What a time to be alive: While we’re looking for signs of alien life in our Solar System and creating vaccines against types of cancer, engineers are also manufacturing self-chilling cans that will guarantee a cold brew wherever you are.
Far from being a futuristic technology you can only dream of when you’re sipping on a grimly warm beer, you can actually purchase one of these little marvels now. 7-Eleven has just released a range of cold brew coffees that come in real-life, self-cooling cans.
Named (of course) “Fizzics Sparkling Cold Brew Coffee”, the containers have been developed by The Joseph Company International, whose history with the tech goes back several decades.
The eponymous inventor, Joseph Mitchell, created a prototype of a self-cooling drink can more than a quarter of a century ago that used an HFC-based coolant system. Seeing as HFCs are an increasingly outlawed type of incredibly potent greenhouse gas and ozone destroyer, this prototype was then banned by the Environmental Protection Agency.
Back in 2012, a CO2 version was released, which works and doesn’t appear to be anywhere near as environmentally threatening as its predecessor. It’s this design by Mitchell and his company’s patented technology that appears to have been snapped up by 7-Eleven – and the coffees are available on a trial basis in the Los Angeles area.
When the cans need to be chilled, a nozzle at their base is turned, which releases CO2 with an accompanying hissing soundtrack. Turning the can upside-down and leaving it be, consumers need only wait around a minute and a half, whereupon the beverage will be chilled by around 16.7°C (about 30°F).
Details are scarce as to what precisely causes the cooling – and we’ve reached out to the company to check – but here’s our best guess based on the demonstration video.
The carbon dioxide part of the can, separate from the beverage, is pressurized and kept as a gas. Opening it to the atmosphere and allowing it to vent causes it to depressurize and expand.
A thermodynamics law known as the Joule-Thomson effect dictates that this type of expansion, via this small opening, causes a refrigeration effect. As the gas expands, the average distance between the molecules grows. Crudely put, this causes a decrease in the individual molecules’ kinetic energy and therefore the overall temperature.
It’s not clear how “environmentally safe” the tech, as the company describes it, is at this point. The CO2, for example, is described as “reclaimed”, which essentially means recycled or reobtained from another process, but no more information is given. It’s not clear how recyclable the cans themselves are compared to conventional ones either.
In any case, the tech behind these cans is, ahem, very cool.