Slashdot Mirror
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
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.
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
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.
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.
This sig has been temporarily disconnected or is no longer in service
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.
I thought Vaporware was the desired result here, no?
If it's American beer, there's really not a difference.
Only two things are infinite, the universe and human stupidity, and I'm not entirely sure about the universe - Einstein