A team of researchers at MIT and in China developed a desalination system that is more efficient and less expensive than previously established methods. The hope is that it will help solve shortages of water in different areas of the globe. The researchers focused on creating a design that also deals with the accumulation of salt over time. “The challenge has been the salt fouling issue, that people haven’t really addressed. So, we see these very attractive performance numbers, but they’re often limited because of longevity. Over time, things will foul,” Evelyn Wang, one of the researchers in the study, said.
The resulting apparatus is a layered system. A dark material is at the top to absorb the sun’s heat, and a thin layer of water above a perforated layer of material sits atop the designated container of the salty water. The perforated material, made of polyurethane, has holes that are 2.5 millimeters in diameter, which is what the researchers deemed to be the optimal size that allows for a natural convective circulation between the warmer upper layer of water and the colder reservoir below. This prevents the salt from accumulating. Further work and testing would be required to test the device in large settings and long runs, according to Hadi Ghasemi, a professor of chemical and biomolecular engineering at the University of Houston.
Image credit: Wang, et.al via MIT News