Why Does Pressure Matter in Your Supercritical CO2 System?

Pressure is important because it is one of the key variables directly related to productivity. If you hold the temperature constant, an increase in pressure will increase the solvating power of CO2. Without achieving proper pressure levels in your system you will fail to extract the full quantity of THC that your plant has to offer in a timely manner. Let’s look at the effect of pressure on CO2 extraction parameters:


In 2017, researchers demonstrated that pressure has a direct effect on the total mass of extract produced. Pressures of 34 MPa (4,931 psi) achieved a total extract mass of 92.57 g (±2.15 g) as opposed to pressures at 17 MPa (2,465 psi) which only achieved total extract masses of 37.21 g (±1.19 g). Nearly three times as much cannabinoid extract (THC + THCA) was produced simply by increasing pressure into the 5000 psi range in the same amount of time.


These cannabinoid extracts were then taken for further analysis to determine the amount of THC that could be recovered from them (via winterization or other post processing methods). It was shown that the higher-pressure settings (4931 psi) had extracted 64.25 g (± 2.54 g) of THC while lower pressure settings had only extracted 28.37 g (±1.48 g) in the same amount of time. Given this data, lets then show a rough potential loss by extracting at the lower pressure:


Original sample → 500 grams (± 2 g) @ 16.63% THC → meaning, 500 g of ground up flower @ 16.63% THC was placed into the extraction chamber.About 83.15 g of pure THC could be recovered.


Pressure  Potential THC in Flower   Actual THC recovered    Yield    Total Loss/Run  
4,931 psi                 83.15 g              64.25 g   77%         18.9 g
2,465 psi                 83.15 g              28.37 g   34%         54 g


This data shows that hitting high enough pressure levels is one of many essential steps to ensuring that a full extraction of THC from cannabis can take place. This will provide a greater amount of extracted material as well as more co-extractants, but when a formulation has the same post extraction protocol, then the time saved in the extraction process is not lost during post processing.


To conclude, when choosing an extractor remember the following:


● Machines capable of higher pressures extract more cannabinoids. Any machine offered in the 2000 psi range will not extract anywhere near the same amount of THC as a machine in the 5000 psi range in the same amount of time.


● Machines in the 5000 psi range will also extract higher amounts of cannabinoids faster than machines in the 2000 psi range.