A novel take on steam turbine turbomachinery is playing a key role in research to produce clean water. As part of a program with the Department of Energy, scientists will use 3D-printed miniature versions of GE’s steam turbine turbomachinery in test to compress and stream a mixture of air, salt and water through a hyper-cooling loop that freezes seawater. By freezing the mixture, the salt naturally separates in solid form, leaving just the ice. The ice then is melted, leaving clean water.

While freezing seawater to treat it is nothing new, the methods being tested by the research team at GE’s Global Research Center in New York are new. Douglas Hofer is leading the development of the turbine technology. He explained that in a low pressure steam turbine, water vapor condenses to liquid water. For the new desalination process, the GE team is extending that idea to freeze liquid salt water into solid ice and salt crystals during its expansion through the turbine.

Cooling the salty water — or brine droplets — by expanding cold gas in the turbine is more efficient compared to conventional thermal desalination systems, Hofer says.

The program with the DOE is underway and lasts through mid-summer of next year.