Dry Ice FAQs
What is Dry Ice?
Dry ice is pure, solid carbon dioxide (CO2). As a gas, CO2 exists naturally in our environment.ÿ It's called "dry ice" because it does not melt.ÿ Dry ice goes directly from a solid to a gas in a process called sublimation.
Dry ice keeps items colder for much longer than traditional ?wet ice? because dry ice is extremely cold, -109 degrees F (-78.5ø C).ÿ Dry ice sublimates into carbon dioxide gas instead of melting, leaving no liquid mess to clean up which is why dry ice blasting is a popular and environmentally friendly way to clean.
Is it okay to add dry ice to beverages?
Yes it is, however, the dry ice must be "food grade". Food grade means the CO2 used to make the dry ice is the same quality CO2 as used for soda fountains and also the dry ice can be used to transport food and produce.
How to make dry ice - manufacturing dry ice:
Dry ice is made from pure carbon dioxide that is a (recycled) byproduct of other industrial processes such as the manufacture of ethanol. The gaseous carbon dioxide (CO2) is first pressurized and refrigerated to formliquid CO2, which then is allowed to expand in an atmospheric chamber.
When the CO2 changes from a liquid to a gas, there is an extreme drop in temperature. This causes some of the gas to freeze, yielding both solid (snow-like) CO2 and the gas form (vapor) of CO2. The "snow" is then hydraulically pressed into dry ice blocks and pellets.
Can you make dry ice at home?
The quick answer is "no". There is no practical or inexpensive method to make enough dry ice at home to use it for freezing. People have tried making dry ice "samples" involving a small CO2 tank and heavy gloves, but not only is this potentially dangerous, it results at best in very small quantities of "snow" that will disappear very quickly. Such methods are NOT RECOMMENDED for safety reasons.
Making dry ice requires a source of CO2 [carbon dioxide] that comes from industrial processes such as those in ethanol plants. Carbon dioxide is a gas.ÿ It can be put under pressure and converted to liquid carbon dioxide [LCO2] that must be kept under pressure in a tank to remain liquid. As liquid CO2 is exposed to normal air temperatures, some of it immediately turns back to a colorless gas [CO2], and some of it freezes into "snow" which can be pressed into dry ice pellets or blocks using hydraulic pressure and a dry ice pelletizer or dry ice block press.
How is dry ice handled safely?
- Never let dry ice touch your bare skin
- always handle it with gloves.
- Dry ice displaces oxygen in the air, so always use it in a well-ventilated area.
- When transporting dry ice in a vehicle, roll down the window to ensure adequate ventilation, especially if you feel short of breath.
- If you're using dry ice in a confined space, open the door and air out the area before entering.
- Never place dry ice in a tightly sealed container or vessel, because it converts back to gas and creates its own pressure.
- When shipping frozen products with dry ice, notify the carrier prior to shipment.