What is Supercritical CO2 extraction?

What is Supercritical CO2 extraction?

Supercritical CO2 extraction is an efficient and clean way of obtaining extracts that prevent plants’ natural properties. This is currently the best method to produce the highest quality cannabinoids extracts.

Supercritical CO2 Extraction – How Does it Work?

Supercritical fluid extraction (SFE) uses supercritical fluid – in this case carbon dioxide – to obtain a pure plant extracts without the use of hazardous chemicals and solvents that could contaminate the final product. SFE allows for the highest purity also because it won’t extract any unwanted ingredients and impurities; as there is no need to purify the product, the whole extraction process is significantly shortened. CO2 extraction is an example of green chemistry because it is a clean and safe process with no negative impact on the environment.

Sometimes referred to as the fourth state of matter, the supercritical state is the state of the substance in which the temperature and pressure have exceeded the critical point (different for every substances) in which the physical properties of a substance such as density, diffusion coefficient, electrical permeability, viscosity etc. are altered; the distinction between gas and liquid blurs. For carbon dioxide, the process of supercritical transition occurs at relatively low temperatures, such that won’t affect the structure of plant components, which is a common issue with higher temperature extractions.

The extraction agent in the supercritical CO2 extraction process is carbon dioxide compressed under high pressure. As the process finishes, the gaseous element discharges to atmosphere, leaving no trace and with no need for additional removal (although it can be also easily collected and re-used). In addition, the process goes without air access, so the ingredients collected are not subject to oxidation

The plant extracts obtained by this method are microbiologically sterile, while preserving the full spectrum of natural ingredients, even more than lyophilisates. It is now the most modern and the most effective method of obtaining polyunsaturated oils, flavonoids and anthocyanins.

Key advantages of the supercritical CO2 extraction

  • possibility to regulate the solubility of individual components in a simple and effective manner, depending on the temperature and pressure under which the process takes place and thus the separation and extraction of the individual components
  • conducting the process at low temperatures, so that the collected components are not degenerated
  • non-toxic solvents resulting with total chemical purity of the final product
  • total and spontaneous discharge of solvent from the extract – no need for additional purification
  • fractionation of collected substances as the process develops
  • the process runs without air, which prevents oxidation.
  • high selectivity of the process, due to good penetration of the solvent into the structure of the raw material.
  • possibility of recollection and recicrulation of the solvent, which significantly reduces costs.
  • no waste

Supercritical CO2 extraction is widely used in cosmetology, pharmacology and many other industries. This process is also carried out to obtain the cleanest cannabinoids, including the CBD. Hemp is often contaminated with heavy metals and other dangerous substances. These plants have the ability to accumulate toxic compounds from the soil, so in order to obtain pure CBD oil, special cleaning techniques are crucial; the supercritical CO2 extraction is the only method that guarantees the complete removal of heavy metals and toxins.

One additional disadvantage of mechanical pressing and other traditional methods of obtaining vegetable oils is their low productivity – only 60-80% of the total volume of the substance is recovered. In comparison, the supercritical CO2 extraction efficiency rate is as high as 95%.

References:

https://colwayinternational.com/news/downloads/213,file,supercritical-extraction.pdf
http://hempoland.eu/pl/ekstrakcja-co2/
http://www.adelia.com.pl/ekstrakcja-nadkrytyczna-co2/