Dry ice can be used for many things. From preserving food, to transporting medical supplies, to making fog in movies… dry ice is a great product. So how is dry ice made?
Dry ice is made of raw carbon dioxide gas (CO2). Methods for creating dry ice may differ a little for each manufacture, but the basic concepts are usually the same.
Carbon dioxide is cooled and compress until it turns in to a liquid. The carbon dioxide needs to be compressed because liquid carbon dioxide cannot exist in a non-pressurized environment on earth. After the liquid carbon dioxide is created, it can be shipped, stored under pressure, or used in the plant to make dry ice. After the liquid CO2 is released from pressurization, most of the liquid carbon dioxide turns in to dry ice snow (some of the carbon dioxide changes back in to gas). Dry ice snow looks very much like normal snow, but as a very short shelf life. Dry ice snow (non-compressed) sublimates very quickly at normal temperatures. Dry ice snow is then pushed in to a chamber and then compressed in to a dry ice block or dry ice pellets. Dry ice pellets and dry ice blocks are the most commonly sold dry ice forms today.