This new solar-powered device can pull water straight from the desert air
By Robert F. ServiceApr. 13, 2017
wringing water from the desert sky is now possible, thanks to a new spongelike device that uses sunlight to suck water vapor from air, even in low humidity. The device can produce nearly 3 liters of water per day for every kilogram of spongelike absorber it contains,
There are an estimated 13 trillion liters of water floating in the atmosphere at any one time,
researchers led by Omar Yaghi, a chemist at the University of California, Berkeley, turned to a family of crystalline powders called metal organic frameworks, or MOFs
- The system Wang and her students designed consists of a kilogram of dust-sized MOF crystals pressed into a thin sheet of porous copper metal.
- That sheet is placed between a solar absorber and a condenser plate and positioned inside a chamber.
- At night the chamber is opened, allowing ambient air to diffuse through the porous MOF and water molecules to stick to its interior surfaces
- in groups of eight to form tiny cubic droplets.
- In the morning, the chamber is closed, sunlight entering through a window on top of the device then heats up the MOF, which liberates the water droplets and drives them—as vapor—toward the cooler condenser.
- The temperature difference, as well as the high humidity inside the chamber, causes the vapor to condense as liquid water,
- which drips into a collector.
- The setup works so well that it pulls 2.8 liters of water out of the air per dayfor every kilogram of MOF it contained,
- zirconium costs $150 a kilogram, making water-harvesting devices too expensive to be broadly useful.
How many 8 oz cups are in a liter?
1 liter of water (l) = 33.81 US fluid ounces of water (fl-oz)
there are 4.22675 cups in one liter
Links
https://www.sciencemag.org/news/2017/04/new-solar-powered-device-can-pull-water-straight-desert-air#