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Ethanol Extraction vs. Supercritical CO2 [Facts]


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Ethanol Extraction vs. Supercritical CO2 [Facts]

  • by Tyler Sewell
  • 02 March, 2020
  • 6 min read
  • CBD Oil Products
  • Health
  • Hemp and CBD Oil Info
  • Science

CBD Extraction Techniques: Supercritical CO2 or Ethanol?

Here, we break down the differences between the two most commonly used CBD extraction methods (ethanol vs. CO2) to help clear the air.

Extraction methods are various processes used to procure and concentrate the medicinal compounds found naturally in hemp.

There is no absolute ‘best method’ when it comes to CBD extraction methods, and it truly depends on what you’re trying to create. In a nutshell, supercritical CO2 has little use other than for producing highly-refined CBD isolates.

In contrast, ethanol is the go-to when opting for a full-spectrum CBD oil with a wide range of beneficial phytonutrients.

Supercritical carbon dioxide (CO2) extraction has exploded in popularity and is arguably the most common choice amongst CBD companies. The question remains, though, as to whether or not that’s a good thing. Let’s explore this topic further.

Supercritical Carbon-Dioxide (CO2) CBD Extraction

Supercritical CO2 extraction requires the use of costly and technologically advanced equipment, and also a well-trained technician to operate the machine.

This particular technology has applications in many areas other than hemp, such as:

  • Sterilizing tissues and organs for transplants
  • Extracting fat from snack foods
  • Removing caffeine from coffee to make decaf
  • Extracting flavor oils from hops

This process involves starting with gaseous CO2 and transforming it into a liquid by cooling it to under -69°F (-56°C) and applying 75 pounds of pressure per square inch.

At this point, the CO2 is now liquid, so the technician gradually increases the temperature and pressure until the fluid reaches a ‘supercritical’ state, meaning that it possesses both the properties of a gas and a liquid.

This dynamic allows for the supercritical CO2 to fill up a chamber like a gas, but soak the extraction material (hemp) like a liquid.

CO2 extraction is recognized in the cannabis industry for having an incredibly low environmental impact. Compared to a butane/propane extraction, CO2 is promoted as one of the safest techniques. However, despite these positives, CO2 is not without its flaws.

After the CO2 passes over the hemp, it goes through a separation chamber, where changes in temperature and pressure allow the CO2 to evaporate and leave behind cannabinoids, terpenes, and wax. The CO2 vapor then passes through a condenser to be returned to its liquid state and saved for future use.

CO2 extraction is often marketed as ‘solvent-free,’ suggesting it is a cleaner alternative to other extraction methods. However, this is usually not the case.

The resulting extract, while full of cannabinoids and terpenes, requires winterization due to the high content of wax and lipids. The most commonly used solvents for this purpose are ethanol (ironic), isopropanol (petroleum-based), or methanol (toxic wood-alcohol).

Most companies using CO2 extractions perform winterization through distillation, which is typically performed at very high heat. In this common method the two benefits of CO2 are lost; a solvent is still employed (“solvent free” therefore is not accurate) and the hemp extract is subjected to high heat (the cold benefits of CO2 are lost).

Furthermore, (and more importantly if you are consuming hemp-derived products for therapeutic benefits), this lengthy purification process, which is required to remove the co-extracted constituents (waxes and plant fats) from the extract, can take away from the final cannabinoid and terpenoid profile.

A study published by Planta Medica in March of 2018 found that CO2 extraction drastically changed the chemical composition of cannabis. Compared with the dried plant flower, CO2 extracts eliminated many of the subtle flavor and aroma molecules that provide nuance and subtlety to the experiential effects of different cultivars.

Advocates of CO2 extraction tout the non-polar nature of carbon-dioxide, meaning that it doesn’t pull out any of the water-soluble components in hemp.

However, this is only a benefit if your end goal is to make CBD isolate, as most experts agree that the full range of compounds found in hemp provides a unique therapeutic synergy known as the ‘entourage effect.’

One sure benefit of this method is that CO2 effectively eliminates any unwanted microbes, assuring that the end product is free from mold and mildew.

While it is a fairly rare occurrence, there are unfortunate deaths related to CO2 extraction from time to time, as a leak of carbon dioxide can go undetected due to the lack of smell or visible fumes – which can ultimately lead to a deadly build-up of CO2 in the environment, causing asphyxiation.

Alcohol (Ethanol) CBD Extraction

Cannabis is a fascinating plant that can produce more than 500 compounds that represent almost every biogenetic class. As such, we choose to utilize ethanol extraction to create the most full-spectrum CBD product possible.

Ethanol is simply, alcohol. It is made from plant fermentation and is a by-product of plants themselves.

