Fragrance compounds are volatile molecules that have an odor or aroma. They are low molecular weight compounds and are found in food, wine, spices, flowers, and many natural products. These volatile essential oils are composed of esters, terpenes, cyclic terpenes, aromatics, alcohols, aldehydes, ketones, and lactones. All of these compounds are readily soluble in supercritical CO2 at low temperatures and low pressures.
So then why the interest in using supercritical fluids (i.e. CO2):
No Solvent residue. No health hazards. Maintains a "natural" state.
As with natural products, SCF CO2 extracts the fragrances more efficiently than petroleum-based solvents, but, maybe more important upon returning to an ambient state, the CO2 becomes a gas, leaving no residue. The fragrance is in its unadulterated state. There is no solvent taste or smell.
Mild Extraction Conditions – 31°C temperature
With temperatures less than body temperature (37°C), little thermal degradation of sensitive compounds occurs. Steam distillation is used in many current procedures, but with this exposure to temperatures over 100°C destroy, many of the “top notes” are destroyed or are swept away, severely reducing their yield.
Fractionation - easy using only CO2 - CO2 is a "tunable solvent"
Load the feedstock into an extraction vessel only once and then by only changing the pressure of the SCF CO2, you can make it have the solubility characteristics of a myriad of different petroleum-based solvents. You don’t need to add or change solvents.
Sometimes SCF CO2 can be used in conjunction with more traditional methods such as soaking perfume feedstocks in an organic solvent for a period of time. The organic solvents containing the extracted the perfumes (essential oils) and accompanying waxes is then decanted and evaporated, leaving a concrete. The essential oils can easily be separated from the wax with SCF CO2. Because of the low temperature, the process gives high recoveries.
At Applied Separations, we have a proven commitment to advancing Supercritical Fluids technology and have worked with companies all over the world to incorporate SCF into their processes. Thanks to a top-notch R&D team, in-house engineers, and visionary approach, we're working hard to develop and enhance applications of this green technology in many unexpected industries.
Contact us and we'll work with you to develop a supercritical fluid application for your needs.