重庆中梁山晚二叠世煤有机地球化学特征

(河北工程大学河北省资源勘测研究重点实验室，河北邯郸 056038)

摘要:以重庆中梁山K1a煤层为研究对象，通过煤样显微组分煤相参数计算表明，K1a煤的成煤环境为潮湿的森林沼泽还原环境，成煤植物以木本植物为主。通过索式抽提和族组分分离实验，利用气相色谱(GC)和色谱-质谱联用(GC-MS)，对煤中有机质的组成特征及分子地球化学参数进行分析。结果表明，中梁山K1a煤层煤样成煤植物以陆相高等植物为主，但不排除海相低等生物的输入;煤层具有偏还原的成煤环境，热演化程度较高;芳烃化合物以萘系、菲系和联苯系为主，热力学稳定性较强的同分异构体占有优势地位，芳烃中硫芴含量高于氧芴，亦表明偏还原的成煤环境。煤样显微组分分析的结果与煤中有机质分析结果相互印证。

关键词:中梁山;晚二叠世煤;显微组分;有机地球化学;饱和烃;芳香烃

Organic geochemistry of the Late Permian Coal from the Zhongliangshan mine,Chongqing

(Key Laboratory of Resource Exploration Research of Hebei Province,Hebei University of Engineering,Handan 056038,China)

Abstract:Samples from K1a coal seam in the Zhongliangshan mine were investigated by microscopy and organic geochemistry.The coal facies parameters show that the Zhongliangshan coal formed in wet forest swamp under reductive environment,and the coal-forming plants were mainly woody plants.After Soxhlet extraction and group components separation,the composition and molecular geochemical features of organic matter were analyzed by gas chromatograph (GC) and gas chromatograph-mass spectrometry (GC-MS).The results indicate that the coal-forming plants were mainly terrestrial higher plants.However,the input of marine phytoplankton cannot be excluded.The coal-forming environment was reductive,and the coal seam underwent relatively higher thermal evolution.Aromatic hydrocarbons were dominated by naphthalenes,phenanthrenes and biphenyls.The isomers of aromatic hydrocarbons with higher thermodynamic stability had an advantage position,and the contents of dibenzothiophenes were higher than dibenzofurans,which also implies the reductive coal-forming environment.The results from microscopic and the organic geochemical analyses verify mutually.

Key words:Zhongliangshan;the Late Permian Coal;maceral;organic geochemistry;saturated hydrocarbon;aromatic hydrocarbon

秦身钧，陆青锋，吴士豪，等.重庆中梁山晚二叠世煤有机地球化学特征[J].煤炭学报,2018,43(7):1973-1982.doi:10.13225/j.cnki.jccs.2017.1264

QIN Shenjun,LU Qingfeng,WU Shihao,et al.Organic geochemistry of the Late Permian Coal from the Zhongliangshan mine,Chongqing[J].Journal of China Coal Society,2018,43(7):1973-1982.doi:10.13225/j.cnki.jccs.2017.1264

基金项目:国家自然科学基金资助项目(41472133);河北省自然科学基金资助项目(D2018402093);河北省高校百名优秀创新人才支持计划资助项目(BR2-204)

作者简介:秦身钧(1977—)，男，河北邯郸人，教授，博士。Tel:0310-8577902,E-mail:qsjhbhd@163.com

煤的显微组分以及有机地球化学特征尤其是生物标志化合物组成能够为成煤植物、成煤环境和热成熟度等提供重要的信息[1-4]。如煤相特征参数可以揭示古泥炭沼泽的氧化还原环境和成煤气候等;煤中有机质正构烷烃的分布可以反应成煤植物的来源、煤样热演化程度以及微生物或无机环境的影响;姥姣烷与植烷的比值(Pr/Ph)可以表明成煤环境的氧化还原程度;奇偶优势指数(OEP)和甲基菲指数(MPI)可以反映煤化程度的高低等。然而，变质程度较高的烟煤和无烟煤具有与低成熟度显著不同的有机地球化学特征，不能按传统的地质意义进行应用[2]。

晚二叠世是地质历史上的重要聚煤期，在我国西南地区形成了丰富的煤炭资源。目前对该地区煤质特征、沉积环境、地层、岩相古地理以及煤中微量元素的富集和赋存进行了较多研究[5-10]，但尚缺乏系统的有机地球化学研究。笔者对重庆中梁山晚二叠世煤中饱和烃和芳香烃的地球化学特征进行了分析，并通过煤样显微组分特征进行佐证，阐明其成煤植物的主要来源、成煤环境和热演化程度等地质意义。

