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New Process Promises Ammonia From Air, Water, and Sunlight 117

Posted by timothy
from the kid-tested-mother-shocked dept.
The synthesis of ammonia is one of the globe's most significant industrial applications of chemistry. PhysOrg reports the publication in the August issue of Science (sadly, article is paywalled) the description of a low-energy process to syntheize ammonia for fertilizer using just air, water, and sunlight, by zapping with electricity water bubbling through a matrix of iron oxide, and sodium and potassium hyroxide. Electricity isn't free, though — "Low energy" in this case means two-thirds the energy cost of the long-in-use Haber-Bosch process. Researcher Stuart Licht is getting some of the energy to run this reaction from a high-efficiency solar cell he's created, which creates hydrogen as a byproduct. Along with the elimination of the need to produce hydrogen from natural gas, the overall emissions are reduced quite significantly. The whole process also takes place at milder conditions, not requiring 450C and 200 times atmospheric pressure as the Haber-Bosch process does. ... But even with Licht's method, [University of Bristol electrochemistry professor David] Fermin points out that we are far away from being able to replicate nature's efficiency at converting nitrogen from the air to useful chemicals, which is done by nitrogen-fixing bacteria. "What is truly remarkable is that nature does it incredibly efficiently at low-temperature," Fermin added. And yet, if something more efficient can replace the Haber-Bosch process, it would lower the energy input of the production of one of the worlds most important chemicals and lead to a notable reduction in global CO2 emissions.
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New Process Promises Ammonia From Air, Water, and Sunlight

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  • by Anonymous Coward

    This tech combined with the ammonia=>hydrogen tech mentioned here http://www.engadget.com/2014/06/27/hydrogen-fuel-cell-breakthrough-ammonia/ could mean cheaper/safer/easier hydrogen for all sorts of uses including fuel cells for homes and hydrogen fuel stations for cars

  • Nitrogen Cycle (Score:3, Interesting)

    by surd1618 (1878068) <tmoore1984@gmail.com> on Saturday August 09, 2014 @02:42AM (#47636117)
    How about we reuse all the fixed nitrogen we already made instead? Right now water in Toledo, Ohio is undrinkable because of algae blooms in Lake Eerie. I'm sure we use a lot of energy in the Haber process, but I think that's a trivial concern compared to the environmental problems we can cause if we keep pumping organic nitrogen into the environment. It could turn out to be a very very bad thing to do overall. I think we'd be way better off if we reduced ammonia production, rather than switching to a more efficient way to make ammonia. I'm all for innovation generally, but to me, this idea reeks.
    • Re:Nitrogen Cycle (Score:5, Informative)

      by budgenator (254554) on Saturday August 09, 2014 @10:22AM (#47637211) Journal

      Drinking Lake Erie water is scarry under the best of circumstances, even Detroit gets most of it's water from Lake Huron north of Port Huron. There is a lot of valuable lipids in that algae for make biofuel. There is a point where reducing nitrogen and phosphorus inputs are going to be effective in reducing blooms because the nitrates and phosphorus already in the eco-system keep recycling, removing the algae removes the fertilizer and breaks down the cycle. The exceptionally cold winter, cold spring, and cool summer also meant there was a very abrupt start to the algae's growth season in the summer rather than a more gradual start in the spring.

    • For 2 days earlier this week water in Toledo, Ohio was undrinkable

      FTFY

    • Algae can fix their own nitrogen with energy derived from photosynthesis, so releasing more nitrogen into the environment does not create algal blooms, because their limiting nutrient is still gonna be limiting, which is usually phosphorous. That's the reason why phosphorous containing detergents are banned, to keep the algae starving for it and not blooming so much.

      And by the way, if the pressurization cost is so high at the Haber Bosh process, they could do it in stages, just like desalination reverse osm

      • by surd1618 (1878068)

        I don't think that vehicles fueled by ammonia would be better for the environment than fossil fuels. This could be true if we didn't make mistakes or none of our vehicles ever leaked anything. But thousands of vehicles loaded with gallons of toxic gas cannot be safe, let alone the waste and by-products, both in manufacture and consumption. I'm not sure if huge increases in acid rain would be nicer than global warming. I'll grant it's not as bad as hydrazine.

