What is better BHO or CO2 Extraction?

Two of the most popular extraction methods of CBD oil

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. 
Two of the most popular extraction methods of CBD oil 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 requires 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.

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

Difference between BHO and CO2 extraction
Difference between BHO and CO2 extraction
co2 vs butane extraction
co2 vs butane extraction

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

What is a BHO extraction?

Butane extraction is a form of hydrocarbon extraction. Butane Hash Oil extraction(BHO extraction) is a butane extraction method for CBD oil, which is the process of using a hydrocarbon like butane or propane as the solvent to extract cannabis concentrates, it is a popular method of extracting the valuable compounds from the cannabis.

Butane Hash Oil extraction (BHO extraction) end result is known as butane hash oil (BHO), which is what is used to make up man other forms of consumable cannabis concentrates.

BHO extraction process

BHO extraction homemade extraction process

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 the 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.

Industrial BHO extraction process

In the closed-loop extraction process, the plant material is packed into the material column. The butane is chilled to cold temperatures in a solvent column and pumped over a packed material column. The separate solvents the cannabinoids and terpenes from the plant to produce BHO crude oil.

In the collection tank, the solvent and BHO extracts are heated in order for the butane to evaporate. A gas compressor pulls out the evaporated butane from the recovery column. The solvent goes through the condensing column, which cools the butane gas into a liquid form again.

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
  • It may come with higher facility costs
  • Not as environmentally friendly as CO2 since butane and propane are petroleum products

Two methods to remove harmful butane

Before consumption, the oils and resins must be cleared (purged) of the butane solvent. To do so, the solution is simply heated. Butane bubbles form in the oil and eventually pop, releasing gas into the atmosphere.

method 1: Hot water

Get the large Pyrex dish and put the BHO extract inside of it. Then, put hot water in the outer, larger dish. This will cause the butane to begin to evaporate, which should take between fifteen and twenty minutes. Replace the hot water as needed to keep it hot. For your safety, be sure there is plenty of ventilation during this process.

method 2: Electric heating pad

Using a purging system is the best way to do it, but many money-conscious people prefer to use an electric heating pad instead. Simply set it to high heat, and then place the medium Pyrex dish on it for an hour or more. Watch it carefully. It is finished once the oil stops bubbling. Honey oil that has begun to become hazy or cloudy in appearance looks that way because of trapped butane. Purge-it again to get rid of all the butane.

How can I check for butane residues?

One simple way of checking if there is any butane left in it is to touch it with a flame — if it catches, there is still butane that needs to be removed.

Is BHO extraction good?

BHO extraction method is a good approach for manufacturers but has potential health risks for consumers.

Cons

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.

In terms of extraction efficiency, BHO extraction is the most efficient and cost-effective method. With an average extraction cycle of less than 1 hour, BHO is the fastest commercial extraction method for CBD oil. So it will be very popular with CBD oil manufacturers, after all, it will bring considerable benefits.

Pros

The BHO extraction end result is considered by many to be a clean, solvent-free product that is safe to eat. However, some will argue that any residual solvent in the concentrate is unacceptable.

An unavoidable fact: BHO extraction will leave butane solvent residues in the extract, requiring technical means to remove them, BHO that is professionally extracted and has passed laboratory tests contains a low risk of residual solvents. Though, homemade extracts are often not pure.
So BHO products are generally considered more irritating to the lungs, even with vaporizers.

Safety Reminders About BHO Extraction

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.

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.

CO2 Extraction Process

Supercritical CO2 extraction process is currently the “gold standard” of cannabis extraction methods because it’s cleaner, more efficient and safer than other methods of extraction. Butane extraction, for example, can leave traces of heavy metals. By comparison, supercritical CO2 extraction yields cannabis oils, waxes and rosins with the highest purity level and no residual solvents. In addition, even though CO 2 is a greenhouse gas (a contributor to global warming), when it is removed from the environment, used in an extraction process, and expelled back into the environment, it does not result in any increase in greenhouse gas emissions.

Supercritical CO2 Extraction Process 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 the 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 potentially toxic or heavy metal residues that can be left behind in BHO.

The conditions of an 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 flavor and bear a profile that most closely resembles the original plant. These extracts are preferred in the market as their scent and flavoring 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 a lower concentration of terpenes and cannabinoids in the concentrate
  • May need winterizing with ethanol 

The CO2 extraction process for CBD oil

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 the 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

co2 vs butane extraction

co2 vs butane extraction
co2 vs butane 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 potentially 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 and 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 the 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 an 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 flavor and bear a profile that most closely resembles the original plant. These extracts are preferred in the market as their scent and flavoring 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 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.

In the debate between BHO vs CO2, there’s no question about which method is the winner. BHO may be fast and cheap, but the results are less pleasant for consumers, and can even be dangerous. Clean, tasty CO2 extracts have quickly become more desirable for cannabis consumers. Whether you’re an investor or a consumer, turn your attention to CO2 extraction to get the most for your money.

Further Reading

What is Butane?

Butane is an organic hydrocarbon with the formula C4H10. It has a boiling point of around 0° C (31° F), making it gas at normal room temperature and pressure. There are two isomers of butane, each with slightly different chemical properties; n-butane has 4 carbon atoms connected in a chain surrounded by 10 hydrogen atoms, and iso-butane has 4 carbon atoms arranged in a “T,” surrounded by 10 hydrogen atoms. Unless otherwise specified, ‘butane’ refers to the n-isomer.

Most BHO extraction operators prefer n-butane due to its lower operating pressure and low vapor pressure.

Butane is relatively non-polar; the molecule has a symmetrical arrangement and none of the bonds are significantly polar, meaning the molecule has almost no charge. As a rule, like dissolves like. In other words, polar solutes will dissolve in polar solvents, and vice-versa.

THC and CBD, along with a large variety of other terpenoids, are relatively non-polar and will readily dissolve in butane, along with lipids and waxes. Chlorophyll, a green pigment found in most plants, can contribute to the foul taste and discoloration of cannabis-derived extracts. Fortunately, chlorophyll is relatively polar and does not readily dissolve in butane.

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.

How to Extraction Cannabis Oil

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 their 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 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 tabbable cannabis extracts such as shatter, crumble, wax, budder, live resin, terp sauce, and so much more. CBD oil CO2 extraction processes 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 require proper gas monitoring, ventilation, fire suppression, and other safety systems in place to protect extraction operators.