Mario Pagliaro
Istituto per lo Studio dei Materiali Nanostrutturati, CNR, Palermo, Italy

Driven by large and increasing demand of natural compounds (lipids, alkaloids, terpenes, proteins, phenolics and glycosides) in medical, nutraceutical, pest and disease control, cosmetic, food supplement, perfumery and aromatherapy products, conventional extraction methods widely relying on distillation using oil-derived organic solvents are being replaced by green methods (1). Informed customers in the digital age do not wish to buy natural products obtained with petroleum derivatives.

This trend, in brief, caused accelerated technical progress which in turn resulted in technologies such as supercritical fluid (SCF) and microwave-assisted extraction (MAE) to exit niche applications and leave academic laboratories to finally enter the marketplace. The few companies using scCO₂ in place of CH₂Cl₂ to decaffainate coffee are no longer alone. Today numerous firms across the world rely on advanced SCF  extraction processes, including advanced supercritical fluid chromatography for the enrichment of omega-3 polyunsaturated fatty acids (2).

For decades, as suggested by Pereira and co-workers, little information about SCF industrial cost ...