What is dry ice?
Dry ice is a solid form of carbon dioxide (CO₂) used primarily for cooling and creating visual effects. Unlike classic ice, which is formed from water, dry ice is formed from carbon dioxide and has unique physical properties. Its temperature is extremely low at -78.5°C, making it a very effective means of storing and transporting materials that require deep freezing.
Dry ice is extremely practical in that it sublimates, meaning it goes directly from a solid to a gas without turning into a liquid. During sublimation, carbon dioxide gas is released, which is colorless, odorless and non-flammable. This process is very effective for applications where intensive cooling is needed without leaving any residual water or moisture that could damage the transported products.
How is dry ice made?
The production of dry ice involves several steps during which carbon dioxide is converted from a gaseous state to a solid state:
Liquefaction of carbon dioxide: The process begins by compressing carbon dioxide (CO₂), which is normally in a gaseous state, under high pressure. During this compression, CO₂ turns into a liquid.
Pressure release: The liquid carbon dioxide is then quickly released into a space with normal atmospheric pressure. As a result, part of the liquid CO₂ immediately turns into a gas, and the rest freezes into solid particles - dry ice is formed in the form of snow mass.
Dry Ice Pressing: This "snowy" dry ice is then pressed into the desired form, either as blocks, pellets or granules. Pressing ensures that the dry ice acquires a solid structure and the required density, which is necessary for its effective use in various applications.
Properties of dry ice
Sublimation temperature: Dry ice has a temperature of -78.5°C, making it ideal for long-term cooling and freezing.
Sublimation: Dry ice sublimates directly into carbon dioxide gas, meaning it leaves no liquid behind. This is advantageous when transporting sensitive materials as it avoids the risk of moisture or condensation.
Hygienic: It is odorless, tasteless, non-toxic and hygienically safe, which makes it suitable for food and healthcare.
Ecological friendliness: When using dry ice, no chemicals or impurities are released, only carbon dioxide, which is part of the natural cycle of the atmosphere.
