Comment on The kinetics of sterane biological marker release and degradation processes during the hydrous pyrolysis of vitrinite kerogen' by G. D. Abbott, G. Y. Wang, T. I. Eglinton, A. K. Home, and G. S. Petch

Journal Article · Wed Jan 01 00:00:00 EST 1992 · Geochimica et Cosmochimica Acta; (United States)

DOI:https://doi.org/10.1016/0016-7037(92)90149-D· OSTI ID:5097108

Marzi, R ^[1]

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1. Centre for Petroleum and Environmental Organic Geochemistry, Perth (Australia)

In order to further develop understanding of the observable changes in sterane isomer ratios, Abbott et al. (1990) conducted a series of hydrous pyrolysis experiments on mineral-free vitrinite kerogen. Using a deuterated model compound, they found that direct chiral isomerization appears to be relatively unimportant. They derived a kinetic model comprising consecutive release and degradation processes for both isomers and, using a bi-exponential concentration-time function, they were able to determine Arrhenius parameters for four individual reactions. Abbott et al. (1990) claimed that these four reactions account for the change in sterane diastereomer ratios in hydrous pyrolysis experiments. Since it has been observed by a number of people that the so-called steraine isomerization is not a unidirectional reaction, an alternative reaction scheme would be most welcome. Although Abbott and coworkers do not claim that the published kinetic data hold true in the natural environments, the question arises as to whether the kinetic data obtained from these hydrous pyrolysis experiments are applicable to sedimentary processes which occur over geological time.

• OSTI ID: 5097108
• Journal Information: Geochimica et Cosmochimica Acta; (United States), Vol. 56:1; ISSN 0016-7037
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
58 GEOSCIENCES
BIOLOGICAL MARKERS
DECOMPOSITION
KEROGEN
PYROLYSIS
ACTIVATION ENERGY
ALKANES
CHEMICAL REACTION KINETICS
GEOLOGIC FORMATIONS
ISOMERIZATION
MATHEMATICAL MODELS
VITRINITE
BITUMINOUS MATERIALS
CARBONACEOUS MATERIALS
CHEMICAL REACTIONS
ENERGY
HYDROCARBONS
KINETICS
MACERALS
MATERIALS
MATTER
ORGANIC COMPOUNDS
ORGANIC MATTER
REACTION KINETICS
THERMOCHEMICAL PROCESSES
020200* - Petroleum- Reserves
Geology
& Exploration
580000 - Geosciences