In the midst of an intensifying global water crisis,
scientists are reporting development of a more economical way to use one form
of the “ice that burns” to turn very salty wastewater from fracking and other
oil and gas production methods into water for drinking and irrigation. The
study on the method, which removes more than 90 percent of the salt, appears in
the journal ACS Sustainable Chemistry & Engineering.
Yongkoo Seol and Jong-Ho Cha explain that salty wastewater
is a byproduct of oil and gas production, including hydraulic fracturing, or
fracking. These methods use water and produce as a byproduct almost 10 barrels
of salty water for every barrel of oil. That water could help people in
water-stressed regions. But it can’t be desalinated economically with
traditional methods. Seol and Cha knew that an alternative called “gas hydrate
desalination” showed promise. A gas hydrate consists of only water and a gas
such as methane, the stuff of natural gas. Thus, when hydrates form, salts and
other impurities are left behind. When the hydrate breaks down, the gas and
pure water are released. However, forming the gas hydrate used in desalination
required costly chilling of the water to 28 degrees Fahrenheit. Seol and Cha
sought to develop a less costly version of the method, which involves a
variation on methane hydrates, chunks of ice retrieved from deep below the sea
that burst into flame when brought to the surface.