Cool it, with a pinch of salt; A new refrigeration system? (1 Viewer)

[JacksinPA]

Science Magazine - Cool it, with a pinch of salt

In countries with harsh winters, putting salt on roads transforms ice into slush. Adding salt depresses the freezing point of water. In other words, ice

www.sciencemagazinedigital.org

Melting a solvent with a salt and then desalinating it enables a reversible cooling cycle

In countries with harsh winters, putting salt on roads transforms ice into slush. Adding salt depresses the freezing point of water. In other words, ice gets colder when salt is added. How much colder? The surface of ice cubes covered with kitchen salt reaches -10°C after a few seconds, whereas ice cubes of pure water remain at 0°C. Lilley and Prasher (1) revisited this cooling principle, and on page 1344 of this issue, they describe how to make it reversible. The idea behind this “ionocaloric” refrigeration is to take advantage of the large temperature change—and therefore the large heat absorption—obtained by melting a “special ice” when put in contact with a specific salt. The authors made this cooling process reversible to achieve an efficient cycle with potential wide applications in refrigeration.

Ionocaloric refrigeration could be considered electrochemical cooling. The latter occurs in liquids containing mobile ions that can be displaced with an external voltage. However, the variation of temperature obtained with electrochemical cooling is limited to a fraction of degrees because there is no accompanying phase transition, such as melting ice (2). Triggering a phase transition with an external stimulus to induce cooling is the essence of caloric materials (3). Such materials could make cooling more efficient without requiring greenhouse gases, contrary to most refrigerators. Most gases used as refrigerants are hydro-fluorocarbons, which are much more potent greenhouse gases than carbon dioxide. Hence, magnetocaloric (4), electrocaloric (5), elastocaloric (6), and barocaloric (7) effects are temperature changes activated by the application of, respectively, a magnetic field, voltage, mechanical stress, and pressure. In the study by Lilley and Prasher, the ions of a salt trigger the melting of another material (called the solvent). Aptly, the authors called this the ionocaloric effect.
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Incredible that it has taken until now to figure this out. More:

Ionocaloric refrigeration cycle​

Developing high-efficiency cooling with safe, low–global warming potential refrigerants is a grand challenge for tackling climate change. Caloric effect–based cooling technologies, such as magneto- or electrocaloric refrigeration, are promising but often require large applied fields for a relatively low coefficient of performance and adiabatic temperature change. We propose using the ionocaloric effect and the accompanying thermodynamic cycle as a caloric-based, all–condensed-phase cooling technology. Theoretical and experimental results show higher adiabatic temperature change and entropy change per unit mass and volume compared with other caloric effects under low applied field strengths. We demonstrated the viability of a practical system using an ionocaloric Stirling refrigeration cycle. Our experimental results show a coefficient of performance of 30% relative to Carnot and a temperature lift as high as 25°C using a voltage strength of ∼0.22 volts.

 

[Rexedgar]

As a child, I found out how cold ice and salt can get. Put some salt in your hand followed by an ice cube and close your hand. Most people let it go quickly!

 

[JacksinPA]

As a child, I found out how cold ice and salt can get. Put some salt in your hand followed by an ice cube and close your hand. Most people let it go quickly!

This ice/solvent cooling cycle might be used in small air conditioning devices. It might be fun to cobble together a device to test this system.

 

[Gateman_Wen]

Science Magazine - Cool it, with a pinch of salt

In countries with harsh winters, putting salt on roads transforms ice into slush. Adding salt depresses the freezing point of water. In other words, ice

www.sciencemagazinedigital.org

Melting a solvent with a salt and then desalinating it enables a reversible cooling cycle

In countries with harsh winters, putting salt on roads transforms ice into slush. Adding salt depresses the freezing point of water. In other words, ice gets colder when salt is added. How much colder? The surface of ice cubes covered with kitchen salt reaches -10°C after a few seconds, whereas ice cubes of pure water remain at 0°C. Lilley and Prasher (1) revisited this cooling principle, and on page 1344 of this issue, they describe how to make it reversible. The idea behind this “ionocaloric” refrigeration is to take advantage of the large temperature change—and therefore the large heat absorption—obtained by melting a “special ice” when put in contact with a specific salt. The authors made this cooling process reversible to achieve an efficient cycle with potential wide applications in refrigeration.

Ionocaloric refrigeration could be considered electrochemical cooling. The latter occurs in liquids containing mobile ions that can be displaced with an external voltage. However, the variation of temperature obtained with electrochemical cooling is limited to a fraction of degrees because there is no accompanying phase transition, such as melting ice (2). Triggering a phase transition with an external stimulus to induce cooling is the essence of caloric materials (3). Such materials could make cooling more efficient without requiring greenhouse gases, contrary to most refrigerators. Most gases used as refrigerants are hydro-fluorocarbons, which are much more potent greenhouse gases than carbon dioxide. Hence, magnetocaloric (4), electrocaloric (5), elastocaloric (6), and barocaloric (7) effects are temperature changes activated by the application of, respectively, a magnetic field, voltage, mechanical stress, and pressure. In the study by Lilley and Prasher, the ions of a salt trigger the melting of another material (called the solvent). Aptly, the authors called this the ionocaloric effect.
======================================================
Incredible that it has taken until now to figure this out. More:

Ionocaloric refrigeration cycle​

Developing high-efficiency cooling with safe, low–global warming potential refrigerants is a grand challenge for tackling climate change. Caloric effect–based cooling technologies, such as magneto- or electrocaloric refrigeration, are promising but often require large applied fields for a relatively low coefficient of performance and adiabatic temperature change. We propose using the ionocaloric effect and the accompanying thermodynamic cycle as a caloric-based, all–condensed-phase cooling technology. Theoretical and experimental results show higher adiabatic temperature change and entropy change per unit mass and volume compared with other caloric effects under low applied field strengths. We demonstrated the viability of a practical system using an ionocaloric Stirling refrigeration cycle. Our experimental results show a coefficient of performance of 30% relative to Carnot and a temperature lift as high as 25°C using a voltage strength of ∼0.22 volts.

This isn't new science, Have they figured out a way to make it work on a scale like a refrigerator yet?