热解和生物降解对木本泥炭生烃与结构演化的红外光谱响应  

Infrared Spectrum Studies of Hydrocarbon Generation and Structure Evolution of Peat Samples During Pyrolysis and Microbial Degradation

作　　者：鲍园[1,2] 琚宜文[1] 韦重韬[2] 王超勇[2] 李小诗[1] 

机构地区：[1]中国科学院计算地球动力学重点实验室中国科学院大学地球科学学院,北京100049 [2]煤层气资源与成藏过程教育部重点实验室中国矿业大学资源与地球科学学院,江苏徐州221008

出　　处：《光谱学与光谱分析》2015年第3期603-608,共6页Spectroscopy and Spectral Analysis

基　　金：博士后科学基金项目(2014M550809);国家自然科学基金项目(41372213);国家科技重大专项项目(2011ZX05034-005;2011ZX05060-005)资助

摘　　要：傅里叶变换红外光谱分析物质分子结构具有独特的优势。为认识成煤有机质在微生物降解和热解阶段的生烃演化特征及物质结构变化特征，采用密封体系生烃热解和厌氧微生物降解岩样生烃物理模拟实验及傅里叶变换红外光谱分析等技术手段，研究了成煤母质（木本泥炭）的生烃演化特征（包括热解作用生成热成因气和微生物降解作用生成生物成因气的生烃潜力）及发生微生物降解和热解作用前后样品的分子结构变化特征及其机理。结果表明随模拟温度的升高，热解气烃类气体（主要为 CH4）累计产率逐渐增加，非烃类气体（如 CO2）分别在250和375℃出现两个产气高峰；随煤岩镜质组反射率的升高，微生物对其降解能力逐渐减弱；镜质组反射率介于1．6％～1．8％的泥炭热解样没有气体产出；泥炭经热解作用后，羟基含量随热解温度的升高先减少后增多，醛羰基、亚甲基和磷酸根的含量降低，芳香酸酯呈不单一减少趋势，伸缩振动 S—O 键在350℃之后的样品中出现且含量逐渐增加，说明其对微生物降解具抑制作用；泥炭经微生物降解作用后，酚、醇羟基、醛羰基、芳香酸酯、亚甲基和磷酸根的相对含量都大幅下降，且这些基团的分子间作用力相对减弱。Hydrocarbon generation and structural evolution would be occurred in the process of from coal-forming material （i.e. peat sample）transforming to the coal.While Fourier Transform Infrared Spectroscopy （FTIR）have a special advantages in ana-lyzing molecular structure of samples.For understanding the characteristics of hydrocarbon generation and structural evolution of coal-forming material during the process of pyrolysis and microbial degradation,based on the physical simulation experiments of closed pyrolysis and anaerobic microbial degradation,the generation potential of thermogenic gas and biogenic gas were studied in this paper,and characteristics of molecular structure evolution and its mechanism was analyzed by FTIR technology.Results show that cumulative gas yields of hydrocarbon gases （mainly for methane）increased with experiment temperature.The gas yield of non-hydrocarbon gas （mainly for CO2 ）exhibited two peaks at 250 and 375 ℃.The degradation ability of anaerobe on coal samples weakened with the maturity increasing and there was no gas generation on the pyrolysis samples with maturity from 1.6% to 1.8%.After pyrolysis,the content of hydroxyl in peat sample decreased first and then increased with the pyrolysis temperature increasing.The content of aldehyde carbonyl,methylene and phosphate reduced.The content of aromatic esters de-creased with nonlinear.The bone of S-O in stretching vibration appeared after 350 oC and its content increased with tempera-ture.This shows that the sulfocompound restrains the activity of methanogenic bacteria.After degradation by anaerobe,the rel-ative content of hydroxyl,aldehyde carbonyl,aromatic esters,methylene and phosphate in peat sample dropped significantly.It is shown that the intermolecular force between these groups weakened.

关 键 词：木本泥炭 热解作用 生物降解作用 分子结构 红外光谱 

分 类 号：P511.5[天文地球—地质学]