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A Clever New Approach To Desalination

Posted by kdawson on from the pass-the-salt dept.

jbeaupre writes "The Economist reports on progress by a company called Saltworks on using saline gradients to do the heavy lifting of desalination. In essence, Saltworks uses solar energy or waste heat to concentrate sea water. They then use the ionic gradient between the concentrated brine and two sea-water streams to pull ions from from a 3rd sea-water stream. It appears to work with entropy by trading the reduced entropy of the desalinated water against the increased entropy of 'mixing' the brine and the other sea-water streams. The article only discusses Na and Cl, but even just removing these ions is a step in the right direction."

8 of 128 comments (clear)

  1. Making Dew by lyinhart · · Score: 2, Interesting

    Thinking about desalination makes me remember that episode of "The Voyage the Mimi" in which they used the process to make drinking water:

    http://video.google.com/videoplay?docid=-524069894840499801# (A/V's not synced)

    --
    Freedom is drinking a beer in the park when you're supposed to be at work.
  2. Maybe by clang_jangle · · Score: 1, Interesting
    From TFA:

    The process begins by spraying seawater into a shallow, black-bottomed pond, where it absorbs heat from the atmosphere. The resulting evaporation increases the concentration of salt in the water from its natural level of 3.5% to as much as 20%. Low-pressure pumps are then used to pipe this concentrated seawater, along with three other streams of untreated seawater, into the desalting unit. As the diagram explains, what Mr Sparrow and Mr Zoshi create by doing this is a type of electrical circuit. Instead of electrons carrying the current, though, it is carried by electrically charged atoms called ions.

    Except for that last absurdly inaccurate statement (made me chuckle), this sounds really good. Not the fastest way to desalinate, so it would take an awful lot of these to meet demand (or one really gigantic one), but still this could be at least a partial solution.

    --
    Caveat Utilitor
    1. Re:Maybe by clang_jangle · · Score: 1, Interesting

      To say, " Instead of electrons carrying the current, though, it is carried by electrically charged atoms called ions" is inaccurate. The electron stream (which we call electricity) is still an electron stream. It would have been more accurate had they said, " Instead of using wires or cables to carry the current, though, it is carried by electrically charged atoms called ions."

      --
      Caveat Utilitor
  3. Vancouver saves the world? by Yergle143 · · Score: 3, Interesting

    OK between this and the General Fusion guys http://www.generalfusion.com/ Canada has got water and energy completely licked. http://www.saltworkstech.com/ OK actually I'm still trying to run the numbers on the both of them (and waiting for some peer reviewed publications.)

  4. Comment removed by account_deleted · · Score: 2, Interesting

    Comment removed based on user account deletion

  5. Re:Anyone else think... by tehdaemon · · Score: 2, Interesting
    An appropriate link: The Last Question

    T

    --
    Laws are horrible moral guides, moral guides make even worse laws.
  6. General Confusion by epine · · Score: 1, Interesting

    Thank you for that link to General Confusion. Made my day. Check out the freshman T-rex with his lava lamp and the sordid diatripe:

    http://www.generalfusion.com/fossil_fuel_crisis.php

    The planet was covered with dense clouds and the atmosphere contained a high concentration of carbon dioxide, producing tropical conditions north of the 45th parallel. For example, many dinosaur fossils were excavated in Alberta, Canada. As the earth's crust cooled down, volcanic activity reduced.

    Riddle of Burgess Shale's fossil-rich deposits solved

    The site, close to the B.C.-Alberta border, is considered crucial to understanding the so-called Cambrian "explosion" of life - a time when the future Canadian land mass was drifting in tropical climes close to the Earth's equator.

    In my historical atlas, the equator is considerably south of the 45th latitude. The dinosaur fossils in Alberta are equatorial in origin. But hey, if you can't get that right, no obstacle to solving the fusion problem. Like it's not a hard problem or anything. The typical Alberta fat cat oilman probably doesn't believe in plate tectonics to begin with. Just a bunch of mud we turn into money. Now they're all excited about version 2: just a bunch of water we turn into money.

    BTW, the Royal Tyrrell Museum in the Alberta badlands is pretty kick-ass if you're into bones.

  7. Reverse osmosis? by macraig · · Score: 1, Interesting

    Isn't this a large-scale demonstration of the same principle used in home reverse-osmosis systems? It sure sounds familiar.