衰减全反射—显微傅立叶变换红外光谱原位分析煤有机显微组分

摘要

Qualitative analysis of band position and quantitative analysis of band strength can provide evidence for the study of chemical composition , structural features and hydrocarbon generation ability of various macerak. In situ attenuated total reflectance-micro-Fourier transform infrared (ATR-FTIR) spectrometry, which could avoid problems caused by physical separation and chemical reagent in traditional single component separation and enrichment process, has been used to characterize coal macerals of three different maturity coal samples from North China Carboniferous system. The results show that; aliphatic and oxygen-containing functional groups decrease but aromatic functional group and aromatization increase from liptinite, vitrinite to inertinite. Aliphatic structure of liptinite is mainly long-chain aliphatic hydrocarbon which is good for oil generation but vitrinite and inertinite is mainly short-chain hydrocarbon which is good for gas generation. For liptinite, the aromatic content of sporophyte is relatively higher which results in poor hydrocarbon generation potential whereas resinite, perib-Hnite and cutinite have relatively better hydrocarbon generation potential. For the same type of maceral, aliphatic functional group decreases but aromatic functional group increases with evolution stages.%不同显微组分的傅立叶变换红外光谱谱带位置的定性分析和谱带强度的定量分析,可揭示其化学组成、结构特点和生烃能力.利用衰减全反射—显微傅立叶变换红外光谱分析技术,对我国华北石炭系3个不同成熟度煤的有机显微组分进行原位分析,避免了传统手段采用单组分分离富集过程中物理分选和化学试剂对显微组分造成的影响.煤有机显微组分红外光谱原位分析结果表明:由壳质组、镜质组到惰质组,其脂肪烃含量和含氧基团呈减少趋势,芳香烃含量和芳构化程度呈增加趋势,反映生油潜力逐渐减小.壳质组脂族结构以长链脂肪烃为主,有利于生油;镜质组和惰质组以短链为主,有利于生气.壳质组中孢子体的芳香烃含量相对较高,生烃潜力较差,树皮体、角质体和树脂体的生烃潜力较好.同一种有机显微组分随演化程度的增高,脂肪族含量降低,芳香烃含量升高.