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Water out of the air?

Tom Clougherty, the new face at the Globalisation Institute, linked earlier today to a fascinating Wired piece about a new way of extracting drinkable water from “thin air”.

Clougherty is wise enough to use the phrase “If reports are to be believed” when talking about the huge benefits that this invention might have. So, the question is: will it work?

It being, approximately, and give or take a big dollop of industrial (and presumably military) secrecy this:

“People have been trying to figure out how to do this for years, and we just came out of left field in response to Darpa,” said Abe Sher, chief executive officer of Aqua Sciences. “The atmosphere is a river full of water, even in the desert. It won’t work absolutely everywhere, but it works virtually everywhere.”

Sher said he is “not at liberty” to disclose details of the government contracts, except that Aqua Sciences won two highly competitive bids with “some very sophisticated companies.”

He also declined to comment on how the technology actually works.

“This is our secret sauce,” Sher said. “Like Kentucky Fried Chicken, it tastes good, but we won’t tell you what’s in it.”

He did, however, provide a hint: Think of rice used in saltshakers that acts as a magnet to extract water and keeps salt from clumping.

“We figured out how to tap it in a very unique and proprietary way,” Sher said. “We figured out how to mimic nature, using natural salt to extract water and act as a natural decontamination.

“Think of the Dead Sea, where nothing grows around it because the salt dehydrates everything. It’s kind of like that.”

The 20-foot machine can churn out 600 gallons of water a day without using or producing toxic materials and byproducts. The machine was displayed on Capitol Hill last week where a half-dozen lawmakers and some staffers stopped by for a drink.

More about this at engadget, where there is comment on the same Wired piece.

Do any of our more tech-savvy commenters have any other news concerning this apparently wondrous gizmo, or any opinions about whether such a thing is, in principle, likely to work?

27 comments to Water out of the air?

  • Clayton

    What an amazing discovery! Water out of thin air! This is most definitely one of those things that totally shatters our understanding of the world, I mean, it’s not like water has been falling from the sky on its own from for the past hundred zillion years.

    By the way, I believe Frank Herbert thought of this a long time ago.

  • Freeman

    A cooled surface causes water to condense out of the atmosphere when the local temperature falls to less than the dew point. So let the water drip off and collect it in a bucket.

    To test for yourself: just leave your refrigerator door open overnight and water from the atmosphere will turn to ice all over the interior. Happy defrosting!

  • Eric

    Allow me to repost a comment I made on slashdot:

    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.

    I doubt they could “make” as much water as the current version, but this was seventy years ago.

  • squawkbox

    I am writing this next to an airconditioner that is producing water out of thin air, and dripping it into my coffee.

  • K

    Eric. Thanks for the description of airship buoyancy problems. Very clearly written.

    I have worked on airplane design which required consideration of fuel burnoff to keep things well behaved. But it never occured to me that airships were actually somewhat heavier-than-air. Or that fuel burnoff was a problem for them.

    As for the water device. I suspect it involves some sort of membrane. Water molecule gets in easily but not out. As long as the water vapor can be condensed to keep the inside pressure low it can work.

    I certainly would like such a breakthrough. The benefits can hardly be imagined.

  • K – yes, I think Clayton is rather obtusely underestimating the significance of the development of such a device. In regards to Frank Herbert’s concept, it is one thing to dream something up; quite another to build it and make it work in all kinds of environments which, if the reports are true, is what Aqua Sciences has done before all others.

  • Nate

    What about Ammonium Nitrate? It’s hydrophillic, no?
    Let the ammonium nitrate pull in moisture, cook it, collect and condense steam (similar to the airship description above).

  • At first glance I thought this was a joke ( I am just out of bed after all). In all seriousness though what are the likely environmental implications? What if too much water is extracted in one area so that there’s not enough to fall as rain on anohter? Its all very well having the Sahara flowing with open water but I can see it making meteorology quite difficult. “We’re due some rain tomorrow if Libya doesn’t switch its water extractor on”
    Feel free to mock, but someone has to mention these things, if only to have them thought about by better brains and finally discounted.

