WHAT IS CO2 EXTRACTION?
Every botanical contains different chemicals and compounds of interest to industrial manufacturers.
SUPERCRITICAL AND SUBCRITICAL EXTRACTION ARE IMPERATIVE IN TODAY’S MARKETS
To produce the highest amount of target compounds with the least amount of undesirable compounds, in the shortest period of time, the extraction parameters that affect mass transfer and solvency can be experimented with.
These parameters include extraction time, flow rate, temperature, and pressure.
In SFE, extraction time is related to the time it takes to reach mass transfer equilibrium between the solvent and matrix in the extraction chamber.
The quantity of solvent feed delivered through the extraction chamber over time.
TEMPERATURE & PRESSURE
The fastest, high-quality extraction will occur at pressures and temperatures that maximize solvent density and solubility while not destroying the desired extractants.
Supercritical carbon dioxide is a fluid form of carbon dioxide obtained where it is held at or above its critical temperature and critical pressure (87.98 F and 1073 psi, respectively).
The near-liquid density of supercritical fluid increases the interactions between the substrate and the CO2. The gas-like property of the supercritical fluid gives it excellent mass transfer capabilities.
These features make supercritical CO2 an amazing solvent for extraction, as it can be passed through a solid organic matrix to pick up desired extractants. As a gas, CO2 loses its solvency power, facilitating separation from the solute.
By changing extraction pressure and temperature, the solvent power and selectivity of supercritical CO2 can be changed to optimize an extraction for a species of interest.
Subcritical solvents are of interest when extracting yields with increased volumes of terpenoids, flavonoids, and other such volatiles.
Subcritical carbon dioxide runs at milder extraction parameters than other solvents, targeting those volatile compounds.
Follow a subcritical run with a supercritical extraction to completely scrub the matrix of any remaining valuable compounds and achieve a full-spectrum extraction.