Supercritical CO₂
Pharmaceutical, food, Power generation, Oil extraction ........

 

 

A Supercritical fluid is one where, at certain temperature and pressure conditions, liquids and gasses reach exactly the same density and so mix together completely forming a new state that combines both liquid and gaseous properties.

Supercritical CO₂ is a "Green" solvent used for processing ultra-pure pharmaceutical and food products.  Supercritical CO₂ allows you to refine compounds without either leaving toxic residues behind or risking thermal degradation of the products. 

Traditional organic solvents have been used for many decades but carry with them high costs plus significant health, environment and safety hazards.

Supercritical CO₂ is now used in a large number of applications - from the processing of coffee and vegetable oil through to producing insulin and anti-asthma drugs.  It can be used for large-scale power generation as well as for low porosity oil-bearing rock cores and hydrocarbon extraction, and even to produce Biocrude, a next-generation non-fossil fuel. Additionally, modern food and pharmaceutical powder generation processes often involve crystallisation using CO₂ in its supercritical state.

The need for new and clean technologies for processing ultra-pure pharmaceutical and food products has led to a rapid rise in the use of CO₂ - which allows users to refine compounds without either leaving toxic residues behind or risking thermal degradation of the products.  The alternative of traditional solvents carries with it high costs together with significant health, environment and safety hazards.

However, the vapour permeability of both the processes' materials and the materials being refined, become increasingly important and we, at Versaperm, have developed an instrument and technique to measure this both quickly and accurately.

The system is fast, accurate and easy to use.

The advantage of supercritical CO₂ is that it can permeate deep into a material's matrix and extract the desired compound more efficiently than by using conventional organic solvents. 

Food applications
Supercritical fluids have liquid-like solvent power and gas-like diffusivity.  Supercritical carbon dioxide is used by the food industry because of its lack of toxicity, lack of flammability, low cost, wide availability, its solvent recoverability, plus the ease of achieving a supercritical temperature (31.1°C) and pressure (7.4MPa).

Supercritical fluid extraction (SFE) overcomes the limitations of solvent residues and restrictions on the use of conventional solvents in food processing. Additionally, particulate products can also be produced by means of supercritical fluid (SCF) processing. These processes are non-flammable, non-toxic, non-polluting and offer recoverable characteristics

Applications of supercritical fluid extraction already go well beyond simply producing coffee or extracting high purity compounds from barbados nuts, berries, black currant, blueberries, brazilian propolis, canola, chamomile, cocoa, coriander, cranberry, crowberry, dodder, elderberry, elderberry, emburana, five-flavour berry, grape,  hop, macela, marigold, maypop, olive, onion, passionflower, pigeon pea, pine tree, raspberry, rice, rooibos, shiyacha, skullcap, sour cherry, soybean, spearmint, stonebreaker, sweet grass, tea, wild cherry and wormwood.

Pharmaceutical applications
Pharmaceutical companies use production processes, such as SFE, which offer a low environmental impact, reduce the use of volatile organic compounds and avoid residues in the finished product.

The principal pharmaceutical use of supercritical fluids involve

1. Extracting bioactive compounds from a mixture (e.g. extraction from natural materials, purification, quantification of active enantiomer etc.)
2. Crystallization and particle formation such as the dry powder used in asthma inhalers

Three main processes are employed in the production of fine and monodisperse powders

1. RESS (Rapid Expansion of Supercritical Solutions). This nucleation process involves the sudden decompression of a fluid containing a dissolved compound
2. SAS (Supercritical Anti Solvent).  This versatile technique uses the CO₂ to act as a non-solvent which induces the crystallisation of the compound
3. PGSS (Particles from Gas Saturated Solutions). This technique is based around the idea that it is easier to dissolve CO₂ in organic solutions (or melted compounds) than the vice-versa 

LINKS

For a press release on Supercritical CO₂ Click here

Wikipedia - Supercritical CO₂

Supercritical fluid extraction: recent advances and applications