Cannabis crude oil is what many people typically call the oil that’s produced during extraction because of the additional steps needed to refine the product. However, some extraction methods, such as hydrocarbon extraction using butane or propane, have essentially rendered this terminology irrelevant due to the high levels of refinement that occur throughout the extraction process itself, thus producing a “crude” oil that’s actually ready-for-sale.
Hydrocarbon extraction (also referred to as BHO extraction) processes have the unique ability to extract the most sought after compounds and leave out the bad-tasting ones, resulting in highly-refined “crude oil” that can be made into artisan-crafted extracts such as shatter, wax, live resin, sauce, budder, crumble, isolates, and more. Unlike other extraction methods, the hydrocarbon extraction can bypass multiple refining processes to produce an elevated and more refined extract.
What Is Crude Oil?
The term crude is associated with a form in its natural or raw state without having undergone any additional processing or refinement. Crude product forms appear in various industries, but perhaps the best analogy is the petrochemical industry. Offshore oil rigs obtain the crude oil needed to be refined into usable products such as gasoline, petroleum jelly, and many forms of fuel.
Petroleum refineries are in charge of transforming the dark brown and generally useless crude oil obtained from pipelines into its more practical parts for consumer products. During the oil refining process, the underlying compound structures are separated and purified through various distillation methods. The resulting oil from the earth can then be sold without more refining or can be refined into smaller molecules to create an even greater variety of products.
Similarly, during a cannabis extraction process, rudimentary resin oil is removed from cannabis or hemp plant matter such as buds, leaves, stems, and seeds and refined into more usable forms.
Solvents Make the Difference
The most common solvents used during cannabis extraction include carbon dioxide (CO2), ethanol, and butane/propane. Traditional “crude” oil made using CO2 or ethanol extraction requires further post-processing to be infused into products or ingested, hence, the “crude” terminology.
Highly-refined “crude” oil made using light hydrocarbons such as butane or propane cuts down on the undesirables and contains a full-spectrum of cannabinoids, terpenes, and other essential compounds. This oil contains a higher amount of the plant’s aromatic terpenes and flavonoids, as well as other essential compounds, and requires no further refinement. It’s ready to be added onto whole-flower or joints, used for vape cartridges, and topicals for localized relief.
Keep in mind that cannabis resin, also known as trichomes, largely reside on whole-flower buds, but a small number of trichomes can also be found in stems and leaves. Seeds can also contain some essential oils but without any cannabinoids.
Crude oil is essentially the cannabis resin (with varying chemical compositions) separated from the plant. The amalgamation of trichomes can be acquired in a number of different ways. In the end, however, manufacturers want a potent and pure product while reducing the costs and improving the output of their production process. BHO extraction is the right solution for that.
How Is Crude Oil Made?
The differences in “crude” oil quality, color, and purity really come to light when we examine the different ways that cannabis resin can be extracted from the plant and the many ways it can be refined into a distillate, isolate, or full-spectrum product depending on the intended product.
Cannabis oil can be made using a variety of solvent-based or solventless extraction methods, each with its own pros and cons. Some of the most popular solvent-based methods occur with ethanol, carbon dioxide (CO2), and hydrocarbons (propane and butane) as solvents, which strip the plant from its resinous oils.
Solvent-based methods utilize closed-loop equipment in lab-grade environments to recycle the solvent and also minimize the risk of leaks to avoid harm to the technician. Ventilation and gas detection systems ensure everyone stays safe and there are no hiccups in the process. Closed-loop equipment, however, ranges in speed and quality.
Solventless methods like dry sifting or pressing raw or frozen cannabis or hemp are used to avoid introducing solvents into cannabis. Solventless methods break off the trichome bulbs from the plant’s surface using agitation, heat, and pressure.
Various sizes of mesh screens are used to separate trichomes and make dry kief, which can later be formed into hash slabs or balls for smoking purposes. Commercial rosin presses can be used to apply heat and pressure onto raw marijuana matter and squeeze out its viscous and gooey insides without the need for closed-loop equipment, however the throughput is typically too low for commercial production.
With solventless methods, extraction companies still have to perform a solvent-based extraction process to produce the concentrated oil and may need to remove the undesirable plant matter from the mix.
Each type of extraction process produces a different type of cannabis oil with varying levels of purity. CO2 and ethanol are efficient solvents used to remove cannabinoids and terpenes from the plant, but can also unintentionally bring in plant waxes, lipids, and chlorophyll during the process, which requires additional post-processing time and cost to remove.
With hydrocarbon closed-loop equipment using butane and propane, however, the cannabis oil produced doesn’t have nearly as much wax, fat, or chlorophyll compared to CO2 or ethanol extraction, but has even more total cannabinoids and terpenes.
How Does BHO Extraction Produce Crude Oil?
Butane and propane’s non-polar characteristics and lower boiling points make it the ideal solvents to pull out a wider range of compounds including those temperature-sensitive terpene compounds that can evaporate in high heat. Compounds such as terpenes and flavonoids have high therapeutic value but are often degraded in the process.
