Chinese Science Bulletin

, Volume 49, Supplement 1, pp 79–83 | Cite as

Thermal cracking ofn-octodecane and its geochemical significance

  • Yongqiang Xiong
  • Haizhu Zhang
  • Xinhua Geng
  • Ansong Geng


The mechanism of carbon isotopic fractionation for gaseous hydrocarbons is revealed by investigating the residual liquid hydrocarbons in laboratory pyrolysates of n-octodecane. The results indicate that cracking and polymerization in the relatively low temperatures and disproportionation reactions leading to light hydrocarbons and polyaromatic hydrocarbons at high temperatures are probably causes for the carbon isotope reversal of gaseous hydrocarbons that is commonly observed in pyrolysis experiments. This study provides significant insight for quantitative modeling of natural gas δ13C values and aid in the identification and assessment of natural gases derived from oil cracking.


n-octodecane pyrolydsis experiment stable carbon isotope gaseous hydrocarbons residual liquid hydrocarbons 


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Copyright information

© Science in China Press 2004

Authors and Affiliations

  • Yongqiang Xiong
    • 1
  • Haizhu Zhang
    • 1
  • Xinhua Geng
    • 1
  • Ansong Geng
    • 1
  1. 1.State Key Laboratory of Organic Geochemistry, Guangzhou Institute of GeochemistryChinese Academy of SciencesGuangzhouChina

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