A US technology company hopes to make a long-standing concept come to fruition with the launch of self-heating drinks containers. HeatGenie was recently awarded the million for bringing its designs to market the in8, over 15 years ago when Nestle had to abandon an identical concept. But the fundamentals behind the technology date back further, dating back to 1897, the year that Russian engineer Yevgeny Fedorov created the first self-heating beverage can. What makes these cans work? Why is it that no one has been able to make them successful, and what’s the latest HeatGenie strategy? To answer this question, we must look further back to World War II.
The towering rock formations that makeup Pointe de Hoc overlook the Normandy beaches, where Allied troops arrived on June 6, 1944. The attacks marked the beginning of the liberation process of German-occupied Europe. The cliffs’ tops were the l spot artillery pieces capable of crushing any troops that tried to take on Omaha and Utah beachheads. Omaha, as well as the Utah beachheads.
The Allied command knew about this, and to shore up the assault and protect themselves, the navy attacked Pointe de Hoc. Believing that this wouldn’t be enough, they had another strategy. A group of US Rangers scaled the 30-meter-high high cliffs and, once they had located the weapons, hurled explosives, destroying the guns. The key to the success was the selection of charges based on thermite. They weren’t the type of “high explosives” typically found in grenades but instead employed a chemical reaction that created hot temperatures sufficient to cause the melting of steel in firing mechanisms.
Surprisingly, what thermite the Rangers employed is extremely simple. It’s corrosion (iron oxide) and powdered aluminum. Together, they are secure and stable, that is, until the mixture receives an explosive kick, usually through the lighting of a magnesium fuse. Then, the fireworks get started. The aluminum snags oxygen in the rust, and during the process, it produces iron, which has a massive explosion of heat. The reaction could easily reach 2500°C, enough heat to create melting (liquid) iron.
The video below illustrates the reaction in slow-motion. The glowing light at the beginning is an iron flame burning. After that, as the fuse reaches the thermite, the results are spectacular, leaving a melted tube and a fiery iron puddle.
Thermite is a prime example of an exothermic, organic reaction that generates energy through heat and light. Fire, usually the outcome of a chemical reaction involving carbon dioxide and oxygen, is the exothermic reaction with which we are most commonly acquainted. But there are many others. Indeed, many of the same soldiers descending at the Normandy beaches on that day had another item in their packed rations: soup containers that self-heated.
They were stoves that could be folded into one with the tubes filled with cordite (more often used to propel small-arms ammunition) in the middle of the can, acting as fuel. They were quick and straightforward to use and could be lit by cigarettes, allowing soldiers to cook a meal within five minutes. However, they were prone to exploding. The habit of exploding and showering the assembled teams with hot soup.
Self-heating cocoa. University of Cambridge
Since then, there have been various attempts to turn self-heating containers into popular products. They rely on a more stable reaction to produce the heat. However, certain have had to contend with explosive problems. It’s called Quicklime (calcium oxide) and quickly heats up when mixed with water. However, it could be more efficient, as it produces approximately 60 calories per gram of reactant (one calorie will heat 1 milliliter of water 1).
The result is that to warm the drink up to 40 degrees, and you’ll need the heating element to take about half of the packaging. This is fine when looking for a tiny beverage on a sunny day; however, when you really need a hot drink in winter, you’re left with a bland cup of coffee.
More powerful cans
What’s needed is a more effective reaction. Something similar to thermite? While packaging a container with an explosive response that could turn off the artillery gun might sound, yet, it’s precisely what HeatGenie plans to do. The company has registered several patents detailing using thermite inside self-heating containers in the past ten years. The reaction used in The US Rangers is still too hot to handle, so they’ve lowered the temperature slightly by replacing corrosion with a less explosive but surprisingly familiar material called silicon dioxide. The new generation of heated cans is fueled with aluminum and glass ground up.
If this reaction occurs, it releases more than 200 calories for every gram of reactant, which can be as high as 1,600. With the background of self-heating packaging, the energy released from the container you hold within your hands might pose somewhat of a risk, and a number of the patents issued by HeatGenie cover safety concerns.
This includes a complicated arrangement consisting of ” firewalls” which can block the “flamefront” should things get too hot, as well as the energy-reducing “heatsinks” to ensure that the heat is effectively transferred to the drink as well as vents that allow the release of any steam. The company claims that only 10 percent of the package is occupied by heating elements, and it could still create a warm coffee in just two minutes (although the precise temperature has yet to be discovered).
In other words, more than 100 years after Fedorov’s initial efforts, do you think HeatGenie finally cracked the self-heating pot? From the investments and patents that the company has made, it could have found a solution to the technical aspect; however, whether it has a great product in its possession is a different matter.