Influencing factors of hydrogen isotopic fractionation of light hydrocarbons during evaporation and implications
文献类型：期刊论文
| 作者 | Liu, Wenna1,2,3; Jia, Wanglu1,2; Wang, Qiang1,2; Chen, Jian1,2; Li, Jinbu1,2; Peng, Ping'an1,2,3 |
| 刊名 | ORGANIC GEOCHEMISTRY
 |
| 出版日期 | 2024-12-01 |
| 卷号 | 198页码:14 |
| 关键词 | Light hydrocarbons Evaporation Hydrogen isotopes Inverse isotope fractionation Carbon isotopes Normal isotope fractionation |
| ISSN号 | 0146-6380 |
| DOI | 10.1016/j.orggeochem.2024.104894 |
| 英文摘要 | The isotopic fractionation of organic compounds during evaporation is one of the most critical issues in the field of stable isotopes. The hydrogen (H) isotopic compositions of light hydrocarbons (LHs) in oil have gained increasing interest in the research of oil genesis in recent years. However, compared to carbon (C) isotopes, our understanding of H isotopic fractionation patterns and influences for various types of LHs during evaporation is limited. In this study, we performed evaporation experiments at a constant temperature on LHs in three systems: single compound, alkane mixture, and light oil. We assessed the contents and H isotopic compositions of individual LHs in the residual liquid phase. The degree of H isotopic fractionation and influencing factors are studied combined with C isotopes. The H isotopic fractionation of LHs exhibits "inverse isotope fractionation" characteristics (a depletion in D in the residual LHs) with progressive evaporation, which is opposite to the C isotopic fractionation. The degree of isotopic fractionation is influenced by the evaporation system, the compounds' molecular weight, and their structure. (1) The isotopic fractionation degree of H and C decreases in the following order: light oil > alkane mixture > single compound system. This difference may be related to the unsaturation level of the evaporative system and the evaporation matrix. (2) For LHs with the similar structure in the same evaporation system, the degree of H isotopic fractionation increases with increasing molecular weight due to the buffering effect of the sample pool, while the magnitude of C isotopic fractionation decreases. (3) For LHs with the same C number, methylcyclohexane (MCH) has a lower evaporation rate and less isotopic fractionation than the other C7 compounds like 3-methylhexane (3-MH), n-heptane (nC(7)), and toluene (Tol). The distinctive fractionation characteristics of H isotopes make them very useful in geological applications. Combining H and C isotopic compositions of the same compound with the commonly used molecular ratios of LHs (e.g., nC7/MCH, Tol/nC(7)) enables full differentiation of three critical processes controlling oil formation: evaporation, thermal maturation, and biodegradation. Furthermore, the differences in H isotopic compositions between C7 LHs (3-MH, nC7, and Tol) may be changed by evaporation, but the variation range is much smaller than that caused by source differences. Therefore, combining H and C isotopes may have great potential for oil source characterizations. |
| WOS研究方向 | Geochemistry & Geophysics |
| 语种 | 英语 |
| WOS记录号 | WOS:001351412100001 |
| 源URL | [http://ir.gig.ac.cn/handle/344008/82103]  |
| 专题 | 有机地球化学国家重点实验室 |
| 通讯作者 | Jia, Wanglu |
| 作者单位 | 1.Chinese Acad Sci, Guangzhou Inst Geochem, State Key Lab Organ Geochem, Guangzhou 510640, Peoples R China 2.Chinese Acad Sci, Ctr Excellence & Innovat Deep Earth Sci, Guangzhou 510640, Peoples R China 3.Univ Chinese Acad Sci, Beijing 100049, Peoples R China |
| 推荐引用方式 GB/T 7714 | Liu, Wenna,Jia, Wanglu,Wang, Qiang,et al. Influencing factors of hydrogen isotopic fractionation of light hydrocarbons during evaporation and implications[J]. ORGANIC GEOCHEMISTRY,2024,198:14. |
| APA | Liu, Wenna,Jia, Wanglu,Wang, Qiang,Chen, Jian,Li, Jinbu,&Peng, Ping'an.(2024).Influencing factors of hydrogen isotopic fractionation of light hydrocarbons during evaporation and implications.ORGANIC GEOCHEMISTRY,198,14. |
| MLA | Liu, Wenna,et al."Influencing factors of hydrogen isotopic fractionation of light hydrocarbons during evaporation and implications".ORGANIC GEOCHEMISTRY 198(2024):14. |
入库方式： OAI收割
来源：广州地球化学研究所
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