Dry ice is the solid form of carbon dioxide (CO2), just as normal ice is the solid form of water (H2O). Dry ice is extremely cold (-78.5°C), therefore it is used in various refrigeration and freezing purposes in the industrial world. With the right ingredients, it's possible to create your own dry ice at home – as long as you use the right safety measures, the process will be quick and easy!
Method 1 of 2: Making Dry Ice with CO2 pill
Step 1. You only need three things to make dry ice at home:
a CO fire extinguisher2, a pillowcase – that you don't mind getting dirty – and an outdoor environment where children or pets won't surprise you.
- You need specifically of a CO fire extinguisher2 for this method, not an ordinary fire extinguisher. Most fire extinguishers use fine chemical powders like sodium bicarbonate or potassium bicarbonate, which will not provide the required amount of CO2 to produce dry ice.
- CO fire extinguishers2 they are typically used in laboratories, kitchens and environments with mechanical equipment. They usually have a plastic horn in the mouthpiece and a pressure gauge.
- You can find these CO fire extinguishers2 in building material stores and online specialty stores.
Step 2. Protect your hands, eyes and limbs
Dry ice is so cold that it can cause frostbite when it comes in contact with the skin. Although using a fire extinguisher does not require the use of protective clothing, take precautions to protect your body from any dry ice that may touch your skin. Wear the following before starting:
- Thick, tight gloves (you can also wear thick gloves under them for extra protection)
- Protective goggles
- Long sleeve shirts and pants
- closed shoes
- Long-sleeved jacket or lab coat (optional)
Step 3. Place the fire extinguisher horn inside the pillowcase, pull the fabric from it and wrap it around the hose
The idea is to prevent the gas from coming out of a place other than the pillowcase fabric.
Use duct tape to create a strong seal if you're afraid the pillowcase will fly off. The fire extinguisher pressure shouldn't be too strong, but the precaution won't hurt
Step 4. When you're ready, press the fire extinguisher trigger and watch the gas blast against the pillowcase
Hold it down for two or three seconds. You may not think the ice is being produced, but it should start building up in the base quickly. Release the trigger after a few seconds. Carbon dioxide will begin to leak through the pillowcase – this is normal and safe as long as you are in a well-ventilated area as recommended.
If you are unable to use the fire extinguisher, check the safety pin, which must have been removed to be able to press the trigger
Step 5. Carefully remove the horn from the pillowcase, but keep the fabric tight to catch any ice that is stuck
A small pile of dry ice must have formed at the base of the pillowcase – it will look like crumbly Styrofoam.
Try not to turn the pillowcase over or handle the ice too much. Even if you're wearing thick gloves, touch the ice chips for just a few seconds so you don't hurt your fingers
Step 6. Scrape the ice off the pillowcase and transfer it to a safer, more practical container, such as a bowl or firm plastic bag
Keep just a pile of ice and make big chunks. Do not seal the container.
If you close an airtight lid, the CO pressure2 it will accumulate and explode. If using a lid, do not press or screw it completely.
- Not all materials are safe for dry ice storage. Check out the suggestions:
- Not use porcelain, ceramic or glass. The intense cold of ice can contract and break these materials.
- Not use expensive metal containers. Ice can damage and twist metal.
- Use firm plastic containers (mainly coolers and ice chests).
- Use thermos bottles, but do not close them.
Step 7. If you cannot find a CO fire extinguisher2, replicate this method with a pressurized CO tank2, which can be found at soldering stores and on the Internet.
The process is virtually the same – attach a horn or mouthpiece to the tank, wrap the pillowcase around it, release the gas for a few seconds and collect the dry ice acorns. The security measures are the same.
- When purchasing the tank, make sure it has a dip tube – which is also sold separately. These tubes scrape off liquid carbon dioxide from the base of the tank, which is what you need to make dry ice. On the other hand, tanks without dip tubes use carbon dioxide from the top of the tank, which will not produce dry ice. Tanks equipped with dip tubes are usually marked with white stripes, while those not equipped have a black finish.
- If you plan on making dry ice frequently, invest in an ice making accessory – basically, a horn with a cloth bag that can be installed and removed from the tanks.
Method 2 of 2: Using Homemade Dry Ice
Step 1. One of the most common uses of dry ice is to create artificial smoke
To do this, just mix it with water – splashing a little water on the ice will create a hissing sound and will produce a lot of carbon dioxide. This is useful for nightclubs, rock concerts, haunted houses and other places where you need to create a mysterious atmosphere.
