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Creating Water from Thin Air
Iphtashu Fitz writes "In order to provide the U.S. Military with water in places like Iraq, the Defense Advanced Research Projects Agency gave millions of dollars in research funding to companies like LexCarb and Sciperio to try to extract water from the air. Amazingly, a company that DARPA didn't fund, Aqua Sciences, beat them all to the punch by developing a machine that can extract up to 600 gallons of water a day from thin air even in locations like arid deserts. The 20 foot machine does this without using or producing toxic materials or byproducts. The CEO of Aqua Sciences declined to elaborate on how the machine works, but said it is based on the natural process by which salt absorbs water."
I recall reading an article about ancient rock mounds, where the rocks were loosely lumped with plenty of space in between. Air filtered through and encountered the cool rock faces of the interior of the mound. Water condensed on the interior rock faces and trickled out the bottom. I'll see if I can find a link.
- None can love freedom heartily, but good men; the rest love not freedom, but license. -- John Milton
at my seitch.
Sincerely,
Muad'Dib
I'm sure they'll be interested.
End of lesson. You may press the button.
Just as long as the superconductors you use on your condensors are not vulnerable to a puppeteer plague.
If that happens its going to take a long time before Louis shows up.
There are 4 boxes to use in the defense of liberty: soap, ballot, jury, ammo. Use in that order- Ed Howdershelt Via Tass
Anyone heard of Tatooine's moisture farmers?
I thought so.
(sorry, it was just too obivious)
What, you're shocked that all the government funded plodders were out done by a Capitalist independent? Government is very poor at creation and is typically very poor at selecting future winners in the technology race. That's why government should be a consumer of technology rather than a producer of the same.
"Man is nothing without the works of man" -- Helvetius
So the government failed to fund a company who promised unbelievable results with no byproducts while not supplying any details? I must say, I'm actually proud of them. Glad to see tax dollars aren't being wasted on Vaporware
Is there a button to switch it from 'water' to 'beer?'
I was thinking of Dune myself. Frank Herbert's notion that man could survive with such limited water supplies apparently wasn't entirely fantastical. However, IIRC no such device was used in the series. Instead, the Fremen relied on farming the naturally forming dew of the planet. Personally, after reading Kim Stanley Robinson's Mars trilogy, I wonder why Herbert never thought of having some Fremen just crash a few comets into the planet to at least provide some selected portion of it with water. Of course, that would have killed off all the sandworms.
Sounds like they probably use a hydroscopic compound such as calcium chloride and then you some type of ion replacement to recover the water (precipitate calcium metal and some other non-soluable salt, such as Fe(III)Cl.
Cool! Amazing Toys.
What I really need is a droid that understands the binary language of moisture vaporators.
Asked to clarify how it worked, the CEO noted- "Just add water, and in a few minutes it'll be ready!".
--Q
Here we are, as promised. About a third of the way down the page. Ignore the Reichian weirdness, the wells were built near the ancient Byzantine city of Feodosiya. There were 13 large conical tumuli of stones, each about 10,000 feet square and 30-40 feet tall, on hilltops. Russian engineer Friedrich Zibold calculated they would each produce more than 500 gallons daily. These theories have been disputed by some archeologists (who don't seem to like it when engineers discover cool archeological stuff and make up theories about it) but the mounds do all have numerous terra-cotta pipes around the base, presumeably to collect the run off
- None can love freedom heartily, but good men; the rest love not freedom, but license. -- John Milton
Some good Vaporware!
Who is going to provide the guards for these condensers, because you know that the local warlords and privileged will abscond with them as another source of wealth and power. There's more than just buying the equipment, there is maintenance and policing, just to name the obvious manpower needs.
Yet further down
Anybody with half a brain knows that there has to be some humidity in the air in order to extract water. Wait, that explains it.
While it is an accomplishment to reduce the humidity requirement, it doe not eliminate it. Indeed given their claim of up to 600 gal/day I'd say that at the minimum required humidity of 14%, it is possible that they may require far more of them than is talked about. A key factor is how rapidly that output drops when the humidity levels drop. if it porduces 600 gal/day at optimum humidity levels, it may only put out say 10 gal/day. If that were the case you could not rely on this for troop support in such areas. A supplemental, sure.
