In situ diamond-anvil cell observations of methanogenesis have provided significant insights into the behavior of methane under high pressures and temperatures. The outcomes of these studies include:
Sensitivity to C−H−O Fluid Composition: Methanogenesis is sensitive to the activity of H2 in C−H−O fluid composition, with kinetic barriers to direct hydrogenation of CO observed. This was noted in a study published in Energy & Fuels [1].
Direct Reduction of CO2 to Methane: The direct reduction of CO2 to methane was not observed under any set of conditions in the experiments conducted, as reported in a study on ResearchGate [2].
Phases and Pressure–Temperature Relationship: The phases and pressure–temperature (P–T) relationship of the CH4–H2O binary system were observed in situ using a diamond anvil cell (DAC) and Raman spectroscopy, as detailed in a ScienceDirect publication [3].
Generation of H2: Another study demonstrated the generation of H2 during experiments using various metal gaskets in a hydrothermal diamond-anvil cell, as mentioned in a ScienceDirect article [4].
Identification of a New Methane Hydrate Phase: A new high-pressure phase of methane hydrate was identified based on its distinct pressure-temperature phase relations, as described in a USGS publication [5].
These findings contribute to our understanding of the conditions under which methanogenesis occurs and the behavior of methane and related compounds at high pressures and temperatures. They also have implications for geological processes and the potential for methane hydrate as an energy resource.