What is better BHO or CO2 Extraction

BHO vs CO2 Extraction: Which Is Better?

Cannabis extraction has allowed processors to convert almost any quality biomass into a high potency cannabis oil with tremendous aesthetic appeal. Whether it is being used for a vape cartridge or an edible, cannabis oil containing its cannabinoids and terpenes must be extracted from the biomass.

Difference between BHO and CO2 extraction
Difference between BHO and CO2 extraction

Two of the most popular extraction methods include Hydrocarbon (BHO) and carbon dioxide (CO2) extraction. Commonly used in other industries, these methods of extraction have found their way into the cannabis industry.

Butane cannabis extraction, require highly flammable solvents, which has the possibility of fast extraction. Even when these methods are applied correctly, solvents such as butane may remain in the concentrates, leading to a slew of health concerns.

The supercritical CO2 extraction is a cleaner and safer extraction method, it is popular because it produces cleaner concentrates with no residual solvents.

In this post, we will explain CO2 and butane extraction methods. So how do CO2 and butane extract CBD, and what are their drawbacks? Let’s take a look…

Read more: Who is the best? CO2 vs. ethanol extraction of essential oil

BHO Extraction

What is Butane Hash Oil (BHO)?

Butane hash oil — or BHO, as it is more commonly known — is a highly concentrated form of cannabis oil. Once collected, the oil is often smoked directly or vaped.

As the name suggests, butane hash oil is created using the butane extraction method. There are numerous different types of BHO on the market including budder, dabs, wax, and shatter.

Consumers find these extracts appealing due to their relatively high THC content. At the high end, these products may have THC concentrations of nearly 90 percent — four times the typical percentage found in an average bud. Intuitively, this exceptionally high THC content will lead to a faster and stronger high when compared with smoking traditional leaf cannabis. Popular shatters and waxes can be created using either butane or supercritical extraction, and a given producer may prefer one method to another for various reasons, including operational limitations.

Features

Often featuring between 60 and 90 percent THC, BHO is one of the strongest cannabis products on the market.

Though BHO often gets a bad rap, this form of extraction creates a delightful end product. BHO tends to be flavorful and features stronger terpene expression than CO2 extraction. Terpenes are flavor and aroma molecules found in plant resins. This means that consumers will get an excellent feel of an individual strain.

Unfortunately, BHO does have a major downside. BHO is more likely to contain residual solvents, which can be irritating to the lungs and exposes your body to excess pollution. BHO that is professionally extracted and has passed laboratory tests contains a low risk of residual solvents. Though, homemade extracts are often not pure.

Pros

  • Lower cost of entry for extraction systems
  • Hydrocarbons’ low boiling point preserves more of the cannabinoids and terpenes for a full-spectrum extract
  • Wide variety of products available, with differing tastes and effects
  • Faster runs than CO2 extractions
  • Can produce a wide variety of extract solutions ranging from distillates to high-terpene full-spectrum extracts (HTFSE).
  • Often considered a stronger product


Cons

  • In an unsafe environment or when handled improperly, the highly flammable solvent can increase the risk of fire and explosion
  • When used improperly, it can increase the risk of residual solvents ending up in the final product.
  • More difficulty gaining approval from jurisdiction
  • May come with higher facility costs
  • Not as environmentally friendly as CO2 since butane and propane are petroleum products

Who is Butane Extraction (BHO Extraction)?

Butane extraction, sometimes referred to as butane hash oil extraction (BHO extraction), is a popular method of extracting the valuable compounds from the cannabis plant to essentially create a cannabis concentrate.

The end result is known as butane hash oil (BHO), which is what is used to make up man other forms of consumable cannabis concentrates, like shatter, wax, honey oil, nug run, and so on.

Butane extraction is a form of hydrocarbon extraction, which is the process of using a hydrocarbon like butane or propane as the solvent to extract cannabis concentrates.

Among the many extraction methods processors are now using, BHO extraction remains popular because of its low-cost and effectiveness. It can be done at home without any fancy machinery.

Maximum Yield Explains Butane Extraction (BHO Extraction)

To extract cannabis compounds from the plant, a solvent is typically used. In addition to butane extraction methods, other types of cannabis extraction include CO2 extraction, alcohol extraction, and dry sieving extraction. There is also what is known as the ‘rosin’ technique that is becoming popular.