  • Nick M

    That is certainly a point. I’m thinking Aral Sea.

  • My guess is it is a system that does not require large amounts of energy – i.e. no cooling plates or heating beads – but relies on natural action.

    I suspect our recent friend the nanotube or other forms of nanotech are involved, as this can increase surface areas considerably (see how lead-acid batteries will return as the ideal form once they get the lead plate surface area up by 40x due to nanotech). With a massive surface area in a compact space you need not be so “aggressive”.

    To me it would mean using the salt or a similar medium to absorb the moisture and then some membrane (as suggested) or other boundary layer using naturally occuring physical/chemical processes to draw out the water from the salt in a steady fashion.

    I delight in the ingenious yet simple solutions. Alas, they are so often dismissed by the ignorant as being “obvious” or “simple” and not worhty of value. Too many see “value” in overcomplex “complicated” “solutions” such as the NHS computer and think it worthy of vast sums and salaries.

  • In addition to the aircon / dehumidifier comments – I have one of the latter in my house, when I am drying laundry it can produce a bucketload of water per day – in the coastal regions of the Chilean desert, whole villages are supplied by dew-catchers which condense atmospheric water each morning.

    Picture: http://www.treehugger.com/files/2005/04/clean_water_fro.php

    Googling the term “dew-catcher” suggests t hat that practice is quite widespread.

  • Pa Annoyed

    The physics of extracting water from air is pretty easy – as noted, refrigerators and air conditioners do it incidentally; dew and rain naturally. You can buy dehumidifiers in the shops. The problem though is that it takes energy to do so. Coming up with a means of getting lots of water without requiring a massive energy input is rather harder. Whether that energy is input into the system during the process of drying out your hygroscopic substances, or continuously with refrigeration, you can’t avoid it.

    It’s quite possible someone has come up with a more efficient way of doing it, that makes it a bit more viable in poor communities, but it would have to be a staggering improvement to make a real difference to agriculture. 600 gallons is about 2 cubic metres – that might well serve a small village, but how many machines are you going to have to buy, and how much electricity will you have to supply, to turn the deserts green?

    WHO advice suggests between 20l/day per person for bare survival for short periods, up to 70l/day per person for subsistence. So you want one of these machines for roughly every thirty people (assuming it is their only source of water). Or put it another way, you can support an extra thirty people per machine. In water emergencies, up to 100 people could survive that wouldn’t otherwise.

    What sort of money can thirty sub-Saharan Africans put forward? These machines had better be cheap!

  • Petronius

    This is great, IF it works. Lately we’ve seen a number a dubious inventions looking for venture capital, including energy from the aether and cold fusion again. Take these with a grain (if not a pound) of salt.

    BTW, in the airship discussion it might be mentioned that one of the solutions to the burnoff problem was to condense out the water vapor present in the exhaust of the engines. The US Navy used this system in the airship Shenendoah. The problem is the drag caused by the condensor coils, which need the airstream to disappate the heat. A similar system was used by US and British troops in North Africa during WW2 to extract water from the exhaust of trucks. You might not want to drink it, but it was suitable for washing or cooling an engine.

  • Jacob

    The key issue is cost.

    In the article they mention a cost of 30 cents per gallon, which presumably expresses the energy cost, and depends on energy prices and availability.

    Maybe the machine makes sense in Iraq or Saudi Arabia, where they have more oil than water. Maybe it is cheaper than sea water desalination, which would be the main point of it, but this remains to be seen.

    If I’m not terribly wrong, desalinated water costs less that 1$ per cubuc meter (probably bow 0.5$). Now compare that to about 75$ per cubic meter for this new method…..

  • Russ

    @ Pa Annoyed:

    Yes, but if true, the ramifications for *agriculture* and high-quality irrigation are pretty immense. Farmers already spend big-bucks on center-pivots, and if they can’t afford them, on laying pipe, etcetera.

