There have been several attempts towards converting air into water. One of them is Water-Gen, which uses a system that optimizes condensation through a set of plastic “leaves” to funnel air in various directions.
Now, researchers from MIT and Berkeley have developed their own version in case we do not have water to consume anymore. It is solar-powered and works in low humidity.
The harvester they invented uses a material known as a metal organic framework (MOF) which extracts the water from the air. What it does is combine metals with organic molecules to form porous structures which are excellent in storing gases and liquids.
It can have different compositions which in turn store various substances like hydrogen, carbon dioxide, or natural gas.
In the case of this research, they used an MOF derived from zirconium metal and adipic acid, enabling the device to harvest water vapor from the atmosphere.
The MOF is heated by the sunlight which allows the water to get into a condenser of the same temperature as the outside air. The vapour condenses into liquid form and drips into a collector.
Upon placing the prototype, with a kilogram of the MOF material, on the roof of an MIT building for 12 hours, it collected 2.8 liters of water under conditions of 20 to 30% humidity.
One of the paper’s senior authors from Berkeley and discoverer of MOFs more than two decades ago Omar Yaghi said that this is a major breakthrough in the long-standing challenge of harvesting water from the air at low humidity.
“There is no other way to do that right now, except by using extra energy. Your electric dehumidifier at home ‘produces’ very expensive water,” he said.
For now they used that MOF material, but Yaghi believes that other MOFs could potentially double the present absorption capacity of the current MOF which is 20% of its weight in water. The device could have a higher efficiency as well when there is a better harvesting technology.
“There is a lot of potential for scaling up the amount of water that is being harvested,” said Yaghi. “It is just a matter of further engineering now.”
Source: The Engineer UK