So are you ready for a cleaner, purer, tastier, safer and overall truly higher-quality cannabis concentrate? Well have we got a treat for you: supercritical CO2 extraction! That’s not actually the treat, though. Rather, it’s a really awesome way to remove all the stuff that makes ganja great from the plant matter on which it resides.
Although fairly new in cannabis concentrate processing, this technology is anything but new to the botanical extraction industry at large. However today, the use of CO2 for cannabis extraction is quickly positioning itself to be one of the leading technologies for industrial hash oil production.
But what exactly is a CO2 extract and how is it produced?
Supercritical fluid extraction (SFE) is the process of separating components from each other by use of a particular type of solvent. These types of solvents are labelled “supercritical” by virtue of the fact that when they are exposed to extreme temperatures and pressures, they display structures that fluctuate between intermediate states of solid, liquid, and gaseousness.
When in this state, supercritical fluids are capable of breaking down structures where they can then be separated, or fractioned. Among the variety of supercritical solvents used for this process, the most common by far is CO2.
CO2 extraction technologies rely on very high pressure, and this pressure strips the plant clean. During the CO2 extraction process, many of the flavorful terpenes are removed from the cannabis resin.
The equipment and processes used for SFE can vary greatly in cost and complexity depending on scaling requirements. Machines capable of producing and fractioning large quantities of product can cost hundreds of thousands of dollars, and these machines are recommended to be serviced by only highly trained professionals in a lab setting.
The first step in the SFE process is to take gaseous CO2 and run it through a chamber where it will be subjected to extremely low (-70°F) temperatures and enough pressure to cause the gas to change into a fluid. Within this state, CO2 exhibits special properties that when reheated and pressurized become supercritical.
At this state, the supercritical fluid passes through a chamber containing the raw cannabis material. Because of its unique properties, this supercritical fluid can pass through the raw cannabis very easily while gently dissolving the membrane of the trichomes to capture their many active compounds.
The next phase in the sc-CO2 extraction process occurs when the compound-enriched solvent passes into another pressurized separation vessel, only this time the pressures and temperatures will fluctuate in order to fraction the compounds such as cannabinoids and terpenes away.
The separation vessel’s final role in the process is to transport the remaining CO2 to a condenser vessel where the temperature and pressure allow the fluid to stabilize back into a gas. Most industrial scale extractors will actually recycle and reuse CO2, a process which is commonly referred to as “closed loop extraction.”
But why, exactly, is it so popular?
Our bodies naturally produce carbon dioxide (CO2) when we breathe so it’s considered a “natural” product. This is in comparison to chemicals like the chlorofluorocarbons (CFCs) found in hairspray which caused such a ruckus in the 1970s and 80s.
The FDA considers it safe which is why CO2 is used, among other things, to keep our soda pop fresh.
CO2 is nontoxic and CO2 extraction processes do not contribute toward carbon emission increases in our atmosphere.
CO2 extraction doesn’t bring any flammable petroleum based solvents (like butane) into contact with your medicine. This removes the danger of explosions from the CO2 extraction process as well as potentially harmful petroleum based butane particles from the final, very fine, concentrated cannabis product.
Pros and cons of C02 extraction
- Clean, less risk of residual solvents
- Easy to put in vapor pens
- Often considered “solventless” and non-toxic (though CO2 is a solvent, it evaporates entirely)
- More environmentally friendly (not a petroleum product)
- Less terpenes
- More expensive
- Often considered a weaker product
Supercritical CO2 produces cannabis concentrates that are much safer, cleaner, less toxic and more aromatic than butane hash oil products. CO2 oil is more cost efficient to produce en masse and more customizable in terms of its cannabinoid content for the consumer.