        • Dude, it's like it's not even worth for me to being to explain, or where to begin, you're so retarded, every single thing you said except the hydrazine one is incorrect, so I'll just keep quiet and let you feel smart.

      • Also, hydrogen, lithium, boron, carbon and nitrogen - is a lineup that pretty much includes the whole beginning of the periodic table, with the exception of helium, which is unreactive, and beryllium, which is pretty toxic, and rare, but, by the way, the most energy efficient of them all, so for military applications it might find a niche. Hydrogen is too light to be used alone, so in combination with lithium, boron, hydrocarbons or hydronitrogens it's still used, so we can ignore hydrogen, with the underst

  • Ammonia fuel (Score:5, Interesting)

    by floobedy (3470583) on Saturday August 09, 2014 @02:51AM (#47636137)

    Something not mentioned here is that ammonia is suitable as a fuel in internal combustion engines. Ammonia is liquid under modest pressures (like propane), is easily transported, and will burn inside an engine.

    If we made ammonia out of nitrogen and water vapor, then it would become nitrogen and water vapor again when burned. It's a closed cycle that would not alter the composition of the atmosphere at all.

    It probably wouldn't be suitable as a fuel for your car, because of safety issues (if you hammered a hole in the fuel tank, the fuel inside would flash boil and could shoot out into your eyes causing a chemical burn). However it would probably be fine for trains, airplanes, ships, and so on, where special handling procedures could be enforced and people could be required to wear goggles before working on the fuel tank.

    • Re:Ammonia fuel (Score:5, Interesting)

      by mlts (1038732) on Saturday August 09, 2014 @03:22AM (#47636219)

      How would that be more dangerous than propane? LP gas would do exactly as stated above, if someone poked a hole in a fuel tank with their drill, they would get sprayed by rapidly evaporating fuel.

      IMHO, this might be the way to have a hydrogen economy. If a nitrogen fixing process is easy and economical, making liquid ammonia is a lot easier and requires less pressure than converting water to hydrogen via electrolysis.

      The downside is that ammonia has a bad rep here in the US. Because it is a major ingredient in meth, anhydrous ammonia tanks tends to be a prime target for "lab assistants" to obtain their reagents. However, if done right, ammonia might just be what is needed to make the "hydrogen economy" a reality, because it has a decently high energy density.

      Of course what would be nice would be a fuel cell that uses ammonia directly without the conversion to hydrogen.

      • Re:Ammonia fuel (Score:5, Interesting)

        by floobedy (3470583) on Saturday August 09, 2014 @03:44AM (#47636277)

        How would that be more dangerous than propane? LP gas would do exactly as stated above, if someone poked a hole in a fuel tank with their drill, they would get sprayed by rapidly evaporating fuel.

        Ammonia is caustic and would cause a chemical burn on the surface of your eyes, unlike LP.

        IMHO, this might be the way to have a hydrogen economy. If a nitrogen fixing process is easy and economical, making liquid ammonia is a lot easier and requires less pressure than converting water to hydrogen via electrolysis.

        It seems much more sensible to use ammonia than hydrogen gas, because ammonia has handling and storage properties similar to propane which solves the major problem of hydrogen gas.

        It makes a big difference if you can store something as a liquid and transport it through pipelines. That explains why oil sells for 10x more than coal, per BTU, and several times more than natural gas.

        • Ammonia is caustic and would cause a chemical burn on the surface of your eyes, unlike LP.

          I don't think the OP Realizes: This is not the propane you get at walmart. That stuff is filled with sufficient.
          Real ammonia is dangerous as hell. I'd be far more afraid of it than propane.

          I''ve personally broken a propane tank before by accident (don't ask) and it was cold... and smelled bad, but it didn't hurt anything. It also wont lite unless the air/gas ratio is just right so it's not like it would explode. Pierce and ammonia tank? That's some scary shit. You'd immediately get burned, severely. If ther

          • lol... "This is not the ammonia you get at walmart"
            I'm half asleep, sorry.

            • by dbIII (701233)
              Here's another way to put it.
              You think Anne Rand is bad? Well An Hydrous is far worse, she's rip your eyelids off in a second.
          • by Anonymous Coward

            those fertilizer plant explosions that are so big they cause earthquakes? That's usually ammonia.