Ethanol is a polar solvent, allowing it to extract both water and fat-soluble plant compounds, such as:

  • Cannabinoids (CBD, THC, CBC, CBG, CBDV)
  • Terpenes (myrcene, limonene, pinene, linalool, b-caryophyllene, terpinene, eucalyptol)
  • Polyphenols
  • Lignans
  • Chlorophyll
  • Flavonoids (apigenin, luteolin, kaempferol, quercetin, and cannflavin A and B)
  • Amino acids (all eight essentials)
  • Alkamides (immune-promoting compounds)

In our ethanol extraction, food-grade ethanol is passed through the hemp flowers and brought to a very low boil. During this simmer, we gently cradle the flowers as they mix with the ethanol and create natural friction, producing a vapor that is full of beneficial compounds. We then recirculate the ethanol through the plant matter multiple times, allowing for maximum extraction.

Our sophisticated ethanol extraction process effectively removes undesirable plant waxes and chlorophyll without the high-heat exposure used in other extraction methods.

Ethanol has been referred to as “the best of both worlds”. This extraction method is recognized for having the efficiency of a butane extraction while maintaining the safety of CO2. The FDA classifies ethanol as safe for human consumption and therefore it is commonly used as a food preservative and food additive.

Now that we’ve talked in-depth about the two primary extraction techniques, let’s discuss the bottom line on choosing which extraction method you should look for in your CBD products.

Petroleum-Based Hemp Extraction

Petroleum-based solvents, such as Butane and Propane, were among the first extraction methods used by farmers, cannabis growers and home-grown CBD enthusiasts. These solvents work well due to their non-polarity, meaning they allow for the extraction of all the desired compounds (such as cannabinoids and terpenes) from the plant material without also extracting undesirable compounds (such as chlorophyll and plant metabolites). The problem with this extraction process is that it involves high heat and high pressure, is highly combustible and highly toxic, ruling out being a viable option by many health and wellness companies.

While petroleum-based solvents have their purpose, in a commercial setting, typically a solvent-based approach or a super critical (CO2) extraction are performed for feasibility and cost efficiencies.

How Do We Ensure Our Products are Clean and Solvent-Free?

We employ distillation techniques to remove the solvent from the extract. Our testing protocols test down to 1 part per million (1ppm) in which no ethanol is found in our extracts.

We strive to keep our products as natural and as close to the hemp plant as possible. Ethanol is well-known in the herbalism world to be the most natural and efficient solvent to get the most beneficial compounds from the plants. These methods have been employed for hundreds, if not thousands of years which is why most of the larger herbal companies are still using ethanol extraction over CO2.

The cannabis industry will continue to emerge with new technologies, making consumption more efficient, effective and more accessible. However, this doesn’t always equate to a better solution for extraction. We have found what works best for us in order to provide our customers with the healthiest products that have true therapeutic potential.

We passionately believe the 500+ phytonutrients extracted from hemp via ethanol extraction offer a far superior user experience to the isolated CBD that results from CO2 technology.

However, some people may prefer to use CBD isolate, due to the perceived ‘purity’ or ‘simplicity’ it offers. While we at Ananda Hemp certainly advocate for the use of full spectrum, ethanol extracted CBD, there is nothing wrong with using CO2 extracted isolate if that is what you prefer.

As always, do your research and make sure to read CoA’s thoroughly.

Our Ethanol Extraction to Supercritical CO2: CBD Fact Sheet breaks down the important facts to know when you're looking to buy the best CBD oil available. Read about

BHO vs. CO2 Hemp Extraction: Battle of the Big Two Extraction Methods

Cannabis concentrates are a must-have product offering for brands looking to reach a growing cannabis consumer base. Concentrated cannabis compounds can be used to make a wide range of medical and recreational products such as topical ointments, edibles, capsules, transdermal patches, suppositories, and small-batch extracts. While THC concentrate products currently dominate the adult-use market, hemp-derived CBD concentrates are tapping into the trending and lucrative health and wellness segment.

Manufacturers looking for a scalable hemp extraction solution must consider their input material, estimated throughput, equipment capacity, state regulations, and product type in order to compete in the highly-competitive “green rush.” Solvent-based extraction is the most viable and efficient method for commercial purposes. The question is: what is the best solvent for hemp/CBD extraction? The two most popular solvents are light hydrocarbons (butane and propane) and carbon dioxide (CO2). Let’s take a look at how they both compare in terms of hemp extraction for CBD.