1 地质背景

重庆中梁山矿位于重庆市西郊，相对于重庆市渝中区方位265°，直距18 km，行政区划隶属重庆市九龙坡区(图1)。中梁山矿区含煤地层主要为二叠系上统龙潭组，区内地质构造条件复杂，断层和褶皱构造发育明显[11];煤层沉积环境为海陆交互相过渡，而且受到峨眉山玄武岩影响。中梁山龙潭组含煤段(龙潭组一、二段)厚56.19～79.16 m，平均71.76 m。龙潭组第1段含煤岩性为灰色页岩夹细砂岩，含煤4层，底部为灰白色铝土页岩;第2段含煤岩性为灰黄色细砂岩夹页岩，含煤6层，底部为灰岩;第3段为灰黄色页岩、细砂岩、粉砂岩夹薄层灰岩，不含煤层。矿区共含煤10层(从上到下编号K1～K10)，其中K1,K2,K3,K5和K9全区可采，煤质以低中灰、中高硫为主(图1仅K1～K3煤层)。

图1 中梁山K1a煤层地理位置及采样编号
Fig.1 Location and samples of ZLS K1a coal seam

2 样品采集与分析

中梁山K1煤层位于龙潭组二段顶部，属于结构复杂煤层。一般构造为煤(1.64 m)、矸石(0.33 m)、煤(0.58 m)、矸石(1.29 m)、煤(0.38 m)，含矸石2层，使煤层形成3个独立分层(从上至下编号为K1a,K1b,K1c)。本次实验选择中梁山煤矿K1煤层K1a分层为研究对象，严格按照国家标准《煤层煤岩采样方法》(GB/T 482—2008)规范进行刻槽采样，共采集23个样品，编号依次为ZLS-顶、ZLS-1、…、ZLS-19、ZLS-夹矸、ZLS-20和ZLS-21。

根据国家标准GB/T 474—2008《煤样的制备方法》对样品进行制备，将其粉碎至200目和40目。对40目煤样进行处理，通过偏光显微镜(Leica DM2500P)观测煤样显微煤岩组分。对200目煤样进行索式抽提和族组分分离实验，通过气相色谱(Agilent 6890)和色谱-质谱联用仪(Agilent 6890-MS5973)对分离得到的饱和烃和芳香烃进行测试分析。气相色谱、色质测试条件:色谱程序升温60～280 ℃，4 ℃/min;起始温度停留5 min，最后280 ℃保持15 min。质谱70 eV，50～650 Da。

3 结果与讨论

3.1 煤样显微组分及煤相特征

3.1.1 显微组分特征

中梁山K1a煤的镜质组反射率Ro=1.46%，属高阶烟煤。对其显微煤岩组分(含矿物基)进行定量统计并对各参数进行计算，结果见表1，K1a煤中镜质组占54.14%～82.26%，平均64.43%;惰质组占10.96%～37.94%，平均25.85%;因演化程度较高，煤样中未观察到壳质组;矿物占6.78%～15.85%，平均9.72%。

镜质组以均质镜质体(29.03%)和基质镜质体(30.17%)为主，其次是碎屑镜质体(2.07%)，结构、团块和胶质镜质体较少;丝质体是惰质组的主要成分(15.86%)，其次是碎屑惰质体(6.43%)、粗粒体(1.26%)、微粒体(1.96%)和菌类体(0.34%)。

表1 中梁山K1a煤显微组分含量(%)和各参数值
Table 1 Content of macerals(%) and related parameters of K1a coal

