MATHEMATICAL MODELING OF STABLE CARBON ISOTOPE RATIOS IN NATURAL GASES
- DSpace Home
- →
- Геология России
- →
- ELibrary
- →
- View Item
JavaScript is disabled for your browser. Some features of this site may not work without it.
dc.contributor.author | Tang Y. | |
dc.contributor.author | Schoell M. | |
dc.contributor.author | Perry J.K. | |
dc.contributor.author | Jenden P.D. | |
dc.date.accessioned | 2021-02-03T02:18:28Z | |
dc.date.available | 2021-02-03T02:18:28Z | |
dc.date.issued | 2000 | |
dc.identifier | https://elibrary.ru/item.asp?id=31885207 | |
dc.identifier.citation | Geochimica et Cosmochimica Acta, 2000, 64, 15, 2673-2687 | |
dc.identifier.issn | 0016-7037 | |
dc.identifier.uri | https://repository.geologyscience.ru/handle/123456789/24451 | |
dc.description.abstract | A new approach is presented for mathematical modeling of stable carbon isotope ratios in hydrocarbon gases based on both theoretical and experimental data. The kinetic model uses a set of parallel first-order gas generation reactions in which the relative cracking rates of isotopically substituted (k∗) and unsubstituted (k) bonds are represented by the equation where R is the gas constant and T is temperature. Quantum chemistry calculations have been used to estimate the entropic (Af*/Af) and enthalpic (ΔEa) terms for homolytic bond cleavage in a variety of simple molecules. For loss of a methyl group from a short-chain n-alkane (≤ C6), for example, we obtain an average ΔEa of 42.0 cal/mol and an average Af*/Af of 1.021. Expressed differently, ¹³C-methane generation is predicted to be 2.4% (24‰) slower than ¹²C-methane generation (from a short-chain n-alkane) in a sedimentary basin at 200°C but only 0.7% (7‰) slower in a laboratory heating experiment at 500°C. Similar calculations carried out for homolytic bond cleavage in other molecules show that with few exceptions, ΔEa varies between 0 and 60 cal/mol and Af*/Af between 1.00 and 1.04. Examination of this larger data set reveals: (1) a weak sigmoid relationship between ΔEa and bond dissociation energy; and (2) a strong positive correlation between ΔEa and Af*/Af. | |
dc.title | MATHEMATICAL MODELING OF STABLE CARBON ISOTOPE RATIOS IN NATURAL GASES | |
dc.type | Статья |
Files in this item
Files | Size | Format | View |
---|---|---|---|
There are no files associated with this item. |
This item appears in the following Collection(s)
-
ELibrary
Метаданные публикаций с сайта https://www.elibrary.ru