Supercritical CO2 Extraction Explained
From terpenes and flavonoids to distillate and isolates, the jargon-filled world of cannabis extraction can seem like strange and unfamiliar territory – especially for those who are less scientifically-inclined. In an effort to simplify and shed light on an often-mystifying process, MediPharm Labs set out to explain our preferred approach to cannabis extraction – the supercritical CO2 method. We enlisted the help of our Vice President of Quality and Scientific Affairs, Dr. Chris Talpas, to guide our narrative.
A plethora of industries employ various extraction methods to achieve their desired outcomes – the food, biofuels, chemicals, pharmaceuticals, metal refinery, and essential oils industries, to name a few. Popular extraction techniques include steam distillation, solvent extraction, maceration, enfleurage, cold press extraction, and water distillation. At MediPharm Labs, our team of experts explored a range of possibilities to determine a superior method of extraction aligned with our vision – to be “the trusted global leader in industrial-scale manufacturing of high-quality cannabinoid-based derivatives.” With a focus on purity and unparalleled standards of quality for our partners, patients and consumers, the choice was an obvious one. Supercritical CO2 extraction was a must for our organization.
The Benefits of the Supercritical CO2 Extraction Method
Simply put, the cannabis supercritical CO2 method is a clean and efficient way of separating an extractant (in this case, cannabis resin) from the remainder of the plant material (cannabis). The desired compounds are dissolved by flowing solvent (supercritical CO2 fluid) through columns packed with cannabis plant material. This process involves the removal of unwanted ingredients and impurities, ultimately resulting in a product of high quality and purity. A substance reaches a supercritical state when both its temperature and pressure have exceeded their critical points and physical properties are altered, blurring the lines between gaseous and liquid states. Supercritical CO2 fluid (sCO2) above its critical points (31.1˚C and 1071 psi) has the mobility of a gas and the solubility of a liquid. MediPharm Labs settled on this extraction method for a variety of reasons, including:
- Non-toxicity - CO2 as a solvent is non-toxic, eliminating concerns for patients or consumers about any remaining toxic solvent residues;
- Non-flammability – CO2 is a non-flammable substance that offers no possibility of explosions or combustion during processing (as compared with other extraction solvents such as ethanol or butane);
- Purity – sCO2 requires no additional post-processing to remove the solvent. What is left over is an intermediate product that is environmentally-friendly when compared with other solvents; and
- Versatility - by altering CO2 pressure and temperature, solubility can be manipulated, thereby increasing selectivity for, and reducing degradation to, desired compounds.
“Supercritical CO2 Extraction is a well-established, scalable and safe extraction methodology that gives us a consistent extract purity profile,” says Dr. Chris Talpas. “MediPharm Labs has enlisted world-renowned extraction expert Dr. Jerry King to assist us in mastering this technology. This technology offers international regulatory acceptance which aligns with our globally compliant platform.”
Dr. Jerry King sits on MediPharm Labs’ Science Advisory Committee and brings more than 53 years of experience in supercritical fluid and technology and other extraction methods to the team.
The Supercritical CO2 Extraction Process
The supercritical CO2 extraction method involves the following steps:
- Gaseous CO2 is cooled to the point where it becomes liquid CO2 (lCO2), which is pushed through the extractor system via a pump.
- lCO2 is pumped through a preheater, which heats and pressurizes lCO2 until it reaches its supercritical point (sCO2).
- sCO2 is pumped through an extraction column which is packed with milled cannabis material.
- As we learned in school, like dissolves like. Due to sCO2 being non-polar, it has an ability to solubilize cannabinoids which are also non-polar compounds. sCO2 is able to pass through and extract the resin from the plant material.
- Once the sCO2 flows from the extraction columns, it encounters a back-pressure regulator or flow control valve which brings about a pressure decrease as it enters the separator/cyclone collection columns.
- The decrease in sCO2 pressure reduces the solubility of the cannabinoids, which allows the cannabis resin to precipitate out of the gas.
- As the sCO2 returns to its gaseous CO2 state, it is recycled through the system to begin the process over.
Just as important as following standard operating procedures, processes and regulations is choosing qualified and reputable equipment manufacturers. MediPharm Labs works with custom manufacturing solutions providers such as Vitalis Extraction Technology. Our equipment suppliers and their equipment are scrutinized and undergo rigorous qualification processes (IQ, OQ, PQ), ensuring that we choose only the best options for our large-scale operations.
To learn more about the high-quality cannabis products developed through our extraction methods, please visit medipharmlabs.com.