            That's ammonium nitrate, which is about as similar to ammonia as nitroglycerin is to glycerin. And the reaction between ammonia and water isn't violent at all.

          • Real ammonia is dangerous as hell.

            I worked at a rubber latex factory during the 80's. We had a 44 gallon drum of liquid ammonia in a corner, I was the high school drop out who was hired to do all the dirty work, part of my job was to carefully fill an old baked bean tin with the stuff, climb a ladder holding the makeshift wire handle behind me as far as my arm would stretch, then carefully pour it into a 13 ton mixing vat of latex. Liquid latex normally smells of ammonia with about the same intensity as supermarket "ammonia" and yet the amm

          • Fertilizer plant explosions are not caused by ammonia, but nitrate, often as ammonium nitrate. Ammonia by itself is not explosive, in fact it won't even burn in air and will snuff out a fire. You need a fuel cell to efficiently use it.

            PS. I just looked it up and the Wikipedia page says:
            "The combustion of ammonia in air is very difficult in the absence of a catalyst (such as platinum gauze), as the temperature of the flame is usually lower than the ignition temperature of the ammonia-air mixture. The flammab

      • by dbIII (701233)

        How would that be more dangerous than propane?

        Don't guess or ask. LOOK IT UP - materials safety datasheets have been on the net since before there was a web - I used to browse them with Gopher.

        However, if done right, ammonia might just be what is needed to make the "hydrogen economy"

        No, and for a very good reason. It doesn't come as ammonia. It comes as something like oil or natural gas, then you get hydrogen out of that, and then you make ammonia out of the hydrogen. It's an extra step. You don't want

        • by floobedy (3470583)

          Don't guess or ask. LOOK IT UP... No, and for a very good reason. It doesn't come as ammonia. It comes as something like oil or natural gas, then you get hydrogen out of that, and then you make ammonia out of the hydrogen. It's an extra step

          Why don't you try LOOKING IT UP by reading the actual article before commenting? The article (and the discussion) is about making ammonia without oil or natural gas, using a process other than Haber Bosch.

          • I was referring to how the above poster can find out about the relative danger of propane and ammonia and get some real understanding. Got it now?

            And yes, I DO know what the article is about and know far more about how much effort is required to make ammonia using current methods than I ever wanted to know (around 1999 I spent about six weeks working all over a fertilizer plant during a shutdown including inside a lot of vessels - and I did some other stuff there at other times). This new process does so
            • by floobedy (3470583)

              I was referring to how the above poster can find out about the relative danger of propane and ammonia and get some real understanding. Got it now?

              I was referring to the paragraph I quoted, in which you were discussing making ammonia. I think you actually understand that.

              You didn't know we were discussing making ammonia without fossil fuels, and you made a big fool out of yourself. As follows:

              It doesn't come as ammonia. It comes as something like oil or natural gas, then you get hydrogen out of that, and t

              • by dbIII (701233)
                Of course I knew that, just as it is very clear to you that I was referring to the current situation of ammonia production. It's also probably harder to get the hydrogen out of the ammonia in secondary processes than from hydrocarbons - plus if it's fuel cell usage you do not need to go all the way down to hydrogen gas anyway.
                How about we treat it like a discussion and not some childish game where you feel a need to score points against others.
                • by floobedy (3470583)

                  Sure. Sorry to have offended you. I thought you were being snitty. I apologize for being aggressive in my response.

                  It's also probably harder to get the hydrogen out of the ammonia in secondary processes than from hydrocarbons - plus if it's fuel cell usage you do not need to go all the way down to hydrogen gas anyway.

                  I was originally thinking that ammonia could be used directly in internal combustion engines, as a replacement for oil when that starts to become scarce. Of course there are replacements for oi

                  • by dbIII (701233)
                    Well more NOx is a bit of a massive downside in that case but that's easy to deal with so long as there is plenty of water around (eg. ships, fixed installations etc). It may suck in L.A., Beijing etc in vehicles but so does everything from combustion if you have a lot in a tight space.

                    That's one reason I was excited about a process which produces ammonia using less energy.

