PETR 101 |
| Abiotic synthesis of organic compounds from the reduction of CO2 has been proposed as a source of organic compounds that can enable biology under deep subsurface extremes. A number of geochemical observations point towards the likely presence of abiotic hydrocarbons in a variety of geologic environments, including gases from serpentinites and hydrothermal vents on the ocean floor. However, experimental demonstration has been difficult and is limited to very shallow (low pressure) conditions and to trace fractions due to thermodynamic barriers. However, such energy barriers for organic synthesis are predictably reduced at deep subsurface conditions, such that the C-H-O volatile reservoir in the deep subsurface (lower crust and upper mantle) can significantly contribute to the overall hydrocarbon resource generation. Although theoretically predicted, due to the lack of clear constraints on the actual reaction pathways, an experimental confirmation of even the most basic hydrocarbon (methane) in deep geological setting has not been convincingly demonstrated. It is not surprising, therefore, that contributions from greater depths have largely been ignored in most energy resource models. In this presentation the author will not only present new experimental results on the feasibility of organic synthesis, but also show viability of microbial utilization (and generating?) of such energy resources under extreme conditions. Optical microscopy and spectroscopy of organic synthesis reactions and biological activity within diamond anvil cells have enabled direct observations of these processes at high pressures and temperatures. These results not only expand our view of the habitable zone but also make the dynamics of deep-earth hydrocarbon synthesis relevant to the overall carbon (energy) cycle model. |
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Symposium on Clean Fuels from Biomass
1:30 PM-5:15 PM, Tuesday, 12 September 2006 Palace -- Twin Peaks North, Oral
Division of Petroleum Chemistry |