Researchers at the KAIST Graduate School of EEWS (Earth, Environment, Water and Sustainability) in South Korea have demonstrated the direct recovery of methane from massive methane hydrates (MHs), artificial MH-bearing clays, and natural MH-bearing sediments using either CO2 or a CO2/N2 gas mixture (20 mol % of CO2 and 80 mol % of N2, reproducing flue gas from a power plant) for methane replacement in complex marine systems.
A paper on their work is published in the journal ChemSusChem. The results, the team suggests, can provide an essential physicochemical background required for large-scale natural gas hydrates NGH production under the seabed.
Natural gas hydrates (NGHs) can be converted into CO2 hydrate by a swapping mechanism. The overall process serves a dual purpose: it is a means of sustainable energy-source exploitation and greenhouse-gas sequestration. In particular, scant attention has been paid to the natural sediment clay portion in deep-sea gas hydrates, which is capable of storing a tremendous amount of NGH. The clay interlayer provides a unique chemical–physical environment for gas hydrates. Herein, for the first time, we pull out methane from intercalated methane hydrates in a clay interlayer using CO2 and a CO2/N2 gas mixture.
Koh, D.-Y., Kang, H., Kim, D.-O., Park, J., Cha, M. and Lee, H. (2012), Recovery of Methane from Gas Hydrates Intercalated within Natural Sediments Using CO2 and a CO2/N2 Gas Mixture. ChemSusChem. doi: 10.1002/cssc.201100644