1. In-situ abiogenic methane synthesis from diamond and graphite under geologically relevant conditions
- Author
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Philip Dalladay-Simpson, Eugene Gregoryanz, Mengnan Wang, Mary-Ellen Donnelly, Ross T. Howie, Miriam Peña-Alvarez, Alberto Vitale Brovarone, SUPA, Centre for Science at Extreme Conditions and School of Physics and Astronomy, University of Edinburgh, Alma Mater Studiorum Università di Bologna [Bologna] (UNIBO), Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Muséum national d'Histoire naturelle (MNHN)-Institut de recherche pour le développement [IRD] : UR206-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Center for High Pressure Science & Technology Advanced Research (HPSTAR), Pena-Alvarez M., Vitale Brovarone A., Donnelly M.-E., Wang M., Dalladay-Simpson P., Howie R., and Gregoryanz E.
- Subjects
Materials science ,Hydrogen ,Science ,General Physics and Astronomy ,chemistry.chemical_element ,engineering.material ,010502 geochemistry & geophysics ,01 natural sciences ,7. Clean energy ,Article ,General Biochemistry, Genetics and Molecular Biology ,Diamond anvil cell ,Methane ,03 medical and health sciences ,chemistry.chemical_compound ,[SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry ,Graphite ,030304 developmental biology ,0105 earth and related environmental sciences ,chemistry.chemical_classification ,0303 health sciences ,Multidisciplinary ,Diamond ,General Chemistry ,Mineralogy ,Abiogenic petroleum origin ,Hydrocarbon ,Geochemistry ,chemistry ,Chemical engineering ,13. Climate action ,engineering ,abiotic CH4 ,Carbon ,[SDU.STU.MI]Sciences of the Universe [physics]/Earth Sciences/Mineralogy - Abstract
Diamond and graphite are fundamental sources of carbon in the upper mantle, and their reactivity with H2-rich fluids present at these depths may represent the key to unravelling deep abiotic hydrocarbon formation. We demonstrate an unexpected high reactivity between carbons’ most common allotropes, diamond and graphite, with hydrogen at conditions comparable with those in the Earth’s upper mantle along subduction zone thermal gradients. Between 0.5-3 GPa and at temperatures as low as 300 °C, carbon reacts readily with H2 yielding methane (CH4), whilst at higher temperatures (500 °C and above), additional light hydrocarbons such as ethane (C2H6) emerge. These results suggest that the interaction between deep H2-rich fluids and reduced carbon minerals may be an efficient mechanism for producing abiotic hydrocarbons at the upper mantle., Using diamond anvil cell and high temperature experiments, this work proves that the interaction between deep hydrogen rich fluids and reduced carbon minerals may be an efficient mechanism for producing abiotic hydrocarbons at the upper mantle’s pressures and temperatures.
- Published
- 2021
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