Recently, I read a social media post where a fan of hydrocarbon extractions said, “People have been extracting plant into oil for 70 years. The vast majority of that is done with hydrocarbon or alcohol. Why the cannabis industry has held on to CO2 being the best extraction method is very puzzling”. Additionally, I have thought long and hard about the op-ed on BHO that I read in CBE in 2016. I am admittedly biased – Apeks Supercritical has built and commissioned more than 500 CO2 extraction systems in cannabis extraction applications over the last 6 years. That being said, I think there is a good reason the cannabis industry has developed a fondness for CO2, and I believe that CO2 is here to stay as a result.

Why CO2 in the first place?

If botanical extraction applications outside of cannabis have been employing other extraction solvents like ethanol or hydrocarbons for decades, why is CO2 even being used in the first place? Asked another way, if CO2 isn’t being used instead of other botanical oil extraction applications, why is it so predominant in the cannabis industry? Both good questions – the answer stems from the cannabis industry’s unique history as an unjustified illegal drug with justified medical benefits and the subsequent legalization without Federal oversight.

One of my first memorable exposures to the cannabis industry as a CO2 extraction equipment manufacturer was through conversation with a doctor in California sometime in the late 2000’s. This doctor had quite a few medical patients and was treating them very successfully with cannabis. He complained at the time that he couldn’t reliably obtain extracted oils that were consistent and/or free of contaminants because most of the oils were being extracted with low-grade butane in basements, garages, hotel rooms, etc. He was interested in doing extractions himself to more reliably produce medicine for his patients but he didn’t want to “mess with butane”. Beyond the explosive dangers inherent to processing with a volatile gas, he felt that butane extractions had contaminants that could cause harm to his patients and he was looking for an easier and cleaner alternative: enter CO2. CO2 is non-toxic, non-flammable, and creates an extracted oil that is 100% free of residual solvents.

The Good, the Bad, and the Ugly of Butane Hash Oil (BHO)

In the late 2000’s, concentrated marijuana products were gaining popularity faster than the legal medical or recreational frameworks were being put in place by state governments. This was great for the progression of marijuana legalization, however, the extraction solvent of choice at the time was butane, and the method of choice was “open blasting”. Open blasting is basically pushing liquid butane through raw plant material and evaporating the butane from the extracted oil in open air to create BHO. No one chooses to be in an accident, but unfortunately an unsettling number of explosions and subsequent injuries and property damage from open blasting gained a ton of media attention, and also gained attention from the authorities. Below are a couple of recent examples.

While butane, propane and any other hydrocarbon can be processed safely under the tight controls of a Class 1, Division 1 explosion proof facility, most, if not all, BHO was not being manufactured under those conditions. The explosions from unsafe BHO manufacturing operations gave a huge black eye to the entire marijuana movement, and regulators, firefighters, and police didn’t want anything to do with it: enter CO2 again! CO2 is the same stuff that firefighters use to put fires out. CO2 immediately gained acceptance from inspectors and regulators as a safer alternative to butane.

Below are a couple of recent articles.

Fitzgerald: Honey oil-don’t try this booming business at home

Behind the Scenes of a deadly hash oil explosion in Portland

A Place in the World it Didn’t Have Before

Suddenly CO2 was becoming very popular in the world of marijuana concentrates. It created a clean product that was in high demand, could never cause a fire or explosion, and the regulators were approving CO2 operations faster than their hydrocarbon equivalent. The demand for CO2 extraction systems allowed CO2 extraction equipment companies to grow quickly, and we subsequently reinvested in the technology. In 2012, CO2 extraction systems could process about 1 pound of raw material every 3-4 hours and used a very inefficient compressed air driven CO2 pump. Today, CO2 extraction systems are capable of processing 5-6 pounds of raw material in 1 hour – a 2,000% improvement!

Now that CO2 has had an opportunity to thrive in the fast-growing cannabis industry, there are more than 30 CO2 extraction equipment manufacturers. The vast majority of them are new entries with limited experience, but a handful of manufacturers like Eden Labs, MRX Xtractors, Vitalis Extraction Technology and yes, my company Apeks Supercritical, have been innovating and improving the CO2 extraction process with an intensity that has never been seen before. CO2 as an extraction technology has been around since the early 1900s, but because the equipment is expensive it needed a high value, low volume product in order to justify the capital expense and find its place in the world: enter marijuana! A high value, low volume product in a medical application which required cleanliness and consistency.

Conclusion

Ultimately, CO2 can thank butane for giving it an opportunity to flourish as an extraction technology. Without butane, there would have been no explosions, no residual solvent testing requirements, and no distaste from the authorities. CO2 manufacturing companies would never have had an opportunity to innovate faster, more efficient and less expensive CO2 equipment. And now that CO2 is more efficient and less expensive, the opportunities for carving out a place in other botanical oil industries like flavorings and natural products are endless!  CO2 is here to stay!