CO2 Hemp Extraction

CO2 extraction, also known as supercritical CO2 extraction, is an increasingly popular method used to extract cannabis compounds from raw cannabis material or trim. The extraction process is also used in pharmacology, cosmetology, and other relevant industries. Closed-loop CO2 equipment uses the naturally-occurring, odorless, and colorless CO2 compound that is capable of dissolving cannabis resin from the plant. Using critical temperatures and pressures, the CO2 compound converts into a supercritical state and adopts gas and liquid-like characteristics.

This supercritical CO2 solvent acts as a gas by filling in every nook and cranny of an extraction tube. CO2 also retains a liquid-like density that is powerful enough to wash away cannabinoids and terpene compounds. The supercritical CO2 fluid can be passed over the raw material to strip away the valuable resinous trichomes. The compound is “tunable” so that the waxes and lipids aren’t separated with cannabis oil. Unfortunately, the high temperatures and pressures used with this method can degrade many terpenes, thereby, significantly altering a cultivar’s unique chemical profile.

This type of extraction method is often favored by some for its general affordability, non-toxicity, and eco-friendliness. Despite these selling points, CO2 extraction requires time-intensive post-processing like winterization and fractional distillation to create a pure product compared to butane hash oil (BHO) equipment that completely eliminates the risk of leaving behind residuals solvents in the finished product in a shorter amount of time than CO2 extraction. For many manufacturers, the high startup CO2 extraction equipment cost can be a dealbreaker. In fact, Hydrocarbon or BHO hemp extraction is losing some of its long-held stigmas and quickly cementing its status as a superior and more versatile extraction method than CO2 hemp extraction.

BHO Hemp Extraction

Hydrocarbon extraction uses hydrocarbons such as butane or propane to dissolve hemp’s trichomes. This method is one of the most frequently used and effective extraction methods, and not just for hemp or cannabis. BHO extractions use engineering peer-reviewed equipment in a Class 1, Division 1 environment that meets the most rigorous standards from the American Society of Mechanical Engineers and The American Petroleum Institute.

The hydrocarbon extraction process involves placing the hemp material into a pressure vessel. Butane or propane are introduced to the vessel to extract the cannabis oils in a quick and efficient manner. The cannabinoid-rich solution is then moved to another vessel where butane and propane are separated from the oil. After the butane has been recovered back to the supply tanks, a final purge can leave behind a pure and potent product. Unique refinement techniques can produce a wide range of textures such as vape pen oil, live resin, and shatter.

BHO Creates Full-Spectrum Products

BHO is a solid choice for industrial hemp extraction. One of the most exciting and innovative features afforded by BHO extraction is the ability to reap a larger concentration of terpenes and other minor compounds. CO2 extraction methods can be efficient at crafting an odorless and tasteless cannabis distillate, but so can BHO. In addition, BHO extraction enables manufacturers to produce high-cannabinoid and high-terpene full-spectrum extracts.

Consumers are increasingly searching for products that capture the essence and complete chemical lineup of a strain. As they become more educated about cannabis and hemp, their product search goes beyond CBD into minor cannabinoids, terpenes, and flavonoid territory. For example, products such as vape cartridges or sublingual tinctures often preserve the strain’s original terpenes to provide users with a synergistic and flavorful experience. This allows consumers to feel the full effects of a specific strain.

A Versatile Hemp Extraction Process

BHO can create a wide range of cannabis concentrates including shatter, wax, crude oil, hash, crumble, live resin, terp sauce, and more. Consumers that are looking for distillates or cannabinoid isolates can find premium BHO-extracted concentrates. Cannabis connoisseurs looking for a robust flavor profile can also find their desired product with BHO-extracted terp sauce comprised of crystallized cannabinoids and syrupy terpenes.

Cost-Effective and Safe

CO2 extraction is a generally safe and effective solvent, but so is hydrocarbon-based extraction (despite industry fear-mongering). As the cannabis extraction sector has become more regulated, building and equipment guidelines ensure the new technology keeps employees and consumers safe. State-of-the-art extraction systems like Luna Technologies’ IO Extractor is capable of meeting the demands of a high-volume and high-throughput brand. More importantly, the equipment offers manufacturers the automation needed to scale on a consistent basis. In terms of cost, closed-loop BHO extraction equipment delivers more value in the long run with a clean and strong cannabis concentrate.

CO2 is a worthy alternative to other popular solvents, but BHO ends up winning in the end as one of the most versatile, efficient, and safe solvent options available. Closed-loop BHO extraction equipment has improved exponentially over the years in terms of safety and throughput capacity. Modern BHO equipment is outfitted with automated ventilation, cooling, and higher yields.

If you’re ready to take your manufacturing capabilities to the next level, reach out to Luna Technologies to find the right BHO solutions for your hemp extraction needs.

Is BHO or CO2 better for making CBD concentrates? CO2 is a decent option, but BHO extraction is one of the most versatile and efficient methods available. ]]>