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Researchers at the University of California, Berkeley and MIT have created a solar-powered device that can condense up to 2.8 liters of water out of the air daily:
The system Wang and her students designed consists of a kilogram of dust-sized MOF crystals pressed into a thin sheet of porous copper metal. That sheet is placed between a solar absorber and a condenser plate and positioned inside a chamber. At night the chamber is opened, allowing ambient air to diffuse through the porous MOF and water molecules to stick to its interior surfaces, gathering in groups of eight to form tiny cubic droplets. In the morning, the chamber is closed, and sunlight entering through a window on top of the device then heats up the MOF, which liberates the water droplets and drives them—as vapor—toward the cooler condenser. The temperature difference, as well as the high humidity inside the chamber, causes the vapor to condense as liquid water, which drips into a collector. The setup works so well that it pulls 2.8 liters of water out of the air per day [DOI: 10.1126/science.aam8743] [DX] when run continuously, the Berkeley and MIT team reports today in Science.
(Score: 4, Informative) by anubi on Saturday April 15 2017, @08:35AM (4 children)
It appears they are focusing on optimizing the hydrophilic properties of Zeolite.
This will be worth following.
Many functional air conditioning systems have used Zeolite for both cooling and humidity control by using the thermodynamic properties of water and driven by sunlight.
"Prove all things; hold fast that which is good." [KJV: I Thessalonians 5:21]
(Score: 3, Interesting) by c0lo on Saturday April 15 2017, @10:36AM (3 children)
I wonder if this can be achieved cheaper with deliquescent salts on a cellulose wool/cotton substrate - e.g. zinc chloride has 5 states of hydration [wikipedia.org]
https://www.youtube.com/watch?v=aoFiw2jMy-0 https://soylentnews.org/~MichaelDavidCrawford
(Score: 3, Interesting) by anubi on Saturday April 15 2017, @11:16AM (2 children)
Interesting point, c0lo! I had worked with some lithium bromide in a absorption refrigeration chiller at Chevron. Its how we kept our LNG tanks cold.
That was some very deliquescent salt with some quite interesting thermodynamics, but was corrosive as all getout.
I was not aware of zinc chloride used as such, thanks! Some in-depth study of the thermodynamic uses of these deliquescent salts will likely bring some very useful ways for us to maintain comfortable lifestyles without bankrupting our environment to do it. Both zinc and chlorine are quite abundant.
After reading what they were doing, I believe in these guys at Berkeley and MIT. I think they are onto something; I am aware of what I have known as the baseline of pretty crude undeveloped technology of absorbents, and see quite a future as to where they can take this technology.
I wish them the best.
"Prove all things; hold fast that which is good." [KJV: I Thessalonians 5:21]
(Score: 2) by c0lo on Saturday April 15 2017, @11:54AM
So cheap I might give it a try... sometime.
https://www.youtube.com/watch?v=aoFiw2jMy-0 https://soylentnews.org/~MichaelDavidCrawford
(Score: 5, Informative) by c0lo on Saturday April 15 2017, @12:50PM
Looks like the Epsom salt [wikipedia.org] (MgSO4 heptahydrate) can be completely dehydrated at 250C [sciencemadness.org] - requires concentrated solar and good condenser to dissipate the heat and recover the water; on the plus side, the substance is cheap and not corrosive (ZnCl2 is acidic and dissolves cellulose).
https://www.youtube.com/watch?v=aoFiw2jMy-0 https://soylentnews.org/~MichaelDavidCrawford