The structural evolution of organic matter during maturation of coals and its impact on petroleum potential and feedstock for the deep biosphere |
| |
| Institution: | 1. Helmholtz Centre Potsdam, GFZ German Research Centre for Geosciences, Telegrafenberg, 14473 Potsdam, Germany;2. Forschungszentrum Jülich, Germany;3. ExxonMobil Research and Engineering Co., Annandale, NJ 08801, United States;4. GNS Science, PO Box 30368, Lower Hutt 5040, New Zealand;1. Department of Earth and Planetary Sciences, Macquarie University, Sydney, NSW 2109, Australia;2. Geoscience Australia, GPO Box 378, Canberra, ACT 2601, Australia;3. CSIRO, PO Box 136, North Ryde, NSW 1670, Australia;4. Helmholtz Centre Potsdam, GFZ – German Research Centre for Geosciences, Germany;1. YPF TECNOLOGÍA S. A., Av. Del Petroleo s/n – (Entre 129 y 143) Berisso, Buenos Aires 1925, Argentina;1. College of Geoscience and Surveying Engineering, China University of Mining and Technology, Beijing 100083, China;2. State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Beijing 100083, China;3. German Research Centre for Geosciences, Potsdam 14473, Germany;1. Linnæus University, Department of Biology and Environmental Science, 39182 Kalmar, Sweden;2. University of Southern Denmark, Department of Biology and Nordic Center for Earth Evolution, Campusvej 55, Odense M, DK-5230, Denmark |
| |
| Abstract: | The structural evolution of coals during coalification from peat to the end of the high volatile bituminous coal rank (VRr = 0.22–0.81%) has been studied using a natural maturity series from New Zealand. Samples were studied using a range of standard coal analyses, Rock–Eval analysis, infrared spectroscopy (IR), X-ray photoelectron spectroscopy (XPS), and pyrolysis gas chromatography (Py-GC). The structural evolution of coal during diagenesis and moderate catagenesis is dominated by defunctionalisation reactions leading to the release of significant amounts of oxygen and thereby to an enrichment of aromatic as well as aliphatic structures within the residual organic matter. Based on the evolution of pyrolysis yields and elemental compositions with maturity it can be demonstrated that oxygen loss is the major cause for increasing Hydrogen Index values or hydrocarbon generating potentials of coals at such maturity levels. For the first time, the loss of oxygen in form of CO2 has been quantified. During maturation from peat to high volatile bituminous coal ranks ～10–105 mg CO2/g TOC has been released. This is equivalent to 2.50E?4 to 1.25E?3 mg CO2 generated from every litre of sediment per year falling into the range of deep biosphere utilisation rates. Immature coals, here New Zealand coals, therefore manifest the potential to feed deep terrestrial microbial life, in contrast to more mature coals (VRr > ～0.81%) for which defunctionalisation processes become less important. |
| |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
