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momentito
Chemical sea-water desalination

Are there any known/designable liquid chemicals that can be added to sea-water that would absorb water into its molecular composition whilst density dispersing the saline impurities to enable seawater desalination an affordable means of obtaining clean drinking water?
einstienear
QUOTE (momentito+Jan 8 2008, 09:47 AM)
Chemical sea-water desalination

Are there any known/designable liquid chemicals that can be added to sea-water that would absorb water into its molecular composition whilst density dispersing the saline impurities to enable seawater desalination an affordable means of obtaining clean drinking water?

yes there is, and already invented, new tablets have been made that enable ANY liquid , let it be pee, to transform into drinkable water

click here to see the website
also here

these websites may be lies, but i have seen a vid on tv!!!
momentito
Vacuum solar desalination.

In coastal desert regions where temperatures are high, water could be evaporatively distilled with the heat of sunlight shinning into plastic tanks of seawater in a vacuum. With zero atmospheric pressure the water would boil very quickly with solar power. The steam would be condensed in a water refinery as clean drinking water.
keepiniteasy20
I prefer the "Waterworld" method...ha... wink.gif
tikay
QUOTE (einstienear+Jan 8 2008, 03:09 AM)
yes there is, and already invented, new tablets have been made that enable ANY liquid , let it be pee, to transform into drinkable water

click here to see the website
also here

these websites may be lies, but i have seen a vid on tv!!!

let it be pee???

hehe, a great thing to have if your lost in the desert I suppose?
momentito
When in times of trouble...Mother Mary comes to me....there will be an answer....let it pee ...let it pee lol
tikay
biggrin.gif ~~~when ye find yourselves in times of trouble...mother Mary comforts thee! bringing words of wisdom...let it peeeee~ let it pee!

thanks for the laugh...and to think I was off looking for something to bring back on the water desalination in Milolii Hawaii. How boring am I?
laugh.gif
Enthalpy
You are making buns? Ferry funny!

Distillation by sun heat can be a very simple means of getting a little bit of drinking water on a lifeboat.

To get more significant amounts, optimized units work at several pressures (hence temperatures) so that the condensation heat of distilled water evaporates sea water at a somewhat lower pressure. You need heat from the Sun only once.

Planning such a project generally involves producing also electricity and home heating from the steam.

However, distillation methods are always expensive, because water absorbs an awful lot of heat to vaporize.

All modern processes use reverse osmosis:
http://en.wikipedia.org/wiki/Reverse_osmosis
as it takes far less energy since the water isn't vaporized.

Alas, even reverse osmosis is expensive. Some of Spain's tourist cities (on the Costa Lotta) use it to feed (¿apastecer?) homes, as this is a requisite to attract tourists. Adelaide, in Australia, has such plans. But agriculture can't rely on this - emirates do have some farms, but profitability isn't their prime goal.
tikay
Milolii uses solar to desalinize about 1000 gallons a day for the small fishing village.

http://www.ibiblio.org/london/permaculture...2/msg02525.html
soundhertz
Whoever invents the cheap simple method on a large scale will rule the world. Water availability will eventually be our greatest challenge. "Global Warming" will be a non sequitur. If ever a scientist wanted to make a pile of money, this is it.
Enthalpy
Milolii: Nice project.

However, complete computations support the idea of converting sunlight to electricity by a thermal means, and use the electricity in reverse osmosis.

Not quite as direct and elegant... But better efficiency per m2 and per $.

There are also projects to produce electricity from temperature differences between surface and depth in the oceans (tested in Hawaii as well, I think). Many of the processes make fresh water as a by-product, which is seen as a decisive advantage.

One stupid obstacle is that as soon as you have pumped cool water from deep in the ocean, people don't let you use it to produce electricity: they want it immediately to keep the air and the lobsters cool in their restaurants.
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