显微组分和参数ZLS-1ZLS-3ZLS-5ZLS-7ZLS-9ZLS-11ZLS-13ZLS-15ZLS-17ZLS-19ZLS-20Average镜质组72.62 64.22 82.26 75.05 56.60 66.10 64.15 54.14 60.00 57.28 56.35 64.43 结构镜质体1.00 0.56 0.70 0.37 0.20 0.17 0.19 0.37 4.72 2.33 0.17 0.98 均质镜质体35.06 29.76 62.26 40.67 16.00 31.69 28.88 31.49 7.17 19.81 16.52 29.03 基质镜质体33.39 30.32 17.22 29.57 31.40 29.98 29.84 20.81 43.21 31.65 34.43 30.17 胶质镜质体0.50 0.38 0.35 0.18 1.00 0.17 0.39 0.37 0.75 0.19 0.70 0.45 团块镜质体1.00 0.75 0.17 1.48 2.00 0.34 0.39 0.37 0.94 0.97 1.57 0.91 碎屑镜质体0.33 1.88 0.70 2.03 4.00 2.21 4.07 0.37 2.64 1.94 2.61 2.07 半镜质组1.34 0.56 0.87 0.74 2.00 1.53 0.39 0.37 0.57 0.39 0.35 0.83 惰质组13.36 22.79 10.96 18.11 35.40 24.70 25.97 37.94 24.15 35.34 35.65 25.85 火焚丝质体1.34 0.94 1.04 0.37 0.20 0.17 0.39 3.68 4.72 0.78 1.57 1.38 氧化丝质体1.67 3.77 1.04 3.88 6.80 3.75 2.91 11.05 6.04 13.20 7.13 5.57 半丝质体4.34 8.66 4.17 4.25 14.40 10.39 13.76 15.47 1.70 10.29 10.61 8.91 粗粒体0.67 1.88 0.35 0.92 1.40 1.87 0.97 0.55 0.19 0.39 4.70 1.26 微粒体1.34 1.13 0.70 1.48 3.20 1.36 2.71 1.29 5.09 2.72 0.52 1.96 菌类体0.50 0.38 0.17 0.18 1.20 0.34 0.19 0.18 0.19 0.19 0.17 0.34 碎屑惰质体3.51 6.03 3.48 7.02 8.20 6.81 5.04 5.71 6.23 7.77 10.96 6.43 矿物14.02 12.99 6.78 6.84 8.00 9.20 9.88 7.92 15.85 7.38 8.00 9.72 黄铁矿8.68 5.46 1.74 2.96 3.40 3.24 3.10 2.03 12.26 2.91 4.70 4.59 黏土矿物4.01 3.01 3.65 3.51 4.20 5.45 6.20 3.31 3.21 3.69 3.13 3.94 方解石1.00 3.95 1.04 0.18 0.00 0.17 0.39 2.21 0.00 0.19 0.00 0.83 石英0.33 0.56 0.35 0.18 0.40 0.34 0.19 0.37 0.38 0.58 0.17 0.35 TPI1.16 1.14 3.29 1.32 0.92 1.19 1.29 2.29 0.49 1.17 0.72 1.36 GI6.75 3.41 8.48 4.89 1.96 3.22 2.95 1.52 3.22 1.80 2.02 3.66 GWI0.16 0.20 0.08 0.18 0.69 0.26 0.38 0.14 0.63 0.31 0.48 0.32 VI1.18 1.15 3.24 1.29 0.89 1.19 1.19 2.32 0.47 1.13 0.75 1.35 V/I5.442.827.514.141.602.682.471.432.481.621.583.07OI0.050.100.040.090.120.110.070.070.080.100.210.09F/M1.151.093.181.250.841.131.162.260.471.110.681.30

注:TPI—植物组织保存指数;GI—凝胶化指数;VI—植被指数;GWI—地下水流动指数;V/I—镜惰比;OI—氧化指数;F/M—骨基比; width=753,height=105,dpi=110

3.1.2 煤相特征

煤相是指煤的原始成因类型，主要由植物保存指数(TPI)、凝胶化指数(GI)、地下水流动指数(GWI)、植被指数(VI)、镜惰比(V/I)、氧化指数(OI)以及骨基比(F/M)来反映。中梁山K1a煤的GI-TPI和GWI-VI关系如图2所示。

图2 中梁山K1a煤GI-TPI和GWI-VI关系
Fig.2 Relation of GI-TPI and GWI-VI of K1a coal

镜惰比(V/I)能够反映成煤泥炭沼泽的覆水强弱和成煤气候的干湿，根据V/I值可划分为:有火灾发生<0.25<潮湿-弱覆水<1<极潮湿-覆水<4<强覆水4种成因类型[12]。中梁山K1a煤的镜惰比(V/I)值在1.43～7.51，表明中梁山K1a煤的成煤环境介于强覆水和极潮湿-覆水之间。

氧化指数(OI)是碎屑惰质体和粗粒体与其他显微组分的比值，可以揭示古泥炭沼泽表面氧化程度的强弱。K1a煤的OI范围为0.04～0.21，反映了成煤环境为还原环境。

骨基比(F/M)是骨架组分与基质组分的比值，主要反映植物细胞破坏程度和沼泽水流活动性的强弱[13]。F/M>1，即水流活动性较弱的滞留环境;F/M<1，即水流活动性较强的活水环境。K1a煤的F/M值介于0.47～3.18，均值1.30，表明水流活动性较弱，大部分植物遗体及细胞结构没有受到强烈的破坏。