                    I'm impressed because you can use it to make so much other stuff and currently it's made at very large scales. A few companies have a

            • Don't get too excited over it. They are zapping iron and water particles with electric, and they probably detected some bound nitrogen in the water, but the energy consumption was huge. In order to make any news release that has any point, they are guesstimating that long term they can drop the price to 2/3 of Haber-Bosch. I wanna see that. In fact I take two electric wires, make them spark, even an empty butane lighter, and keep sparking the flint stone on it, or two pieces of granite smacked together, spa

              • And by the way, LiI, lithium iodide, probably has a lower melting point and electrolytic decomposition temperature, than most of the other crap, like lithium chloride. Plus there may be aprotic polar solvents that really drop the melting point of it, but they might be different than the ones in lithium batteries, because at high temperature the molten lithium might attack the oxygen in the organic molecules. Similarly hexafluorophosphate may be unstable against molten lithium at high temperature, but any el

        • There are other ways to get the hydrogen other than hydrocarbon fuel.

          • by dbIII (701233)
            The problem is that currently none of them are anywhere close to being as easy.
            It appears from what little we have about this new process that the hydrogen is coming from brute forcing it out of water with electricity. Once again - you get your hydrogen and then you make your ammonia. Going backwards to get the hydrogen out again is an extra step involving extra losses and ammonia isn't a very good way to store hydrogen anyway.
        • MSDS's are often useless for anything but the very basic informations. You're better off reading some chemistry book from 1850 about a material, to learn to know it, and understand it, than from an MSDS. And MSDS is only there to cover a corporation's ass from lawsuits, as they are always unrealistic, like with a bar of soap they might say you wear full protective clothing, rubber gloves, steel toe shoes, rubber apron, faceshield, safety glasses, ear protection, and hardhats. Almost any chemical place or ev

          • There is so much wrong with that. If you dance into a leakage of HCl 20% on your tennis shoes you are screwed so fast you won't know what hit you. S3 safety shoes are required for a reason when working with hazardous chemicals.
            You should, however, test your safety shoes if you are going to walk on them all day. Your employer should allow you to buy your own and refund you (within reason). Take half a day to get the right ones, your back and knees are on the line here.

    • Another thing not mentioned is that ammonia and a lot of other useful fertilizing substances are quite prevalent in ... piss.

    • by surd1618 (1878068)
      Even if it only made 0.0001% nitric oxide and some kind of catalytic converter caught 95% of that, it would still destroy the environment faster than fossil fuels. And that's if none of the ammonia ever escaped from vehicles, let alone the industrial production and transport.
      • by floobedy (3470583)

        Even if it only made 0.0001% nitric oxide and some kind of catalytic converter caught 95% of that, it would still destroy the environment faster than fossil fuels.

        I doubt that. Burning a gallon of gasoline in an internal combustion engine produces about 1.5 grams of NOx, which is more than would be emitted by 0.0001% from ammonia combustion.

        And that's if none of the ammonia ever escaped from vehicles, let alone the industrial production and transport.

        Ammonia is a basic building block of life and is already

  • While it is theoretically more energy efficient to get our hydrogen from electrolysis than from methane, we mostly don't do so. Why? Because we can skip the whole burning fuels to create electricity steps, and go directly to making hydrogen. If we count the inefficiency of creating electricity then electrolytic efficiency decreases substantially.

    This new method uses electrolysis to generate a mixture of ammonia and hydrogen. This will likely be very useful in the future as solar and wind become widely depl

  • Some background (Score:5, Informative)

    by Okian Warrior (537106) on Saturday August 09, 2014 @03:33AM (#47636245) Homepage Journal

    Here's some background on the Bosch Haber process.

    Whether a reaction will occur is based on whether energy is required and whether the reaction increases entropy. In the case of nitrogen+hydrogen => ammonia, the reaction is both exothermic and increases entropy at room temperature and pressure. If one could somehow ignite the process it would be self-sustaining.

    The problem is, to ignite the reaction you first need to break N2 molecules into individual N atoms, and this requires a great deal of initial energy which is regained in subsequent steps. Something like 7eV per molecule to break them apart. The molecules in normal air have a bell-curve spread of energies, but very few of them reach energies this high: the reaction happens at room temperature, but very *very* slowly. A handful of molecules per second will react.

    To get around this you can raise the temperature, increasing the probability that molecules will have enough energy to break apart. The entropy produced is inversely proportional to temperature, so when you start to have N2 molecules with enough energy to break apart, the reaction is no longer favored because it would result in an entropy decrease.

