There are trillion liters of water in Earth’s atmosphere but it doesn’t help in arid areas. But Scientists have developed a new device that can pull pure drinking water out of thin air, using only the power of the sun. The technology is far from commercialization right now, but if scientists are able to scale it up, it could change the life of billions of people who live in quasi-desertic regions.
Previous tries of harvesting water from the atmosphere required a high level of humidity, such as foggy weather, or a gigantic amount of energy. But this device, according to its inventors, works with only 20% of humidity which is typical of most of the arid regions on the planet, and it is powered solely by sunlight.
The technology uses a highly porous layer that captures water from ambient air, a solar energy collector to heat up the layer, and a condenser to transform the vapor into drinkable water. The porous layer soaks up water vapor from the air at night and the condenser, enclosed in an airtight chamber, releases liquid water during the day using the sun’s energy.
Lead researchers Omar Yaghi at the University of California, Berkeley, and Evelyn Wang, at MIT, reported in Science that the harvester can draw almost 3 liters of drinking water per kilogram of adsorbent at 20% of humidity; what is a lot if you consider that the machine is currently the size of a tissue box!
The porous layer is made from a material called metal-organic framework (MOF) that was first developed by Yaghi 20 years ago. MOF are metal atoms linked to carbonic molecules in a repeated pattern, to form a three-dimensional structure. By choosing different metals and organics, scientists can render the structure more or less solid and porous.
When Yaghi developed a MOF that was excellent at absorbing water in 2014, it was the trigger for the development of the water harvesting device.
Needless to say that if this technology reaches commercialization, the impact on human health and economic development in arid countries will be mind blowing. Countless of lives will be saved and agriculture will be able to flourish in regions where it’s currently unthinkable.
“It has been a longstanding dream” to harvest water from desert air, says Mercouri Kanatzidis, a chemist at Northwestern University in Evanston, Illinois, who wasn’t involved with the work. “This demonstration … is a significant proof of concept.”