This cool new approach to refrigeration could replace harmful chemicals

Scientists at Lawrence Berkeley National Laboratory have developed a new potential means of alternative cooling, ionic caloric cooling. In this method, electrically charged atoms or molecules (ions) change the melting point of a solid material. This is similar to how winter storms add salt to roads before they change the way ice forms. According to a recent paper published in Science, their proof-of-principle experiments used salts made of iodine and sodium with organic solvents to achieve energy-efficient cooling.

“The refrigerant situation is an open question. No one has succeeded in developing an alternative solution that cools things, works efficiently, is safe, and does not harm the environment,” said co-author Drew Lilley. I’m here. “We believe that the ionocaloric cycle, if implemented properly, has the potential to achieve all these goals.”

There is a long history of scientists looking for better alternatives to refrigeration, including refrigerators designed by physicists Albert Einstein and Leo Szilard. Their collaboration was sparked in 1926 when news broke of his tragic death in Berlin from toxic gas fumes that leaked into the house while the whole family was asleep. when it was posted. Such leaks were occurring with alarming frequency as more people replaced their traditional iceboxes with modern mechanical refrigerators that rely on toxic gases like methyl chloride, ammonia and sulfur dioxide as refrigerants.Einstein was deeply moved by the tragedy and said Szilard must have had a better design.

Einstein and Szilard focused on absorption chillers. Instead of a mechanical compressor, this refrigerator used a heat source (then a natural gas flame) to drive the absorption process, releasing coolant from a chemical solution. An earlier version of this technology was introduced in his 1922 by a Swiss inventor. Szilard used his expertise in thermodynamics to find ways to improve the design. His heat source drives a combination of gas and liquid through his three interconnected circuits of pressurized ammonia, butane and water, requiring no electricity to operate the appliance (heat source selection ), and there were no moving parts either.

On one side was a flask filled with butane (the evaporator), and just above the butane a new vapor (ammonia) was injected, making a very important difference. This reduces the boiling temperature, drawing energy from the surroundings as the liquid water boils, cooling the compartment in the process.Einstein and Szilard’s refrigerator concept was never commercialized. The introduction in 1930 of Freon, a non-toxic refrigerant, proved more economical.