The atmosphere of Earth keeps together almost 13,000 trillion liters of water. However, creatures don’t have access to all this water to satiate their thirst, especially those in desert areas. A new device can offer a solution. The invention harnesses the power of sunlight to collect water vapor out of thin air. The results are impressive even in environments with low humidity, such as the Sahara desert. One such device can produce even 3 liters a day.
3D Networks of Crystaline Powders Can Collect Water from Desert Air
Starting from the premise that the atmosphere has the equivalent of 10% of the planet’s freshwater, researchers believed in a new device as a solution for thirst crisis. Thus, there were several projects that took shape over the past years. Some of them used fine nets to extract water from banks of fog. Others relied on dehumidifiers to condense liquid out of air. However, none of them ended up being productive in the long run.
Nonetheless, a recent invention holds high expectations. The team of researchers had Omar Yaghi, a chemist at the University of California, Berkeley, as their leader. Together they managed to find a viable solution in metal organic frameworks or MOFs for short. These are crystalline powders that are porous enough to create perpetual 3D networks. Yaghi managed to create such structures 20 years ago. However, it was only recently when the author thought to tweak the device as a solution to thirst crisis.
The MOF-801 Works Especially under Low-Humidity Conditions
After collaborating with a Cambridge engineer, Evelyn Wang, on employing MOFs in automobile air conditioning, Yaghi contacted his colleague again for a new idea. This is how MOF-801 came to life. Together with her students, Evelyn designed a system with two pounds of MOF crystals incorporated into a sheet of thin porous copper metal. The sheet works as a screen between a solar absorber and a plate for condense.
The device works by staying open during night time. This is when water from desert air gets stuck to the interior and forms cubic droplets of small sizes. During the day, the chamber is closed. The sunlight heats the MOF which turns the droplets in vapors and guides it to the cooler condenser. Afterward, the vapor condenses into liquid water under the pressure of temperature difference and high humidity. A collector stores the drinking water to as much as 2.8 liters a day.
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