Sorption-based atmospheric water harvesting captures water vapor from the air using specialized materials, or sorbents, and thermal energy to produce freshwater. In research published in Advanced Functional Materials, investigators developed a wind-driven strategy that they showed provides a cost-effective and sustainable approach to freshwater production.
The strategy involves the use of what's called hygroscopic polymer sponges that are very porous and take up water. The sponges are integrated with wind-powered eddy current heating, a process that converts wind kinetic energy into thermal energy to release water from the saturated sponges. Under fluctuating ambient air conditions, the method generated 9.9 liters of water per day for every 1 kilogram of sponge material.
"Most sorption-based atmospheric water harvesting systems rely on solar thermal energy or electrically generated heat for sorbent regeneration," said corresponding author Haiqing Li, PhD, of Nanjing Tech University, in China. "Our work introduces wind-powered eddy current heating as a new renewable-energy pathway that bypasses the intermediate electricity generation step and directly converts wind kinetic energy into heat with an energy conversion efficiency exceeding 90%, broadening the range of renewable energy sources available for atmospheric water harvesting."
The strategy could support off-grid freshwater production, particularly in wind-rich coastal and island communities, as well as remote regions where access to freshwater or reliable electrical infrastructure is limited.
URL: https://onlinelibrary.wiley.com/doi/10.1002/adfm.77465