植物组织保存指数(TPI)反映植物组织降解程度和细胞结构保存完好程度。凝胶化指数(GI)可表示泥炭沼泽的潮湿或干燥[12,14-15]。由图2可知，研究区煤的沉积环境为潮湿森林沼泽，TPI平均值为1.36，表明植物结构保存程度较好，ZLS-9和ZLS-20样品植物细胞结构保存相对较差。

地下水流动指数(GWI)可反映矿物的含量、地下水对泥炭沼泽的控制程度及地下水位的变化。植被指数(VI)可反映成煤植物类型[12,14-15]。GWI值介于0.08～0.69，均值0.32，表明泥炭沼泽相对较低的水位和较为潮湿的环境;VI值范围为0.47～3.24，均值1.35，说明成煤植物具有木本亲和性，受到草本或低等水生生物的影响。

结合各煤相参数，中梁山K1a煤的成煤环境为潮湿的森林沼泽还原环境，成煤植物以木本植物为主，同时受到低等生物影响。上述推论在煤有机地球化学分析中得到印证。

3.2 煤样有机质特征

3.2.1 煤中有机抽提物特征

抽提得到的可溶有机质由饱和烃、芳香烃和极性化合物组成。由表2可知，中梁山K1a煤层煤样有机质的含量范围为2.66～8.22 mg/g，芳香烃含量均明显高于饱和烃，因而产生了较低的饱芳比(0.13)，这是以陆相高等植物为主的成煤母质特征，对应着上述样品均为腐植煤的事实。

表2 中梁山K1a煤样有机抽提物含量分布
Table 2 Content of organic extracts of coal samples from ZLS No.K1a

注：饱/芳为饱和烃和芳香烃含量比值。

3.2.2 煤中饱和烃特征

(1)碳数分布。

由表3和图3可知，煤样饱和烃的碳数分布范围在C14～C27，主峰碳在C17或C16附近，呈单峰分布。原有高碳数峰的消失主要源于煤样成熟过程中的热解，以及明显的细菌生物降解作用，后者的证据是色谱图中普遍出现的“鼓包”[16]。中梁山晚二叠世煤的沉积环境为海陆过渡相沉积，因此其有机质输入除了高等植物，海相低等水生浮游生物的贡献亦不能排除。尤其在ZLS-13和ZLS-20两个样品中，低碳数与高碳数正构烷烃比值明显偏高，说明它们受海相生源的输入更为明显。这一点与煤相参数的分析结论相互印证，即ZLS-13和ZLS-20两个分煤层煤样受海相输入较为明显，它们的V/I,GWI和VI数值表明其处于极潮湿-覆水的环境，且成煤植物主要是木本植物，但受低等水生生物的影响较大。

表3 中梁山K1a煤样饱和烃色谱参数
Table 3 Parameters of saturated hydrocarbons of coal samples from ZLS No.K1a

注:其中Ci为主峰碳;数据根据色谱图积分结果计算。

图3 中梁山K1a煤中饱和烃的色谱图
Fig.3 GC chromatograms of the saturated hydrocarbon fraction from K1a coal

(2)奇偶优势指数(OEP)。

奇偶优势OEP值可用于判断有机质的成熟度，中梁山K1a煤样OEP均值为0.93，接近于1，无明显的奇偶碳优势，表明煤层的成熟度较高。

(3)姥鲛烷(Pr)/植烷(Ph)、Pr/nC17和Ph/nC18。

姥鲛烷Pr和植烷Ph为典型的类异戊二烯烃生物标志化合物，Pr/Ph通常用于指示沉积环境的氧化还原状态和有机质的演化程度[17]。一般腐植煤Pr/Ph的值较高，但该数值的相对大小，也可反映成煤中局部氧化还原环境的不同:数值越大，氧化性相对越强。中梁山较小的Pr/Ph值(0.35～1.21)说明其具有较强的还原环境。大多数煤样的Pr/nC17和Ph/nC18数值彼此接近稳定在0.3～0.5，表明煤样有机质热演化成熟度较高，个别样品如ZLS-11较高的数值可能源于该样品受到过较强的生物降解作用[1]。

