What is CO2 dry ice? What is the formula for dry ice? What are its uses in preserving food and in industry? What is the production process of dry ice? Let’s find out in this article from Migco.

What is dry ice?

Dry ice is the common name for solid carbon dioxide (CO2), a compound that is odorless, colorless, and tasteless. Dry ice is also known as dry ice, dry ice, dry ice, dry smoke, CO2 ice, and is a solid form of carbon dioxide (CO2). This is the common name for carbon dioxide in its solid (frozen) state.

liquefied co2 gas — Solid CO2 dry ice is the common name for solid carbon dioxide

Discovered in the early 20th century, it was first produced commercially in the United States in 1920. In 1925, it was officially named dry ice.

What is the formula for dry ice?

Dry ice is actually produced by compressing carbon dioxide gas into a liquid state, removing the heat generated by the compression (see Charles’s law). The liquid carbon dioxide is then rapidly expanded. This expansion reduces the temperature and causes a portion of the CO2 to freeze into “snow.” This “snow” is then compressed into pellets or blocks.

Therefore, the formula for dry ice is CO2.

Solid CO2 dry ice production process

It consists of the following 3 stages:

CO2 gas is compressed and cooled under high pressure 870lb/in2 (395 kg/cm2) to create a liquid form while removing excess heat.

The liquid CO2 expands and evaporates rapidly at room temperature with low pressure (4500cm Hg) into gas, and a portion of the liquid freezes into dry ice snow.

Hydraulic pressure is applied to compress the dry ice snow into various shapes, with blocks or pellets being the most common.

The density of compressed CO2 depends on the time and pressure applied. The density of the dry ice blocks can reach a maximum of 1.56 g/cm3 at a temperature of -78.64°C.

*Diagram of the solid CO2 dry ice production process*

Due to its extremely low temperature of -78°C, it is widely used in various fields:

Hospitals & clinics

Food processing & distribution

Industrial cleaning and technical processes
Stage effects

Applications of solid CO2 dry ice

In daily life, dry ice is used in many applications such as medicine, entertainment, and various related industries:

Dry ice keeps frozen food items cold during export or long-distance domestic and international transport…

Dry ice for preserving fish — Using dry ice to preserve frozen food to maintain freshness and flavor

Dry ice is used in medical facilities to cool biological samples, cell samples, pharmaceuticals, vaccines, organs, tissues, blood… ensuring proper preservation and preventing spoilage.

Creating smoke effects on stage, commonly used at wedding receptions

Cleaning dirt and grease from machinery, with the advantage of not requiring disassembly of machine parts. This saves costs and increases efficiency for businesses.

Advantages of using dry ice in industry

It is a non-abrasive, non-flammable, and non-conductive cleaning method

Environmentally friendly and does not contain pollutants

High purity, suitable for use in the food industry

On-site cleaning without the need for extensive disassembly of machine parts.

Used to remove product residue, waste, contaminants, paint, oil, and biofilm.

Carbon dioxide (CO2) is a non-toxic, liquid gas that is inexpensive and easy to store at the workplace.

Safety when using dry ice

Always wear rubber gloves or use tongs when handling dry ice. Do not touch dry ice directly, as it is very dangerous and can cause frostbite.

Do not store dry ice in airtight containers. As dry ice sublimates, the increased gas pressure can cause the container to explode. Ensure the container is well-ventilated and has a lid to allow air circulation.

Do not store dry ice in the freezer, as it will make your freezer too cold and may cause it to shut down. If there is a power outage, dry ice is the best way to keep food and drinks from spoiling.