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 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. Our BHO vs. CO2 extraction guide details each extraction method and its pros and cons to help you choose the right extraction method for you.
Behind the Cannabis Extraction Process
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). Here, we will just focus on CO2 and butane/propane for now. Ethanol is a popular solvent for high-volume hemp extractions.
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.
Butane Hash Oil (BHO) Extraction
Closed-loop butane hash oil (BHO) extraction uses light hydrocarbons such as butane and/or propane. The solvent mixture is washed over the dried or fresh-frozen biomass, which dissolves its chemical compounds such as cannabinoids and terpenes. Once the resin is dissolved, the butane is removed through a purging process and is finished in a vacuum oven.
Butane, in particular, is a non-polar and flammable gas. Open blasting techniques have given BHO a bad name due to amateur extractions and poor ventilation that have led to explosions. New standards in cannabis plant extraction facilities have made this method very safe for operators.
Due to the solvent’s low boiling point, processors have been able to preserve more of the plant’s terpenes for better flavor and aroma from their concentrate. For terp hunters and dab connoisseurs who prefer to taste the original flavor of a cannabis strain, BHO extracts are the way to go.
Lower cost of entry for extraction systems
Hydrocarbons’ low boiling point preserves more of the cannabinoids and terpenes for a full-spectrum extract
Faster runs than CO2 extractions
Can produce a wide variety of extract solutions ranging from distillates to high-terpene full-spectrum extracts (HTFSE).
Generally produces is stronger potency
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
Supercritical CO2 Extraction
Supercritical carbon dioxide extraction is touted as one of the safest methods to use in the cannabis market. It is widely used in other industries such as decaffeination of coffee. This process uses carbon dioxide in its supercritical state, which is odorless and colorless, non-toxic, and non-flammable.
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.
CO2 extractions are known as tunable processes since operators can manipulate temperature and pressure settings to target specific compounds and avoid pulling out undesirable compounds such as chlorophyll and other undesirables.
Despite the tunability of the solvent, many CO2 extractions produce bitter-tasting oils that contain a higher concentration of humulene and limonene producing a citrusy and hoppy aroma. Subcritical extraction uses lower pressures and temperatures to preserve more of the terpenes although it does take longer.
CO2 extracts may undergo a winterization process that removes the lipids and waxes using an ethanol solvent. The solution must undergo post-processing to remove the ethanol solvent.
While CO2 is seen as a safe solvent, it does pose a risk of asphyxiation if the CO2 levels get too high in the extraction room.
CO2 extractions usually produce lower potency concentrates than BHO extraction. CO2 extractions can produce extracts with between 50 and 75% THC, although there are some systems that can produce higher potency cannabis concentrates.
Non-flammable and non-toxic
Relatively affordable and accessible solvent
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
BHO vs. CO2 Extraction: Which One Is Better?
In the cannabis extraction industry, operators use a variety of solvents, each with their own advantages and disadvantages. Ultimately, there is no perfect solution for every cannabis operator. The right type of extraction method depends on a variety of factors including the desired end products, the company’s budget, and local laws, among other things.
Butane hash oil extraction usually does not require as much post-processing as CO2 extraction and can produce more terpene-rich oils. CO2 concentrates usually do not capture the natural aroma and flavor of the original strain. While you can reintroduce terpenes into oil, it may not completely resemble the original chemical profile.
However, carbon dioxide extraction boasts a safety angle for the health-conscious consumers who do not even want to risk consuming any harmful hydrocarbons. In addition, as a non combustible solvent, CO2 is often seen as a safer alternative for operators.
There is no right or wrong answer when it comes to choosing a solvent for your plant material. All extraction methods produce a high quality cannabis extract . In fact there are many ways to overcome the perceived disadvantages of each solvent with the right budget, training, purification methods, and operator experience.
You also need the right equipment and workflow to achieve a high quality concentrate. Your workflow is only as strong as its weakest components. If you have low quality solvent or a system that is not capable of withstanding the pressures and temperatures of your process, you will not produce a quality product.
Elevate Your BHO and CO2 Extracts with Color Remediation
Media Bros is a leader in color remediation technology. Founded with a scientifically engineered approach to make extractions better, we produce a line of color remediation media to improve the clarity and color of extracts made using light hydrocarbons and supercritical carbon dioxide.
CRX: CRX can remove undesirable pigments while preserving the terpene and cannabinoids. The granular size works with high flow and low pressure systems. It does not need preparation and is ready to use.
CRY: CRY is an aggressive variant of CRX with 1.5 times the embedded silica content to handle stubborn colors and low quality cannabis.
CR2: CR2 eliminates the bitter CO2 taste and creates a concentrate with better purity and aesthetic appeal.
Start creating high clarity, pure, and flavorful concentrates with BHO and CO2 extraction systems. Contact us to request a sample and learn more about our color remediation products.