Chinese researchers develop seawater system for hydrogen and fresh water

Researchers at the Dalian Institute of Chemical Physics, part of the Chinese Academy of Sciences, have developed a 250-kilowatt system capable of producing hydrogen and fresh water simultaneously from seawater. The technology addresses the energy inefficiency and technical challenges typically associated with seawater electrolysis, such as electrode corrosion from chloride ions and mineral deposits from calcium and magnesium.

Instead of using energy-intensive desalination processes before electrolysis, the system utilizes the waste heat generated by an alkaline electrolyzer. This heat is directed into a vacuum distillation tower, allowing seawater to evaporate at relatively low temperatures between 40 and 50 degrees Celsius. The resulting vapor is condensed into fresh water, which can then be used for electrolysis or other applications.

According to the study published in Nature Energy, this method increases the electrical efficiency of the total system by 14.4 percent compared to conventional methods. Additionally, the process allows for the potential recovery of valuable resources from the remaining concentrated brine, such as salt, bromine, and uranium.