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Science Technology

Alchemy in the Desert, Diesel Exhaust into H2O 63

Carl Bialik writes "The Wall Street Journal is reporting that 'Using technologies developed for the space program, the U.S. Army is conducting an experiment that could convert the exhaust pipes of military vehicles into water fountains.' The idea is meant to help alleviate the logistical challenges presented by two essential army liquids: water and diesel fuel. A soldier in the desert needs about 20 gallons of water a day, for all purposes; 'Water gets to the front in vulnerable, slow-moving truck convoys that require armed escorts, or it is pumped from local rivers, lakes or ponds and purified by heavy-duty filters.' And maybe, in the future, it will also be extracted from diesel exhaust. The president of a company that developed the test technology tells the WSJ: 'This is one of those things where, when you first hear about it, you think the scientists have gone out of their minds. But once you taste the water, you realize the potential.'"
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Alchemy in the Desert, Diesel Exhaust into H2O

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  • We all know vehicle exhaust is pretty nasty.

    Anyone know how the filtration system performs in regards to removing exhaust toxins(benzene, sulfates, etc)?

    • by DasBub ( 139460 ) <> on Wednesday October 05, 2005 @01:18AM (#13719784) Homepage
      I hear that reading the article is generally a good thing to do before posting.

      Thanks for playing.
      • I did RTFA.

        However, TFA only talks about piping the exhaust through a cat and 6 proprietary filters - making it comparable to tap water.

        Potable water is essentail for life. However, it doesn't mean there aren't nasties in it still. Fore example, the city water I get is primairly ground water (95%). This water has uranium in it. If this water was piped directly into homes/businesses, it would be approaching acceptable limits. So what is done about the uranium? Dilute it down with mountain runoff!

        So just
        • While I grew up in a household that lived off of bottled water until my parents got around to buying an inline filter (we had a well with some minor bacterial problems, drinkable but certainly not Evian), there are plenty of people that don't have the money to waste on bottled water or fancy filters (such as myself now that I'm on my own). They live off of city tap water their entire lives. As you alluded to in your post, there are acceptable limits for contaminants defined by the U.S. government. It wouldn
        • i also did rtfa ... this article is just complete nonsense from the militar point of view:)

          if the filter system gets 1 bullet, it's baked and the regular soldiers who can't fix it will just die into water exhaust. maybe a bullet is even overdone, one serious bump on a "good" iraq highway and you're baked. and there is no walmart over there neither to get the spare parts :D. if you go into desert, all you take along should be fixable by you and by simple means.

          if they need water, then they better rely on thi
        • You intake uranium every day in your food anyhow, and it's actually a very common element (just not the isotopes used to build nukes). It's in everyone's drinking water. .htm [] has some info you'll want to read.
    • you know what's real nasty? having to use water purification tablets.

      oh yeah, a bullet in the head is nasty too.

      that firms only reason to exist and get money would be in having a way to purify that water though.
      • if you really hate tablets, get a real filter. sure it costs a good chunk of change, but I've talked with hardcore hikers and they swear by their filter.

        For me, I don't hike enough (heak I stoped ever since my JR year of college), but I just brought about 2 gal of water and it's good nuf for half done wiht pleanty to spare.

        Tip: Put a gallon jug about 2/3 full into the freezer a day before departing for a long day hike. The best ice water you've ever drank!
  • by Muhammar ( 659468 ) on Wednesday October 05, 2005 @12:54AM (#13719712)
    "But once you taste the water, you realize the potential."

    Perhaps a coffee flavoring agent for Folger's "value roast" blend, sold for office use only?
  • by jd ( 1658 ) < minus city> on Wednesday October 05, 2005 @01:09AM (#13719757) Homepage Journal
    But once you taste the water, you realize the potential

    This could mean any of the following:

    • Their process uses electrical currents, so what you get when in contact with the water really IS the potential
    • They've discovered a way to turn the pollutants into hallucinogenic substances, allowing them to earn a fortune
    • Same as the above, only they can pipe it into their opponent's water supply
    • Same as the above, only the troops are now berserkers and think they're indestructible
    • They've discovered a way to turn the fumes into something that will make photographs invisible to journalists
    • The water is, in fact, the elixier of life, so forever guaranteeing no US casualties
    • They have discovered a way to fractionally condense diesel fumes which they will patent and use to collect the revenue gained by suing every school in the western hemisphere for having physics or chemistry textbooks
  • by Wierd Willy ( 161814 ) on Wednesday October 05, 2005 @01:13AM (#13719770) Journal
    Scientific American had an article about 15 years ago on this.

    Wired has a good article on this:,1294,65035, ml []
  • Chlorine? (Score:2, Funny)

    by deglr6328 ( 150198 )
    It is quite surprising to hear them say they use chlorine for disinfection as the last step of the process. It does not look like they are using a reverse osmosis device to filter the water, only mechanical and carbon filters and judging from the look of the water color after filtering but before treatment by chlorine, it is not clean at all. Its brown! This would worry me A LOT if I had to drink it. The addition of chlorine to such a mixture is going to immediately create lots and lots of different types o
    • Re:Chlorine? (Score:2, Informative)

      by GameMaster ( 148118 )
      From the article:

      "From there, the decidedly unappetizing-looking water moves to a series of six "treatment beds," which consist of proprietary carbon filters developed by LexCarb. The first four filters strain out black gunk so that the water becomes amber. The final two filters remove remaining impurities, resulting in water that is as clean, or cleaner, than the tap water of many U.S. cities."