3.2.3 煤中芳香烃特征

芳香烃在腐植煤抽提物中占有较大的比例，主要来源于成煤植物在成煤过程中，经过生物降解或热裂解转化产生，储存有丰富的地球化学信息，同时也是煤化工主要原料和燃煤有机物污染物(PAHs)的主要来源。从中梁山K1a煤层煤样中检测出了萘系列、菲系列、联苯系列、芴系列、苯并萘并噻吩系、芘、和蒽等多环芳烃及其烷基类衍生物(图4，表4)，并且以萘系(均值25.48%)和菲系(均值24.66%)化合物为主，其次是联苯系列(均值11.82%)、芴系(均值9.61%)和硫芴系(6.55%)化合物，其他烃系化合物含量均小于6%。

(1)萘系列:K1a煤中萘系含量范围为16.93%～36.89%。K1a煤中仅ZLS-20检测到萘，萘的烷基同系物主要有甲基萘(MN)、二甲基萘(DMN)、三甲基萘(TMN)和乙基萘等，并且萘系含量为DMN>TMN>MN。二甲基萘以2,6+2,7-DMN(5.25%)和1,3+1,7-DMN为主(2.67%)，三甲基萘以1,3,6+1,2,7-TMN(2.67%)为主，一取代物中2-MN(3.07%)具有较明显的优势(详见表5)。上述发现说明在煤层热演化过程中，长链的取代芳烃会趋向裂解成短链，并且β-取代物的含量明显高于α-取代，这是由于前者的热力学稳定性高于后者的原因。

图4 中梁山K1号煤中芳香烃的色谱-质谱
Fig.4 GC chromatograms of the saturated hydrocarbon fraction from K1a coal

表4 可识别的芳香烃化合物
Table 4 Identification of aromatics compounds

芳香烃化合物ZLS-1ZLS-3ZLS-5ZLS-7ZLS-9ZLS-11ZLS-13ZLS-15ZLS-17ZLS-19ZLS-20Average萘系列19.9229.1028.8523.3221.3330.2326.3920.8526.4816.9336.8925.48N0.000.000.000.000.000.000.000.000.000.001.710.16MN1.185.023.592.482.157.462.871.875.281.3312.304.14DMN9.0413.8614.4411.3010.2113.9813.419.5611.666.9514.5311.72TMN6.617.257.466.396.325.886.756.066.495.535.566.39乙基萘0.540.861.030.730.630.971.030.640.760.431.070.79氧芴系列5.164.964.774.625.024.354.894.964.885.423.854.81DBF0.150.170.190.170.180.160.200.150.220.170.190.18MDBF2.482.392.442.222.271.982.232.242.222.321.812.24芴系列8.609.0510.259.4810.269.829.9410.879.3010.697.439.61Fluorene0.800.851.281.121.021.321.371.180.850.990.911.06MFLU3.843.614.834.054.184.283.924.633.764.543.104.07C2-FLU3.053.873.373.554.113.423.764.093.824.252.843.65硫芴系列6.856.106.866.777.365.946.677.026.257.604.606.55DBT1.761.651.801.671.711.411.621.421.151.631.131.54MDBT3.493.143.443.573.883.013.413.903.444.042.453.43DMDBT1.010.811.000.931.061.021.031.040.991.240.620.98菲系列27.6122.3524.7925.5527.2220.5524.1027.9424.3627.8718.8724.66P5.104.464.804.724.413.834.364.883.854.843.494.43MP10.538.419.459.329.807.628.9410.218.7410.306.789.10DMP7.255.876.556.937.775.466.567.586.957.544.806.66TMP3.192.562.813.023.512.652.893.433.503.362.343.02联苯系列14.8015.9510.8010.2910.4311.209.559.1112.4111.0214.5111.82Bi1.893.051.191.081.121.880.930.772.261.243.591.73MBi7.668.025.125.065.065.444.534.175.945.257.135.76DMBi5.254.884.494.154.253.884.094.174.214.543.794.34苯并萘并噻吩系列5.013.573.666.255.616.556.465.564.657.194.205.34BNT0.910.620.551.050.700.590.940.820.691.030.780.79MBNT2.101.441.582.372.393.943.462.251.993.651.472.42DMBNT2.001.501.532.832.522.012.062.491.972.501.952.12苯并萘并呋喃3.222.542.783.143.222.452.773.312.913.362.192.90芘系列3.062.352.703.613.433.143.173.683.443.632.413.15荧蒽系列0.380.350.370.460.520.420.440.530.470.520.350.44 系列2.681.771.983.142.932.392.662.992.522.942.542.59苝系列0.350.210.240.470.380.350.370.410.330.410.410.36蒽系列2.371.701.942.562.272.612.612.782.012.421.752.27

