CO₂ Extraction

Supercritical CO₂ fluid extraction is a process for creating high purity extracts and oils containing non-polar, lipid soluble bioactive compounds by using supercritical fluid carbon dioxide as a solvent. Extraction by supercritical CO₂ extraction is cleaner, safer, and more eco-friendly than other solvent extractions since it uses a nontoxic, non-flammable solvent compared to the toxic hydrocarbon solvents such as hexane, and acetone used in many extraction processes. 

Under the process conditions, CO₂ becomes a highly dense gas that behaves just like a liquid solvent and is able to permeate every part of the plant mass and cell walls to dissolve and extract non-polar, lipid soluble compounds.  The resulting extract has higher purity, is completely microbe-free due to the effects of high pressure, and is low in heavy metals and other water-soluble contaminants. 

The types of extracts that can be made with supercritical CO₂ include oils, plant essential oils, phenolic compounds of high concentration, carotenoids, flavors, fragrances, alkaloids, and other water insoluble plant compounds. Draco manufactures sea buckthorn oil, black pepper oil, pomegranate seed oil, CBD oil, fresh cut ginger oil, honokiol bioactive from magnolia bark, and many other botanicals using supercritical fluid CO₂ extraction. 

Since every compound has specific solubility and lipophilic characteristics, fine tuning the pressure and temperature conditions allows extracting a broad range of compounds or a narrow choice of single compounds if required. For example, rosemary contains non-polar diterpenes that include carnosic acid and carnosol, but by tightly controlling the extraction parameters, it is possible to extract just carnosic acid for high purity applications. 

Another benefit of supercritical CO₂ processing is the extraction of high purity oils that can be preserved in spite of their highly fragile nature such as omega 3 and 6 unsaturated fatty acids that are easily oxidized. It can also be used for bioactive phytocompounds such as lipophilic flavonoids and phenolics that are insoluble in water. 

Supercritical CO₂ Extraction – Features

• For non-polar, lipophilic compounds – as a complement to water extraction
• Effectively extracts essential oils, carotenoids, terpenes, oil soluble vitamins, unsaturated oils, alkaloids
• Oxygen-free atmosphere –  protects from oxidation
• No solvent residues of hydrocarbon solvent extractions (hexane, acetone, etc…)
• Better than cold pressing oils – which are exposed to sensitive-compound-damaging heat and oxidation
• Lower temperature process – could be as low as 31 ˚C (warm)
• High efficiency extraction with no waste – exhaustive yield of bioactives from plant mass
• Customizable –  Many different plant fractions are possible by changing T and P
• Contaminant free – low extraction of heavy metals and in-organics
• Bacterial inactivation – SCF sterilization
• Non-toxic CO₂ –  converts back into a gas after extraction and leaves no residue
• CO₂ is recycled internally – does not add to the burden of greenhouse gases