      Supposedly, the water is "cleaner than tap water in many U.S. cities" before they add the chlorine solution. The b
      • Re:Chlorine? (Score:2, Informative)

        by merphant ( 672048 )

        I used to work for a RO company; essentially the membrane splits salty water into extra salty water ("brine") and clean product water. A simplistic explanation is that the polar water molecules split the salt lattice into ions, which get surrounded by more H20 molecules. This means you get big H20/ion clumps that can't squeeze through the membrane, and a bunch more smaller plain old H20 molecules that do get pushed through the membrane. Typically before the membrane you have some prefilters to get out the b

        • It would be nice if they could transition to less destructive missions or disappear entirely, but at this point (and every point in the future) I think some of our "friendly neighbors" in the mideast and asia would be a little too pleased by that move. :-)
    • Re:Chlorine? (Score:4, Informative)

      by DasBub ( 139460 ) <> on Wednesday October 05, 2005 @02:45AM (#13720056) Homepage
      If you re-read the article you'd notice that the amber-coloured water was after four filtering steps, not the entire six.

      After the amber stage is reached, it goes through two more filters and then chlorine is added to keep the water from getting funky while waiting to be dispensed.

      So chlorine isn't used as a filtering agent, more of a preservative.
    • halogenated polycyclic aromatic hydrocarbons

      To quote Colonel O'Neill: "Uh ... what?"
  • First a Slashdot story about U.S. preparations for war: Army Eyes Anti-Sniper Robot [], then, after two other stories, this story, also about preparations for war.

    The mood in the U.S. is violent, and pro-violence, in general, it appears.
    • Whether you agree with the war or not, it's still natural to want to see the troops overseas get the best equipment we can give them. Unlike Vietnam, even the anti-war movement doesn't blame the individual troops and wish them dead (Honestly, I don't even know how prevalent that opinion was during Vietnam).

      Besides, military technology has always been a popular topic of discussion. The U.S. military gets all the neat toys so tech guys want to see what is cutting edge and sometimes the stuff ends up filtering
    • The US military has always been a prime innovator. Some of the technologies are destructive (that's their primary job after all, to defend the country with force) and many aren't:
        - computers
        - ARPAnet
        - jet aircraft (actually British military)
        - etc. other examples are all around us we don't even recognize.

      Notice that many of these probably weren't invented by the military, but the military made them work.
  • Skeptical! (Score:3, Funny)

    by mister_llah ( 891540 ) on Wednesday October 05, 2005 @01:34AM (#13719830) Homepage Journal
    I'd try it, but I'm afraid it'd give me gas! *rimshot*
  • Alchemy? (Score:4, Funny)

    by helioquake ( 841463 ) * on Wednesday October 05, 2005 @01:38AM (#13719851) Journal
    Alchemy? It seems like the process takes a simple chemical combustion, not atom-altering alchemy.

    It's bad when the old chemistry trick is viewed like some kind of magic...
    [nontheless, this is a cool stuff, though. Beats drinking my own urine via filtering.]
    • I'm surprised that people are surprised about this. Where do they think the water that drips out the end of their tailpipe comes from?
    • Alchemy? It seems like the process takes a simple chemical combustion, not atom-altering alchemy.

      AAHHH but they didn't tell you about the Transmutation Circle [] in the exhaust pipe! ;-)
    • Beats drinking my own urine via filtering.

      No it doesn't! Dune Rulez!!!11!1

    • hmmm, drinking your own urine...

      they should hook up a urinal to the inlet of this filtering setup, and add that reclaimed water to the mix. I bet if it cleans diesel exhaust enough to drink, it ought to clean urine just fine.
    • The general formula of hydrocarbons is CH2(n). From this you get:

      CH2 + 3/2 O2 -> CO2 + H2O

      An interesting thing is that the molecular weight of CH2 is 14, while the MW of H2O is 18; thus, you can recover as much or more weight of water than you supply as fuel. I seem to recall this being used on Zeppelins to replace the weight of the fuel they burned so that they would not have to vent (and later replace) lifting gas, but I am unable to find a reference with Google.

  • Moisture farming? (Score:3, Interesting)

    by rdwald ( 831442 ) on Wednesday October 05, 2005 @02:05AM (#13719919)
    Hamilton Sundstrand...also is completing a $1 million contract for a high-powered dehumidifier the size of a dorm-room refrigerator that can extract water vapor from the air, even in the desert. The Army plans to display the water-from-air box this week in Washington, D.C., at the annual convention of the Association of the U.S. Army, a lobbying and support group for active and retired personnel.

    They've invented vaporators!
    • Funny, that what I thought of at first too. Too much Star Wars as child I guess. I wonder if this could have civilian application in desert regions like the middle east or the Southwestern United States. I have to imagine that electicity might be a cheaper commodity in desert regions than water.