表5 中梁山K1a煤中可识别的芳香化合物
Table 5 Identification of aromatics compounds in K1a coal-seam of Zhongliangshan Mine

序号芳香烃化合物ZLS-1ZLS-3ZLS-5ZLS-7ZLS-9ZLS-11ZLS-13ZLS-15ZLS-17ZLS-19ZLS-20平均1萘ndndndndndndndndndnd1.7122-甲基萘0.773.772.551.741.515.602.041.273.900.959.693.07 31-甲基萘0.411.251.040.740.631.860.820.601.380.382.611.07 4联苯1.893.051.191.081.121.880.930.772.261.243.591.73 52-乙基萘0.410.660.810.560.480.740.820.490.560.290.840.61 61-乙基萘0.130.200.220.170.150.230.220.150.200.140.230.19 72,6+2,7-二甲基萘3.826.066.885.054.366.536.524.324.662.826.745.25 81,3+1,7-二甲基萘2.153.283.042.512.453.172.762.053.011.603.402.67 91,6-二甲基萘1.602.272.021.711.642.161.761.421.941.212.191.81 101,4+2,3-二甲基萘0.901.511.701.351.181.471.591.151.320.821.551.32 111,5-二甲基萘0.330.450.480.400.370.400.490.380.460.300.350.40 121,2-二甲基萘0.230.290.320.280.220.250.290.250.270.190.290.26 134-甲基联苯4.755.153.353.173.213.442.882.673.853.344.593.67 143-甲基联苯2.902.871.761.881.862.001.651.502.081.912.542.09 15C3-萘1.171.421.341.141.021.071.231.041.060.891.101.13 16氧芴0.150.170.190.170.180.160.200.150.220.170.190.18 171,3,7-三甲基萘0.921.051.100.920.980.880.980.850.980.740.830.93 181,3,6-三甲基萘1.531.641.731.491.511.411.581.421.501.301.231.49 191,3,5+1,4,6-三甲基萘0.250.280.290.270.240.230.270.250.290.230.240.26 202,3,6-三甲基萘0.430.470.490.430.470.380.440.400.490.380.350.43 211,2,7-三甲基萘1.271.341.431.161.141.091.271.161.061.050.981.18 221,6,7-三甲基萘0.740.770.800.710.720.610.730.690.840.680.590.72 231,2,6-三甲基萘0.290.300.270.260.240.210.250.250.260.250.240.26 24芴0.800.851.281.121.021.321.371.180.850.990.911.06 253,5+3,3′-二甲基联苯0.680.640.610.570.590.520.540.580.660.640.490.59 263,4′-二甲基联苯1.751.641.421.321.371.241.261.281.351.471.261.40 274,4′-二甲基联苯2.141.951.791.651.691.581.681.681.611.801.531.74 283,4-二甲基联苯0.680.640.670.610.600.540.620.640.580.630.510.61 294-甲基氧芴0.640.640.670.600.620.530.610.610.590.610.490.60 302-甲基氧芴0.750.680.630.590.630.540.600.600.680.710.540.63 313-甲基氧芴0.530.530.560.510.490.450.510.510.460.500.380.49 321-甲基氧芴0.560.540.580.530.520.450.510.520.490.500.410.51 333-甲基芴0.590.530.530.490.560.420.470.520.600.570.380.51 342-甲基芴1.311.291.731.561.531.821.261.871.281.761.241.51 351-甲基芴1.941.792.572.002.102.042.202.241.882.211.482.04 36C2-氧芴?0.770.700.400.360.400.450.460.480.380.490.300.47 37C2-氧芴?0.600.550.560.510.590.460.500.550.560.560.380.53 38C2-氧芴?0.510.500.520.720.910.760.920.860.831.190.720.77 39硫芴1.761.651.801.671.711.411.621.421.151.631.131.54 40C2-氧芴?0.330.300.320.300.320.250.270.300.310.320.210.29 41C2-氧芴?0.320.340.350.330.370.300.320.360.360.380.240.33 42菲5.104.464.804.724.413.834.364.883.854.843.494.43 43C2-芴0.940.831.000.901.071.031.061.180.931.150.750.99 44C2-芴0.381.631.181.381.470.961.191.431.321.431.021.22 45C2-芴0.970.650.750.730.810.700.770.860.800.880.520.77 46C2-芴0.760.750.440.540.750.720.740.630.780.790.540.68 474-甲基二苯并噻吩1.451.301.441.391.481.151.331.511.301.400.911.33 482-甲基二苯并噻吩0.610.570.600.830.970.650.810.890.851.000.640.77 493-甲基二苯并噻吩0.480.400.430.420.480.370.230.490.470.500.290.41

