低熟煤中常量、微量元素与煤生烃潜力参数的相关性研究

A preliminary study on the correlations among major elements,trace elements,and parametersof coal hydrocarbon-generation in low rank coal

应用电离耦合等离子体原子反射光谱(ICP-AES)和X射线荧光光谱(XRF),对新疆准噶尔六道湾侏罗纪低熟煤中36种微量元素的质量分数进行了测定,同时作岩石热解分析,有机碳测定,并对获取的各种数据进行回归分析,以考察它们之间的相关性。实验结果表明,除个别具有一定化学催化能力的元素外,多数常量元素及其所形成的矿物质,由于其对成煤有机物质的负增量作用,会明显降低煤的生烃潜力;微量元素对煤的生烃性能影响则较为复杂,既与其对煤的各种化学组成的有机亲和性之差异有关,亦与其在煤的大分子热裂解成烃中的某种化学催化作用有关。此外,由于某些微量元素所特有的古气候、古成煤沼泽类型的“指相”作用,亦能间接地指示煤的生烃潜力。其中Cu既是一个有着与煤的大分子物质较强亲和力的元素,又是一个可以显示古气候古成煤沼泽类型的“指相”元素,因而在指示煤的生烃潜力方面可能具有普适性。

This paper mainly described the influence of normal and trace elements on hydrocarbon generating potential and organic carbon determination of Jurassic low rank coal from the Liudaowan coalfield, Zhungaer, Xinjiang, China. Coal samples were examined using inductively coupled plasma-atomic emission spectrometry and X-ray fluorescence spectrometry. The results show that almost all of the major elements and their minerals, except some elements which play as a catalyst in processing of coal derived hydrocarbon, have passive roles in the processing obviously. These are likely attributed to the elements and their minerals reducing the content of organic matter in coals. However, trace elements play complex roles in the processing. The reasons are not only the difference of organic affinity between trace element and coal chemical composition, but also trace elements playing as a catalyst in pyrolysis of coal macromolecule. Additionally, some trace elements in coals, which indicate the paleoclimate and the types of bog in coal-forming period, can also show hydrocarbon generating potential of coal, such as Cu which has a strong affinity to organic macromolecule in coals. Cu is a facies element, and may be an indicator element of hydrocarbon generating potential.