Hydrocarbon extraction has arguably become the most popular and useful method of culling chemical compounds from cannabis leaves, buds, and trim. Extraction companies tend to like the process because the equipment doesn’t cost a lot and they can make products from parts of the cannabis plant that don’t look appealing to consumers.
What Are Hydrocarbons?
Hydrocarbons are a category of organic compounds that only consist of hydrogen and carbon. They don’t contain any atoms other than hydrogen and carbon.
There are several families within the hydrocarbon category, including alkane, alkene, and alkyne. Alkens and alkynes vaporize more easily than alkane, so the hydrocarbon extraction industry doesn’t use them.
That leaves alkanes as the most useful type of hydrocarbons when extracting compounds from cannabis and other plant materials.
Currently, the most popular alkanes used for hydrocarbon extraction are:
- Butane (n-butane C4H10)
- Propane (2-methylpropane C4H10)
- or a blend of Butane or Propane
Benefits and Disadvantages of Hydrocarbon Extraction
Hydrocarbon extraction makes it possible for companies to create cannabis concentrates such as:
- Diamond (Pure THCa)
- Live resin
Some reports show that sales of cannabis concentrates could reach $8.5 billion by 2022. Concentrates often appeal to consumers who want to avoid smoking cannabis flowers. Many also find the concentrates useful for medical reasons because they maintain better control over their doses.
The growth of cannabis concentrates will expand the overall industry considerably. Without hydrocarbon and closed loop (more on that below) extraction methods, businesses can’t sell certain parts of the cannabis plant. For example, very few people would want to purchase cannabis leaves because the leaves don’t contain many useful chemical compounds. By concentrating the compounds found in leaves, companies can create products that fetch high prices.
Instead of losing money by throwing away parts of the cannabis plant, companies can enhance their profits by keeping plant materials and extracting compounds.
There are, however, some potential dangers connected to hydrocarbon extraction. Luckily, closed loop extractors practically eliminate problems that can arise while using hydrocarbons to extract compounds from cannabis.
Potential dangers of hydrocarbon extraction include:
- Exposure to butane or propane, which can cause a variety of immediate and long-term health concerns.
- Exposure to exhaust after using the solvents to extract compounds.
- Fires or explosions that occur when the hydrocarbons get exposed to an ignition source like fire or an electrical arc.
Since closed-loop extraction mitigates the potential dangers of hydrocarbon extraction, businesses should make sure that they choose equipment designed to protect employees and consumers.
The Benefits of Closed Loop Extractors
Closed loop extractors have proven themselves the most effective and safe way to pull chemical compounds from cannabis. Any company that makes or wants to make cannabis concentrates should consider the benefits of closed loop extractors before purchasing equipment.
Closed Loop Extractors Improve Safety
Some businesses worry about using hydrocarbon extraction methods because they have heard about its safety risks. Most safety concerns that get reported come from individuals and small businesses that do not use professional closed loop extractors.
With closed loop equipment, employees never get exposed to butane or propane. Before starting the process, hydrocarbons stay in a solvent vessel. During the extraction process, solvents circulate through material vessels to collect compounds like terpenes, CBD, and THC. The butane or propane then returns to the solvent vessel. This closed loop means that companies can collect compounds and recapture solvents without letting anyone get exposed to potentially harmful chemicals.
Closed loop extraction’s safety works best when pressure stays below 250 pounds per square inch (psi).
Closed Loop Extractors Work Quickly
Closed loop extractors that use hydrocarbons can collect chemical compounds quickly. The speed varies depending on several factors, such as the size of the extractor and how much plant material gets put into the matter unit. Typically, businesses can expect closed loop extractors to process 1 to 1.5 pounds of plant material within a minute. That means a company processing 40 pounds of cannabis material can expect to collect compounds within 40 minutes to an hour.
CO2 extraction methods, which are not as popular as hydrocarbon extraction methods but still used in the industry, take 6 to 10 hours to do the same amount of work. That level of inefficiency makes CO2 extraction costly.
Closed loop extractors do most of the work on their own. Someone needs to monitor the machinery and adjust gauges as needed. Other than that, the equipment operates independently.
Closed Loop Extraction Boosts Yields
CO2 extraction methods have an extraction yield that rarely exceeds 8% by weight. With CO2 extraction equipment, companies can only hope to get 12.8 ounces for every 10 pounds of plant material. More often, the yield falls closer to an ounce per pound.
