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Supercritical Applications

Supercritical fluids based technologies are involved in a wide variety of industrial applications which have shown significant progress in recent years. Many industrial sectors are concerned including food, cosmetics, pharmaceutics, materials, chemistry, energy and waste treatment.The related supercrical fluid processes include extraction, impregnation, formulation, sterilization, cleaning, energy and waste treatment among others.

Some example of the industrial applications based on the utilzation of supercrical fluids are listed below:

Food industry

The use of Supercritical CO2 as an extraction solvent for natural products is the oldest and the most developed process on an industrial scale, with applications especially in the food industry. 

Decaffeination of coffee : this is the first example of the industrialization of supercritcal fluids (Mawwell, USA).The decaffeinated coffee produced presents a full aromatic profile (as a result of the low temperatures used and the absence of organic solvent). The extracted caffeine is, on the other side, sold to the pharmaceutical and food industries. There is therefore very little waste formed at the end of this process, making it economically and environmentally sustainable for now 30 years!

Corks free of “cork taint”: DIAM Bouchage (France) extracts Trichloroanisole (responsible of the so called "cork flavor") from cork using supercritical CO2 and already produces annually more than a billion corks.

Other examples of industrial applications in the food industry include the production natural colorants and aromas, the elimination of pesticides,  the extraction of lipids, the sterilization of milk and fruit juice, the deodorization of fish oil, the encapsulation of oils, treatment and valorization of food waste ...

Cosmetic industry

Antioxidant such as polyphenols, carotenoids and tocopherols (vitamin E), which are found in a wide variety of fruits and vegetables (beta carotene in carrots, lycopene in tomato...) can be selectively extracted using supercritical CO2. In addition, the textures of the extracts obtained (thyme, rosemary, lavender, chamomile...) are free from traces of organic solvents.

Pharmaceutical industry

Among the spectrum of the extracts obtained from plants, diterpenes (antioxidants), triterpenes (phytosterols), or even the tetraterpenes (carotenes) which may be of interest to the pharmaceutical sector, can be easily extracted. Supercritical fluids may also be utilised for the production of fine powders, in particular for the formulation of active principles. Pierre Fabre laboratories (France) which have developped the production of fine powders by supercritical CO2, were awarded the Pierre Potier 2009 "Innovation in chemistry for sustainable development" for its Formulplex ® process. This process uses supercritcal fluids to increase the bioavailability of active principles. Very recently, Critical Pharmaceuticles (United Kingdom) offers biocompatible and biodegradable polymers (synthesized using environment friendly supercritical CO2) for medical and pharmaceutical applications.

Polymer and plastics industries

In the plastics industry, the diffusion of supercritical CO2 in polymers is accompanied by a swelling of these materials and a change for their physico-chemical properties. Supercritical CO2 is a good plasticizing agent in particular because it reduces the glass transition temperature. The resulting polymer properties are usually improved (resistance, thermal stability, purity). Examples of applications iinclude the impregnation of medical material, the purification of polymers from residual solvants or monomers, the extrusion of elastomers, the synthesis of polymers and composites...

Chemical industry

Catalysis and biocatalysis of various organic compounds can be efficiently carried out in supercritical CO2. Industrialization of the process include the continuous catalytic hydrogenation of aromatic compounds.

Material industry

Some applications involve the drying of aerogel, the synthesis and deposition of nanaparticles,the cleaning of wafers ...

Wood industry

Superwood (Denmark) has industrialised the impregnation of wood with fungicides dissolved Supercritical CO2 ensuring a lack of mould, avoiding long baths and saving substantial amounts of fungicides.

Textile industry

Dyeing of textiles : The ecological and economical issues of conventional dying of textile are met when Supercritical CO2 is used as an alternative solvent. FeyeCon (Holland), which success in the field of Ssupercritical CO2 dying (DyeCoo ® process) is widely acknowledged, has grown steadily since its creation 20 years ago.

Tanning of leather : Based on the same idea, the tanning of skin into leather by supercritical CO2, thus avoiding the use of large quantities of aqueous solutions often difficult to treat. The chromium salts, even found natural tannins, can impregnate a skin to heart in order to it turn into leather.

Dry-cleaning : the process using supercritical CO2 is industrialized in the USA as an alternative to the chlorinated solvents used in the conventional method. Existing pilot plants can also be found in France and Germany. 

Energy production

The very promising recent developments observed in the areas of liquefaction and gasification of biomass (from agricultural wastes) in subcritical and supercritical water opens up the way to novel energy sources. 

Waste treatment and valorization

Oxidation in supercritical water oxidation (SCWO) has been greatly studied over the past 30 years particularly for the valorization and treatment of waste. The oxidation of (biological and chemical) refractory or hazardous waste in supercritical water is promising because it allows a fast burning of substrates in a confined and homogeneous environment where oxygen and organic compounds are soluble. Less complex waste (such as sewage sludge and aqueous effluent contaminated with high organic content) can also be treated by wet air oxidation (WAO) also known as oxidation in subcritical water. These processes also appear to be promising for the recovery of metals which precipitate under hydrothermal conditions.The use of supercritical CO2 for the extraction of valuable compounds from various co-products and wastes of the agro-food and platics industries are also under investigation.

Many more applications are available! Do not hesitate to contact us for more information.