Fresh Water Harvested from Desert Air

fresh-water-harvested-from-desert-air

Researchers have successfully carried out trials on a new water harvester that can extract drinkable water from the air – offering a solution to people living in water-deprived areas.

The team from UC Berkeley experimented with a prototype water harvester and were able to deliver drinkable water with only sunlight as power.

“There is nothing like this,” said Omar Yaghi, who invented the technology underlying the harvester and trialled it in the Arizona desert.

Yaghi said the concept could deliver water at very low humidity for people living in water-limited areas.

The experiment suggests the harvester should be easy to scale up by simply adding more of the water absorber, a highly porous material called a metal-organic framework, or MOF.

They anticipate that with the current MOF (MOF-801), made from the expensive metal zirconium, they will be able to harvest about 200 milliliters (about 7 ounces) of water per kilogram (2.2 pounds) of MOF, or 3 ounces of water per pound.

“This laboratory-to-desert journey allowed us to really turn water harvesting from an interesting phenomenon into a science,” commented Yaghi.

The James and Neeltje Tretter chair in chemistry at UC Berkeley and a faculty scientist at Lawrence Berkeley National Laboratory will unveil the team’s findings in the June 8 issue of the journal Science Advances.

Yaghi says he has created a new MOF based on aluminum, called MOF-303, that is at least 150 times cheaper and captures twice as much water in lab tests.

This will enable a new generation of harvesters producing more than 400 ml (1.5 cups) of water per day from a kilogram of MOF.

“There has been tremendous interest in commercializing this, and there are several startups already engaged in developing a commercial water-harvesting device,” Yaghi said. “The aluminium MOF is making this practical for water production because it is cheap.”

Yaghi is working with King Abdul Aziz City for Science and Technology in Riyadh, Saudi Arabia, on the technology as part of their joint research Center of Excellence for Nanomaterials and Clean Energy.

The field tests lay out a blueprint allowing engineers to configure the harvester for the differing conditions in Arizona, the Mediterranean or anywhere else, given a specific MOF.

“The key development here is that it operates at low humidity because that is what it is in arid regions of the world,” Yaghi said.