Submitted via IRC for Fnord666
In desert trials, next-generation water harvester delivers fresh water from air
Scientists who last year built a prototype harvester to extract water from the air using only the power of the sun have scaled up the device to see how much water they can capture in arid conditions in Arizona. Using a kilogram of MOF[*], they were able to capture about 7 ounces of water from low-humidity air each 24-hour day/night cycle. A new and cheaper MOF could double that.
[...] "There is nothing like this," said Omar Yaghi, who invented the technology underlying the harvester. "It operates at ambient temperature with ambient sunlight, and with no additional energy input you can collect water in the desert. This laboratory-to-desert journey allowed us to really turn water harvesting from an interesting phenomenon into a science."
[*] Metal-organic frameworks (MOFs) are:
compounds consisting of metal ions or clusters coordinated to organic ligands to form one-, two-, or three-dimensional structures. They are a subclass of coordination polymers, with the special feature that they are often porous. The organic ligands included are sometimes referred to as "struts", one example being 1,4-benzenedicarboxylic acid (BDC).
Also at Berkeley News.
Practical water production from desert air (open, DOI: 10.1126/sciadv.aat3198) (DX)
(Score: -1, Offtopic) by Anonymous Coward on Sunday June 10 2018, @10:49PM
I hate you! And I hate the harvest!
https://cad-comic.com/comic/some-cheese-to-go-with-that/ [cad-comic.com]
(Score: 2) by Whoever on Sunday June 10 2018, @10:56PM (1 child)
But how do they protect the water from the worms?
(Score: 0) by Anonymous Coward on Sunday June 10 2018, @11:04PM
The
waterspice must flow!(Score: 2) by wonkey_monkey on Sunday June 10 2018, @11:13PM (3 children)
Are we going to call this a windtrap or a moisture vaporator?
Well... clean-enough water from very slightly damp air, anyway.
systemd is Roko's Basilisk
(Score: 3, Informative) by Anonymous Coward on Sunday June 10 2018, @11:49PM (1 child)
It's called an air well. https://en.wikipedia.org/wiki/Air_well_(condenser) [wikipedia.org]
(Score: 3, Funny) by wonkey_monkey on Monday June 11 2018, @04:56PM
Eh, well.
systemd is Roko's Basilisk
(Score: 4, Funny) by Muad'Dave on Monday June 11 2018, @11:59AM
Clearly a windtrap (I'm biased, of course).
(Score: 1, Troll) by nitehawk214 on Sunday June 10 2018, @11:13PM (3 children)
Let me guess, this is a big of a scam and as easily debunked as the last "water from dry desert air with no input energy" Kickstarter scams.
"Don't you ever miss the days when you used to be nostalgic?" -Loiosh
(Score: 3, Funny) by Anonymous Coward on Sunday June 10 2018, @11:18PM
No, this company is legit. It's got a female CEO.
(Score: 1, Interesting) by Anonymous Coward on Monday June 11 2018, @04:05AM (1 child)
It's possible to pull water out of the air, just not as much as that KS indicated and not with so little energy.
Personally, I can't see how they could possibly do this in a way that's efficient enough to be worthwhile. At a certain point, having cities in certain areas is just not viable.
I'm also somewhat curious what the impact of sucking that moisture out of the air would be. While there isn't much moisture in the air, it must have some effect that needs to be examined when done on an industrial scale.
(Score: 0) by Anonymous Coward on Monday June 11 2018, @07:10PM
"'m also somewhat curious what the impact of sucking that moisture out of the air would be."
this is what i was thinking. if there's only a little moisture in the air and you come in and steal it, like an asshole, what happens to the ecosystem that was depending on that.
(Score: 4, Informative) by frojack on Sunday June 10 2018, @11:16PM (3 children)
Except for these other things that have been around for quite a while:
https://soylentnews.org/article.pl?sid=14/04/14/0051250 [soylentnews.org]
https://soylentnews.org/article.pl?sid=16/03/25/0329250 [soylentnews.org]
https://soylentnews.org/article.pl?sid=16/10/11/170204 [soylentnews.org]
https://www.smithsonianmag.com/innovation/this-tower-pulls-drinking-water-out-of-thin-air-180950399/ [smithsonianmag.com]
And some slightly different ones:
https://www.treehugger.com/clean-technology/waterseer-can-produce-11-gallons-day-clean-drinking-water-air.html [treehugger.com]
No, you are mistaken. I've always had this sig.