    Obviously cost even there would be a severe issue, as 600 gal ain’t anywhere near as much as it sounds, when a small backyard swimming pool has 12,000 gal in it…

  • Low power solution: Use a hygroscopic salt like lithium chloride or ammonium nitrate to capture water vapor from air- the air can be very dry to start with. The strong salt solution can be passed in a counterflow column against the air.

    Then pump the diluted solution to an elevated pressure and through a reverse osmosis membrane to extract the captured water while the salt is concentrated into the side stream. No heating or cooling of the soultion is required, so no bulky, heavy, and corrosion-prone heat exchangers are needed. The re-concentrated solution can be passed through an energy recovery device such as a water turbine so that the net pumping work needed is only the desalination of the salt solution (plus losses).

    Granted, the liquid-to-air contactor is a lot like a heat exchanger- but can be made of teflon or such, and needs lots of area, but not thin walls. A bit like the porous pads of an evaporative cooler, but working in reverse.

    Some sort of sulphate might be better than a chloride or nitrate, since RO membranes can reject sulphates much more thoroughly. Sugar can also serve quite well, but may ferment if airborne microbes get into the solution. This system wants a very hygroscopic salt or organic compound that is easily separated by RO- selection is an exercise for a 3rd year chemistry student.

    David Jones (no relation), the author of “The Inventions of Deadalus” column that ran in Nature and New Scientist for many years, came up with this basic idea about 20-30 years ago. Tongue in cheeck, he suggested a water tower filled with treacle, with an exposed upper surface, and sufficent height to allow RO purely by hydrostatic head at the bottom.

    (This may not involve rockets, but it is plumbing, my forte.)

  • veryretired

    One of the major points in Lonborg’s book, “The Skeptical Environmentalist”, was that the immense costs associated with many of the steps demanded by the proponents of ” The Litany” would soak up resources better used in other areas.

    The expense of Kyoto, for a minimal return, was one example, among others, of a terrifically expensive proposition made without any consideration of which other possible initiatives made more sense.

    Lonborg then proceeded to discuss the enormous impact on public health and, especially, child mortality, if only a fraction of the money was spent on providing clean water for various parts of the earth that are in desperate straits. Millions of lives could be saved.

    Now, this particular “invention” might be something and it might not, but to dismiss any potential development in this area as childish or meaningless is a pretty cavalier attitude towards people who are in real trouble.

    If anyone remembers, one of the big scandals of the ’70’s was the accusation by pre-anti-globalists that the Nestle company was killing babies in the developing world by selling cheap powdered baby formula.

    As it turned out, there was nothing wrong with the formula—it was that few of the people had access to clean water. When mothers mixed the formula with polluted water, the kids got severe diarrhea and died.

    Norman Borlaug, the father of the Green revolution in agriculture, was recently at an international meeting about the failure of African farmers to adopt the modern methods that have fed billions in other parts of the world. One of the key problems, among many, is the lack of clean water for irrigation.

    I live in the Midwest of the US, the nothern tier of which is the remains of a huge post-glacial swamp. If a person just started walking in any direction, within a few miles they would be walking into water.

    Someone mentioned Dune. I live in a fresh water Calaban. (Was that the Atriedes’ planet’s name?) I cannot imagine life in the opposite environment, esp. for a family with young children.

  • Alasdair Robinson

    Speaking of environmental concerns, water vapour is responsible for about 90% of the “greenhouse effect” that keeps the earth at a nice balmy temperature. Without water vapour the average temperature on Earth would drop to about -17°. I wonder if Aqua Sciences has given this much thought.

  • Robert

    If you let salt absorb moisture from the air at night when it is cooler and more water would be about in the air, then you could use the sun to ‘cook’ the water out during the day. Condense and store said water and there you are.
    Is my cheque in the post?

  • I wonder if Aqua Sciences has given this much thought.

    Speed: “I can’t breathe. That lousy machine is sucking everything out of the air. I’m telling you that thing could kill us. They’ll find us here in the morning with our tongues on the floor.”

