As you are probably already aware, cannabidiol (CBD) is one of the most well-known compounds that is found in the cannabis plant. Over the years, scientists have discovered and researched many different cannabinoids, all of which have a range of effects on the human body. In fact, research is ongoing. But, CBD is one of the most well-researched cannabinoids and is being sold in mainstream markets all over the Western World.
With its rapid growth in popularity, there are more and more questions popping up about CBD. One of the queries at the top of people’s minds is how CBD is extracted from the cannabis plant, and more importantly, how this is done without illegal substances, like THC, being extracted with it. In this article, we will tell you everything you need to know about how CBD is extracted using the CO2 extraction process.
What is CO2 Extraction?
CO2 extraction is a process that makes use of pressurized carbon dioxide to pull out the desired phytochemicals, like hemp, from a plant. At certain pressures and temperatures, CO2 acts like a solvent but without the dangers of actually being one. It’s the most expensive extraction method, and it’s widely considered to be the safest and most effective extraction method in the world.
CO2 extraction is the standard extraction method that is used in the food and herbal supplement industries. CO2 is also a common food additive. In fact, CO2 is used in the production of carbonated soft drinks, as an extraction solvent when making essential oils, and in removing caffeine from coffee beans in the production of decaffeinated coffee.
CO2 is thought to be a “tunable solvent” which makes it extremely versatile. By controlling temperature and pressure, CO2 is effective in creating a wide range of end products. In the world of cannabis, the CO2 process pulls out all the essential cannabinoids, waxes, and terpenes from the plant material.
CO2 extraction is divided into three categories; supercritical, subcritical and “mid-critical” – a general range that falls between the two. But supercritical is easily the most commonly used. It’s actually the most regularly used extraction method of all because it’s believed to be the safest and delivers the purest end product.
Why Use CO2 Extraction?
The primary reason for using the CO2 extraction process is because it’s considered to be the safest and cleanest method for extracting plants such as cannabis, hops, and a variety of organic crops and nutraceuticals. The ability of CO2 extraction to “tune” the extraction process by means of temperature and pressure can’t be overstated – especially when using a system that separates constituents during an extraction.
In addition, CO2 is a sanitizing agent which means that it will prolong shelf life, using the proper environment and system. Here are a few of the other benefits of using CO2 extraction:
- Efficiency: This process ensures higher yields, minimal extraction times, and low energy/maintenance consumption enhances the cost-efficiency through medical innovation.
- Purity: Right now you are breathing out CO2. Evaporated CO2 that exists from the SFE-CO2 process will leave you with just about no residual solvent. Low temperatures help to retain ideal organic states.
- Versatility: CO2 extraction allows you to pinpoint the desired components to extract from the botanical material with a solvent that is “tunable” in a system that optimizes speed, quality, and product development opportunities.
Within our natural atmospheric pressure and temperature, carbon dioxide rests in a gaseous state. CO2 needs to be frozen, compressed into a liquid, and then even further for it to reach its supercritical point. When done under controlled circumstances, the supercritical CO2 process can be used to dissolve substances into “fractions” which can then be removed.
There are a few reasons why CO2 is especially useful when it comes to botanical extractions, specifically cannabis:
- CO2 is classified as a naturally occurring compound. It’s in existence all around us and the human body produces it.
- When it comes to non-polar solvents, CO2 is among the safest. The FDA has even labelled as safe for industrial extractions, which makes it much less controversial than petroleum-based hydrocarbons like propane or butane.
- The conditions that enable CO2 to be changed from a fluid state to the supercritical state can take place without exceeding temperatures above 90°F. This means that there is less risk of compromising the naturally volatile compounds that are found in cannabis.
- Another unique quality of CO2 is that its solubility will change with pressure. This allows for the fractioning of the many different types of biomolecules that are found in cannabis strains. Thus, CO2 extraction can be used to pull many different cannabinoids from the plant, such as CBG, CBD, THCA, and THCV, along with terpenes and other compounds.
CO2 Extraction Equipment and Process
CO2 extraction is a method that requires a lot of specialized know-how and equipment. It works by using a closed loop system, which means that the process is done in a completely separate circuit to anything else. First, the CO2 must be cooled to -56˚C, while the pressure should be increased to 75 pounds per square inch (psi). This will put the CO2 into a “supercritical” state, which means that the boundaries between being a gas or liquid form are blurred, leading it to act like both at the same time.
While in this state, the CO2 will act a bit like a solvent. It’s passed through a chamber that contains the plant material. While it’s still dense like a liquid, it can fill the entire chamber like a gas. This is perfect or extraction because it doesn’t lead to any damage or denaturing.
The CO2 pulls the terpenes and cannabinoids out of the plant. Passed into a separator, this is then broken down into different parts. The extracted compounds are sent off to a collection container, while the CO2 is put through a condenser and converted back to its original state. This is where it can be recycled and used over and over again in the process.
The subcritical CO2 extraction process is very similar, but involves a lower pressure, and is therefore less expensive. However, it takes longer to complete and produces a smaller yield.
CO2 extraction creates high-quality and safe CBD products, which is why many companies tend to favor this technique. The technical ability and expense involved often drives up the price of products, but it’s usually worth the quality.
Final Thoughts on CO2 Extraction
The main thing that cannabis users should take away from this article when it comes to CO2 extraction is that supercritical extraction will produce cannabis concentrates that are safer and overall more appealing. Essentially, supercritical CO2 extraction ensures the production of end products that are cleaner, contain significantly less toxicity, and are overall more aromatic than those butane hash oil products.
Whenever purchasing a product, you should do as much research on the method of extraction as possible. After all, most of us want to know what we are putting into our bodies.