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Water is normally thought to be the solution to extinguish fires, not ignite them. But when subjected to certain conditions, normal H2O can do the exact opposite. In order to create this magical liquid that scientists call 'supercritical water', it is first compressed at 217 times the air pressure found at sea level and then heated above 703°F (373°C).
At this critical point, the water is neither solid, liquid or gas - but something that scientists describe as a 'liquid-like gas'. This supercritical water has the capability of rapidly oxidizing or 'burning' any organic substance it comes in contact with. The best part is that except for some rare hotspots the combustion occurs without any pesky flames. But most importantly, unlike other waste burning methods, it results in only two byproducts - water and carbon dioxide
These qualities make supercritical water a great candidate to help clean our sewage systems as well as other waste materials produced in cities, aboard ships and even in space. However, though it is being used on a limited basis by the US Navy to purify the waste streams aboard some ships and the city of Orlando in Florida to process municipal sludge, supercritical water has yet to be deployed on a wide scale.
That's because there is one issue that still needs to be resolved - How to deal with the salts naturally present in the water from rapidly precipitating when it is heated. The reason this is a problem is that the salts that leave the water, stick to the insides of the metal reactors where the waste and supercritical water are housed and cause them to corrode.
However, Mike Hicks of NASA's Glenn Research Center in Ohio believes that a solution can be found - not on earth but in space, which is why he has partnered with the astronauts aboard the International Space Station.
He thinks that studying the properties of supercritical water in a gravity-free environment will allow researchers to learn how the precipitating salts behave on a very fundamental level. This may help them figure out how to keep it away from the metal components of the reactor vessels.
The experiments that comprise of six test runs, each lasting approximately 15 days, began on the first week of July 2013 and will continue until July 2014. If successful, it will spur widespread applications of this unusual purifier- Who knew that water could be used to burn!
Resources: geekapolis.fooyah.com, redorbit.com, Science.NASA.gov