Making water harvesting easier with low-energy solutions

Efficiently harvesting water from the air and reducing humidity are increasingly vital for improving living conditions worldwide. However, conventional methods of reusing water-adsorption polymers-used in atmospheric water harvesting and desiccant air conditioning-face challenges, particularly with energy-intensive desorption processes. Researchers at Osaka Metropolitan University have introduced a novel solution that significantly lowers the energy requirements for desorption.

Traditionally, desorption processes require heating to approximately 100C. The research team, led by Graduate School of Engineering student Daisuke Ikegawa, Assistant Professor Arisa Fukatsu, Associate Professor Kenji Okada, and Professor Masahide Takahashi, developed a liquid moisture adsorbent that performs effectively at just 35C.

This advancement leverages random copolymers of polyethylene glycol, which strongly adsorbs water, and polypropylene glycol, which is less effective at water adsorption. The variation in hydrophilicity between these polymers initiates a water transfer mechanism that disrupts water clusters, allowing water to be released with minimal energy input.

"This technology has the potential to be applied not only to water supply in arid regions and places with limited energy resources, but also to ensuring access to water in times of disaster and emergency," Dr. Fukatsu proclaimed.

Professor Takahashi added, "Improvements to this technology are also expected to lead to reductions in greenhouse gases and more efficient use of water resources. From now on, we will aim to improve the liquid moisture adsorbent and increase the efficiency of the entire system in order to make it practical."

Research Report:Liquid Polyether-Based Water Harvester for Near Ambient Temperature Operation via Hydrophilicity-Difference-Induced Water Transfer