厌氧微生物降解下镜煤与暗煤化学结构差异特征及其演化规律  

Characteristics and evolution of chemical structural differences between vitrain and durain during anaerobic microbial degradation

作　　者：李丹 鲍园[1] 徐凤银 刘向荣 胡宜亮[1] 王小婧 LI Dan;BAO Yuan;XU Fengyin;LIU Xiangrong;HU Yiliang;WANG Xiaojing(College of Geology and Environment,Xi'an University of Science and Technology,Xi'an 710054,China;Postdoctoral Research Station of Mining Engineering,Xi'an University of Science and Technology,Xi'an 710054,China;College of Energy(College of Modern Shale Gas Industry),Chengdu University of Technology,Chengdu 610059,China;State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation,Chengdu University of Technology,Chengdu 610059,China;College of Chemistry and Chemical Engineering,Xi'an University of Science and Technology,Xi'an 710054,China)

机构地区：[1]西安科技大学地质与环境学院,陕西西安710054 [2]西安科技大学矿业工程博士后流动站,陕西西安710054 [3]成都理工大学能源学院(页岩气现代产业学院),四川成都610059 [4]成都理工大学油气藏地质及开发工程全国重点实验室,四川成都610059 [5]西安科技大学化学与化工学院,陕西西安710054

出　　处：《煤炭科学技术》2025年第3期174-186,共13页Coal Science and Technology

基　　金：国家自然科学基金面上资助项目(42172200)。

摘　　要：为探究厌氧微生物降解作用下镜煤与暗煤化学结构差异特征及其演化规律,以黄陵矿区侏罗系延安组2号煤层(原煤、镜煤与暗煤)为研究对象,进行厌氧微生物降解不同类型煤生烃模拟试验,利用傅里叶红外光谱和X射线衍射技术分析不同降解阶段下(Ⅰ、Ⅱ、Ⅲ阶段)煤的官能团结构和微晶结构演化特征。结果表明,镜煤与暗煤累计甲烷产量分别为343.58和281.13μmol/g,镜煤产气高峰期比暗煤产气高峰期出现时间早14 d。受宏观煤岩类型影响,镜煤高取代芳烃占比明显大于暗煤,且脂肪结构侧支链更丰富,暗煤则富集含氧官能团和芳香结构,其微晶结构更稳定。微生物降解煤的主要官能团是不稳定的脂肪结构侧支链,镜煤和暗煤脂肪结构CH_(2)/CH_(3)比值分别从2.20和1.77增加至2.36和2.17,芳香碳含量的变化不超过0.05,其他官能团结构演化无统一规律。微晶结构参数中镜煤和暗煤堆砌度和堆砌层数降低,Lc分别从1.28 nm和1.38 nm降低至1.22 nm和1.27 nm,Nave分别从3.51和3.82降低至3.34和3.50,碳原子网面间距增大,即芳香结构弱桥键断裂,芳香核边缘不规则小分子量芳香层片脱落。变异系数散点图显示镜煤与暗煤的芳烃取代基区间变异程度最大,镜煤微晶结构变异程度明显高于暗煤。微生物降解作用下镜煤前期主要脱落芳香层片之间填充的有机物,碳原子面网间距降低,同时会破坏芳香结构,引起脂肪结构丰度增加,暗煤前期主要脱落芳香核边缘脂肪结构和含氧官能团,在微生物降解镜煤和暗煤的整个过程中脂肪结构始终被破坏,芳香结构桥键逐渐断裂,引起芳香核边缘结构解体。To explore variations in chemical composition and evolutionary trends between vitrain and durain during anaerobic microbial degradation,we performed simulation experiments on hydrocarbon generation through anaerobic microbial degradation using samples from No.2 coal seam(raw coal,vitrain,and durain)sourced from the Jurassic Yan'an Formation in the Huangling Mining area.Fourier transform infrared spectroscopy and X-ray diffraction techniques were utilized for analyzing changes in functional group structures as well as microcrystalline structural evolution at different stages(I,II,III)of degraded coals.The results indicate that the cumulative methane production from mirror coal and dark coal was 343.58μmol/g and 281.13μmol/g,respectively.The peak gas production time for vitrain occurs 14 days earlier compared to that of durain.Notably,the peak gas production time for vitrain occurred two week earlier compared to durain.Furthermore,vitrain exhibits a substantially higher proportion of highly substituted aromatic hydrocarbons in comparison to durain.Additionally,the aliphatic structure exhibits a greater abundance of side chains in vitrain.On the other hand,durain is characterized by an enrichment of oxygen-containing functional groups and aromatic structures,along with a more stable microcrystalline structure.Microbial degradation primarily affected the unstable side chains of the aliphatic structure.Under microbial degradation,the CH_(2)/CH_(3)ratio of the aliphatic structure in vitrain and durain increased from 2.20 to 2.36 and from 1.77 to 2.17,respectively.The aromatic carbon content re-mained virtually unchanged,with variations not exceeding 0.05.Additionally,other functional groups did not exhibit a consistent trend.Among the microcrystalline structural parameters,both the stacking degree and the number of stacking layers for vitrain and durain exhib-ited a decrease.Specifically,the Lc values decreased from 1.28 nm and 1.38 nm to 1.22 nm and 1.27 nm,respectively,while the average number of stacking layers(Na

关 键 词：镜煤 暗煤 厌氧微生物降解 官能团结构 微晶结构 

分 类 号：TD845[矿业工程—煤矿开采]