A typical example is shown in Q4 above. Supercritical carbon dioxide is used in the extraction of functional ingredients such as health foods, flavors and dyes, hops used in beer, and sesame oil. Traditionally, extraction at 30 MPa or lower has been the mainstream, but recently even higher pressure extraction has been used (see below).
Features of Supercritical Carbon Dioxide Extraction
- No solvent residue
- Extraction can be performed at near room temperature, and the unique aroma of the raw material is preserved.
- Minimal contamination
- Low viscosity and high fluidity
(Comparison with solvent extraction of carotenoids)
Features of high-pressure supercritical carbon dioxide extraction
- Increased productivity and reduced processing costs
- Safe and efficient extraction of small amounts of high value-added functional ingredients
- Reduction or elimination of co-solvent
At the research level, there are published examples of recovering platinum and rhodium from waste automotive catalysts by extracting them by forming complexes with chelating agents and precious metals.