Have you ever thought about what is dry ice exactly? This small, strange concoction can have many applications such as medical, food production, transportation and industrial purposes. It's very cold and will reach temperatures from -61 to -78 degrees Celsius. Manufacturers called it dry because instead of melting like a liquid, it evaporates. It's also very dense, so it sinks to the bottom of the container.
What's Dry Ice?
Dry ice is actually another form of carbon dioxide. It's carbon dioxide in its frozen form. It can reach up to –78 degrees Celsius and when you submerge it into gas at normal atmospheric pressure, it doesn’t leave any wetness or dampness behind. This is a substance that’s safe to use on food as well because it’s just gas.
That's why you see a lot of chefs use it in the kitchen to freeze their ice cream or pudding as fast as possible. However, they must handle it very carefully because of its low temperatures. If it touches the skin, dry ice can cause burns. If you intend to use it, make sure you do it in a well-ventilated area. Otherwise, the gas might cause suffocation.
Always look for a reliable manufacturer that has a lot of experience in making dry ice. If you want something of great quality, you can buy heavy-duty Techni ice packs for many purposes. They're FDA-approved, 100% Australian made and most importantly, are reusable. They're very lightweight and can last 6 times longer than regular ice.
Short History of Dry Ice
The story of dry ice starts in the early 1900s. It had its first commercial production in the 1920s and got its name in 1925. People immediately started noticing it and found a way to incorporate it into their industry. They soon realised how useful and practical it could be, so the demand for dry ice grew.
For instance, the food and agriculture industry uses dry ice to prevent products from rotting during shipping. Dry ice preserves food for as long as possible by preventing bacterial development and slowing deterioration because of low temperatures. This keeps the food crisp, fresh, and tasty.
The entertainment sector relies on dry ice to simulate smoke without using an open flame and putting everyone in danger. It allows pest management professionals to shut gopher burrows without harming wildlife and force the gophers out of their tunnels. It also repels mosquitoes and can be used as a cleaning solvent to prevent corrosion.
How is Dry Ice Made
Dry ice is a byproduct from the refining of petroleum, ammonia or some other chemicals. The most efficient way to make dry ice is to take it during the ammonia production process. Some manufacturers burn natural gas and separate the hydrogen and carbon atoms. Then, they combine the hydrogen and nitrogen to create ammonia.
The carbon that’s left out, is combined with oxygen, and that’s how we get carbon dioxide. When this process is complete, the producers clean the dry ice to make it suitable for food usage. They do this by running the gas through a chamber that absorbs CO2 and the remaining gases are vented out. When all the other gasses are out, the absorbent is heated and releases the clean gas by a blast of clean CO2.
The excess carbon dioxide can then be eliminated and transferred to the liquefaction stage. The CO2 is compressed and cooled at a pressure of roughly 870 lbs/in2. Once it has been liquefied, it can be transported to a plant where it will be transformed into its ultimate solid state.
Next, manufacturers depressurise it to turn it into a solid substance. They put it in a tank with normal atmospheric pressure. This removes the pressure into the liquid and turns it into gas again. During this time, the gas expands, drops the temperature and 46% of the carbon dioxide turns into snow.
It condenses on a press and under 60t of force and after 5 minutes, it’s formed into ice blocks. This is how every ice block, including the Techni ice packs, is made. The final touch is to pack them into tight and insulated packaging. This prevents them from sublimation into gas again.
Types of Dry Ice
There are several types of dry ice. This is a distinction made according to its shape. The first one is high-density dry ice. This one lasts longer and it’s easy to handle. It's mostly used for blast cleaning because of its hardness. The second type is pellets. They have a large surface area and melt faster. This is the reason kitchens and chefs use them for food purposes.
Laboratories also use them to safely transport blood plasma and lab specimens and to conduct lab experiments. Many movie and theatre companies and productions also use them to create fog effects. The third type is slices or slabs. They're also used for food and medicine purposes, and help aeroplanes keep their food safe and preserved. The last type is blocks which are large, heavy and melt slowly.
Where to Use Dry Ice
Dry ice has many purposes in all kinds of different industries and sectors. It's used in transportation when packages and containers with plants, food, medical supplies or chemicals need to be transported somewhere. The dry ice packs will keep them safe. One of the most popular usages is in the food industry. Freezing ice cream, fruits, meat, vegetables and other foods.
Some commercial kitchens even use it to kill bacteria and mildew on their surfaces. Next, is medical usage. As we said, it can kill bacteria and mildew which are a big NO in the medicine field. The medical personnel use it to preserve vaccines, blood samples, organ transplants and medical supplies. Some doctors use it to remove warts or to slow down hair loss.
Tips on Handling it Safely
Dry ice is very practical and has many purposes, but it can also be harmful and dangerous if you don’t handle it properly. Always use it in a ventilated area because too much carbon dioxide evaporation can give you headaches, and cause vomiting and nausea. Never try to taste or swallow dry ice. Also, don’t touch it without some thick gloves because the extremely low temperature may burn your fingers.
If you’re transporting it somewhere, do it in a ventilated vehicle or an open one, because when concentrated in one place, carbon dioxide becomes toxic and dangerous. Don't store it in a sealed container because it releases pressure. Styrofoam is probably the best storage option for dry ice. And last but not least, never throw it down the toilet. The extremely cold temperature can cause damage to the piping.