Burning Ice Creates Drinkable Water from Fracking Wastewater
While our natural resources dwindle, there's one valuable resource that many forget to account for: water. Although much of our planet is covered by this liquid, our world is in the midst of an intensifying global water crisis. Now, though, researchers have developed a method to use one form of the "ice that burns" to turn salty wastewater from fracking and other oil and gas production methods into water for drinking and irrigation.
Salty wastewater is created with many oil and gas production activities, including hydraulic fracturing, or fracking. Put simply, workers pump water and chemicals at high pressures beneath the ground in order to open up cracks to access the valuable materials contained within. This method can produce as much as 10 barrels of salty water for every barrel of oil. This salty water, unfortunately, cannot be used as drinking water afterward; it cannot be desalinated economically with traditional methods.
That's why researchers developed this new technique to remove the salt from this water. Called "gas hydrate desalination," this method could potentially well people in water-stressed regions.
A gas hydrate consists of only water and a gas, such as methane. When hydrates form, salts and other impurities are left behind. When the hydrate breaks down, though, the gas and pure water are released. Yet forming the gas hydrate used in desalination requires chilling water to a costly 28 degrees Fahrenheit. That's why researchers developed a less costly method that involves chunks of ice retrieved from deep below the sea that burst into flame when brought to the surface.
The scientists formed the hydrates from water and carbon dioxide with the gases cyclopentane and cyclohexane, which made the method work more efficiently. This new technique removed more than 90 percent of the salt. That's compared with a mere 70 percent with the previous gas hydrate technique. In addition, the process works at room temperature.
The findings could be huge for recycling water in dry areas. It could also help mitigate the impacts of hydraulic fracturing, making it a little less dangerous for the environment.
The findings are published in the journal ACS Sustainable Chemistry & Engineering.