08 Jun '18 19:55>
https://phys.org/news/2018-06-trials-next-generation-harvester-fresh-air.html
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the water harvester can extract drinkable water every day/night cycle at very low humidity and at low cost, making it ideal for people living in arid, water-starved areas of the world.
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It operates at ambient temperature with ambient sunlight, and with no additional energy input you can collect water in the desert.
...
The trial in Scottsdale, where the relative humidity drops from a high of 40 percent at night to as low as 8 percent during the day, demonstrated that 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. The researchers anticipate that with the current MOF (MOF-801), made from the expensive metal zirconium, they will ultimately 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.
But Yaghi also reports that 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 (3 cups) of water per day from a kilogram of MOF,
metal-organic frameworks, which are solids with so many internal channels and holes that a sugar-cube-size MOF might have an internal surface area the size of six football fields. This surface area easily absorbs gases or liquids but, just as important, quickly releases them when heated. Various types of MOFs are already being tested as a way to pack more gas into the tanks of hydrogen-fueled vehicles, absorb carbon dioxide from smokestacks and store methane.
..."
"...
the water harvester can extract drinkable water every day/night cycle at very low humidity and at low cost, making it ideal for people living in arid, water-starved areas of the world.
...
It operates at ambient temperature with ambient sunlight, and with no additional energy input you can collect water in the desert.
...
The trial in Scottsdale, where the relative humidity drops from a high of 40 percent at night to as low as 8 percent during the day, demonstrated that 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. The researchers anticipate that with the current MOF (MOF-801), made from the expensive metal zirconium, they will ultimately 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.
But Yaghi also reports that 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 (3 cups) of water per day from a kilogram of MOF,
metal-organic frameworks, which are solids with so many internal channels and holes that a sugar-cube-size MOF might have an internal surface area the size of six football fields. This surface area easily absorbs gases or liquids but, just as important, quickly releases them when heated. Various types of MOFs are already being tested as a way to pack more gas into the tanks of hydrogen-fueled vehicles, absorb carbon dioxide from smokestacks and store methane.
..."