  • Jacob

    Don’t worry. There is NOTHING that man can do to lower or raise the temperature of the whole globe significantly.

  • Jacob

    Ok, here is a comparison of prices:

    Water desalination(Link): 1000 – 4000 $/AF which is 0.81 to 3.24 $/cubic meter (depends on the plant and system of production).

    Water from “thin air” – 80 $/cubic meter.

    No comparison at all. Not suited for large scale production of water.

    It might nevertheless be useful. Desalination requiers a big plant, enormous investment, and is geared toward producing huge quantities of water.

    In some cases, where you need small quantities, and prefer to haul along a 6 foot machine rather than a water tank – well – it may be useful.

  • Midwesterner

    “There is NOTHING that man can do to lower or raise the temperature of the whole globe significantly.”

    Jacob, nothing like an equivocal statement, eh?

    Wrong, though. And fairly convincingly demonstrated from data and research.

    And this shows that by far the warmest winter on record in Madison was the one that followed 9-11. Which is highly collaborative.

    Here is the transcript of a BBC Science and Nature program.

    That same day that David Travis was looking at the sky in amazement, I was just a few miles away, doing the same thing. When I drove to work that day, my chin was on the steering wheel as I stared up at the sky. I had to swerve back on the road occasionally, and force myself to stop staring when traffic approached. When I got to work, I just stood and stared at the sky.

    Why? Because, never since my childhood, have I seen the sky here in the Midwest so crystal clear and deep. It was bringing back memories of a sky that most of the next generation, who don’t remember before airline dereg, have never seen. In the coming days, as flights slowly resumed, the sky returned to ‘normal’.

    David Travis showed that this effect was more than visual. That contrails significantly effect temperature.

    We do effect global temperature. And it’s difficult for rational people proposing rational responses to maintain credibility with people like yourself making such sweeping statements that are quite clearly false.

  • Ron

    Alasdair, mandrill –

    Aqua Sciences has probably not worried too much about the environmental effects of extracting water from air since the impact is effectively nil. I took a quick jaunt over to the USGS web site (sorry, lost the link). If I did my conversions correctly, the atmosphere contains about 1.29E^13 liters of water at any given time. That’s the whole earth of course, but to provide some more perspective a 1″ rainstorm will dump 17.38 million gallons of water in a square mile area.

    Also, remember that water is not destroyed when used, just rented for a while (to paraphrase an old joke). It evaporates somewhere along the line and enters the atmosphere again.

  • K

    Cost counts, or everyone would do this almost everywhere. But don’t compare it to desalination or purification costs – different market.

    The entire value is that air extraction doesn’t require a ground water source. Many areas simply lack water – fresh, saline, or otherwise contaminated.

    Couple of points. The water vapor in air comes from ground water evaporation. If man extracts water from the air then more evaporation of ground water will occur to replace it. It is a matter of vapor pressure. Otherwise rain would eventually dry the air of the entire planet.

    We will not create deserts by taking water from the air.

    Someone mentioned there is more water in the air at night. No. The amount of water is the same down to the dewpoint. What changes is the relative humidity.

    But it is easier to extract water from air when it is cooler at night. When nature does it in winter the result is frost, in summer we have dew.

    Petronius. Are you sure the problem was drag on the coils? Airships go pretty slow, I would think drag would be less of a problem than the weight of the coils. But that is just guessing on my part. You may know.

  • Dishman

    … a solar powered salt cycle air conditioner, with the fresh-water side as a drain and the cooling coils fed open air… you might actually be able to get a little bit of electricity out of the process as well… (an inefficient solar power plant).

    It doesn’t sound like that’s what they’re doing, though. I don’t think we’ve got the material sciences down to use the Lotus Effect. Lots of possibilities, though.

  • Tim

    It is a pretty cool idea. Not sure of the unit costs though. I did find out a way to own the technology a heck of a lot cheaper than I am sure the units cost. Just buy shares in UCS: http://finance.yahoo.com/q?s=UCSY.OB