• 论文
主办单位:煤炭科学研究总院有限公司、中国煤炭学会学术期刊工作委员会
不同煤阶煤热解过程中孔隙结构变化规律研究
  • Title

    Study on pore structure change during different coal grade pyrolysis

  • 作者

    尹振勇许浩汤达祯陈艳鹏赵天天

  • Author

    YIN Zhenyong, XU Hao, TANG Dazhen, CHEN Yanpeng, ZHAO Tiantian

  • 单位

    中国地质大学(北京) 能源学院中国石油勘探开发研究院

  • Organization
    1. School of Energy Resources, China University of Geo-sciences (Beijing), Beijing , China; 2.Research Institute of Petroleum Exploration and Development, Beijing , China
  • 摘要

    为了研究不同煤阶煤样品在热解过程中的孔隙变化规律,采用自制的煤炭热模拟装置对内蒙古褐煤、新疆长焰煤和韩城烟煤进行热模拟试验,并用ASAP2020M型全自动比表面积分析仪分析了煤焦样品在热解过程中孔隙结构变化。N2吸附解吸试验表明:3种煤焦样品的吸附脱附曲线之间没有或存在较小的回线,孔隙形态较为单一,主要由连通性差的半开孔组成(单侧封闭的楔形、圆柱形和狭缝状孔),孔隙体积对应的孔径呈多峰分布,内蒙古褐煤的孔体积主要来自过渡孔的贡献,新疆长焰煤孔体积主要来自过渡孔和微孔的贡献,韩城烟煤的孔体积主要来自微孔的贡献,3种煤焦的比表面积主要由孔直径为2~3 nm的孔贡献,随着煤化程度的增加,其吸附量、比表面积和总孔容呈现减小趋势,总孔容和比表面积成正相关;煤化程度高,有利于微孔的发育,煤化程度低则有利于过渡孔的发育。随热解温度升高,煤中挥发分剧烈析出,更多的孔隙开放,煤焦的吸附量增加。当温度过高时,煤焦碳骨架发生熔融坍塌,部分微孔转化为过渡孔和中孔从而使吸附量下降。随热解温度的升高,内蒙古褐煤的吸附量呈增高的趋势,新疆长焰煤的吸附量先增高后降低,韩城烟煤的吸附量呈降低的趋势,对比不同阶煤样品的孔径随热解温度的变化规律可知,内蒙古褐煤孔隙更加发达,有利于煤中气化剂和气体产物的输送。


  • Abstract
    In order to study the pore variation of different coal-grade samples during pyrolysis, this paper used a self-made coal thermal simulation device to carry out thermal simulation tests on Inner Mongolia brown coal, Xinjiang long flame coal and Hancheng bituminous coal, and used ASAP2020M automatic surface area analyzer. The pore structure changes of coal char samples during pyrolysis were analyzed. N2 adsorption desorption experiments showed that:there was no or small loop between the adsorption and desorption curves of three kinds of coal samples, and the pore morphology are was relatively simple. It is mainly composed of semi-openings with poor connectivity (wedge-shaped, cylindrical and slit-shaped holes enclosed unilaterally). The pore volume distribution corresponding to pore volume had a multi-peak distribution. The pore volume of coal char in Inner Mongolia mainly came from the contribution of transition pore; Xinjiang coal char pore volume mainly came from the contribution of transition pore and micropore; Hancheng coal char pore volume mainly comes from the contribution of micropore. The specific surface area is mainly contributed by the pore diameter of 2~3 nm. With the increase of coalification, the adsorption capacity, specific surface area and total pore volume decreased,and the pore volume is positively correlated with the specific surface area. The high degree of coalification is conducive to the development of micropores, while low degree of coalification is conducive to the development of meso-pores. As the pyrolysis temperature increases, the volatile matter of the coal species is violently precipitated, more pores are open, and the adsorption amount of coal char is increased. When the temperature was too high, the coal coke skeleton would collapse, and a fraction of micropores would be transformed into transition pores and mesopores, which would decrease the adsorption capacity. The adsorption amount of coal char in Inner Mongolia showed an increasing trend. The adsorption amount of coal char in Xinjiang first increased and then decreased. The adsorption amount of coal char in Hancheng showed a decreasing trend. By comparing the pore sizes of different coal grade samples with pyrolysis temperature, it can be observed that Inner Mongolia lignite is more conducive to the transport of gasification agents and gaseous products in coal.
  • 关键词

    煤热解低温液氮吸附煤气化孔隙结构

  • KeyWords

    coal pyrolysis; low-temperature liquid nitrogen adsorption; coal gasification;pore structure

  • 基金项目(Foundation)
    国家自然科学基金资助项目(U1703126)
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主办单位:煤炭科学研究总院有限公司 中国煤炭学会学术期刊工作委员会

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