CO2 Extraction: Your Complete Guide to CO2 Cannabis Oil

Many medical and recreational cannabis consumers prefer to inhale cool, immediately rejuvenating, cannabinoid-infused vapor than fairly combustible cannabis smoke.

However, many health-minded cannabis consumers keep consumers focused (perhaps including you), and they want to avoid inhaling all of the residual petroleum particles in butane hash oil into their lungs. We completely agree.

So, are you ready for a cleaner, purer, tastier, safer, and overall truly higher quality cannabis concentrate? Well, we've got a treat for you: supercritical CO2 extraction (!

But, it's not actually a treat. Rather, it's a really great way to remove all the things that make ganja great from the plant it resides in. This way, you don't have to burn cannabis to get all the mind-altering and medicinal benefits.

Best of all, for those aestheticians who are sensitive to their health, this extraction method does not leave trace amounts of toxins in the finished product. Now, this is something to keep in mind.

This article will break down some of the basics behind supercritical fluid extraction, as well as the biochemical benefits of CO2-extracted cannabis concentrates. We will also provide you with some simple steps for extracting your own kief crystals concentrate at home using dry CO2 ice.

The Added Value of CO2 Extraction
Types of Carbon Dioxide Extraction Source:

Supercritical CO2 is increasingly being used as an inexpensive, recyclable and environmentally safe industrial solvent to create high quality products of.

Fruit and nut extracts
Fruit and nut aromas
Omega 3 oil
Tobacco extracts from e-cigarettes
HOP-extraction of oil from beer
Oil extraction from algae (as an alternative energy source)
Cannabis oil
Supercritical CO2 extraction Source:

You might look at that list and say, "Hey, it's really cool to use CO2 extraction for so many different products. But why is it so popular?" Good question! Here's the deal.

Our bodies naturally produce carbon dioxide (CO2) when we breathe, so it's considered a "natural" product. In contrast, chemicals like chlorofluorocarbons (CFCs) found in hairspray caused such a stir in the 1970s and 80s.
The FDA considers it safe, which is why CO2 is used to keep soda pop fresh.
CO2 is non-toxic and the CO2 extraction process does not add to the carbon emissions in our atmosphere.
CO2 extraction does not bring any flammable petroleum-based solvents (such as butane) into contact with your drug. This eliminates the risk of explosions during CO2 extraction, as well as potentially harmful petroleum-based butane particles in the final, very fine, concentrated cannabis product!
So now that you understand why CO2 extraction is such an excellent process, let's delve a little deeper into the science behind how it works.

Supercritical CO2 Extraction 101
Warning: If you are not an industrial chemist, or are not advanced enough in reading this article, the following description may seem a bit complicated.

A CO2 extractor essentially freezes and compresses CO2 gas into a "supercritical" cold liquid state. "What does it mean to be in a supercritical state?" We're glad you asked.

Carbon dioxide (CO2) normally behaves as a gas at standard temperatures and pressures (i.e., where humans can survive without special equipment). The gas can be changed into a solid without much effort. This solid is called dry ice. These are the two most common stages of carbon dioxide that occur outside the laboratory.

Using special equipment (for example, in a laboratory), you can turn CO2 gas into a liquid by increasing the pressure to 75 pounds per square inch and keeping the temperature below -69 below. rr! Liquid CO2 is the starting point for our CO2 extraction.

From this liquid state, we will increase the temperature and pressure to a certain point above. We won't discuss the numbers here because it gets very complicated. Just know that when you increase the temperature and pressure of the liquid CO2, the fluid becomes supercritical.

This means that it can take on properties that are intermediate between those of a gas and a liquid at the same time. That's okay, right? A supercritical fluid can fill a container like a gas while still maintaining its density like a liquid.

This supercritical property of CO2 is ideal for chemical extraction because it is "milder" than other compounds and does not cause damage or denaturation (not suitable for consumption). Also, because solubility in CO2 varies with pressure, supercritical CO2 can be used to extract selected compounds (rather than a combination of all compounds) with only a few adjustments.

So, now that you have a thorough understanding of what supercritical CO2 is, we can turn our attention to how it can be used to make cannabis extracts.

Using supercritical carbon dioxide to make cannabis extracts
Compound Extract Source:

As you can see in the diagram above, you start with liquid carbon dioxide (top left). You raise the pressure of the liquid CO2 through the compressor (top middle) and then raise the temperature through the heater (top right).

The supercritical CO2 is then passed through some of the advanced tanks contained in the pumping unit (bottom right). It is at this point that the CO2 draws all the necessary wool and terpene oils and/or waxes out of the plant material.

This solution (supercritical CO2 containing all the ganja goodies) is then passed through the separator (bottom middle) where it is broken down into its component parts.

The hairy families, terpenes and other items are sent to the collection vessel ("extract" in the picture above), while the supercritical CO2 is passed through the condenser (bottom left), where it becomes liquid again. This liquid is then sent to a storage tank, where it can be used to restart the process.

And, don't worry if you are wondering if there is any residual CO2 left in the extract. Once the extraction process is complete, reducing the pressure of the CO2 allows the liquid CO2 molecules to turn back into a gas and evaporate into the atmosphere.

This is probably the easiest part of the process: simply leave the extract at room temperature.

This is the same chemical reaction that causes the soda pop to open and heat up into a flattened form. Some industrial supercritical machines can even simplify this process by recapturing, recovering and reusing the CO2 gas released after the extraction is complete.