In the desert water may seem absent. Omar Yaghi and his team have shown that a part of that resource can be recovered from the most unsuspectable source: air.
The principle arises from a family of materials called MOF, metal-organic structures characterized by an extraordinaryly high porosity.
Their microscopic structure allows to capture molecules present in the environment, including water vapor.
From this property was born the idea of using MOFs to effectively collect the water present in the atmosphere even where moisture is very low.
The operation of the device follows a relatively simple cycle.
During the coolest hours, the material captures the steam in the air.
When the heat of the sun comes, the previously adsorbita water is released in the form of steam inside the system.
At that point it can be condensed and collected as liquid water.
The most interesting aspect is the environment in which this technology has been experienced.
Normally, extracting water from the air becomes much more difficult when moisture decreases. The systems developed with the use of MOF have been studied and tested even in arid and desert conditions.
MOF-based prototypes have been experimented on the field in the Arizona desert and, subsequently, also in the Death Valley, demonstrating that it is possible to collect the water present in the atmosphere even in very low humidity conditions.
This does not mean having developed a machine capable of solving the problem of world water scarcity alone.
The amount of water obtained depends on the material used, environmental conditions and system size. Turning a scientific prototype into an economic and usable technology on a large scale also represents a completely different challenge.
But the idea developed by Yaghi and the researchers who have worked on this technology changes however the way to look at the problem.
When we think of the water reserves we can imagine rivers, lakes, underground faldes or desalination plants.
Much more rarely we think of the atmosphere.
Yet even above one of the most arid landscapes of the Earth continue to move invisible water molecules.
The challenge is not to create them from nothing.
It is able to capture them sufficiently efficiently to make them a usable resource.
And this is where this research becomes particularly fascinating: it does not promise to make water appear where it does not exist.
Try to recover what was already there, suspended in the air, but until recently it seemed too difficult to recover.