续表

序号芳香烃化合物ZLS-1ZLS-3ZLS-5ZLS-7ZLS-9ZLS-11ZLS-13ZLS-15ZLS-17ZLS-19ZLS-20平均501-甲基二苯并噻吩0.940.870.970.930.950.841.041.010.811.140.600.92 513-甲基菲3.222.612.922.853.012.362.763.112.683.212.092.80 522-甲基菲4.393.463.903.853.903.103.644.193.394.162.803.71 539-甲基菲1.541.231.381.381.571.131.321.521.461.521.001.37 541-甲基菲1.391.101.241.241.331.031.221.401.211.410.891.22 55C3-芴0.370.320.350.340.420.340.370.430.420.430.250.37 56C3-芴0.550.410.420.430.520.460.520.540.460.480.320.46 57C2-硫芴0.740.560.740.660.780.640.600.720.710.730.430.66 582-苯基萘2.552.112.332.432.021.952.332.722.282.701.712.28 593-乙基菲0.330.290.310.320.390.280.330.380.360.390.230.33 60C2-硫芴0.270.250.270.270.280.380.420.320.280.500.190.31 613,6-二甲基菲0.850.680.750.770.900.630.760.880.830.920.560.78 622,6+3,5-二甲基菲1.311.021.151.191.320.941.131.311.181.330.851.16 632,7-二甲基菲1.060.911.031.091.170.871.041.181.001.120.711.02 642,10+3,10+1,3+1,9-二甲基菲1.701.331.491.581.821.191.461.681.661.711.091.52 652,9+1,6-二甲基菲0.990.880.971.051.170.830.991.131.011.070.710.98 661,7-二甲基菲0.690.540.600.650.710.510.610.720.660.720.450.62 672,3-二甲基菲0.640.510.560.600.670.500.580.680.600.670.430.59 68C3-硫芴0.580.500.610.600.710.500.610.670.670.700.410.60 69苯并萘并呋喃[2,1-d]0.920.690.770.830.890.650.760.900.780.910.580.79 70苯并萘并呋喃[1,2-d]1.340.981.081.201.270.921.131.351.151.370.901.1571苯并萘并呋喃[2,3-d]0.420.330.350.420.450.330.380.470.400.470.300.3972芘0.250.200.230.260.300.360.250.320.260.450.170.28 73苯并萘并呋喃[3,2-d]0.540.530.580.690.620.550.510.600.580.610.410.57 741,3,6-三甲基菲0.420.340.380.190.210.190.180.230.510.220.330.29 752,7,9-三甲基菲0.520.400.440.500.590.410.480.570.550.570.360.49 762,6,9-三甲基菲0.660.540.600.690.810.590.650.770.710.750.470.66 772,3,6-三甲基菲0.240.200.210.250.300.230.230.280.290.280.180.24 781,6,9-三甲基菲0.440.360.410.470.550.410.440.520.460.490.320.44 791,7,9-三甲基菲0.390.310.330.410.490.360.400.490.480.480.320.41 80C3-菲0.510.390.440.510.560.460.500.570.510.560.360.49 81C1-苯并蒽0.920.660.740.850.880.690.770.930.830.920.610.80 82C1-苯并蒽0.590.440.581.170.801.061.180.870.690.790.540.79 83C1-苯并蒽0.530.380.380.240.230.560.380.620.180.370.380.39 84甲基荧蒽0.380.350.370.460.520.420.440.530.470.520.350.44 852-甲基芘0.280.210.230.290.330.260.280.340.320.340.220.28 864-甲基芘0.310.230.260.320.390.290.310.360.350.370.250.31 871-甲基芘0.200.150.160.210.240.210.210.260.230.240.160.21 88C2-苯并蒽0.320.230.250.310.360.300.280.360.320.330.220.30 89C2-芘0.380.260.320.440.470.440.460.540.380.460.350.41 90C2-芘0.330.250.330.450.450.440.510.510.400.480.330.41 91C2-芘0.320.260.260.340.350.380.320.370.300.370.230.32 92C2-芘0.980.780.901.290.900.770.840.971.180.920.690.93 93苯并萘并噻吩0.910.620.551.050.700.590.940.820.691.030.780.79 94 1.230.820.931.401.331.161.291.421.181.371.121.20 95C1-苯并萘并噻吩0.580.400.460.710.690.650.680.760.600.710.510.61 96C1-苯并萘并噻吩0.900.610.681.080.960.790.930.660.560.950.510.78 97C1-苯并萘并噻吩0.270.280.290.310.280.340.210.370.210.220.170.27 98C1-苯并萘并噻吩0.350.160.150.270.472.161.640.450.631.760.280.76 993-甲基 0.870.600.661.101.040.710.840.950.850.970.890.86