Hydrocarbon extraction used with a closed-loop system, however, gets yields between 14% and 30% by weight. With closed loop extraction, businesses can expect every 10 pounds of cannabis to produce 22.4 to 48 ounces of extract. On the high end, closed loop extraction that uses hydrocarbons can nearly double the amount of extract companies get from CO2 methods.
Closed Loop Extraction Offers Versatility
Closed loop extraction can use a combination of hydrocarbons to get versatile results. More often than not, users choose solvents with higher levels of propane. The mixture of hydrocarbons, however, depends on the expected result.
Concentrate May Offer Healthier Alternatives to Smoking Cannabis
Even people who benefit from the effects of cannabis compounds often feel reluctant to smoke the plant for THC or CBD. While cannabis smoke probably doesn’t cause as much harm as tobacco smoke, the American Lung Association encourages people to take cannabis in edible forms.
All smoke contains carcinogens and other irritants that may damage a person’s throat and lungs. People who have smoked marijuana before may have experienced coughing fits caused by the smoke.
Concentrates may offer a healthier alternative to smoking cannabis. Hydrocarbon extraction creates concentrated compounds that people can consume as liquids or pills.
Some studies show that vaporized cannabis may also cause less harm than smoking cannabis flowers. The full effects, however, are unknown.
Anyone looking for an alternative to smoking cannabis can explore concentrates to get the effects they want without inhaling the harsh smoke.
Temperatures and Pressures Used during Extraction
Companies that want to extract compounds from cannabis and hemp need to make sure that they stay within certain pressure and temperature ranges.
Most engineers that design professional extraction equipment say that pressure should never exceed 300 psi. At 300 psi, though, equipment pushes against safety boundaries. Keeping pressure at or below 250 psi makes maintains a safe working environment without decreasing the efficiency of closed loop extraction equipment.
Temperature ranges remain safe and effective when they stay between -30 and 110 degrees Fahrenheit.
Chemical Compounds That Extractors Can Pull From Cannabis
A 2017 study identified 62 compounds in cannabis. Hundreds more become available after heating plant matter. Researchers still have a lot to learn about the effects many of these chemicals have on the human body.
Currently, the cannabis compounds that show the most medical and commercial promise include:
- CBD, which may offer benefits treating anxiety disorders, epilepsy, cancer, Alzheimer’s disease, and numerous other ailments.
- THC, which could help people living with chronic pain, depression, glaucoma, and alcoholism.
- Terpenes, which affect the taste and smell of cannabis and may even enhance the effects of CBD and THC.
Closed-loop hydrocarbon extraction makes it possible for companies to remove these compounds from cannabis. The extraction method is particularly useful when it comes to terpenes, which are very sensitive to temperature. Butane and propane have low boiling points, so hydrocarbon extraction techniques can remove terpenes from plant material without altering their chemical structures.
As scientists learn more about the effects of CBD, THC, terpenes, and other chemical compounds found in cannabis, it’s likely that hydrocarbon extraction will become even more useful for companies that want to target specific chemicals.
The Steps Involved in Closed Loop Hydrocarbon Extraction
Closed loop extraction may look complicated to outsiders who have never used the equipment. Professionals, however, tend to break the process into seven relatively simple steps.
Loading the Material Vessel
The first step involves loading cannabis into one or more material vessels. The cannabis put into the material vessel can include trim, leaves, flowers, or any other part of the plant.
Most companies choose materials that they cannot sell directly to consumers. The leaves of a cannabis plant, for example, contain low amounts of useful chemical compounds. The leaves, however, do not typically earn profits in dispensaries. Putting the unused parts of the cannabis plant into a closed loop hydrocarbon extraction system removes the desired chemicals so they can be sold as concentrates or similar products.
Creating a Vacuum
A closed loop extraction system works by sealing all of the vessels and creating a vacuum that pulls solvent from its vessel through the tubes and material vessels.
Controlling the Temperature of Closed Loop Extraction
Before the solvent can extract the right compounds from cannabis, the closed loop system needs to heat or chill the chemical. The best closed loop extraction systems come with chiller and heater units that can set the solvent’s temperature specifically.
Introducing Solvent to the Material Vessel
As solvent gets introduced to the material vessel, it extracts chemicals from cannabis plants. The compound that gets extracted depends on variables such as the solvent’s temperature and how much pressure gets created by the system’s vacuum.
Transferring Chemicals to the Collection Vessel
As the solvent gets pulled through the material vessel, it distributes extracted chemicals into the collection vessel. The plant matter left in the material vessel becomes refuse at this point because it does not serve a known commercial or medical use.
