Posted on 07/09/2021 1:41:29 PM PDT by blam
Could the holy grail of turning salt water to drinkable water finally be upon us?
A new report from Interesting Engineering seems to suggest that could be the case – detailing a new nanofiber membrane, developed by Yunchul Woo and his team at the Korea Institute of Civil Engineering and Building Technology, that appears to be “stable in the long term” for desalinization. And it can be done “in minutes”, the report says.
Membranes had been used in the past, but there is often a challenge in keeping them dry for long periods of time. When they become wet, their filtration characteristics become ineffective and large amounts of salt can pass through.
Woo’s team has created a membrane “made of nanofibres that have been fabricated into a three-dimensional hierarchical structure” by using a technology called “electrospinning”. This new membrane is said to be highly water repellant.
Water from one side is heated and allows water vapor to pass through the membrane, which is then condensed on the other side. The process is called membrane distillation.
“Since the salt particles are not converted to the gaseous state, they are left out on one side of the membrane, giving highly purified water on the other side,” the report says.
It also notes that the researchers used silica aerogel in their membrane fabrication process.
Upon testing the technology for 30 days continuously, they found the membrane filtered out 99.9% of salt without wetting problems.
Desalinization is the obvious answer to the global issue of over 785 million people lacking clean drinking water. Up until now, scientists have been unable to figure out a quick, cost-efficient and effective way to turn salt water into drinkable water.
Fresh water only accounts for 2.5% of the total water available on Earth, the report notes.
“The Saudis and Israelis get a large chunk of their water from desalination. What do they do with the leftover brine?”
They eject it offshore under water through high pressure mixing nozzles where the velocity and flow factors instantly mix it with you guessed it less salty seawater rendering the now mixed water stream only slightly more salty than the original seawater being in near saline equilibrium this mixed stream further mixes and dilutes itself to be undetectable as a distinct water body in a few hundred meters of travel. In other words after a few hundred meters the much feared brine is a giant nothingburger. The fear mongering over brine disposal is used to further an agenda in the real world when handled with competent engineering it’s a nonissue.
“This graph assumes the fluid is at the temperature indicate by the x axis already before adding the additional heat.”
It doesn’t assume. It gives you the value at any temperature.
“So in the process you must include the energy needed to get to that temperature.”
Or remove energy to cool it down.
“Also, 650 K is 377C or 710F; way higher than 210F for sea level boiling.”
Your point?
“I have a BS in chemistry. “
LOL!
“posting a phase diagram”
I didn’t post a phase diagram. Once again you prove you are full of BS.
You’re going full retard. Again.
One version of vacuum flash evaporation requires pumping to lower the pressure, depress the boiling point. The other point is to raise the pressure of the outflow product stream to enable condensation. The heat should be recycled from the condensate outlet to inlet to prevent ice formation at the boiler/evaporator.
Osmotic pressure rises with brine concentration—diminishing returns issue.
“In other words after a few hundred meters the much feared brine is a giant nothingburger. The fear mongering over brine disposal is used to further an agenda in the real world when handled with competent engineering it’s a nonissue.”
That’s my take as well. The environuts doing what they do so well - putting roadblocks to any advancement that might help humanity, because in their eyes humans are just parasites who are destroying “mother earth” and their precious sensibilities.
I’m all for being a good steward of what we have been blessed with, but at the end of the day true environmentalism is mostly about humanity’s self interest. In other words, it is in our interest to take good care of what we’ve been given.
We don’t want to be so foolish and short sighted that we destroy that which we need to survive, enjoy and thrive. But neither do we want to be relegated to the status of an un-natural cancerous growth on “mother earth” to be eradicated, like the environazis want to do.
We are the only entity in nature that has the capability to care and do something about his surroundings. They keep to want to personify “mother earth” and to give it “feelings”. In reality mother earth couldn’t care less if a meteor were to strike it tomorrow and blow it up to smithereens - only us humans would care (and might actually be able to do something about it if we saw it soon enough).
Of course water evaporates at ambient temperature.
But in the “dish of water on the table” scenario you propose, the latent heat of vaporization cooling the water as it evaporates is a gradual loss, replenished by the ambient air.
Ever get cold getting out of a swimming pool or a shower? That’s latent heat of vaporization.
If you heat water, it evaporates faster. The higher the temperature you heat it to, the faster it evaporates.
You don’t have to heat it to boiling to get it to vaporize.
That was the point I made that you went full retard on.
But whatever temperature it evaporates at, it still loses the latent heat of vaporization, a point you seem to be trying to obscure.
I’m not trying to obscure anything.
You’re just a narcissist trying pretending you’re the smartest guy in the room when you’re just the biggest weirdo that nobody ever pays any attention to.
Yep. Dig some lakes and put the rising seawater in them. Then sell lakefront property for big bucks.
Are you mistaking me for the other guy you’re arguing with?
Cost. Yes, you can eventually get just water and salt. But every process you use to extra additional water costs more money. And clean water doesn’t sell for but so much.
This is why desalination has never taken off: every part of it has a steep cost/benefit from energy costs to disposal costs to environmental impacts (e.g. killing every living thing at the brine dumping point). But salt water is relatively abundant, particularly for places that need a lot of water. So the search continues for a cheaper, more effective, less damaging way to do it. That’s the whole purpose of this article. Sadly, it seems that breakthrough has yet to be found.
I have a bad habit of associating steam with water heated until it becomes a vapor.
I’m terribly sorry for that.
Actually, if you reduce the air pressure, water boils at a lower temperature. Ships heat the water and then inject a fine mist into a low pressure chamber. The water boils instantly and is drawn off and condensed while the solids fall to the bottom of the vessel.
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