Scientists from the University of California have successfully tested a prototype solar powered water purifier in the deserts of Scottsdale Arizona. The device is a Zirconium based metal-organic framework called MOF-803 that captures three ounces of water per pound of the metal.
They’ve successfully confirmed that the device can inexpensvely capture water every day and night at very low levels of humidity making it a valuable resource to those more arid low income desert regions who need it most. The device should be easy to scale up by adding more of the porous metal organic framework.
“it operates at ambient temperature with ambient sunlight and with no additional energy input you can collect water in the desert” said Omar Yaghi who invented the underlying technology.
In the Arizona town of Scottsdale humidity can drop down to as low as 8 percent during the day and yet the water purifier was still able to function throughout the night.
On top of all this Omar Yaghi has recently created an even newer model (MOF-303) that captures twice as much water in laboratory tests. It is also 150 times cheaper, certainly bringing it within the realm of affordability for those living in more arid regions.
This new metal organic framework is based on aluminum.
MOF-303s cubic-octaheral structure
Yaghi is presently working with President Prince Dr Turki Saud Mobhammed Al Saud of King Abrul Aziz City for Science and Technology in Riyadh Saudi Arabia. They’re carrying out a joint research project at their Center of Excellence for Nanomaterials and Clean Energy hopefully in an attempt to bring this technology to poorer communities who need it most.
MOFs are already being used to pack more gas in to Hydrogen and methane fuel tanks, and to absorb more carbon dioxide from smoke stacks before it reaches the atmosphere. With recent advance in nano sized 3D printing it may become easier to print these metal organic frameworks using more detailed geometric techniques.
Metal organic frameworks are created with an extremely porous material (the most porous). So much so that an MOF the size of a sugar cube may well fit as much surface area as an entire football field. The tiny microscopic holes of an MOF capture liquids from gas. Then upon re-heating can release them in to a condensation capturing device. The harvested water is clean enough to drink or use for bathing.
The MOF device is composed of a box within a box, during the day the top of the outer box is left open so that air may reach the MOF grains inside the smaller box. Then when they replace the lid of the outer box so that both of them heat up – evaporating the water from inside the smaller box. Then the evaporated water molecules aggregate on the inside of the outer box and drip down to the bottom where the researches can extract the water with a pipette.
Cover photo: Metal Organic Framework 801