Nov 25, 2012
Interesting, thanks for adding! How is it geoengineering? Sounds like fuel extraction.
Nov 25, 2012
It's geoengineering as the methane in the deep water may be headed to the surface if no intervention is applied. By recovering the methane from the reservoir/source strata, emissions to atmosphere are prevented.
Dec 1, 2012
Thank you for the proposal. 1) Does this proposed approach seek to capture methane bubbles after they have already been formed in water that is supersaturated with methane? Or does it also seek to raise deeper subsaturated water to intermediate depths where it becomes supersaturated, leading to bubble formation? 2) Can you please clarify how the flow in such pipes would be self-sustained? 3) Does potential exist for flexibility in timing and location of situating pipes for bubble capture -- and how can monitoring play a role?
Dec 2, 2012
The bubbles are induced by lifting the water. The presence of bubble reduces density and causes a self-sustaining flow. Plant can be moved when methane is exhausted. Please note that this process is already employed to remove CO2 from Lake Nyos. As such it is simply a matter of site survey and equipment adaptation to treat methane.
May 3, 2013
So, why would this not work if applied to clathrates in the ocean sediments? Could one not cover an area with plastic to channel the emissions to a central point and then, presumably, use this approach? Would this not be much less expensive than extracting the clathrates. Is there any estimate of how much methane (absolute amount, and fraction) is being released from such lakes, etc.? How big an issue is this?
May 3, 2013
If there was a supersaturated methane stratum in the water column caused by clathrates, it could removed the methane from that stratum. However, as it's not acting to adjust the general water pressure, it doesn't serve to depressurize and thus decompose the clathrates. It's unclear whether, and how much methane is being released in this way. It's only likely to be the case in deep lakes which are poorly mixed. You'd need to do a detailed survey, possibly including some measurements, to establish which lakes are likely to be responsible for methane flux. However, the ability to generate significant amounts of energy is a big plus for this technique, so the costs can be offset by gas recovery - as in the cited KivuWatt scheme.
Jul 10, 2013
Thank you for sharing your ideas and for the work invested to create this proposal. Your proposal has been considered carefully by the judges, and while the proposal has interesting ideas, and we appreciate the response to questions that were raised, it is unclear how much methane is released in this way and what part of it the scheme would address and whether this could make a significant difference.