhile the polycondensation occurred between different aromatic rings to generate polycyclic aromatic hydrocarbons, eventually leaded the coal structure tending to aromatization.
出处
《实验室研究与探索》
CAS
北大核心
2017年第9期5-9,共5页
Research and Exploration In Laboratory
基金
国家重点基础发展(973)计划资助项目(2011CB201304)
关键词
黑山煤
热重分析
裂解-气相-质谱联用
裂解反应机理
heishan coal
thermogravimetry
pyrolysis-gas-phase-mass spectrometry
pyrolysismechanisme