    Since 4 moles of reactants result in 1 mole of product, increasing the pressure of the reactants will tend to favor the products [wikipedia.org], so you can use this to offset the deficit in entropy.

    The Bosch-Haber process tries to find a "sweet spot" by increasing the temperature to get a reasonable number of N2 molecules to break apart, and high pressure to make the process favor the products.

    At 200 ATM and 400 degrees, the yield is 15% (!).

    Reaction vessels for this pressure and temperature are expensive, and the process requires multiple cycles of compression, decompression, removal of ammonia, and recompression. This takes a *lot* of energy and uses *very* expensive compressors which wear out over time and have to be replaced.

    I haven't read the paywalled article yet, but if I'm understanding the abstract, they are breaking apart the nitrogen electrochemically. Just as running a current through molten NaCl will break it into atomic sodium and chlorine, running a current through nitrogen dissolved in KOH and NaOH breaks it apart and the reaction then proceeds at normal conditions. The reaction also supplies its own hydrogen by breaking apart water.

    Much of the "green revolution" is due to the use of nitrate fertilizers, and the source material is finite: guano from Peru, for example. [wikipedia.org]

    If this process is as efficient as the abstract suggests and can be industrialized, it would be *huge*. It would give us an essentially infinite source of nitrogen-based fertilizer and reduce the worldwide consumption of energy by a couple of percent.

    Coupled with a source of renewable energy, it would mean that the world could sustain its food production at current levels indefinitely.

    This could be really, *really* big news.

    • by Okian Warrior (537106) on Saturday August 09, 2014 @05:28AM (#47636439) Homepage Journal

      Before I get slammed by a P-Chem major, here's what's really going on with the entropy.

      The reaction is exothermic, and this release of heat increases the entropy of the universe. At the same time, 4 atoms of source become 1 atom of product, so this aspect of the reaction *decreases* the entropy of the universe. (There's more ways that 4 atoms can be arranged in a box than there is to arrange 1 atom.)

      At room temperature, the entropy increase from the release of heat is greater than the entropy decrease from the reduction in states, so the reaction is favored.

      The entropy from the release of heat is inversely proportional to temperature. Double the [absolute] temperature and you halve the increase in entropy from the release of heat. With higher temperatures, the entropy increase from "release of heat" is smaller than the entropy decrease from "change of states", the total change of entropy is negative, and the reaction is no longer favored.

      I wrote a simpler/shorter explanation to avoid losing sight of the main point.

      • by Livius (318358)

        I have to know: what does the 'P' in "P-Chem" stand for? (My best guess so far is something like probability.)

        • PChem stands for Physical Chemistry and is a two semester course generally taken by third year chemistry majors after at least two semesters of General Physics (calculus based), two semesters of calculus, though three semesters would be better, and a year of organic chemistry. Some might call it theoretical chemistry and generally covers chemical thermodynamics, chemical kinetics and quantum chemistry with some specialized applications such as electrochemistry, transport phenomena, and more.. It's not descr
          • On the advice of an ex-girlfriend, my lab partners and I got together and had Irish coffee the morning of our final PChem class, the one where the professor did a sort of view-from-orbit of everything we had learned during the second semester (quantum mechanics). She was right, it did make more sense if you were slightly drunk.
      • As chemistry majors know there are two aspects studied in understanding chemical reactions: chemical thermodynamics and chemical kinetics. Okian Warrier has described one of these, though without fogging the discussion with numbers, and I'm sure those are readily available. Kinetics involves the study of the mechanisms of reactions which involves the examination of details of molecular and atomic interactions, intermediate association of reactants and products, molecular structure, breaking of bonds, electr
    • Re:Some background (Score:5, Insightful)

      by mdsolar (1045926) on Saturday August 09, 2014 @09:51AM (#47637089) Homepage Journal
      "it would mean that the world could sustain its food production at current levels indefinitely" Sort of. We still need to get the effects of the faster nitrogen cycle under control. Right now, more corn means fewer shrimp as a huge dead zone develops in the Gulf of Mexico. The corn then feeds pigs in Pennsylvania and the nitrogen in the manure wrecks the oyster and crab harvest in the Chesapeake. All this can be fixed, but since one form of food production is stealing from another, the sustainability is in question for now.
      • by khallow (566160)
        The trade offs aren't that severe. There's a lot more corn and such grown than seafood production lost.
    • If this process is as efficient as the abstract suggests and can be industrialized, it would be *huge*. It would give us an essentially infinite source of nitrogen-based fertilizer and reduce the worldwide consumption of energy by a couple of percent.

