Succeeded in experiment to dissociate and recover gas from surface methane hydrate at the world's first

Shimizu construction worked with the Russian Academy of Sciences Academy of Land Atmospheric Research, Kitami Institute of Technology and Hokkaido University in an experiment to dissociate and recover gases from methane hydrate trapped in the surface of the lake at the bottom of the lake at a depth of about 400 meters It is said that it succeeded. We have said that we have taken a major first step toward establishing new methane hydrate gas recovery technology.

Methane hydrate attracts attention as a next-generation energy alternative to petroleum, etc. There is abundant abundance of deep methane hydrate in the 100 to 300 meters basement. The main target of Japan's methane hydrate resource development is the enormous methane hydrate in the deep seabed of the eastern Nankai Trough, but with this technology, not only in the deep seas in Japan but also in the Sea of ​​Okhotsk and the Japan Sea This technology will be very effective for the future of Japan as it will also be able to use methane hydrate in the surface layer.

Outline of gas recovery experiment, photographs of the situation of actually collecting etc. are as follows.
Succeeded in gas recovery experiment of methane hydrate at Baikal Lake / News Release 2009 - Shimizu Corporation

What was recovered this time is not deep methane hydrate, but surface methane hydrate. Deep methane hydrate can break down the phase equilibrium state by just slightly changing the temperature and pressure conditions, so it is possible to dissociate and recover the gas using heating and decompression methods, Because surface methane hydrate is in a stable state at low temperature only by the amount close to the bottom of the sea, it is necessary to devise a way to efficiently recover the gas, and the technology for that has been experimented this time.

Outline of gas recovery experiment from methane hydrate

This is a hydrate dissociation chamber equipped with a water jet for digging and stirring. It is a steel-made / brown tubular chamber fitted with 32 water jet nozzles (16 horizontal jets and 16 vertical jets), and the lower part is open. Drilling and stirring the methane hydrate layer at the bottom surface of the lake by water jet, methane hydrate dissolves in water, pumping this dissolved water on the lake, methane hydrate dissolved in water is pumping seawater pressure The gas is separated from the water by the decrease, the separated gas is collected on the lake, and the work is completed.

Methane hydrate contained in the surface core actually sampled at the bottom of Lake Baikal.

As a result of stirring for about 100 minutes, 90% of the recovered gas is a hydrocarbon gas such as methane and ethane, and it seems that the composition and properties of the gas are almost same as the methane hydrate dissociation gas.

It seems that we confirm the topography and ground condition around the site by submersible survey using MIR (Mir) No. 2 manned submersible owned by Russian Academy of Sciences. MIR can have a maximum dive depth of 6000 meters, one operator, and two people to dive.

In this survey, we made a dive of 8 hours, confirmed the topography and ground condition of the site selected for the experiment site, and further installed special equipment for penetration test developed by Shimizu Corporation on the manipulator of the MIR, It is said to have checked the hardness.

Incidentally, this experiment was the first in the world to succeed in disassembling and recovering gas from the surface methane hydrate including the ocean floor or the lake bottom, and this success secures diversified reserve resources for Japanese resource development From the point of view, it has a big meaning.

Is it possible that Japan will become a resource exporting country as it is?

in Note, Posted by darkhorse