Methane hydrates from deep sea sediments could be used to provide clean energy in the next decade. Huen Lee and colleagues, Graduate School of Energy, Environment, Water, and Sustainability, Korea, extracted CH₄ out of natural gas hydrate (NGH) and fixed CO₂ and N₂ in the NGH at the same time by using a swapping mechanism.

They found that the clay portion of underwater sediments contains significant amount of intercalated methane hydrates. By testing a mixture of CO₂/N₂ against pure CO₂ in a high-pressure reactor they could achieve better recovery results of CH₄ with the mixed gas. The team reports that 85 % of the CH₄ fixed in the sediments could be recovered by the use of CO₂/N₂.

However, further research is needed in order to make this process suitable for industrial use. Safety questions have to be answered in order to avoid the diffusion of CO₂, N₂ and CH₄ into the atmosphere.

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• Recovery of Methane from Gas Hydrates Intercalated within Natural Sediments Using CO₂ and a CO₂/N₂ Gas Mixture,
  Doing-Yeun Koh, Hyery Kang, Dae-Ok Kim, Juwoon Park, Minjun Cha, Huen Lee,
  ChemSusChem 2012, 5 (7).
  DOI: 10.1002/cssc.201100644