CO2 AS A SOLVENT
Clean, efficient, and versatile; the extraction possibilities provided by carbon dioxide are endless
CO2 products are overtaking the market
Cleaner, Safer, Greener
Solvent selection is very important for applications in the food, nutraceutical, and pharmaceutical industries, where health and safety legislation place severe restrictions on the types of solvents that can be used. Supercritical CO2 is non-toxic and non-flammable, removing both the concern of toxic solvent residues in your products and of combustion/explosion during operation of the system. CO2 extracts are pure and require minimal post-processing, removing the residues of heavy metals or butane. Carbon dioxide is generally recognized as safe by the FDA and EFSA. This makes CO2 the ideal solvent for processing food and medical extracts.
It is more environmentally responsible to use CO2 as a supercritical solvent. Carbon dioxide is produced as a natural organic waste from fermentation and respiration, and so can be captured for use without the need for synthesis and processing. This protects against additional costs, both financial and environmental.
Wider Extraction Parameters
CO2 retains solvency power as either a liquid (subcritical) or supercritical fluid. By changing extraction pressure and temperature of supercritical CO2, its solubility and selectivity for a species of interest can be changed to optimize an extraction. CO2 displays exceptional extractant selectability over a wide range of pressure, from 300 to 3000psi. In this same way, it is even possible in CO2 extraction to refuse undesired compounds such as chlorophyll.
CO2 as a solvent operates at lower conditions than other solvents. Due to its interesting properties, Supercritical CO2 can be described as a "green" solvent. The critical point of CO2 is easily accessible (critical temperature 31°C and critical pressure 74 bar) allowing the fluid to be used at mild conditions (temperatures 40-60°C) without leaving harmful organic residues. Using CO2 as a solvent, no organic residue is found in either the extract and solid residue and no thermal degradation appears. When CO2 is converted back to a gas, it no longer holds onto the oils, resulting in very high-quality products.
Through only modest changes in the temperature and pressure, the physical properties of CO2 can be manipulated. A wider range of extractant selectability is available when working with pressures lower than 3,000 psi; CO2 has solvency power from 300psi up. Moreover, by changing extraction pressure and temperature, the solubility and selectivity of the solvent (CO2) for species of interest can be changed to optimize the extraction, while even refusing undesired compounds.
At subcritical parameters it is possible to remove extractants that are thermolabile, resulting in more aromatic extracts. Extracts obtained from CO2 most closely resemble the natural starting material, which is the goal of essential oil extraction.
Supercritical CO2 has a polarity comparable to liquid pentane and, therefore, it is compatible for the solubilization of lipophilic compounds such as lipids and essential oils. By utilizing this technology, compounds of interest can be extracted from the plant material without any reaction to the CO2; resulting in a pure, transparent amber oil.