Schematic of regenerative ionocaloric cycle. Credit: Science (2022). DOI: 10.1126/science.ade1696 Posted on 12/27/2022 11:59:51 AM PST by Red Badger
Schematic of regenerative ionocaloric cycle. Credit: Science (2022). DOI: 10.1126/science.ade1696
A pair of researchers at Lawrence Berkely National Laboratory used a commonly known, naturally occurring phenomenon to build a new kind of environmentally safe refrigerator.
In their paper published in the journal Science, Drew Lilley and Ravi Prasher describe how expanding on the idea of using salt to melt road ice to design and build a new kind of refrigerator. Emmanuel Defay, with the Luxembourg Institute of Science and Technology, has published a Perspective piece in the same journal issue outlining the work done by the pair in California.
For many years, people around the world have used salt to melt road ice to make travel easier. Though technically, the salt does not melt the ice, its dark color attracts heat, allowing the ice below it to melt, which than allows the salt to mix with the water. And it does not refreeze because the salt dramatically lowers the freezing point of the water.
It was on this part of the process that the researchers focused. They noted that a similar process could result in cooling a material simply by mixing it with sodium iodide (NaI) salt due to the phase transition. The second material in this case was an ethylene carbonate (EC) solvent. They further noted that repeatedly cooling a material should also cool the environment in which it is contained. And to make that happen, all they had to do was remove the salt, and then add it again.
The researchers call their process "ionocaloric" refrigeration, and built such a refrigerator to prove that it was viable. They started with a box and then added a mixing device to mix their two ingredients and another device that performed electrodialysis to remove the salt. Then tested the resulting device to determine if it would keep the temperature inside the box at a steady cool temperature, and if so, if it was more or less efficient than other refrigeration devices.
Their testing showed that their refrigerator was able to maintain a cool temperature and that it was approximately as efficient as refrigerators now on the market. The big advantage of the approach is that it does not emit any hydrofluorocarbons or other pollutants. They acknowledge that it does have one drawback—it takes quite a while for the mixed solution to cool.
More information: Drew Lilley et al, Ionocaloric refrigeration cycle, Science (2022). DOI: 10.1126/science.ade1696 Emmanuel Defay, Cool it, with a pinch of salt, Science (2022). DOI: 10.1126/science.adf5114
Journal information: Science
modern day ice cream churn?
I bet these guys never heard of a swamp cooler either
I made a ghetto 5gal bucket evap cooler and dumped
Salt on the ice long long ago
Why bother? If it works, once it’s mass produced, it’ll become the new evil…
ethylene carbonate:toxic and hazardous:
https://fscimage.fishersci.com/msds/09022.htm
converts to ethylene glycol if consumed, which is EXTREMELY toxic to kidneys even in very small amounts ...
“Though technically, the salt does not melt the ice, its dark color attracts heat, allowing the ice below it to melt, which than allows the salt to mix with the water. And it does not refreeze because the salt dramatically lowers the freezing point of the water.”
Maybe someone can help me. So I can bite that ice can only lower the freezing point of liquid water and not already frozen water, but how does salt have a “dark color” that is so dark, it attracts heat, over the whiteness of ice and snow? I see salt as white to clear, so what is going on?
road ice..................
sodium iodide (NaI) salt
ethylene carbonate
Isn’t this this similar premise for a DC battery that is using the difference in chemical potential and then returning it with electro-mechanical energy?
bkmk
I see salt as white to clear, so what is going on?
= = =
You might be a white supremacist, and don’t recognize that white IS black, absorbing heat (and adding to global warming also).
Perhaps, salt crystals can absorb solar heat while the frozen show rejects it. I wouldn’t call that ‘dark color’. Perhaps a real scientist can clarify.
So, then...
...my next fridge will work half as well as the last one (which worked half as well as that preceding it)?
/s
I’m a big fan of hydrofluorocarbons.
They’ve made my life better in so many ways.
Hopefully I’ve stockpiled enough to last the balance of my life.
R-11, R-22, R-134
Environmetally friendly? Perhaps. But it still uses electricity which will be increasingly in short supply as more coal plants get shut down. Under the currenr regime, this tech is a non-starter.
“Isn’t this this similar premise for a DC battery that is using the difference in chemical potential and then returning it with electro-mechanical energy?”
The cooling is via the phase change. A DC voltage provide for the transfer of the salt ions.
“I bet these guys never heard of a swamp cooler either
I made a ghetto 5gal bucket evap cooler and dumped
Salt on the ice long long ago”
That is not a swamp cooler. A swamp cooler cools via evaporation of liquid water not the melting of ice,
That part is bullshit, IMO. Road salt works at night ...I'm not totally clear on how road salt gets started, but the liquid brine around the salt crystal seems to dissolve the ice surrounding it. A salt crystal on solid ice will melt a hole down through it. It seems to work better on traveled roads where traffic churns it up than on a driveway.
Also, a swamp-cooler works best in very low humidity. I rarely see them other than in deserts.
This statement bothers me: “approximately as efficient as refrigerators now on the market.”. If the efficiency was better they would be screaming that number from the rooftops. Based on that alone, we can assume it’s less than current refrigerators. Just how less is the key. Since this article cherry picked data and showed a spiffy schematic of the cycle they are hiding the real efficiency.
Lawrence Berkely National Laboratory salt comes from San Fraqncisco where everything is covered with dark filth.
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