Depending on the size and maintenance requirements, as well as the phsyical inputs other than air, it may not be cost effective to use these in more arid regions. Now, places like the southern US they would be quite useful.
What I'd like to know is the size and power requirements. Something like this could be quite useful in high-rise buildings. Pumping water to the upper levels requires a significant amount of power. If instead we could put a few of these on tops of buildings and use them to bring water down, we might see a net win in terms of supply and energy usage. Imagine places like Phoenix or Las Vegas.
Pheonix has an average daily humidity of about 55% IIRC. Thus it would stand to reason that these units could pump out their maximum output. Depending on their size and power requirements, several of these atop an office building in Phoenix could produce several thousand gallons per building. As office buildings their water requirements might be low enough to satisfy with these units. They would have the further advantage of dehumidifying the hot air of Phoenix, thus possibly resulting in a slight cooling load reduction.
Even small residential units could be tremendously benefited. The average person requires 125 gal/day. Thus one of these could supply the water needs (not counting grass lawns) of a family of four in Phoenix. If the house is designed with greywater and systems for landscaping purposes it is possible that one of these could fully supply the average water requirement of a family of four in Phoenix. Which leads to the question
Anyone from Phoneix care to share how much you pay for water? If you've got a spouse and a pair of kids, and this unit eliminated your water usage bill (there would still be sewage), how much would it save you per year?
40,000 of these units in Phoenix would drop the summer daily demand for water by 24Mgal/day, or 5-12% depending on the season (Summer to Winter).
Essentially, if this proved cost effective then the more arid parts of the country might be able to make large savings on their infrastructure and supply costs. Which would be yet another miltary requested technology applied to positive civilian use.
The next question is: does it scale up and down? Can it be scaled down to be an effective one-person supply? Do larger units demonstrate a better-than-linear increase in water production?
Combine this with greywater systems, solar thermal heating (water and home), and appropriate landscaping and we would be a long ways toward a more sustainable system - without major changes and reductions to our standard of living.
My Suburban burns less gasoline than your Prius.
It sucks the moisture out of the air, then you heat it up and evaporate the water, leaving the salts behind to be reused.
The great thing about is, all you need is a heat source. You can either burn fuel, or use waste heat coming off a turbine, or even use solar energy -- you need temperatures above boiling, but not too much higher.
This is the same stuff they use for solar-powered heat pumps, except there they use a closed loop system, and evaporate the water at low pressure to get air conditioning.
Government is very poor at creation and is typically very poor at selecting future winners in the technology race.
See also the Internet you're using to post your comment. Oh wait, DARPA created that, nevermind.
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1) Water from plants is always drinkable. I'm talking about water from the root system, not some stagnant water you could slurp out of a recess between branches. The easiest way is to take a large trash bag, grab a cluster of branches and put the bag around them (make sure the open end of the trash bag is tightly sealed to prevent air from going into the enclosed bunch). It forces the tree to "sweat" water from its root system. After about 24 hours you can slit the bottom of the bag and drain it into a nalgene bottle. You can only do one group of branches per 24 hour period, so you need to use different trees to gather water. I tried it out when I was in Eastern Oregon (which, for all intents and purposes, is an inland desert) and averaged about 1 liter of water per 24 hours. I had 6 trash bags that I normally have in my hiking ruck, so I could feasibly harvest 6 liters per day if I was SOL somewhere.
2) A cluster of birch trees usually means there's water underground.
3) Any multi-celled berry (ie: raspberry) is edible.
Anyway, I thought it was pretty cool shit, and informative. :)
I like big butts and I cannot lie.
A solar still produces water in the desert and uses no external energy source other than sunlight (there is plent of that in the desert)
Of course it has a shelf life. Over time bacteria could potentially grow in your bottled water. Bottling methods aren't 100% sterile, nor do they maintain their seal until the end of the universe. Hence you assign everything meant for human consumption a shelf life based on some extremely conservative estimate of how long the product is likely to remain uncontaminated under "normal" storage conditions.
Two things.
