To investigate the structural features and provide an alternative method for high value-added utilization of coal, Lingwu coal was first extracted with organic solvent at room temperature. Then its extraction residue was oxidized in aqueous sodium hypochlorite(ASHC) under mild conditions. The effects of oxidation conditions, such as temperature, reaction time, the ratio of Lingwu coal extraction residue(LCER, g) to ASHC(m L) and p H value, on the product distributions and compositions were investigated. The results of gas chromatography/mass spectrometry(GC/MS) suggested that 53 kinds of methyl esterified products were detected in total, and benzene carboxylic acids were the main oxidation products, while chloro-substituted benzene carboxylic acids were the main by-products. Higher yield and fewer kinds of organic acids could be obtained at lower p H value, especially for the main objective product, benzene carboxylic acids.
分别以CS2和甲醇为溶剂，辅以超声波对先锋褐煤进行常温萃取，利用傅里叶变换红外光谱（FTIR）和气相色谱/质谱（GC/M S ）分析萃取物的组成及结构。结果表明，两种萃取物中共检测到124种有机化合物；CS2萃取物中烃类化合物相对含量较高，占CS2萃取物总量的52．08％，从C14～C30（除C23外）烷连续分布；甲醇萃取物中含氧和含氮化合物相对含量较高，分别占甲醇萃取物总量的39．28％和20．95％；此外还检测到多种生物标示物。
依次采用石油醚、环己烷、二硫化碳、丙酮、甲醇和等体积的丙酮/二硫化碳混合溶剂对白音华褐煤(BL)进行分级萃取得到萃取物(E_1-E_6),利用甲醇、甲苯和等体积的甲醇/甲苯混合溶剂对萃取残渣进行连续热溶得到热溶物(SP_1-SP_3)。利用傅里叶变换红外光谱(FT-IR)、气相色谱质谱(GC/MS)和实时直接分析-质谱(DART-MS)对萃取物和热溶物的组成和结构特征进行了分析。BL总的萃取物产率和热溶物产率分别为9.37%和21.84%。E_5和E_6的FT-IR谱图中有较强的羟基吸收峰,而E_1的FT-IR谱图中脂肪C-H的伸缩振动峰强度明显高于其他萃取物;三种溶剂热溶物的FT-IR谱图相似,但SP_1和SP_3的FT-IR谱图中羟基吸收峰较强。E_1和E_5中GC/MS可检测化合物分别以烷烃和芳烃为主,E_5中还含有较多的含氧化合物;三种热溶物中化合物均以烷烃和芳烃为主,SP_3中酚类、酮类和酯类等含氧化合物的含量较高。DART-MS可检测出萃取物和热溶物中GC/MS无法检测出的较强极性和难挥发化合物;热溶物中含量较高的化合物的碳数和等价双键数(Double bond equivalent,DBE)分别集中分布在10-25和2-16,并且DBE随碳数增加而增加。