    • Speaking of getting water out of air in deserts, it can be done, even in air with little or no water vapor, but is very energy-intensive. Here's how: first, you liquify air. Separate out the hydrogen, then burn it. Condense the water vapor that results. This actually works, but takes a heap o power to run the liquifier compressor/fridgeration unit. The heat from the burning could be used in part to provide some of the compressor power but cannot supply all the energy. In theory, a solar-powered engine could
      • Re:Moisture farming? (Score:3, Informative)

        by Grotus ( 137676 )
        You realize that there is about half of one part per million of Hydrogen in air, right? Since at 32C (90F) the maximum water vapor is around 50,000 PPM, even with a relative humidity of 1%, there is still 500 PPM of water in the air, or 1000 times as much water as Hydrogen.
        • You brought up a good point. But surely the numbers cannot be constant across the globe, but only some idealized average. Also, I would assume that water vapor in a desert will rise, that is, stratification would occur and so air near the ground would be drier. Nonetheless, on researching, I find quoted in various places that the average relative humidity in the Sahara Desert is 25%. Though 'average' is a very loose term in this case. Somehow I still cannot see desert air containing any significant moisture
  • Only in Iraq will you realise the potential as you taste the water.
  • by tacocat ( 527354 ) <> on Wednesday October 05, 2005 @05:59AM (#13720566)

    I don't think this will work quite like a catalytic converter, which reduces he emissions into something less nasty. Rather it just extracts chemical H2O from the emissions. I was hoping for news that someone can actually convert the diesel exhaust into something less nasty. That would be a good thing.

  • What?!??! (Score:1, Troll)

    by mnmn ( 145599 )
    "needs about 20 gallons of water a day, for all purposes"

    We all know US soldiers are spoilt, but 20 gallons is rediculous. Did the world war 1 solders shower daily? Did the Civil war veterans need Jacuzzis? Its crappy food and rationed water for all other armies, bathe when you run across a river.

    "But once you taste the water, you realize the potential."

    I'll probably realize the potential too. In fact once I taste THAT water, I'll probably invest in nortel and place advanced orders on Duke Nukem Forever as
    • Re:What?!??! (Score:3, Interesting)

      by Handpaper ( 566373 )
      You beat me to it.
      I would add, though, that throughout the Napoleonic wars, and wherever in the world they operated at that time (including the Caribbean and Mediterranean), the Royal Navy's water ration was "one gallon per man, per day, for all purposes". This was an Imperial gallon, about ten US pints, but it shows what can be done if you try :)

      • Re:What?!??! (Score:2, Interesting)

        by sexylicious ( 679192 )
        Yes, and you could always smell the British and French before you saw them. ;)

        Actually, in the heat, the Army wants you to drink a gallon every four hours. And living in the high desert in California, I can honestly tell you that just breathing dehydrates you because the air is so dry. And it's not even as hot as the middle east!

        I would think the rest of the water is for shaving, face washing, food preparation, coffee, and cleaning. Showers aren't done too often unless you are near a base. Instead
        • by mnmn ( 145599 )

          Shaving? Out to fight for your country.. and looking awesome.

          Towlettes for wiping? Thats new to me.

          Food prep? Coffee? thats even more luxurious than my life, all in addition to the paycheck.

          If its WAR, its getting people to go and fight. Heck even uniforms are considered too formal, expensive and luxurious for armies in Afghanistan. Youre going to a place where either you or the other person will die. This becomes a matter of life and death. You dont shave, browse the web, drink coffee and watch movies
  • A soldier in the desert needs about 20 gallons of water a day, for all purposes

    Unless "all purposes" includes taking a shower or using a flushing toilet I'm not sure I understand this estimate. A person in the desert needs to drink perhaps 1 gallon of water a day to stay sufficiently hydrated. Where does the other 19 gallons go?
    • And the bulk of it is for bathing and the like. Amazing. I can understand this for established camps perhaps, but surely they don't bother with this on the front lines? If cleanliness is really that much of an issue, wipe down with a sponge. It'll take half a gallon of water and you'll end up almost as april fresh.
  • ...there is nothing here but a way to capture and purify the water vapor in engine exhaust. No magic, no alchemy. When hydrocarbons are burned, lots of various reactions take place, but most significantly:

    C + O2 = CO2, and
    H + O2 = H2O

    Internal combustion engine exhaust is chock full of that nasty pollutant, dihydrogen [] monoxide []. The only new and interesting development here is someone is attempting to perfect a method to capture that H2O in a useable form, at a rate of "one gallon of water for ever

  • A soldier in the desert needs about 20 gallons of water a day,

    Twenty gallons a day? I think not. That's a typo. They'd have to drink almost seven pints an hour over a 24 hour period. This article [] seems more reasonable in saying they need 3 or 4 gallons a day. The article says two gallons of diesel produce 1 gallon of water chock full of sulfer, benzene, and soot. Yum! Why not just fit the soldiers with Dune style stillsuits? [] They can drink their recycled pee and sweat. Yum!

"This is lemma 1.1. We start a new chapter so the numbers all go back to one." -- Prof. Seager, C&O 351