- Again, remember to make carbon dioxide outdoors and in well-ventilated places. Although unlikely, the production of a lot of CO2 in an area with poor ventilation it can eliminate oxygen, making breathing impossible.
- If you use a container with a hole for ventilation, you can create a contraption that releases smoke like a narrow jet. This effect can be strong enough to power a small engine or turn a weathervane.
Step 2. Another common use of carbon dioxide is the creation of carbonated beverages (effervescent beverages such as soft drinks, beer, champagne, sparkling water, etc.)
). Putting dry ice in water releases CO2, which will eventually agglomerate into the small bubbles characteristic of these drinks. Despite the process of creating these drinks - homemade or industrial - using CO2 in the gaseous state (instead of solid, as in the form of dry ice), dry ice will also have a similar effect.
Do not consume the drink while it is still on dry ice.
Wait for it to completely bubble up before drinking. Swallowing dry ice can cause serious health problems, as the inner tissues are even more vulnerable to burns than the skin.
- Some people don't like the taste of charred drinks with dry ice. Try the process with a small amount of the liquid before pouring ice into the entire drink.
Step 3. Use dry ice to keep food and drinks frozen
It is much colder than regular ice, so food and drink can be kept much cooler. However, food can get too cold – place a bottle of champagne on dry ice, for example, and it might crack or partially freeze, so use it only on food that is served frozen (such as ice cream, popsicles, etc.).).
- To use dry ice in an ice box, add the food first, place the ice on top and put the lid on (do not close it completely). Cool air is drawn down so this will efficiently keep the box cool. If there is free space, fill it with newspapers (the extra air will make the dry ice sublime (turn to gas) faster.
- Dry ice also works to keep ordinary ice frozen in a cooler.
- Typically, you will need about 4.5 to 9 kg of dry ice for every 24 hours you need to keep food frozen (depending on the box).
Step 4. Surprising as this is, dry ice can be used to keep grains and pasta fresh
To do this, place the ice in the base of a cooler. Make sure the ice surface is not frozen as this can introduce moisture and wet the food. Pour the food onto the dry ice and place the lid on the box (don't close it completely) for about five or six hours - the ice needs to completely sublimate until there is no solid. When finished, close the lid.
- As ice sublimes, it forms CO2 in gas, which is heavier than air. As more gas forms, air is forced out of the container. Without any air, it is difficult for bacteria or pests to survive, which greatly extends the life of the food.
- For this method, use approximately 115g of dry ice for each 4 L container.
Step 5. Use dry ice to shrink solid materials
As mentioned above, dry ice is so cold that it causes materials such as ceramic and metal to shrink slightly to touch. In certain situations, this can be used to your advantage. Check out two examples below:
Fixing Dents in Cars:
If you have a dent in your car body, dry ice can help. Wear thick gloves to press a block of dry ice into the dent. If possible, press it against the inside of the place. Hold the ice in place until it freezes a few inches around the dent and let the area warm up again. Repeat as needed.
This trick is great for removing tile floors. Place a sheet of dry ice centered on the floor so that it touches the entire surface. Wait until the tile has completely frozen, and if it doesn't come off on its own, tap it with a hammer and screwdriver to loosen the adhesive at the edges.
Step 6. Use dry ice to kill pests in your garden
As carbon dioxide is heavier than air, it will displace air from any container (as seen in the food preservation method). You can use this principle to kill moles and other pests that destroy your garden. To do this, fit pieces of ice – about 5 cm – in the holes and cover them with earth. Do this in as many holes as possible. The ice will sublime and turn into CO gas2, removing the oxygen from the place and suffocating the animals.
- If you want dry ice in large quantities, your best bet is to go to a store. Some markets sell dry ice, but if you can't find one near you, buy it online.
- For extreme needs, it is possible to purchase dry ice making machines. However, they can cost a few thousand reais.
- Handle dry ice in a well-ventilated area. As solid carbon dioxide turns to gas, it replaces oxygen in the air.
- When storing ice, do not cover the container. As it sublimates, the gas must dissipate into the air. Container will crack if left unopened.
- If you are a child, do these experiments only under adult supervision and wear thick leather gloves to handle the ice.
- Don't let dry ice touch your skin. You will get a painful burn.