About Carbon Dioxide

Carbon dioxide (CO2), while technically not a cryogenic fluid, is another familiar example of a gas that freezes.  It can be cooled and frozen as “dry ice”.

Dry ice (frozen carbon dioxide) is a normal part of our earth’s atmosphere.  It is the gas that we exhale during breathing and the gas that plants use in photosynthesis.  It is also the same gas commonly added to water to make soda water.  Dry ice is particularly useful for freezing, and keeping things frozen because of its very cold temperature: -109.3°F or -78.5°C.  Dry ice is widely used because it is simple to freeze and easy to handle using insulated gloves.  Dry ice changes directly from a solid to a gas (sublimation) in normal atmospheric conditions without going through a wet liquid stage.  Therefore it gets the name “dry ice”.