For the butane extraction method, the user first tightly packs a glass cylinder with marijuana. At one end of the glass tube, a screen ensures plant material does not fall out. This screened end is held over another glass receptacle. Next, a butane torch is held or affixed to the opposite end of the glass tube, and butane is blown into the tube. The heated cannabis plant material will eventually release its oils and resins, which are collected in the additional container.

Before consumption, the oils and resins must be cleared (purged) of the butane solvent. To do so, the solution is simply heated in hot water (almost boiling). Butane bubbles form in the oil and eventually pop, releasing gas into the atmosphere. The final result is considered by many to be a clean, solvent-free product safe for consumption. However, some people will argue that any residual solvent left in the concentrate is unacceptable.

It is typically argued that BHO products are harsher on the lungs, even when a vaporizer is used.

Notes

The National Fire Protection Association has assigned a flammability rating of 4 (on a scale of 0 to 4), classifying n-butane as extremely hazardous. For these reasons, most states that allow for BHO extraction systems require a properly ventilated Class 1/Division 1 explosion-proof room. Both the room and BHO extraction system must be inspected by a certified industrial hygienist or engineer to be sure they conform to regional and municipal codes and nationally recognized accreditations. Workers must be adequately trained and understand the hazards associated with working with closed loop BHO extraction systems.

Even with proper training, equipment, and environment, BHO extraction systems can be dangerous. In 2014 in the US, there were 3 BHO extraction explosions, 30 injuries, and 32 explosion related deaths. This is in comparison to 12 explosions and 18 injuries in 2013.

Supercritical CO2 Extraction

Supercritical CO2 Extraction is quickly becoming the preferred solvent in the Cannabis industry. Despite having a more costly initial setup, CO2 is cheaper than butane, making the system more cost-effective to run.

During the CO2 extraction method, the carbon dioxide gas is converted into a liquid and the pressurized solvent is passed through the biomass to dissolve its terpenes and cannabinoids. In its supercritical state, CO2 has properties of a gas and liquid which make it perfect to dissolve the active ingredients in the plant material.

Features

CO2 is also non-toxic- it is a natural waste product from human bodies and fermentation. Due to this and its gaseous state at atmospheric pressure, all extracts made from SCE are pure and completely clean of any potential toxic or heavy metal residues that can be left behind in BHO.

The conditions of a SCE system can be manipulated to fractionate desired compounds like terpenes, cannabinoids, waxes and esters out of the oil mixture in differing concentrations. This also provides the opportunity to refuse undesired compounds like chlorophyll from the extract. Manipulation in this manner makes SCE the perfect option for drug manufacturers looking to obtain higher concentrations of different biologically active components.

CO2 has solvency power at a much lower set of extraction parameters in comparison to other solvents, and therefore can extract compounds that usually are degraded at higher temperatures or pressures such as terpenes. Carbon dioxide extracts are accordingly stronger in aroma and flavour and bear a profile that most closely resembles the original plant. These extracts are preferred in market as their scent and flavouring are highly valued by purveyors.

Pros

  • Non-flammable and non-toxic
  • Relatively affordable and accessible solvent
  • Eco-friendly

Cons

  • Relatively longer run time than BHO
  • Prohibitively expensive systems
  • Standard operating procedures may result in lower concentration of terpenes and cannabinoids in the concentrate
  • May need winterizing with ethanol 

Supercritical CO2 extraction process for CBD

Supercritical CO2 extraction process for CBD
Supercritical CO2 extraction process for CBD

The CO2 cannabinoid extraction process starts with a simple setup. First, the plant material is placed in an extraction column. Next, a compressor and heating element increases the pressure and heat to allow the CO2 to reach its supercritical state. Supercritical CO2 maintains properties of both a liquid and a gas, passing through the cannabis like a gas while also dissolving materials like a liquid. A sudden reduction in pressure between the material column and the collection jar causes the CBD to separate from the CO2, allowing the raw CBD oil to be collected. Unlike the butane extraction method, this material requires no additional processing to eliminate residual solvents.

The difference between butane and CO2 extraction

Cost

Despite having a more costly initial setup, CO2 is cheaper than butane, making the system more cost-effective to run. In a closed-loop supercritical extraction system, CO2 is constantly recycled- again, reducing cost. As CO2 is produced by natural means, if it is released back to the environment it does not have a negative impact on the atmosphere, making it a much safer and environmentally responsible choice than BHO. SCE does not require the same explosion-proof facility setup that BHO does, or safety equipment and training for operators to work with.

