Position-specific carbon isotopic composition of thermogenic propane: Insights from pyrolysis experiments

Zhang, Lin; Li, Yun; Jiang, Wenmin; Xiong, Yongqiang

doi:10.1016/j.orggeochem.2022.104379

Cited by 19 publications

(4 citation statements)

References 52 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In their model, the carbon isotope fractionation factors were calculated based on an isotope mass balance of the pyrolysis fragments. However, the assumptions in their model were not tested or validated, therefore accuracy has not been demonstrated for the PS δ 13 C values of propane reported from these two groups 4,10,11,25 …”

Section: Discussionmentioning

confidence: 99%

“…However, the assumptions in their model were not tested or validated, therefore accuracy has not been demonstrated for the PS δ 13 C values of propane reported from these two groups. 4,10,11,25 were selected after rigorous tests using a mixture gas of C 1 -C 3 (70% C 1 , 7% C 2 , 3% C 3 , and 20% He) (NWU) and pure C 3 (TTU 24 ), respectively. The conditions of the two systems (Table 1) show that the difference in the He flow rate (1.2 vs. 2.5 ml/min) is the main cause for the difference in the optimum temperatures of the two systems.…”

Section: Isotope Fractionation Of Terminal and Central Carbons Of Pro...mentioning

confidence: 99%

“…Although PS isotope geochemistry of propane is still in its early stage, many studies have proven that intramolecular distributions of carbon and hydrogen isotopes within propane molecules can provide valuable information on origin and history of natural gases. 4,[7][8][9][10] So far, several methods have been developed to measure PS isotope composition of propane, e.g., gas chromatography-pyrolysis-gas chromatography-isotope ratio mass spectrometry (GC-Py-GC-IRMS), 11 isotopic nuclear magnetic resonance (NMR), 12 high-resolution IRMS, 13,14 and enzymatic and chemical degradation. 15 Each method has its advantages and weaknesses.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Establishing the accuracy of position‐specific carbon isotope analysis of propane by GC‐pyrolysis‐GC‐IRMS

Liu

liu

et al. 2023

Rapid Comm Mass Spectrometry

View full text Add to dashboard Cite

Position-specific (PS) δ 13 C values of propane have proven their ability to provide valuable information on the evolution history of natural gases. Two major approaches to measure PS δ 13 C values of propane are isotopic 13 C nuclear magnetic resonance (NMR) and gas chromatography-pyrolysis-gas chromatography-isotope ratio mass spectrometry (GC-Py-GC-IRMS). Measurement accuracy of the isotopic 13 C NMR has been verified, but the requirements of large sample size and long experimental time limit its applications. GC-Py-GC-IRMS is a more versatile method with a small sample size, but its accuracy has not been demonstrated. Methods:We measured the PS δ 13 C values of propane from nine natural gases using both 13 C NMR and GC-Py-GC-IRMS, then evaluated the accuracy of the GC-Py-GC-IRMS method. Results:The results show that large carbon isotope fractionations occurred for both terminal and central carbons within propane during pyrolysis. The isotope fractionations during the pyrolysis are reproducible at optimum conditions, but vary between the two GC-Py-GC-IRMS systems tested, affected by experimental conditions (e.g., pyrolysis temperature, flow rate, and reactor conditions).Conclusions: It is necessary to evaluate and calibrate each GC-Py-GC-IRMS system using propane gases with accurately determined PS δ 13 C values. This study also highlights a need for PS isotope standards for propane and other molecules (e.g., butane and acetic acid).

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Isotope Fractionation Of Terminal and Central Carbons Of Pro...mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Establishing the accuracy of position‐specific carbon isotope analysis of propane by GC‐pyrolysis‐GC‐IRMS

Liu

liu

et al. 2023

Rapid Comm Mass Spectrometry

View full text Add to dashboard Cite

show abstract

“…The central and terminal carbon atoms carry isotopic signatures from precursors, and also could undergo different bond-cleavage pathways. [8][9][10] For instance, the difference on isotopic signatures between central and terminal carbon positions of propane could indicate the temperature of a basin or the extent of thermal cracking. [11][12][13] For these reasons, development of position-specific isotope analysis (PSIA) measurements allows to track isotopic compositions at different molecular positions, and thus providing new evidence to investigate propane's origin, fate, and mechanisms of formation.…”

Section: Introductionmentioning

confidence: 99%

Modeling position specific carbon isotopologue fractionation of thermogenic propane and precursors

Jin,

Peng

2024

TIG

View full text Add to dashboard Cite

<p>Position specific isotope analysis (PSIA) of thermogenic propane allows to track carbon isotopic compositions at different molecular positions, and thus providing new evidence to investigate propane��s origin, fate, and mechanisms of formation. However, the link between observed ��<sup>13</sup>C PSIA signals of propane and carbon isotopologue signatures of precursors in source organics still remains unclear, and understanding the underlying mechanisms requires a more sophisticated model. Here we developed a mathematical framework to simulate position specific carbon isotopologues of propane and its precursors based on mechanistic understanding of thermogenic propane��s bond-cleavage pathways. Besides, our model also allows integrating multiple signals including temperature, and isotopic characteristics of source compounds. Our model is validated by precisely reproducing propane��s experimental PSIA data obtained during cracking of different kerogens, and also correctly quantified the initial carbon isotopic signatures and the initial fraction of the different precursors in the source materials. Our model allows to include more complex reaction mechanisms to elucidate unknown reaction pathways, and could also guide and optimize future experimental studies to test different hypothesis.</p>

show abstract

Position-specific and clumped isotope equilibria in propane: Ab initio calculations beyond the harmonic and Born-Oppenheimer approximations

Yin,

Zhang,

Liu

et al. 2024

Chemical Geology

View full text Add to dashboard Cite

Position-specific carbon isotopic composition of thermogenic propane: Insights from pyrolysis experiments

Cited by 19 publications

References 52 publications

Establishing the accuracy of position‐specific carbon isotope analysis of propane by GC‐pyrolysis‐GC‐IRMS

Establishing the accuracy of position‐specific carbon isotope analysis of propane by GC‐pyrolysis‐GC‐IRMS

Modeling position specific carbon isotopologue fractionation of thermogenic propane and precursors

Position-specific and clumped isotope equilibria in propane: Ab initio calculations beyond the harmonic and Born-Oppenheimer approximations

Contact Info

Product

Resources

About