What is CO2 Extraction and How Does it Work?
If you know your CBD oils, you’ll know there a few different ways in which the CBD can be extracted from the raw hemp material.
Some low-end companies use crude extraction operations that employ chemical solvents like hexane and butane (which is essentially lighter fluid), but this method can compromise the molecular structure of the CBD if done incorrectly, and more importantly, it can result in an end product that contains harsh chemical residues — not stuff that you want to be ingesting as a byproduct.
As such, if you’re looking for the cleanest, purest, and most effective tincture possible, most any self-respecting manufacturer will tell you that CO2 extraction is the only way to go.
But what is CO2 extraction, exactly, and why is it better than other methods when processing raw hemp material into CBD oil? Let us explain.
Why Supercritical CO2 is Safer than Other Extraction Methods
We’ll be honest – supercritical CO2 extraction is not an easy process to understand (or describe). We’ll go over the fundamentals as clearly as we can, but to contend with the actual molecular processes that are taking place, you really need to have a working knowledge of organic chemistry.
That being said, we can single out several easy reasons why CO2 is preferred over other, solvent-based extraction methods:
- It is safe, pure, and natural. CO2 is a 100% natural compound that’s all around us. It’s in the air we breathe, in the fizzy beverages we drink, and in the packages of fresh foods that we buy at the grocery store. In fact, it has been approved by the FDA as a safe material for industrial extraction since the 1980’s.
- It has unique “supercritical” properties. If you know your chemistry basics, you’ll know that most compounds exist in one of three natural states: gas, liquid, or solid. When maintained under precise combinations of temperature and pressure, however, a few select compounds (such as CO2) are able to exist in a “supercritical” state between liquid and gas. When in this state, CO2 is able to separate, or “fraction-off” active hemp compounds (like CBD) in nearly a 100% efficient manner.
- In normal concentrations, it is inert, non-toxic, non-combustible, and non-harmful to humans. Chemical solvents like propane and butane are extremely combustible (i.e. they can explode easily). In addition, researchers in Oregon have discovered that butane cannabis extractions can release benzene – a known carcinogen – when heated to extreme temperatures. CO2, on the other hand, is entirely inert (chemically inactive), non-toxic to humans, and non-combustible.
- It is sustainable. This is a huge advantage, especially for the environmentally conscious. While other solvents (like butane and propane) are petroleum-based and wreak havoc on the environment, CO2 is a 100% natural and sustainable compound. In fact, if you remember from high school biology class, it is essential for the survival of all plants (and humans, for that matter).
- It evaporates completely. Solvent-based CBD oils (i.e. oils that are produced with butane or hexane) need to be processed many times over in order to eliminate residual chemical compounds. And even still, it is nearly impossible to purify them completely. CO2, on the other hand, is easily separated from CBD by evaporation when maintained at a precise temperature and pressure.
How Does CO2 Extraction Work?
Again, the exact process of supercritical CO2 extraction is fairly involved, as it includes several complex steps to adjust temperature and pressure to crucial levels. However, it is easy enough to explain and understand the basic fundamentals behind the process.
First, raw plant material containing the CBD is loaded into a large canister. Next, CO2 gas is compressed and cooled (in a separate canister) to an extremely low temperature (about -70℉) in order to condense it from a gaseous phase to a fluid phase.
Once in this fluid phase, the CO2 is reheated slightly (typically to temperatures no higher than 120℉), to allow it to enter a “supercritical” state where neither gas nor liquid properties are dominant.
In this pressurized, supercritical phase, the CO2 is then “injected” into the canister containing the raw hemp, at which point it “flows” over the plant material to “collect” the active compounds.
Once all of the active hemp compounds are collected, the supercritical CO2 (sc-CO2) is sent to another canister where the CBD is fractionated (separated) off. This results in a pure, viscous, CBD-rich fluid to “ooze” out into a collection jar (after which it will undergo further purification).
Finally, the sc-CO2 which has just been separated from the plant material is recycled, or “decompressed,” to allow it to return to its natural gaseous state, where the cycle can be repeated.
Why Doesn’t Every Company Use CO2 Extraction?
In a word, if you’re wondering why every CBD oil company doesn’t employ a supercritical CO2 extraction process, it’s because it can be incredibly expensive.
The machines themselves (which are large by the way, and can take up almost an entire room) can cost hundreds of thousands of dollars, and this is not to mention the cost of maintenance and calibration, which must be done routinely by certified technicians.
Petroleum-based solvent extraction is infinitely cheaper, but as we’ve discussed, it typically results in low-quality end products – and not to mention potentially dangerous to consume.
Companies who are willing to make the investment in CO2 extraction equipment are dedicated to manufacturing only the purest, safest, and highest-quality CBD oils — guaranteed.