Ethanol extraction systems are the industry standard for extraction of active ingredients from cannabis material, particularly the hemp variety. While butane and CO2 extraction are popular methods of extraction, ethanol extraction can offer a high level of cannabinoid and terpene isolation and safety with the most advanced systems.
Whether you are a cannabis consumer or processor looking to find out more about this efficient extraction method and the system options, our ethanol extraction systems guide breaks down the type of equipment used and how it works.
What Is Ethanol?
Whether you know it or not, ethanol, also called grain alcohol, is found across a wide range of industries. This clear, colorless, and flammable liquid is the main ingredient in alcoholic drinks such as beer and wine.
You can find alcohol in cleaning agents, health products, and personal care products. It is also found in bio fuel and is used as a solvent.
But, where does ethanol come from? This solvent is commonly fermented from starch and sugars in corn, sugar beets, sugar cane. Since corn is plentiful, ethanol in the U.S. is mainly made from corn.
Processors prefer to use organic alcohol since it is generally regarded as safe (GRAS) and food grade so they can create products fit for human consumption. Denatured alcohol is not fit for human consumption since it contains additional chemicals such as heptane, methanol, and other chemicals.
Under normal room temperatures, ethanol can ignite. It has a flash point of 55º F and a boiling point of 173º F.
What Is Ethanol Extraction?
Compared to other extraction methodologies such as hydrocarbon extraction, ethanol extraction can provide operators with a higher throughput. Ethanol has been used as a solvent in pharmaceutical and food processing industries for over half a century.
Ethanol extraction equipment requires a lower upfront investment compared to other processes without sacrificing high extraction efficiency.
The benefits of ethanol extraction include:
Throughput and efficiency: Compared to other extraction methods, ethanol extraction provides the quickest run times on the market.
High volume: Due to state and local regulations, operators can store more of the ethanol solvent so they can process higher volumes of biomass per day.
Hemp friendly: Ethanol is very efficient at producing full spectrum extracts and tinctures from industrial hemp.
Compliant: Due to strict compliance regulations of other solvent types, ethanol extraction can simplify the licensing process to get a business off the ground quicker without compromising safety and compliance.
Safe: Ethanol extractions run at lower pressures and use approved organic solvents.
Ethanol-Based Cannabis Products
Ethanol Extraction Guidelines
In the pharmaceutical industry, ethanol has been used in the production of extracts, tinctures, capsules, and other pharmaceutical applications. It is generally regarded as a safe and efficient solvent to use. There are some guidelines operators must follow for workplace safety.
The Food and Drug Administration (FDA) classifies ethanol as a Class 3 solvent, which has a low toxic potential. This is especially important for pharmaceutical manufacturing.
This process leaves under 5,000 ppm or 0.5 percent residual solvents. However, manufacturers must employ various quality control procedures to keep these residual levels low.
Several states with legal cannabis markets have enacted lower cut off points suggested by the Occupational Safety and Health Administration (OSHA) and the National Institute for Occupational Safety and Health (NIOSH).
Both organizations set the exposure limit for ethanol at 1,000 ppm of total weighted average (TWA) in a full shift (eight hours). In short, some states only allow ethanol-based products to be sold if they have under 0.1% residual ethanol. Products with higher levels do not get sold to the public.
The National Fire Protection Association (NFPA) classifies ethanol as a Class 1 Division 2 Group D flammable liquid. In the presence of ignition sources, ethanol vapor can lead to a fire and explosion.
Ethanol’s lower and upper explosive limits are 3.3% and 19%, respectively, by volume in air. Due to its NFPA classification, OSHA requires keeping ethanol vapors at 25% of the 3.3% limit.
Manufacturers can do so with adequate ventilation in their storage areas. Storage areas must contain under 0.83% by volume ethanol vapor. OSHA and NFPA define adequate ventilation as areas with a system that can cycle the room’s air volume six times per hour.
Ethanol vapor is heavier than air. Essentially, its vapors do not rise. Instead, they tend to stay on the ground. For this reason, adequate ventilation is needed to cycle the room’s air.
