The use of supercritical fluids (SCFs), particularly CO
2
and water, is attracting immense interest as regulatory constraints tighten (such as the recent "REACH" directive issued by the European Union) and consumer demands grow for products free of potentially hazardous residual chemical compounds.
Today, the most numerous applications on an industrial scale involve using supercritical fluids as solvents to extract, fractionate or purify natural products from agriculture (algae and plants) and fishing (fish oils) to obtain a variety of products: food ingredients, fragrances and flavors, nutraceuticals, cosmetics and pharmaceuticals. But many other applications are being studied today, mainly for the synthesis, processing and shaping of high-performance materials (ceramics, foams and aerogels, powders, fibers and fabrics, nano-structured materials, composites and polymers) in industrial sectors including pharmaceuticals (drug formulation), microelectronics, coatings and paints, heat and sound insulation, mechanics, etc. Similarly, there is keen interest in the use of supercritical fluids as media for chemical or biochemical reactions.