西安科技大学学报2023，Vol.43Issue(6)：1118-1127,10.DOI:10.13800/j.cnki.xakjdxxb.2023.0610
陕南地区中煤阶煤分子结构演化特征
Molecular evolution of medium rank coal in Southern Shaanxi
摘要
Abstract
In order to study the changes of functional groups in the structure of medium rank coal in southern Shaanxi,8 medium rank coal samples from Shangluo coal district in northern Qinling and Zhenba coal district in upper Yangtze were taken as the research objects.The coal structure was char-acterized by X-ray diffraction and FTIR,and the relative content and structural parameters of functional groups were obtained by peak fitting.The results show:with the increase of vitrinite reflectance,the distance between aromatic ring layers gradually decreases while the stacking degree and ductility grad-ually increase,and aromaticity displays a turning point at a reflectance of 1.30％.The benzene ring substitution in the aromatic structure of medium rank coal is mainly trisubstituted and disubstituted.With the increase of metamorphic grade,the proportion of benzene ring disubstituted increases.The gradual shedding of the aliphatic structure leads to a decrease in the relative proportion;the intensity of the absorption peak of the oxygen-containing functional group gradually weakens,and the relative content of the carbonyl group is the lowest when the reflectivity is 1.30％.The relative content of self-associated hydroxyl group,ether oxygen hydroxyl group and ring hydroxyl group see a trend of first de-creasing and then increasing.The cyclization of chain like structure in coal molecular structure increa-ses the relative content of ring hydroxyl group after the reflectivity is 1.30％.The enhancement of cy-clization leads to the decrease of methyl content,the spatial arrangement of molecular structure is close,and the relative content of self-associated hydroxyl group increases.The infrared structural pa-rameters such as aromatic carbon ratio,aromaticity,aromatic ring polycondensation degree and CH2/CH3 increase with the increasing reflectivity.The change of maturity is related to the conversion of ether oxygen or phenolic hydroxyl group.Overall,the relative content of aromatic structure increases,the aliphatic structure decreases,the degree of condensation increases,and the hydrocarbon generation potential increases with reflectivity,reflecting a decrease in the hydrocarbon generation potential of coal structure.关键词
中煤阶煤/X射线衍射测试/傅里叶红外光谱/煤分子结构/陕南地区Key words
low-medium rank coal/X-ray diffraction analysis/Fourier trnasform infrared spectrometer/coal molecular structure/Southern Shaanxi分类
化学化工引用本文复制引用
李焕同,邹晓艳,张卫国,乔军伟..陕南地区中煤阶煤分子结构演化特征[J].西安科技大学学报,2023,43(6):1118-1127,10.基金项目
构造与油气资源教育部重点实验室开放课题项目(TPR-2022-06) （TPR-2022-06）
国家自然科学基金项目(41502160) （41502160）