Ethanol release can occur due to a variety of factors including:
Accidental release (spills, containment failure)
Inadequate venting of gases
The maximum cabinet storage limit of ethanol is 60 gallons. If the stored ethanol solvent is outside of the flammable cabinet, the limit is 25 gallons.
Ethanol Extraction Process
Compared to both CO2 extraction and light hydrocarbon extractions, the ethanol extraction process can provide manufacturers with benefits from both methods.
For one, this technique offers incredible results, especially when dealing with high-volume hemp. In addition, its systems and solvents are moderately priced compared to other extraction equipment.
During the extraction process, the ethanol is washed over the raw biomass material to dissolve the desired active ingredients, particularly cannabidiol (CBD) from hemp. Afterward, the ethanol is separated from the crude extract through evaporation processes. At the end of the process, manufacturers are left with a pure and potent cannabis oil.
Here is a quick break down of the ethanol extraction process as it goes through the equipment:
The ethanol is loaded into vessels.
The ethanol is brought down to below-freezing temperatures using chillers and jacketed vessels.
The ethanol is sprayed from the tank to the extractor, to completely soak the hemp biomass.
The ethanol is circulated to complete the run.
The extract solution is pumped out through the filter assembly into a separate collection vessel.
Ethanol extraction processes can be performed under cold or warm temperatures. A warm ethanol extraction method is the Soxhlet technique.
In this technique, ethanol is boiled in a flask or pot under vacuum. Then, the system recondenses the alcohol above the biomass column with a condenser. The ethanol is continually washed over the herb to dissolve the cannabinoids.
Some processors prefer this warm ethanol approach because it is time efficient and requires a relatively low solvent-to-biomass ratio.
Room Temperature and Chilled Conditions
While warm ethanol production can give you great results, the most common types of ethanol extraction occur at room temperature or cooled environments.
These conditions allow manufacturers to preserve more of the cannabinoid acid forms that can be used to create a variety of materials including shatters, THCA crystals, and other cannabinoid-rich oral products.
Room temperature ethanol extraction will reap more of the waxes and pigments compared to cooled down methods, which may not require additional dewaxing and clarification procedures.
Challenges During Ethanol Extractions
While the process is extremely effective at processing high volumes of cannabis, it is not without its challenges and risks.
For instance, ethanol is an efficient solvent that can dissolve all the plant’s therapeutic compounds, but also its undesirables.
As a polar and hydrophilic solvent, it is capable of binding to water-soluble components of the cannabis plant. When processors get stuck with these unwanted plant compounds, they must perform a post processing refinement to improve the oils purity.
Some cannabis extraction companies argue that reduction of water-soluble plant extraction can be offset by running the system at very cold temperatures (under -5º F). However, this extraction method is not the best for all cannabis concentrates.
For instance, making high-terpene full-spectrum (HTFSE) extracts and isolates requires other solvents (butane and propane) other than ethanol.
Ethanol extraction does not usually produce concentrations greater than 80% during primary extraction runs,.
However, isolate can be made by using additional purification techniques. The purification methods used to refine the crude extract requires a lot more labor and expenses and are very difficult to scale. This refinement usually requires distillation and additional solvents such as pentane, hexane or heptane
On the other hand, for large-scale processing, the additional purification techniques can be cost-effective compared to other extraction types such as hydrocarbon extraction which can have strict storage limits, thereby reducing the efficiency of its use for continuous-feed extractions.
The ethanol’s flammability requires experienced and trained operators to use the systems in a lab grade setting with adequate ventilation. Top-of-the-line ethanol extraction systems can include components that reduce the risk of fire and explosions to keep operators safe.
Regardless of the safety functions, the operator should always maintain safety protocol since the risk for fires is never completely eliminated.
While ethanol has some downsides, overall, it is an affordable and scalable extraction method that can produce a consistent and pure cannabis product.
Ethanol Solvent Management
One of the biggest problems when dealing with ethanol extraction is the downstream processing.
Ethanol extractions require between 0.6 to 1 gallon of ethanol per pound of biomass. This extraction requires a high volume of ethanol solvent to properly separate cannabis compounds with an over 90 percent efficiency rate.