No toxic solvent residue

CO2 is also non-toxic- it is a natural waste product from human bodies and fermentation. Due to this and its gaseous state at atmospheric pressure, all extracts made from SCE are pure and completely clean of any potential toxic or heavy metal residues that can be left behind in BHO.

Carbon dioxide is gaseous at atmospheric pressure, removing the need for an extra step to remove the solvent from oil extracts as in BHO.

SCE extracts are FDA-approved, safe for use in products ingested by humans.

More extraction options

Although both butane and CO2 are chemically inert, BHO is not a fully oxidized product, meaning that the cannabinoids obtained could continue to change structure and therefore lose the intended effect.
The pressure and temperature parameters of both extraction and separation will greatly influence the composition of your final oil product. The solubility and mass transfer properties of the target material within the solvent CO2 determine the operating conditions for that extraction. The conditions of a SCE system can be manipulated to fractionate desired compounds like terpenes, cannabinoids, waxes and esters out of the oil mixture in differing concentrations. This also provides the opportunity to refuse undesired compounds like chlorophyll from the extract.

Manipulation in this manner makes SCE the perfect option for drug manufacturers looking to obtain higher concentrations of different biologically active components.

Unique CO2 extract

Uniquely, carbon dioxide has solvency power at a much lower set of extraction parameters in comparison to other solvents, and therefore can extract compounds that usually are degraded at higher temperatures or pressures such as terpenes. Carbon dioxide extracts are accordingly stronger in aroma and flavour and bear a profile that most closely resembles the original plant. These extracts are preferred in market as their scent and flavouring are highly valued by purveyors.

 John A. Mackay, Ph. D:Additionally the CO2 is a better extraction for the terpenes in the cardamom. The beta-pinine, Cineole, linalool, alpha-terpinol and bornelole. The increase in the propane pressure will allow us to increase the yield of the CO2 (Illes, V, et. al. Proceedings of the Fifth Meeting of Supercritical Fluids, Nice, France, Tome 2, 555-560).

This example is the same with the butane and cannabis. Butane is a stronger solvent and if left too long will continue to pull out more and more polar compounds like chlorophyll. With the fine-tuning of CO2, you can eliminate or you can pull out the chlorophyll if you choose the wrong conditions.

Read More: Busting the Myth: Examining CO2 versus Butane Extraction

So fast extractions are possible with butane but little control of all the material, while CO2 can be tunable and therefore is able to collect all of the same material, just through a segmented process.

Further reading: Cannabis extractions

Cannabis extractions are mechanical and chemical processes that convert raw cannabis plant material, including its hemp variety, into concentrated cannabis extracts. The extract contains a high concentration of the plant’s most active cannabinoids including tetrahydrocannabinol (THC) and cannabidiol (CBD) among other minor cannabinoids and aromatic terpenes.

Cannabis plants contain the most amount of cannabis resin (trichomes) from its flowering buds, but you can find trichomes in lower concentrations in its fan leaves and trim. During the extraction process, extractors can use a range of methods including mechanical, solventless processes like dry sifting, ice water extraction, and rosin pressing.

In contrast to solventless processes, solvent-based extractions generally provide a higher throughput and efficiency. Solvents used to dissolve the resin glands from the plant material include CO2, ethanol, and light hydrocarbons (butane and propane).

BHO made using butane and/or propane is widely used to create dabbable cannabis extracts such as shatter, crumble, wax, budder, live resin, terp sauce, and so much more. CO2 extractions are commonly used to create cannabis oil for vapor cartridges.

Both solvents can be hazardous when used in unsafe conditions. Butane is flammable and CO2 has a risk of asphyxiation at dangerous levels. Due to their hazard, extractors must use closed-loop extraction systems, which create a sealed process that maintains the solvent inside the system and recycles it for later use.

Solvent-based extractions are performed in a lab-grade environment with peer-review extraction equipment. Processing facilities that meet the building and fire codes requiring proper gas monitoring, ventilation, fire suppression, and other safety systems in place to protect extraction operators.

Picture of supercritical CO2 extraction machine