Over the past decade, the United States has experienced an explosion in demand for hemp products. One of the most popular of these products is cannabidiol (or CBD oil), the consumable, non-psychoactive chemical found in cannabis. With its many medical uses and relaxed legal restrictions, the demand for this CBD continues to grow. In addition to the increasing demand, the methods used to process this valuable extract are expanding and improving. In this article, we’ll look at the most popular methods of extracting CBD oil.

Supercritical Carbon Dioxide (CO2) Extraction

The first method of CBD extraction is the CO2 method. This is currently the most effective method, however, it also requires the most equipment and know-how. It’s been a commonly used extraction method in the food and supplement industry and is now often used in commercial extraction for cannabis products.

So how does it work?

First, the carbon dioxide is sealed in a chamber where the pressure is increased and the temperature is decreased to -70 degrees fahrenheit. When the CO2 reaches this low temperature, it condenses into a liquid. It is then reheated and pressurized into a supercritical state, where it has properties of both a gas and a liquid. In its supercritical state, carbon dioxide can be used as a solvent.

At this point, a pump forces the CO2 into a second chamber which contains the cannabis material. The CO2 fills the chamber and, in its supercritical state, dissolves the cannabinoids and terpenes from the plant matter.

The solution is then pumped into a third chamber. Within this chamber, the pressure is lowered, allowing the cannabinoids and the CO2 to separate. The oil is collected and the CO2 is pumped back into the CO2 tank where the process begins again.

There is a similar process that uses carbon dioxide called subcritical extraction. Rather than using high pressure, this method uses low pressure which is less expensive, however it is significantly slower and produces a smaller yield.

Solvent Based Extraction Method

The second extraction method we’ll look at is the solvent-based extraction. In this method, a solvent such as ethanol, butane, or propane is combined with the plant material. Like the supercritical CO2, the solvent’s molecules attach themselves to the cannabinoids and terpenes, dissolving them from the rest of the plant matter. The desired materials are then separated from the solution and any solvent remaining is purged from the final product.

Although butane and propane are generally considered to be the most efficient solvents, they are both combustible and more overhead is required to safely execute the process. The equipment used must be able to handle increases in pressure (although not nearly as much as CO2 extraction) and must be explosion proof, including pumps.

The equipment used in ethanol based extraction, on the other hand, has none of those requirements. As a solvent, it is generally recognized as safe by the FDA and is used for similar processes throughout the food and supplement industry.

However, ethanol’s high polarity means that it binds with more than just the desired material, cannabinoid and terpenes. As a result, a significant amount of filtration and post-processing is required to remove matter such as fats, lipids, and chlorophyll. But the development of new extraction techniques, such as chilling the ethanol, allow it to bypass the undesired materials which makes the process much more efficient.

Although it produces a comparatively smaller yield than CO2, solvent based extraction is generally cheaper and has a much lower energy consumption.

Each type of extraction has its benefits and drawbacks. Performing these extractions at larger scales requires not just the right knowledge but also the right equipment. If you have any questions about your equipment, give us a call. We’re happy to help.