Some automated extraction solutions can minimize the necessary solvent levels using high-tech, built-in technology to get the ethanol requirements down to 0.5 to 0.6 gallons per pound.
Automation capabilities have enabled ethanol extraction equipment to offset the issue of high volumes of ethanol solvent recovery. Centripetal force is capable of removing as much of the solvent as possible from the biomass, up to 95%-98%.
For proper ethanol solvent recovery, processors require large solvent recovery systems such as rotary or falling film evaporators to gently remove the residual solvent from the final product. A rotary evaporator is a cost-effective option. A falling film evaporator is another slightly higher-priced option, but with much higher throughput.
Rotary evaporators work by using vacuum distillation to evaporate the ethanol solvent from the processed material. The solution is heated to turn the liquid ethanol into vapor. Those vapors will then separately be condensed back into a liquid, after being cooled, generally with a chilled condenser.
Ethanol Extraction Equipment
Ethanol extraction can provide businesses with a tremendous value for their investment, but how does one know which ethanol extraction systems to choose? Which one will be able to handle the business growth and increasing throughput over time?
Cannabis processors have a variety of different types of ethanol extraction equipment to choose from.
On the low-tech spectrum, ethanol extraction can be performed in a basic container where the ethanol and the cannabis material can be agitated manually.
On the high-tech side, commercial operators can invest in automated ethanol extraction equipment that can control temperature, inject ethanol solvent, and perform inline de-waxing and clarification steps.
Some extraction systems can operate with multiple solvent types including light hydrocarbons and ethanol
The best systems have been evaluated by a professional engineer. Operators should look for peer-reviewed equipment that is suitable for use in their specific state. In many cases, extraction equipment manufacturers will get peer-reviewed equipment from every major legal cannabis market.
Turnkey Ethanol Extraction System
Processors can invest in a turnkey ethanol extraction system that features all of the ethanol vessels needed for production. The system can come with the necessary filter, pumps, distillation tower, and solvent recovery unit.
These ready-to-use systems are the preferred systems for large volume commercial production capable of handling 100L or more. They can help jump-start a business that requires high-efficiency cannabinoid extraction.
Custom Extraction System
If an operator cannot find the right ethanol extraction system to meet their high-volume or unique needs, manufacturers can create a custom and turnkey system that can meet all of their extraction needs, from space limitations to storage requirements.
Custom ethanol extraction equipment can be built to a business’ exact specifications to work within their workspace without reducing efficiency or safety.
Processors that want to create hemp-derived CBD products will require a centrifuge extractor. Centrifuge extractor systems are manufactured to work with low-temperature ethanol in cannabis processing.
They can include a touch screen display for easy and quick operation. They may also include automatic valves and fully adjustable agitation settings.
High quality systems are properly sealed and have no dead corners so every part of the material is perfectly processed. It can also handle fast operations and is easy to clean so technicians do not face big bottlenecks in production during clean-up.
Molecular distillation systems can easily distill botanical and cannabis extracts. The system refines the crude extract after the initial extraction to create a pure and potent product.
Distillation systems are fitted with high-performance settings and controls. Like other parts of the system, it can be easy to clean and reassemble.
Crystallization reactors are designed to purify extracts and crystallize them through a slow cooling process. They must meet ASME Boiler and Pressure Vessel codes to handle the processing workflow.
Crystallization reactors can handle a wide range of volume to well over thousands of pounds. The crystallizing reactor column is a crystallizing unit in which a chilled liquid quickly cools down the jacket.
Crystallization reactor models vary between the type of jacket used, the structure of the agitator, and the outlet type. They are designed to be used with CBD oil that has been winterized and distilled first.
High-performance chromatography equipment can help processors separate distinct compounds to create a more refined product. High-quality chromatography equipment must meet FDA, GMP, and cGMP standards.
Best Ethanol Extraction Systems
In terms of ethanol extraction equipment, there are several extraction solutions for different capacity requirements, from small batch to high-volume systems. Generally, the type of equipment chosen depends on the budget and desired end product.
While system types are plentiful in the industry, there are a few manufacturers that make some of the best cannabis extraction equipment on the market.
