Dry ice is the solid form of carbon dioxide (CO2)

When you think about dry ice, you may picture spooky Halloween displays or those mysterious white chunks that smoke in your frozen food deliveries.

But have you ever wondered what dry ice is, how it's made, and what else is it used for?

Let’s take a deep dive into everything dry ice.

What is CO2?

CO2 is a naturally occurring gas in our atmosphere. It is a building block of life on Earth and is a vital commodity in a number of core industries.

CO2 is a highly versatile molecule with numerous industrial applications. 

• Carbonate drinks
• Preserving food during shipping (dry ice)
• Shielding gas in welding (preventing oxidation and improving weld quality)
• Medical procedures
• Fire suppression systems
• Environmentally friendly cleaning (dry ice blasting)

Learn about dry ice and CO2 safety here.

What is dry ice?

Dry ice is the solid form of CO2.

Dry ice is the product of a carbon capture and utilization process

The process recycles CO2 that was captured during industrial processes, such as ammonia production and oil refining. The CO2 is captured and recycled. This CO2 would have otherwise been discarded into the atmosphere as industrial waste.

The recycled CO2, or dry ice, provides further economic and environmental value by eliminating negative externalities of common sanitation, parts finishing, surface preparation, and transport cooling processes, such as environmental and health effects from chemical use, unnecessary water use, additional greenhouse gas emissions via refrigerated trucks, and additional waste from cleaning rags/pads.

Dry ice is dry

Unlike water ice, dry ice does not melt into a liquid. It sublimates, or turns back to gas, leaving no liquid, moisture, or residue - hence the name "dry" ice. 

Dry ice is cold

Dry ice maintains a temperature of -109° F (-78° C) and sublimates back to gas. This low temperature makes it an excellent cooling product.

Dry ice is safe and non-toxic

Dry ice is the solid form of CO2, a gas naturally present in the atmosphere and exhaled by humans. In an industrial context, dry ice does not introduce harmful chemical contaminants or residues to cooling or cleaning processes.

The CO2 gas released during sublimation is an inert gas that dissipates into the atmosphere. 

Curious about the history of dry ice? Read about it here.

How is dry ice made?

The CO2 that is captured from other industrial processes is compressed and cooled until it becomes a liquid. This liquid CO2 is then transferred to facilities that produce dry ice. It is held in a holding tank at those facilities until they're ready to convert it to dry ice.

The liquid CO2 is then piped to a dry ice production machine. The previously pressurized liquid CO2 is pumped into a snow chamber, where the pressure drops to near atmospheric levels. As the CO2 enters the snow chamber, it undergoes rapid expansion due to the drastic pressure drop. This rapid expansion causes the temperature of the CO2 to significantly drop as well. During this process, the liquid CO2 partially transforms into a mixture of solid CO2 (dry ice) and gaseous CO2. The extreme cooling causes some of the CO2 to freeze directly into a snow-like form, often referred to as "CO2 snow." The CO2 snow is then compressed by hydraulic or mechanical presses into blocks, slices, pellets, or nuggets of dry ice.

What's needed to make dry ice?

In order to produce dry ice, you will need liquid CO2 and the proper infrastructure.

Infrastructure

The first step that must be taken before producing dry ice is making sure you have the proper infrastructure in place.

This infrastructure includes:

• Bulk or mini-bulk tank to hold liquid CO2
• Proper piping
• Dry ice production machine (pelletizer, reformer, or slice maker)
• CO2 Recovery System (capture excess CO2 and recycle it for efficiency - Optional)

Learn more about needed infrastructure here.

Liquid CO2

Once proper infrastructure is in place, it is time to find a supplier for liquid CO2. Liquid CO2 is typically supplied by industrial gas companies, specialty gas distributors, or regional providers.

With the infrastructure in place and your first delivery of liquid CO2, you can begin producing dry ice.

(Dry ice production infrastructure example with Cold Jet PR120H Pelletizer)

What is dry ice used for?

In industrial or commercial applications, dry ice is utilized in a variety of industries.

Industrial cleaning with dry ice blasting

This may come as a surprise, but dry ice is an extremely effective method for cleaning.

Dry ice blasting is used widely in food and beverage, plastics, automotive, and almost every industrial or manufacturing setting to clean machinery and processing equipment. Dry ice is also effective in remediation efforts (mold, smoke, water), historical restoration, and even car detailing.

Dry ice blasting is similar to sandblasting, soda blasting, and pressure washing in that it propels dry ice pellets or MicroParticles at supersonic speeds toward a surface with a contaminant. Upon impact, the dry ice sublimates, lifting dirt and contaminants off the underlying substrate.

Dry ice blasting is also used in surface preparation processes, such as preparing automotive parts to be painted or coated, as well as in deburring and deflashing processes in the plastics industry.

Read about dry ice blasting here.

Food Processing

Dry ice is a food-approved cooling medium that ensures food items, such as meats, seafood, and baked goods, remain safe during processing, production, storage, and transportation. Dry ice helps maintain freshness, preserve texture, and prevent bacterial growth.

Dry ice aids in maintaining critical temperatures, preventing hot spots and therefore curbing microbial growth without adding water to the process. 

Learn about dry ice for food processing.

Food Shipping

Dry ice is an ideal refrigerant for shipping perishable goods over long distances, especially when mechanical refrigeration isn't feasible or reliable. It keeps items frozen or chilled without the mess of melted water.

By maintaining consistent low temperatures, dry ice reduces the risk of spoilage and product degradation. Additionally, its lightweight nature and lower carbon emissions make it an environmentally friendly choice for the food industry.

Learn about dry ice for food transportation here.

Medical and pharmaceutical

Dry ice is crucial for the safe transport and storage of vaccines, biological samples (like blood, tissue, and organs), pharmaceuticals, and other temperature-sensitive medical supplies that require ultra-cold conditions. Its residue-free sublimation is a major advantage.

Dry ice is also used in laboratory settings for creating cold baths for chemical reactions, preserving sensitive lab samples, and in some cryopreservation techniques.

Learn about dry ice for medical and pharma here.

Have more questions about dry ice?

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