Freeze fracking

Despite the benefits of cheap fuel from fracking, it requires a lot of water and the waste water subsequently needs to be treated. Research is looking into using liquid nitrogen which is available on site and does not need treatment or disposal after use.

Researchers at the Colorado School of Mines claim they have developed a method to unlock hydrocarbons trapped in shale with using any water at all. They are seeking to perfect Cryogenic fracturing, which replaces water with searing cold liquid nitrogen (or carbon dioxide). Used at temperatures below minus 321 Fahrenheit, it is pumped underground at high pressure. Once it comes into contact with the heated, pressurized shale, a reaction occurs which caused the shale to crack open and creates fissures through which the hydrocarbons can gush out.

Nitrogen liquefies at –196 °C.