A Comparison Study on the δD Value of Polycyclic Aromatic Hydrocarbons in Hydrous Pyrolysate of Herbaceous Peat with Different Water Medium  

作　　者：DUAN Yi WU Yingzhong XING Lantian WU Yingqin ZHAO Yang LI Zhongping MA Lanhua DUAN Mingchen 

机构地区：[1]Northwest Institute of Eco-Environment and Resources,Chinese Academy of Sciences and Gansu Provincial Key Laboratory of Petroleum Resources,Lanzhou 730000,China [2]Shaanxi Center of Mineral Geological Survey,Xi'an 710068,China [3]College of Petroleum Engineering,Liaoning Shihua University,Fushun,Liaoning 113001,China [4]Earthquake Research Institute of Lanzhou,SSB,Lanzhou 730000,China [5]Business School,Gansu University of Political Science and Law,Lanzhou 730070,China

出　　处：《Acta Geologica Sinica(English Edition)》2023年第6期1734-1743,共10页地质学报（英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant Nos.41972110 and 41772108)。

摘　　要：To investigate the influence of diagenetic water media on the hydrogen isotopes of individual sedimentary aromatic compounds,a series of hydrous pyrolyses were conducted on herbaceous peat.Polycyclic aromatic hydrocarbons(PAHs)in hydrous pyrolysed samples and their hydrogen isotopic composition characteristics were studied.The aqueous medium demonstrated a significant influence on the hydrogen isotopic composition of the individual PAHs generated during pyrolysis.The results showed that the PAHs formed after pyrolysis in the presence of a saltwater medium with high δD value from a salt lake had a heavy hydrogen isotopic composition.The PAHs formed after pyrolysis in the presence of a fresh water medium with low δD value from a swamp had a light hydrogen isotopic composition.The difference in the average PAHδD value between the two hydrous experiments varied from -174‰ to -109‰,suggesting that the hydrogen isotopic composition of individual sedimentary PAHs can reflect the source of the diagenetic water medium.In addition,a comparative study found that the hydrogen isotopes of PAHs were superior to those of n-alkanes in the same sample for diagenetic water indications.The results indicated that the exchange of water-derived inorganic hydrogen and organic hydrogen was more intensive in freshwater experiments than in saltwater experiments.With an increase in the simulation temperature,the average δD value of PAHs generated in the hydrous simulation experiments showed an increasing trend,reflecting that the δD value of sedimentary PAHs formed with the participation of diagenetic water media was still closely related to the thermal maturity of organic matter.Comparative studies showed that theδD values of different types of organic compounds produced by hydrous pyrolysis of peat were in the order,PAHs>n-alkanes>methane.

关 键 词：hydrogen isotope PAHS hydrous pyrolysis herbaceous peat water medium 

分 类 号：P593[天文地球—地球化学] P618.13[天文地球—地质学]