Flammable ice is also known as: methane ice, methane hydrate, methane clathrates.
The Japanesehave announced they have successfully extracted methane from a methane hydrate reservoir 30 miles off Japan’s east coast and 980 feet beneath the seafloor. They are the first to have achieved this feat.
Flammable ice is formed when a methane molecule gets trapped within interlocking water molecules. The water molecules when under pressure and at cold temperatures become crystallized and form a cage around the methane molecule.
nasa.gov
The Japanesehave been attempting to extract gas hydrates, which are under and surrounding their nation in very large quantities, for years. The U.S. and India, as well as a few other nations, are also heavily invested in methane hydrate research. Many believe it is the hydrocarbon fuel source of the future. Methane is the main component of natural gas.
Gas hydrate根据美国地质调查局的数据,从可燃冰中提取的碳氢化合物比过去、现在和未来提取的所有煤炭、石油和页岩气都要多。天然气水合物在大陆边缘的沉积沉积中最为普遍(天然气从断层向上迁移,撞击冷水,被沉积物覆盖并被压缩)。它也可以在南极洲的冰下和连续的永久冻土层内或下面找到。1&2
MH21 Research Consortium
Low temperatures天然气水合物的形成需要一定的压力以及充足的天然气和水的供应。可燃冰在冰点以上的温度下,只要压力足够大,就能保持完整。为了保持稳定,这些高压和低温条件必须持续存在。
usgs.gov
Gas hydratedeposits, near arctic coasts, will in the future be warmed by rising seas and temperatures and release their methane into the atmosphere, just as methane is escaping from below and within melting permafrost. As methane is a potent greenhouse gas approximately 25 times more potent than CO2, the question is, will this technology help or hinder. Where hydrates are susceptible to melt, will this new technology be able to soak up the methane before it reaches the atmosphere, or are many of these small pockets of methane too far apart, whereby extraction will not be economically feasible?
Gas hydrates are crystalline and take up solid space, just like solid ice. When warmed or depressurized, gas hydrates release their methane (it pops or fizzes out) and what remains is simply water, which after disassociation may easily migrate to another location. Therefore, sinkholes and instability are potential hazards surrounding spent gas hydrate reservoirs.
It is not yet publicknowledge exactly how the Japanese have extracted the sub seafloor gas. Certainly depressurization was employed, along with possibly injecting the ice with a carbon dioxide/nitrogen mixture.3 If the latter is true, there might be hope for us yet, as we could (as the hopeful and ideal picture above shows) inject the carbon dioxide emissions from a shore side power plant into the gas hydrate reservoir and displace the methane, sending it up the pipe and into our gas tanks. Miraculously the hydrate stays intact as a solid, after the carbon dioxide displaces the methane, so there is no threat of collapse of the seafloor. Scientists have labeled gas hydrates a somewhat mysterious substance, for they are still learning they have more to learn.
If these ideal conditions of extraction are not met, and we are simply going to add trillions of gigatons more carbon into our atmosphere, this discovery is not a positive. But if we replace in the near term all coal and oil (especially tar sands oil) with natural gas produced from methane hydrate, this technology would help us reduce emissions short term. The Japanese estimate they are five years away from a commercially viable product.
Yet, numerous questions need to be answered as to extraction processes, potential leakages and environmental cost.
www.eoearth.org
For the past 650,000 years大气中的甲烷含量在320到790ppb4之间波动,今天的甲烷含量在1758 ppb5以上根据Eric Pianka博士的说法,“从长期冻结的甲烷包合物中突然释放出大量气态甲烷,这与二叠纪-三叠纪界线250英里处的大灭绝事件有关。多达96%的海洋物种和70%的陆地脊椎动物在那时灭绝了。甲烷在20年和100年的全球变暖潜力分别为62和21。
According to the USGSan estimated 99 percent of gas hydrates are in ocean sediment, with only 1 percent in permafrost areas. Methane ice has a very high concentration of methane. If you melt a1cubic meter block of methane hydrate, you will release about160cubic meters of methane gas.4* Methane when burned, breaks down into one carbon and two water molecules, both powerful greenhouse gases.
This USGS video shows how methane pops and fizzles out of the ice and at minute four, the ice is lit on fire.
Many of usfirst heard of methane hydrates when told that the containment dome placed over the Gulf BP spill drill site became buoyant and would not stay in place over the well due to rising methane hydrates.
Resources:
[1,4]Gas Hydrates and Climate Warming: Carolyn Ruppel and Diane Noserale, United States Geological Survey, May/June, 2012.soundwaves.usgs.gov
[2]Study suggests large methane reservoirs beneath Antarctic ice sheet: Tim Stephens, University of California Santa Cruz, August, 2012.
[3] CO2/CH4交换第一次现场试验。日本石油天然气公司。2012年5月。jogmec.go.jp
[4]ipcc.ch
[6] Eric R. Pianca, Univ of Texas.zo.utexas.edu
* [One litre of methane clathrate solid contains, on average, 168 litres of methane gas (atSTP).wikipedia
Read More:
Wood’s Hole Science Center:woodshole.er.usgs.gov
Climate Bomb? Methane Vents Bubble on Seafloor off East Coast: Study August, 2014:nbcnews.com
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