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Desalination Technology

Home Forums Archive Infrastructure Desalination Technology

This topic contains 23 replies, has 18 voices, and was last updated by Avatar of Morganism Morganism 3 years, 4 months ago.

Viewing 9 posts - 16 through 24 (of 24 total)
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  • #6848
    Avatar of Michael-Hawkins
    Michael-Hawkins
    Participant

    Desalination through distillationg is very simple and incredibly cheap if you actually have a purpose for the heat that ends up in the steam/water.

    A simple still requires inredible amounts of energy to produce a little water, but it can be economised greatly. The first step would be to use the distillate as well as the waste fluid to pre-heat the feed water. What heat remains in the “now fresh water” may be used for heating if required, perhaps fed into thermal batteries for the night (that would be done before pre-heating the feed, not after).

    I don’t intend to give up hot showers in the long run either …

    The waste product (water with a highly elevated salt content) may be used to produce salt. We will most certainly have some need for salt ourselves, but I doubt it would make a good export product. Dumping the waste back into the ocean may be more economical, we are just talking about salt into the ocean here. We exhale, vapor forms clouds and the rain dilutes the ocean back.

    #6852
    Avatar of i_is_j_smith
    i_is_j_smith
    Participant

    I just watched an episode of Survivorman that I had seen before where he distills water from his own urine using nothing more than a cup, a hole in the sand, and a piece of plastic. You put the “bad” water in the hole (he just peed in the hole), cover the hole with the plastic, place something in the center of the plastic to make it dip down, then put the cup under the low point of the plastic. Wait a day and PRESTO a cup of drinkable water.

    Standard solar distillation. No reason a seastead couldn’t do this on a large scale. People keep talking about how space is a premium, but I disagree. We are on the open ocean here, people. We got all the open space we need. No reason you couldn’t float a massive solar distiller next to the seastead. Make it a hybrid distiller/raincatcher and you could have plenty of fresh water. Throw in a few commercial watermakers as a backup and you should be good-to-go.

    #6871
    Avatar of libertariandoc
    libertariandoc
    Participant

    Michael wrote:

    Desalination through distillationg is very simple and incredibly cheap if you actually have a purpose for the heat that ends up in the steam/water.

    A simple still requires inredible amounts of energy to produce a little water, but it can be economised greatly. The first step would be to use the distillate as well as the waste fluid to pre-heat the feed water. What heat remains in the “now fresh water” may be used for heating if required, perhaps fed into thermal batteries for the night (that would be done before pre-heating the feed, not after).

    I don’t intend to give up hot showers in the long run either …

    The waste product (water with a highly elevated salt content) may be used to produce salt. We will most certainly have some need for salt ourselves, but I doubt it would make a good export product. Dumping the waste back into the ocean may be more economical, we are just talking about salt into the ocean here. We exhale, vapor forms clouds and the rain dilutes the ocean back.

    Hmm. Like cooling a nuclear plant?

    +++++++++++++++++++++++++++++++++++++++++++++++++++++++

    I won’t be wronged. I won’t be insulted. I won’t be laid a-hand on. I don’t do these things to other people, and I require the same from them.

    #6872
    Avatar of libertariandoc
    libertariandoc
    Participant

    i_is_j_smith wrote:

    I just watched an episode of Survivorman that I had seen before where he distills water from his own urine using nothing more than a cup, a hole in the sand, and a piece of plastic. You put the “bad” water in the hole (he just peed in the hole), cover the hole with the plastic, place something in the center of the plastic to make it dip down, then put the cup under the low point of the plastic. Wait a day and PRESTO a cup of drinkable water.

    Standard solar distillation. No reason a seastead couldn’t do this on a large scale. People keep talking about how space is a premium, but I disagree. We are on the open ocean here, people. We got all the open space we need. No reason you couldn’t float a massive solar distiller next to the seastead. Make it a hybrid distiller/raincatcher and you could have plenty of fresh water. Throw in a few commercial watermakers as a backup and you should be good-to-go.

    I’ve done that too – the amount of square footage needed is pretty impressive (for enough for a person to just survive in temperate conditions, you would need 5 or 6 separate 6′ square collection devices / solar stills. One cup of water a day isn’t going to do it. The collectors cannot be floating on the ocean, btw unless they are stabilized. The rocking of the waves will spill the collected water, contaminate it with seawater or whatever you’re distilling, and spend more than half the time pointed in a direction less than optimal for collecting the sun’s heat.

    +++++++++++++++++++++++++++++++++++++++++++++++++++++++

    I won’t be wronged. I won’t be insulted. I won’t be laid a-hand on. I don’t do these things to other people, and I require the same from them.

    #6876
    Avatar of i_is_j_smith
    i_is_j_smith
    Participant

    I use this website as a reference (http://www.solaqua.com/solstilbas.html) and it says you can get up to six liters of water a day in the summer per square meter.

    In a survival situation you can of course only get a cup or so from your urine. We have all the water we need…we just need to distill it. A few very large raincatcher/solar distiller platforms floating next to the seastead should work fine. You can stabilize them just as you do the seastead…I would have them inside a breakwater. But I’m sure you can design the system so that it can handle shaking and rocking without loss of water. It doesn’t have to be just a floating cup!

    And a circular pit-style distiller should work pretty well during the day. If you wanted to get fancy you could build a slant-style distiller and give it some basic sun-tracking mechanisms.

    I prefer commercial watermakers, as long as we have the power for them. My point was just that we don’t really need to worry about space so much…we have all the open space we need out on the ocean.

    #11127
    Avatar of
    Anonymous

    fdecruz wrote:

    It sounds like a good technology. The money is still needed to build the desalination plants though.

    SPAM

    If this is from a ‘bot, it is the most “sensible” one I ‘ve seen yet, soon we may not be able to tell ‘bots from people.

    #11484
    Avatar of goedjn
    goedjn
    Participant

    peters wrote:

    Just out of interest, does anyone have information on the methods and their efficiency of gathering air humidity and converting it into liquid water?

    The Wikipedia article on the closest topic seems to be more of a commercial resource, offering some comparisions, but a more conclusive source would be welcome.

    In my country, we call that a “dehumidifier”….

    I’m thinking that co-generation using a solar-fired steam turbine and distillation plant has possibilities.

    #12104
    Avatar of Carl-Pålsson
    Carl-Pålsson
    Participant
    #13363
    Avatar of Morganism
    Morganism
    Participant

    the easiest humidity capture i have seen is called a mist net.

    Here is the latest in desalination tech
    http://www.purdue.edu/newsroom/research/2011/110503WoodallWater.html

    gives heat too…..

Viewing 9 posts - 16 through 24 (of 24 total)

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