Cannabis Extraction Guide: 3 Common Methods and Top Equipment

Cannabis products, such as cannabidiol (CBD), vapes, tinctures, gummies, capsules, and other edibles are growing in both popularity and demand. The primary reason is that cannabis-based products have numerous health benefits, from helping to cope with chronic pain to treating anxiety and depression.

While there are many different kinds of cannabis products on the market, it helps to know if they live up to their promises. For this reason, it is helpful to familiarize yourself with the different kinds of cannabis extraction methods. This requires knowledge about the processes and the extraction machines for cannabis oil. Different methods will make use of various kinds of specialized machinery, each with their pros and cons. The use of a particular procedure depends on certain factors such as safety, yield, extraction time, efficiency, complexity, and the type of solvent being used. Therefore, knowing how your cannabis oil is extracted will help you assess the quality and potency of the final product.

This article aims to highlight the three most common methods and equipment used for cannabis extraction for commercial purposes. Additionally, it sheds light on the benefits and drawbacks of each type of process. This information will help you make a much more informed decision when you go shopping for CBD products.

The Carbon Dioxide Method Of Cannabis Extraction

Cannabis extraction using carbon dioxide, or CO2, is one of the most widely used methods in the cannabis products industry. The basic concept is to make use of CO2 to extract the useful components from the cannabis plant. These include CBD, other useful cannabinoids, and terpenes that have various therapeutic properties.

While there are two types of CO2 extractions, namely supercritical and subcritical, they essentially use the same type of equipment. The difference between the two kinds of extraction methods involves using different temperature and pressure conditions.

Supercritical Versus Subcritical

The supercritical method involves carbon dioxide to behave like a gas and a liquid at once. This supercritical state is achieved by altering the pressure and temperature so that the CO2 is at or beyond its critical pressure and temperature.

The subcritical method involves lowering the temperature and pressure from the supercritical state so that the CO2 converts into a liquid.

Compared to the supercritical state of CO2, the subcritical state is ideal for extracting terpenes and any kinds of lighter or temperature-sensitive oils.

Extraction Process and Equipment

This method involves the following processes and equipment:

  1. Compression Chamber – Helps convert the CO2 into a supercritical or subcritical state.
  2. Extraction Vessel/Chamber – Contains the cannabis plant. The CO2 passes through the extraction chamber to pull out the essential components from the cannabis plant.
  3. Separator – Allows useful compounds to collect in a collection chamber. The low-pressure environment of the separator helps pass the CO2 through a condenser and be reused for another extraction cycle.

Benefits Of CO2 Extraction

  • Superior efficiency during extraction with no residuals.
  • Safe to use and avoids any kind of denaturing of the plant or biomass.
  • It doesn’t contain any kind of unwanted, large molecules such as chlorophyll.
  • Machinery can easily be modified according to the desired concentration or type of extraction such as temperature-sensitive extraction.

Drawbacks Of CO2 Extraction

  • Costly equipment requiring advanced set-up space.
  • Operational assistance from qualified professionals is needed to operate machinery.
  • Requires a certain level of product quantity to break even in terms of profit and loss.
  • Equipment may be subject to common types of wear and tear due to the use of high pressure.

The Hydrocarbon Method of Cannabis Extraction

This method makes use of hydrocarbons, such as butane, methane or propane, for extracting the useful compounds from the cannabis plant. Essentially, the hydrocarbons are converted into a liquid and then used for extraction by adjusting pressure requirements. It makes use of closed-loop extraction equipment.

Extraction Process and Equipment

This method involves the following processes and equipment:

  1. Recovery Cylinder – This contains the hydrocarbon which is the solvent used in the extraction process.
  2. Material Column – This contains the cannabis plant. The hydrocarbon is passed through the material column to extract the useful chemical compounds from the plant.
  3. Collection Vessel – Both the hydrocarbon and the extracted components are collected in the collection vessel. 
  4. Warm Water Bath – This provides adequate heating conditions to preserve useful compounds from the extraction process. Since hydrocarbons have low boiling points, it is vaporized, leaving behind the needed cannabis oil.
  5. Molecular Sieve – This helps remove any remaining moisture from the cannabis extracted oil.
  6. Condensing Coil – This helps to return the vaporized hydrocarbon to the recovery cylinder so that it can be used in the next extraction cycle.

Benefits Of Hydrocarbon Extraction

  • It does not extract molecules such as chlorophyll.
  • Machinery and equipment are more cost-effective than the CO2 extraction equipment.
  • A faster method of extraction when compared to the CO2 extraction method.
  • Yields a high-quality end-product.

Drawbacks Of Hydrocarbon Extraction

  • Flammable nature of hydrocarbons makes this process unsafe.
  • Securing an ideal environment to use hydrocarbon solvent in a safe space may be very costly.
  • Regulations on the use of easily combustible hydrocarbons may limit extraction levels.
  • Machinery cannot be adjusted for customized extraction as in the CO2 extraction method.
  • Since final products may contain residual materials, testing is required before the product goes on the market. 

The Ethanol Method Of Cannabis Extraction

This method makes use of ethanol as the solvent for cannabis extraction. It is essential to recognize that while the traditional method of ethanol extraction strips the plant of all its components, including unwanted compounds like chlorophyll, advancements in technology have enabled superior methods such as the use of supercooled or cryogenic ethanol.

The supercooled ethanol extraction method combines the best of both worlds; the safety of the CO2 extraction method coupled with the high rate of efficiency of the hydrocarbon extraction method.

The traditional method involves passing ethanol on the cannabis plant and allowing some time for the extracted material to collect. The next step is to heat the liquid to evaporate the ethanol and obtain the cannabis oil. This is followed by extensive post-processing to get rid of the chlorophyll.

Extraction Process and Equipment

This method involves the following processes and equipment:

  1. Solvent Storage – This contains the ethanol in the supercooled or cryogenic state.
  2. Holding Tank – This contains the cannabis plant.
  3. Extraction Vessel – The supercooled ethanol is used to extract useful components from the cannabis plant (without chlorophyll). It functions in a negative pressure environment to pull the desired compounds.

Other equipment may include sock filters (for effective filtration) and pneumatic actuators (to maintain pressure differentials).

Benefits of Ethanol Extraction

  • Using supercooled ethanol will eliminate any post-processing requirements.
  • The supercooled method is safe to use.
  • The supercooled method results in high-quality cannabis oil.
  • The supercooled method ensures that the end-product is free from residuals.

Drawbacks of Ethanol Extraction

  • The final product will contain chlorophyll if supercooled ethanol is not used. This will require extensive post-processing such as winterization and filtration. 
  • If the supercooled method is not used, safety measures need to be taken due to the flammable nature of ethanol.
  • If supercooled extraction is not used, a lower concentrate will be obtained as a result of post-processing.

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