Distilling and Recovering the Solvent
After the solvent does its job, the system distills and recovers it so employees do not have to come into contact with potentially harmful chemicals. Distillation turns the solvent into a vapor that can float into the correct chamber. The solvent gets moved back to its original solvent vessel, where it remains safely. Depending on the type of solvent and the number of previous uses, the owner may perform another extraction with the solvent or swap the solvent with a fresh batch.
Removing Extract From the Collection Vessel
Removing extract from the collection vessel is perhaps the easiest and most rewarding part of closed loop hydrocarbon extraction. The collection vessel holds all of the chemicals that have been removed from the cannabis plant matter. Depending on the compound, it may have an intense citrus, pine, or skunky odor to it.
Employees need to take care when removing extracted compounds from the collection vessel. Skin contact probably will not harm the product’s usefulness, but it may lower its value. Ideally, the extracted compounds are kept free from any potential contaminants.
Additional Steps for the Best Hydrocarbon Cannabis and Hemp Extracts
Companies can add a few additional steps to improve hydrocarbon extraction and closed loop extraction processes.
Canabis concentrates often contain waxes, fats, or lipids that can interfere with purity standards. Adding a dewaxing column to a closed loop extraction system helps remove the wax for cleaner concentrates. It isn’t essential, but dewaxing can dramatically improve the quality and value of concentrates.
Color Remediation Columns (CRC)
Color remediation columns contain filters that help remove impurities from cannabis and hemp concentrates before they enter the collection vessel. Like dewaxing columns, CRCs can dramatically improve the purity and value of concentrates.
Companies can get the most from their cannabis and hemp plant material by adding secondary separators to their closed loop extraction systems. The secondary separator helps ensure that the solvents and concentrates get separated before reaching the end of the process. Adding this step improves the system’s efficiency and makes it easier to reuse solvents.
Using Crude Extract to Make Cannabis and Hemp Products
The crude extract that comes from hydrocarbon extraction systems can be ingested in a variety of ways depending on the intended results.
Many companies in the cannabis and hemp industries, however, process their crude extracts into high-value products that they can sell to medical and recreational consumers. By adding value to their products, the companies can earn higher profits.
The industry will continue developing new products as the technology improves and more states make cannabis legal. Currently, some of the most popular cannabis and hemp products made from crude extract include:
- Tinctures – liquids with cannabis compounds suspended in them. Typically taken by placing a drop or two under the tongue, tinctures take effect within half an hour.
- Capsules – gelatine capsules filled with cannabis oil or cannabis extract. Capsules are taken orally, so they must pass through the digestive system. People may not notice the effects of cannabis capsules for up to 2 hours.
- Vaporizer cartridges – convenient cartridges that come loaded with CBD or THC extracts. The cartridges are designed to fit vaproizers that heat the extract. Cannabis compounds ingested as vapor may have effects within seconds or minutes.
- Hash – a pressed, sticky version of cannabis concentrate that people can consume by vaporizing or smoking. Hash usually has noticeable effects within seconds or minutes of ingestion.
- Shatter – also known as wax and dabs. Shatter is a refined version of crude extract that usually feature high THC profiles. The potent product can have immediate effects on consumers.
The Future of Cannabis and Hemp Consumption
No one knows how cannabis and hemp consumption will evolve over the next few decades. Extraction, however, will likely play an important role as people look for more ways to get the effects that they want from cannabis without smoking flowers.
Hydrocarbon extraction opens the door to a whole new world of ingestion. Thanks to reliable extraction methods, companies can add cannabis and hemp compounds to anything from pills to cocktails. As the types of available products expand, the types of consumers will probably expand, too.
State and federal governments may even play a role in helping the cannabis and hemp extraction industry grow. The Kentucky House, for example, passed a bill in February 2020 that could legalize medical cannabis (if the Senate passes it into law). The bill, however, does not permit smoking cannabis. Instead, it attempts to make medical consumption healthier by narrowing options to oral consumption methods, such as pills and tinctures.
It’s unclear whether such a restrictive law would appeal to other states that currently prohibit cannabis consumption. If other state governments, or perhaps the federal government, finds this approach more suitable than liberal laws that allow smoking, the extraction industry would likely experience explosive growth.
Few informed people deny that cannabis has medical value. How governments regulate access to the plant’s compounds, however, will partially define how the industry shifts over the next century.