续表

注:nd代表未检测到。

(2)菲系列:K1a煤中菲系含量范围为18.87%～27.94%。菲及其烷基同系物在煤样中均有检出，菲系取代芳烃以短链的甲基同系物为主，包括甲基菲(MP)、二甲基菲(DMP)和三甲基菲(TMP)。其相对含量为MP>DMP>P>TMP，体现了在成煤过程中，TMP脱甲基化转变为DMP和MP的趋势。由于热演化的进行，甲基菲会通过甲基重排，热力学控制下的3-MP和2-MP比例不断增加，致使甲基菲含量表现为2-MP>3-MP>9-MP>1-MP。二甲基菲中热力学稳定的2,6+2,7-DMP往往占优势，三甲基菲比例较低。

RADKE等提出甲基菲指数MPI-1=1.5(2-MP+3-MP)/(P+1-MP+9-MP)和MPI-2=3(2-MP)/(P+1-MP+9-MP)，MPI值随热演化程度的增加先呈现出增加趋势后减小[18-19]。K1a煤的MPI-1值为1.40，MPI-2值为1.59，说明煤样的成熟度较高。

(3)联苯系列:K1a煤中联苯系含量范围为9.11%～15.95%。煤样中检测到的联苯系列主要有联苯(Bi)、甲基联苯(MBi)和二甲基联苯(DMBi)，含量以MBi(5.76%)为主，且表现为4-MBi>3-MBi，即对位的取代物更为稳定。

(4)芴系列:K1a煤中检测出了分子结构相似的三芴化合物，即芴(FLU)、氧芴(二苯并呋喃，DBF)和硫芴(二苯并噻吩，DBT)，以及各自的烷基同系物，它们可能来源于相同的母质并在一定条件下相互转化。中梁山K1a煤样中硫芴含量高于氧芴，反映了一种偏还原的成煤环境。

对于芴的烷基取代物而言，甲基芴(MFLU)、二甲基芴(C2-FLU)和三甲基芴(C3-FLU)的相对含量依次降低，1-MFLU的含量最高，C2-FLU和C3-FLU的同分异构体难以辨识。氧芴取代物主要是一甲基取代(MDBF)，其中2-MDBF含量相对较高。硫芴取代物也以一甲基取代为主(MDBT)，且含量为4-MDBT>1-MDBT>2-MDBT>3-MDBT，与热力学稳定性的顺序不完全一致，说明一甲基取代硫芴在当前成熟度下受到动力学和热力学的共同控制[3]。

K1a煤样中也检测到了苯并萘并呋喃系列(BNF)和苯并萘并噻吩(BNT)系列，BNF的烷基取代主要是甲基取代MBNF，BNT的取代物主要是一甲基取代MBNT，其次是二甲基取代DMBNT。它们应当与氧芴和硫芴系列具有同源性，较高的苯并萘并噻吩含量也与偏还原的成煤环境有关。

(5)其他芳烃系列:K1a煤中还检测到了荧蒽(FLTs)、 (Chs)和芘(Pys)等多环芳烃，它们通常被认为是高温作用下的产物。

4 结论

(1)中梁山K1a煤样显微煤岩组分以镜质组为主，惰质组较少，未观察到壳质组;煤相参数表明，K1a煤的成煤环境为潮湿的森林沼泽还原环境，成煤植物以木本植物为主。

(2)中梁山K1a煤样的有机质含量较低，饱芳比较低，呈典型的腐植型特征。通过对饱和烃参数研究，正构烷烃主要呈前峰低碳数群分布，主峰碳多为C17或C16，反映出K1a成煤母源有陆相高等植物和海相低等生物输入;煤样热演化成熟度较高，而且伴随细菌的生物降解作用;较小的Pr/Ph表明煤层成煤环境主要为还原环境。与煤显微组分分析结果相互印证。

(3)中梁山K1a煤中芳烃化合物以萘系、菲系和联苯系芳烃为主。有机质经过热演化作用，热力学稳定性较强的芳烃占有优势地位。芳烃中硫芴含量高于氧芴，以及较高含量的苯并萘并噻吩，亦佐证该煤层偏还原的成煤环境。

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