When you think of dry ice you likely think of stage effects at a concert, Halloween haunted houses or even fancy “smoking” cocktails. While dry ice can be used for amazing visual effects, there is so much more to it. Let’s take a look at what dry ice is, where the raw material comes from, how it is made and some of the uses for it outside of the ones mentioned above.
Reformed dry ice blocks and pellets
Dry Ice 101
Put simply, dry ice is the solid form of CO2. CO2 is a naturally occurring gas in our atmosphere, but for the purposes of sustainability, recycled CO2 is used to make dry ice. Dry ice maintains a temperature of -109° F (-78° C) and sublimates back to gas. This means that unlike water ice, dry ice will not leave behind any liquid.
Where does the liquid CO2 come from?
Many industrial gas companies supply liquid CO2. The best part is that it is captured from other industrial processes, such as ammonia production plants and oil refineries, and recycled for secondary uses. This makes it an environmentally sustainable cooling and cleaning solution. Liquid CO2 is made from taking CO2 gas, pressurizing it and cooling it. This liquid CO2 is the only raw material needed to produce dry ice.
How is dry ice made?
In order to produce dry ice, you will need liquid CO2 and the proper 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 a bulk- or mini-bulk tank of liquid CO2, proper piping and a pelletizer, reformer or slice maker. Once this is in place, it is time to find a supplier for liquid CO2. 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)
The liquid CO2 is first pumped into a holding tank where it is chilled to -109° F (-78° C). Once it reaches temperature, it is pressurized to create snow. If you are using a pelletizer, the snow is compressed and extruded through a die-plate to create dry ice pellets. Die-plates range in size from 3mm to 19mm. The required size of dry ice pellets will depend on the application in which it is being used.
From here, blocks or slices of dry ice can be made from the pellets by feeding them through a reformer. Once the pellets enter the reformer, they are positioned into a die in the shape of the block to be made. The pellets are then pressed together using extreme force to create a block or slice.
What is dry ice used for?
Dry ice has three main applications: cooling, cleaning and surface preparation. While using dry ice for cooling is fairly well known, cleaning with dry ice is gaining popularity with industrial companies, disaster restoration specialists, automotive detailers and many other industries.
Cooling with Dry Ice
Dry ice is an effective cooling medium for many reasons. One of the main reasons is the fact that it maintains a consistent temperature of -109° F (-78° C) . This allows companies to ship perishable goods and pharmaceuticals at ultra-cold temperatures (such as the COVID-19 vaccine) with confidence. Since it does not melt, there is no water or residue left behind. Instead, it sublimates, or turns right back to its gaseous state. Dry ice losses weight during sublimation, in turn increasing fuel efficiencies during shipping. It also does not require additional refrigerants, which release harmful pollutants into the atmosphere.
Cleaning with Dry Ice
This may come as a surprise but, dry ice blasting is an extremely effective method for cleaning. From industrial machinery, weld lines, and even food processing lines to smoke, soot, and mold damage dry ice is the most environmentally sustainable cleaning method. In principle, 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.
Unlike sandblasting, soda blasting and pressure washing, dry ice blasting does not require additional abrasives, water or chemicals and creates no secondary waste. Dry ice is a non-abrasive, non-toxic and non-conductive medium. This means you can clean delicate surfaces without the concern of damaging them. It is also non-toxic and non-flammable, meaning you can clean your equipment while it’s running.
Surface Preparation and Postprocessing with Dry Ice
Dry ice blasting can be used to prepare surfaces prior to welding by removing any excess materials or lubricants. It can also be used in the deflashing process of plastic parts, removing the need for manual postprocessing. We also offer integrated blasting systems that allows you to integrate our dry ice blasting and production machine with a robotic cell to automate this process. This allows manufacturers to increase their throughput, reduce machine downtime and minimize manual intervention so operators can focus on more value-added tasks within your operation.
Are you ready to start producing your own dry ice? Contact us today for a consultation with one of our dry ice experts!