(Score: 2) by captain normal on Monday June 11 2018, @02:03AM (1 child)
Yep, plus there is this: "Last October, a University of California, Berkeley, team headed down to the Arizona desert, plopped their newest prototype water harvester into the backyard of a tract home and started sucking water out of the air without any power other than sunlight..."
Wonder if this tract home has an irrigation system with maybe a lawn?
October in Arizona can be quite humid, with monsoonal moisture flowing up from Mexico.
If this really works they should go to someplace like Blackrock Desert in July to test it.
When life isn't going right, go left.
(Score: 2) by FatPhil on Monday June 11 2018, @06:10AM
Great minds discuss ideas; average minds discuss events; small minds discuss people; the smallest discuss themselves
(Score: 0) by Anonymous Coward on Monday June 11 2018, @03:17AM
Air wells have been used for thousands of years. The use of MOF is the new bit. https://en.wikipedia.org/wiki/Air_well_(condenser)#Zibold%27s_collector [wikipedia.org]
(Score: 1) by SemperOSS on Monday June 11 2018, @12:00AM (1 child)
At last some scientist has read Frank Herbert's Dune and acted upon it.
I don't need a signature to draw attention to myself.
Maybe I should add a sarcasm warning now and again?
(Score: 2) by HiThere on Monday June 11 2018, @12:06AM
I think they're using a different and more compact technology that the Fremen had. IIUC the Fremen technology was basically based around cooling air until it reached its dew point.
Javascript is what you use to allow unknown third parties to run software you have no idea about on your computer.
(Score: 0) by Anonymous Coward on Monday June 11 2018, @12:35AM (5 children)
You can't harvest enough water from dry air to be worth anything. Extremely simple chemistry equations you probably learned in high school make this quite clear. There is no amount of cleverness that will make it possible to extract meaningful amounts of water from air that doesn't contain much water. Even if you were beside a rain forest these stupid things wouldn't generate enough water from the air.
(Score: 2, Offtopic) by realDonaldTrump on Monday June 11 2018, @12:46AM
It's solar. And maybe it wouldn't work in a rain forest. But it works in sunny Arizona. And maybe we'll build it into our magnificent Border Wall!!!!
(Score: 2) by frojack on Monday June 11 2018, @01:46AM (2 children)
Define "meaningful amounts". (See, I'm even giving you a chance to define your own weasel words.).
How bout 25 gallons of clean drinking water per day? Does that mean anything to you?
https://www.smithsonianmag.com/innovation/this-tower-pulls-drinking-water-out-of-thin-air-180950399/ [smithsonianmag.com]
No, you are mistaken. I've always had this sig.
(Score: 4, Touché) by suburbanitemediocrity on Monday June 11 2018, @03:05AM
The AC on my house in Arizona has been producing this much water per day at least since 1990. And hey, since I put up some solar panels and a big inverter ten years ago, it has been 100% solar powered.
I wouldn't drink the water without filtering it and running it through a UV sanitizer (legionaires and all), but that is way over engineering where it's not needed. A couple hundred meters of collection area and a big water tank is far less expensive, will collect more water even in the desert (600gallons/1000sqft/inch of rain (that's 5000 gallons in Phx, AZ/1,000sqft)), low tech (nothing to break), will last 100 years and can be built by grade schoolers.
(Score: 0) by Anonymous Coward on Thursday June 14 2018, @03:12PM
We can compare the operation of these systems with the cost of pumping water into a tank (where water is plentiful) and shipping it to where the device is proposed to be installed. We all know it is possible to condense water out of air. You can go to the store and buy a machine to do it: it is called a dehumidifier.
A "meaningful amount" means the device can produce a comparable amount of water, in a comparable amount of time, for a comparable amount of energy, as just shipping the water from a big lake somewhere else in the water.
However, turning water vapour into liquid water takes a tremendous amount of energy. The water is in a gaseous state because the water molecules have enough thermal energy to overcome the hydrogen bonds between different water molecules. To turn it into a liquid you need
to remove all that energy, which is approximately 2.2MJ per litre of liquid water.