Decarboxylation, or the process of applying heat to the compounds to activate them, can occur naturally or during oven drying processes. Light terpene oils can easily boil away if manufacturers aren’t careful. Using blended hydrocarbon solvents can produce a more complex terpene profile with a light color.
Butane hash oil (BHO) extraction, or hydrocarbon extraction, can produce a broad-spectrum or full-spectrum product rich in cannabinoids, terpenes, and flavonoids. For medicinal users, consuming a strain’s entire original compounds can amplify the health benefits due to the compound’s entourage effect that occurs within the body.
Getting full-spectrum concentrates from the extracted oil can be easy or nearly impossible depending on the solvent used. Butane is able to dissolve more of the desirable compounds and leave behind the chlorophyll and harsh compounds.
While BHO extraction can produce this full-spectrum product for a more complex and beneficial experience, it can just as well be created into a distillate oil free from terpenes and flavonoids for vape cartridges, edibles, and topicals.
Post-Processing and Refining
After the marijuana “crude” oil has been removed from the hemp or cannabis plant material, the solvent and undesirable chlorophyll, fat, and waxes are removed using a number of filtration methods, especially in the case of CO2 and ethanol-extracted crude oil. Post-process distillation and filtration can help purify the oil even further.
For instance, in the case of vape pen cartridges, concentrate manufacturers can completely distill the oil to filter out the flavonoids and plant pigments producing a clear and inhalable extract.
For edibles, however, complete distillation may not be necessary. Some plant pigments and flavonoids may be present in edibles without ruining the product’s integrity. Less refining means manufacturers can save time and money processing the extract.
Post-processing techniques have gotten so advanced and precise that they can filter out any contaminants squeezed out of the crude oil due to plant or residual contamination. For instance, some industrial crude oil can be contaminated but refined later on. Advanced filtration techniques can remove contaminants like fungicides and residual solvents.
Cannabis and hemp extraction methods that use CO2 may require winterization, which involves dissolving the extract in ethanol to separate the fats, waxes, and flavonoids. Sub-zero temperatures help coagulate and solidify the fats on the top player for further filtration using various screens or funnels.
When winterization is complete, the residual ethanol must be removed from the extract. Many manufacturers use a rotary evaporator to heat the mixture under vacuum from a vacuum pump. The ethanol used during winterization evaporates and is contained in a condenser. The result? Extract without ethanol.
Some manufacturers may use equipment with in-line, de-waxing columns to bypass or reduce the need for winterization. In-line de-waxing utilized sub-zero temperatures, like winterization, but only requires a single solvent, unlike winterization that requires an initial solvent and ethanol for the winterization process.
In-line de-waxing systems use surface area created by baffles, beads, or other media to capture undesirable compounds while allowing the extract solution to pass through. Ethanol is typically avoided to reduce the risk of degrading terpenes, which results in a less flavorful extract and can increase manufacturing production costs in some cases.
Hydrocarbon Extraction for a Better Crude
With hydrocarbon extraction, manufacturers can forgo the need for a cumbersome winterization freezer needed for the refinement. You won’t need a costly rotary evaporator or fractional distillation apparatus, either. All you’ll need is a compatible vacuum oven to remove the residual solvent and the trace amount of chlorophyll, waxes, and fats.
Hydrocarbon extraction’s versatility makes it a great solvent and production method for nearly any manufacturer. Hydrocarbon extractors can distill large volumes of trim or low-quality buds to take out as many cannabinoids as possible. We know it won’t be as aromatic as oil from buds, but manufacturers can still use every part of the plant with hydrocarbon extraction.
Further Processing: Distillation
For those looking to go beyond the high-purity extract that comes from hydrocarbon extraction, BHO oil can be further refined into a distillate. Distillation can produce a range of CBD and THC cannabinoids with over 95 percent purity. Distillation can also produce other minor cannabinoids such as THCV and Delta-8. Distillation allows manufacturers to use specific temperatures to boil away some compounds while leaving the desired ones like CBD for CBD oil alone.
Distillation allows manufacturers to produce predictable and consistent products that taste, smell, and feel the same every time. Hydrocarbon’s cannabis oil can be further crafted into cannabinoid isolates of THC, THCA, CBD, CBDA, and more psychoactive compounds.
CO2 and ethanol extraction are fine for making distillates such as vape oils and THC or CBD isolates but can end up costing manufacturers more than other refining methods. Hydrocarbon extractions can produce the following premium concentrates without the high expenses of other methods:
- Live Resin
- THC or CBD Isolate
- Vape Oil
Automated Hydrocarbon Extraction
Luna Technologies’ IO Extractor is the leading provider for automated hydrocarbon extraction equipment in the cannabis and hemp industry. Our automated extraction solution ensures manufacturers keep pumping out gobs of light-colored and translucent oil for a wide range of cannabis and hemp products.
On-site commissioning and equipment training can help manufacturers get up-and-running as fast as possible. Hydrocarbon extraction with the IO Extractor takes full advantage of the power of butane and propane to process up to 18 pounds of dried biomass or 25 pounds of frozen biomass per hour to produce premium THC and CBD products. High quality cannabis and hemp extracts have never been easier to make at a large scale.