How dry ice is formed

First of all, gaseous CO2 is liquefied under pressure. For the production of dry ice, the liquid CO2 is taken from an insulated reservoir (up to 22 bar). As the pressurized liquid CO2 flows into the depressurised machine, the liquid CO2 expands very quickly.

The temperature of the liquid CO2 drops rapidly and the CO2 changes into its solid state. The result is snow with a temperature of -78.9 °C. This is subsequently compressed under pressure and pressed to form blocks, discs, tablets or pellets.