A tanker truck holds about 50,000 L of water. Suppose we fill it in Chicago, IL and drive to Phoenix, AZ (about 3,000 km). According to wikipedia [wikipedia.org] a heavy truck requires about 2.5 kJ per tonne-kilometer. So the truck hauling 50 tonnes of water travelling 3000 km yields about 400 MJ of energy required to transport 50,000 L. The whole process might take 2 days. 400MJ in 2 days is about 2.5 kilowatts.
Let's now consider condensing water. At 2.2MJ per litre, condensing 50,000 litres will require removing 110 gigajoules of energy from the water vapour. To do that in 2 days means we need to remove energy from the water vapour at a rate of about 600kW.
A good heat pump could be about 200-300% efficient at removing energy from the water, provided we have a bigass heatsink that can dissipate that 600kW. That still gives us a power input requirement of about 200kW assuming there are no losses (and glossing over the fact that there might not even be enough water vapour in the air to do this), roughly 100 times the power requirement of just trucking it halfway across the continent.
Even air freight halfway around the world will be an order of magnitude cheaper.
The reason these devices are a dumb idea is not because they can't possibly work. The reason is they are simply too expensive to operate for the purposes of obtaining potable water, compared to the much simpler, cheaper, faster and safer methods available.
But I guess you can't raise millions of dollars on Indiegogo flexible funding just by driving a water truck across the country.
(Score: 2, Informative) by Anonymous Coward on Monday June 11 2018, @02:04AM
One missing piece of data -- the relative humidity in Arizona isn't all that low, see https://www.currentresults.com/Weather/Arizona/humidity-annual.php [currentresults.com]
Since the air temps in AZ are often high (increases ability to hold moisture), the absolute amount of moisture in the air is significant.
If you want dry air, go into any heated house in the winter when it's below freezing outside (assuming no added house humidification). Heating cold outside air (nearly independent of the RH% at the cold outside temp) winds up with very low RH % at room temps.
(Score: 2, Redundant) by requerdanos on Monday June 11 2018, @01:14AM
I didn't recognize the acronym, and so consulted TFA [sciencedaily.com]. Apparently MOF in this context is any of the various "metal-organic framework" formulae that they're using as "water absorber".
(Score: 3, Interesting) by takyon on Monday June 11 2018, @01:19AM (3 children)
What would happen if you had thousands or millions of these units collecting water in Arizona or another desert area? Would humidity levels drop semi-permanently?
[SIG] 10/28/2017: Soylent Upgrade v14 [soylentnews.org]
(Score: 2) by frojack on Monday June 11 2018, @01:43AM (2 children)
What little wild life and plants there is there, would certainly be affected I would think. Many desert animals rely on air extraction.
No, you are mistaken. I've always had this sig.
(Score: 2) by suburbanitemediocrity on Monday June 11 2018, @03:37AM (1 child)
Wouldn't make a difference unless they were inside a climate controlled house. There are trillions of tons of water in the atmosphere.
(Score: 2) by bob_super on Monday June 11 2018, @04:51AM
Yup, we're pretty much in "windmills stop the winds" orders of magnitude.
(Score: 0) by Anonymous Coward on Monday June 11 2018, @08:05AM
I've looked at the article and somewhat understand how these MOFs look like, but what I would like to see is how safe these compounds are.
(Score: 3, Touché) by rigrig on Monday June 11 2018, @08:21AM (3 children)
Glad to see a compromise has been reached about the use of imperial vs SI units.
(Although not a very fair one, as apparently they use some non-imperial ounce in the US?)
No one remembers the singer.
(Score: 0) by Anonymous Coward on Monday June 11 2018, @09:32AM
"About" makes it also sound very scientific. Could've been 6 ounce, could've been 8. I dunno exactly.
(Score: 0) by Anonymous Coward on Monday June 11 2018, @02:19PM
My guess (without reading TFA) is 200 g of water. This is 7.055 oz.
(Score: 0) by Anonymous Coward on Monday June 11 2018, @03:54PM
Obviously, they mean Arizonan Imperial Ounces.
(Score: 0) by Anonymous Coward on Monday June 11 2018, @04:10PM
How big does a MOF have to be before it becomes a Grand MOF?
(Score: 0) by Anonymous Coward on Tuesday June 12 2018, @05:39PM
I need to apply for a job there, because my first job was programming binary load-lifters. They're similar to these vaporators in most respects. Now I'm off to polish up my Bocce.