Capna Systems’ Ethos 6 is their latest iteration capable of drawing 98.6% of the cannabinoid content from raw plant material. It is a good choice for small to medium-size operators. The all-in-one system does not require any post-processing so operators can produce fully dewaxed cannabis extracts. No need for winterization.
Processors can choose from the semi-automated Ethos 6 system or the fully automated Ethos X. Ethos 6 can process upwards of 14 pounds of cannabis biomass per hour. It has an 85% solvent recovery rate.
Its internal cold storage can hold 40 gallons for cannabinoid extraction. Based on this storage limit, it can extract over 70 pounds of cannabis biomass on a single fill.
Precision Extraction’s commercial-grade, closed-loop ethanol extraction equipment includes the X10 MSE, perfect for mid-level commercial production and craft applications. This extractor can work with ethanol and light hydrocarbons.
It processes between 10 to 27 pounds per hour with ethanol and up to 10 pounds per hour with butane or propane. In an 8-hour shift, processors can expect to process up to 200 pounds per hour.
The X40 MSE is designed for mid or large-scale commercial production. It can process between 10 to 72 pounds per hour with ethanol and up to 36 pounds per hour with hydrocarbons, depending on the butane and propane blend. It can process up to 575 pounds per 8 hour shift.
Eden Labs’ Coldfinger BenchTop is the perfect choice for small-batch operators. Designed for research and small-scale operations, this system has plenty of extraction power while being easy enough for one person to clean in the kitchen sink.
The system is capable of collecting and reusing the solvent. It can extract 2 to 8 pounds of biomass per batch in a 12 to 48 hour time period.
The larger commercial extractors can handle larger volumes of biomass in cold and warm/wash ethanol extractions.
Operators can process 120 to 160 pounds of biomass per hour. Ethanol systems come in two models: (25-gal) and High Performance (100 gal.). A 500 gallon option is available for solvent recovery.
Maratek provides operators with cryogenic ethanol extraction equipment for small or large scale production. The EV-M is capable of handling ethanol and light hydrocarbon solvents. It can process between 60 and 90 pounds per hour with a 99+% solvent recovery.
Delta Separation’s centrifuge utility platform CUP series of ethanol extraction systems (CUP-15 and CUP-30) has a 97% ethanol removal rate from biomass. The CUP-15 can process 8 to 14 pounds of plant material per batch with a 10 to 20 minute run time. Process about 300 pounds per 8 hour shift. The extraction can require between 12 to 13 gallons of ethanol.
The CUP-30 can process 25 to 30 pounds of material per batch with an average run time of 10 to 20 minutes. It can process about 600 pounds per 8 hour shift and requires between 25 to 30 gallons of ethanol.
ExtractCraft’s Source Turbo is an ideal at-home botanical extractor and ethanol recovery system. It is the size of your coffee maker and super simple to use, too. A mobile app gives operators insight into the performance and progress of the extraction.
The EtOH Pro is another good choice for small scale operators or home use. It has a 4-liter (1 gallon) capacity. It even has ethanol recovery and post-process purging capabilities. The result is pure extracts.
Cedarstone Industry creates custom stainless steel extraction equipment for commercial cannabis production. Ethanol extraction solutions come in systems that can hold 100L and higher.
Root Science’s lineup of extraction equipment includes the EFR, CRYOEXS 400, and CRYOEXS 800. The EFR offers operators a semi-automated C1D1-compliant design. It uses a flexible batch style method that includes extraction, filtration, and solvent recovery. It can process between 30 and 60 pounds of biomass per hour with a 95 to 98% recovery rate.
Extraction System Training
With the purchase of an ethanol extraction system, manufacturers generally include a hands-on, on-site training for a day or two for operators working at your facility. Some manufacturers can also provide installation for a nominal fee.
Training may include:
Inspection of system components
On-site pressure and vacuum test
Solvent only runs to clean equipment
Emergency shutdown procedures
Overall, the purpose of installation and basic training is to empower operators with extraction and post-processing best and safe practices. Manufacturers go over troubleshooting procedures to prepare extraction technicians to handle the different challenges they may face.