      No good deed goes unpunished.

    • by khallow (566160)

      Much of the "green revolution" is due to the use of nitrate fertilizers, and the source material is finite

      Methane gas actually is the finite resource in question for nitrate fertilizer, used as a hydrogen source for the Bosch-Haber process. Guano is valuable as a source of phosphorus. Once that runs out, it's time for crushing phosphorus-bearing rocks.

      If this process is as efficient as the abstract suggests and can be industrialized, it would be *huge*. It would give us an essentially infinite source of nitrogen-based fertilizer and reduce the worldwide consumption of energy by a couple of percent.

      I agree though there is a trade-off between solar powered-nitrogen fixing and agriculture. They can't both use the same sunlight. But keep in mind that ther

  • So, how does this process compare economically to just growing nitrogen-fixing bacteria?

    -jcr

    • After someone's worked out a decent design for a pilot plant for the process that question will look a lot less like "I can't buy it at Walmart NOW? Then why waste my time?". For the moment it's just as irrelevant and likely to get at best polite answers from people attempting not to be patronising, although that's going to leave people unaware of how stupid such questions are very early in development of a new technology so I think it's better to be blunt.
  • It's Science. Accessible through any respectable library.
  • Would be develop a way to make air, water, and sunlight into petroleum without needing all the time it takes nature to do the same thing.
  • by TheRealHocusLocus (2319802) on Saturday August 09, 2014 @10:45AM (#47637281)

    When I hear about clever-but low energy processes that have low yield because -- and only because -- the scientists feel the need toss a stock photo of a windmill or solar cell into the paper to trigger that warm fuzzy feeling, I think to myself, "How cute."

    Decades of cuteness now. It's not cute any more.

    The world needs less cuteness and more large scale thinking. Gigawatts not milliwatts. We also need to get into reverse osmosis in a big way, so we can start to manufacture fresh water from salt and pipe it inland. This requires massive amounts of energy.

    Real Humans do not need to wait for rain, real humans need not wait for oil and gas to diminish in order to achieve the next step. Real humans better wake up and resume the industrial revolution. We are smart enough to keep it clean.

    Follow us down the rabbit hole [slashdot.org]...

    • I agree 100%. Using LFTR's you could direclty synthesize fertilizer from air. Solar power will always be too expensive and unreliable. Especially compared to a LFTR.

      http://nucleargreen.blogspot.c... [blogspot.com]

      • Grandparent is wrong about CUTE solar. TFA was about an invention by the same people who invented a kind of solar cell and the grandparent naively thought that it wasn't an opportunity to show off their other tangentially related invention... it was only about being "cute."

        Solar is not too expensive and it is extremely reliable!

        1) Solar costs less than nuclear. It's upfront cost is high (like nuclear) but it has zero fuel costs for it's lifespan unlike everything else except wind and hydro. (Nuclear fuel is

  • I have a device that produces ammonia from water and air already. It's called a "cat".
    • by X10 (186866)

      You have a special cat. Mine need additional components to create the ammonia.

    • You do so as well. BUt with your own urea and a light amount of electrolysis, you can produce your own hydrogen. Rotting bread dough produces tremendous amounts of hydrogen as well. I think hydrogen is being actively suppressed, along with diesel passenger cars.
  • This is a first step. Ten years from now our cars will run on synthetic gasoline, created from CO2, H2O and electricity from sunlight.

  • Russia has been using natural gas in efforts to economically blackmail various parts of Europe for a while now.

    One of the effects of this is to cause prices of fertilizer and as a result grain production and food costs in Eastern Europe to vary quite a bit depending on the political situation. This innovation would help considerably.

    Another nice aspect of this is that China is using a lot of coal in fertilizer production because for them it's a cheaper source of hydrogen than natural gas. This would help Ch

  • More specifically the symbiotic bacteria that they host. Nature has solved this problem already (and more than once) - no high pressures or temperatures needed.

    http://en.wikipedia.org/wiki/Azolla

     

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