1: Water does have a shelf life, which is why if you're storing it for long periods you have to add stabilizers.
2: The bottles can leach into the water over time, and some plastic bottles are set up so that they will begin to bio-degrade in a couple years, hence the date stamped on each bottle when you buy them.
My mom says I'm cool.
It's only an issue if water is permanently removed from the environment, which it generally won't be. Water was in the air and in a few hours, it is back again.
This is actually much better than trucking in water from afar or pulling it out of deep wells. In that case, you are altering the environment. Water not previously in the environment is being added.
Meh, I also do not think we should have gone to war in Iraq. It is, however, not correct or productive to place the blame on the troops, and since they're over there following orders as best they can, they deserve our respect and the best logistics/support that we can manage to give them.
One time I threw a brick at a duck.
All the Alton Brown geeks in the house should have perked up their ears when they read that. Salt is hydroscopic; it attracts water. Sugar is also hydroscopic, but salt is much cheaper (especially if you don't need food-grade salt).
There are two ways salt is harvested by humans: evaporation and mining.
I can see using salt to grab the moisture in the air present in the pre-dawn skies, but I don't rightly know how to make the salt give it back up. I assume they just cook the rocks and capture the steam. Salt, being a rock, can be heated lots of times before degrading.
I imagine a process like this would produce fairly clean water.
Give up for Food Science! Hell ya!
If a job's not worth doing, it's not worth doing right.
One of the problems which has dogged airships from day 1 is the inability to replace the weight of burned fuel. There's a couple ways you can deal with this problem, but none of them are ideal. Modern blimps and airships are actually heavier than air, relying on lift from engine pods to get the airship in the air. As they burn fuel they get lighter, but they're never actually "lighter than air". Early airships were much too large for this strategy especially since engine technology was far less advanced.
The most successful airship in history, the Graf Zeppelin, used a gas called Blau Gas to power its engines. Blau Gas is just a mixture of propane and hydrogen that weighs the same as air, so when you burn it and the gas volume is replaced by air of the same weight you don't have any buoyancy problems. Graf Zeppelin used hydrogen, which is relatively cheap, for its lifting gas. If it became too light they could vent enough hydrogen to restore neutral buoyancy.
But this scheme wasn't very efficient, from an engineering perspective. Every cubic meter of fuel was a cubic meter that couldn't be used for lift. Also, as they designed the Hindenburg they were concerned about safety, so they decided the Hindenburg would be filled with helium instead of hydrogen. Since heliem is about 10% less efficient as a lifting gas, Zeppelin engineers decided they just couldn't live with Blau Gas. Also, Blau Gas has the same safety drawbacks as hydrogen. Helium is much more expensive than hydrogen, so if the company was to be profitable there was no way they could just vent helium when the ship was too light. So if they were to use diesel fuel exclusively in the Hindenburg, they needed a way to add weight to the airship in flight.
The solution was to remove water from the air and use it as ballast to replace the now-missing diesel fuel. The system they designed used a silica gel, the same stuff that comes in a little packet labeled "DO NOT EAT" when you buy a pair of shoes. Ambient air was blown over the gel, which is highly water absorbent. The gel was then heated using waste engine heat to produce water vapor, which was collected in a condenser. Eventually they decided to use the diesel exhaust (which is apparently very humid) instead of ambient air. This was 70 years ago.
Yep. Star Wars, the story of a poor kid on Arakkis who grew up and went to Trantor. But movies and TV series routinely rip off whatever they can, tweaking it just enough to (usually) avoid lawsuits.
Not to say that science fiction (and other) writers don't rip off too, but they're usually much better at filing off the serial numbers, and taking from totally different genres (as well as being long since in the public domain). Asimov's inspiration for the Foundation Trilogy (back when it was a trilogy) was, loosely speaking, "The Rise and Fall of the Roman Empire". Forbidden Planet was loosely based on Shakespeare's "The Tempest" (and of course Star Trek ripped off a lot from Forbidden Planet). And so on.
(In fact Hollywood is often closer to the original when they rip something off than they are when they buy the property and make a movie from it. Joke. Joke.)
-- Alastair