煤层夹矸型黏土矿物对甲烷的吸附研究

发布时间：2018-03-24 23:38

本文选题：煤层夹矸　切入点：黏土矿物　出处：《煤炭学报》2017年08期

【摘要】：黏土矿物是煤层中最重要的矿物质,煤层中有机质与黏土矿物复合能改善黏土矿物对甲烷的吸附能力,因而煤储层中黏土矿物对甲烷的吸附不容忽视。分别选取黏土矿物含量较高的煤层夹矸和纯黏土样品,采用X-射线衍射、红外光谱及扫描电镜表征,并进一步分析了样品中总有机碳(TOC)含量、有机质的类型和成熟度,结合孔径、孔隙体积和比表面积测定结果,探讨造成夹矸型和非煤黏土矿物甲烷吸附能力差异的主要原因,研究影响夹矸型黏土矿物吸附能力的控制因素。结果表明:夹矸型黏土矿物对甲烷的吸附能力依次为铵伊利石高岭石伊利石金云母;单纯的外表面积大小并不能完全反应出黏土矿物的甲烷吸附特性,需结合不同黏土矿物层间域等多方面因素综合考虑;有机质含量较高的夹矸型黏土矿物样品比纯黏土样品具有更多的微小孔隙,尤其是孔径小于6 nm的孔隙,对样品比表面积的增加起到了关键作用,进而也增强了其甲烷吸附能力。通过分析黏土矿物的甲烷吸附贡献率发现,黏土矿物及其有机复合体具有较强的甲烷吸附能力,在煤层夹矸中对甲烷的吸附贡献较大。
[Abstract]:Clay mineral is the most important mineral in coal seam. The combination of organic matter and clay mineral in coal seam can improve the adsorption ability of clay mineral to methane. Therefore, the adsorption of methane by clay minerals in coal reservoir can not be ignored. The coal seam gangue and pure clay samples with high clay content are selected and characterized by X- ray diffraction, infrared spectroscopy and scanning electron microscope. Furthermore, the content of total organic carbon (TOC), the type and maturity of organic matter in the samples were analyzed, and the main reasons for the difference of methane adsorption capacity between gangue type and non-coal clay mineral were discussed, combined with the results of pore size, pore volume and specific surface area measurement. The influence factors on the adsorption capacity of gangue clay minerals are studied. The results show that the adsorption capacity of gangue clay minerals to methane is ammonium Illite kaolinite Illite phlogopite. The pure surface area can not completely reflect the methane adsorption characteristics of clay minerals, which should be considered synthetically by combining with different clay mineral interlaminar domains. The mineral samples of gangue clay with higher organic matter content have more tiny pores than pure clay samples, especially the pores with pore size less than 6 nm, which play a key role in increasing the specific surface area of the samples. By analyzing the contribution rate of methane adsorption of clay minerals, it is found that clay minerals and their organic complexes have strong methane adsorption ability, and the contribution to methane adsorption in coal gangue is greater.
【作者单位】：中国矿业大学(北京)地球科学与测绘工程学院;河南工程学院资源与环境工程系;
【基金】：国家自然科学基金资助项目(41602171) 北京市自然科学基金资助项目(8164062) 北京市科技新星计划资助项目(2015B081)
【分类号】：P618.11

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