Supercritical Fluids

A fluid is in “supercritical state” when it is placed at a temperature above its critical temperature and at a pressure above its critical pressure. Above these conditions there is no frontier between liquid and gas, and small changes in the temperature or pressure could result in continuous changes in the fluid’s density, solvent power and other physical properties.

Supercritical Fluids can be placed in conditions where they have several advantageous properties of both liquids and gases, leading for instance to much faster mass transfer rates which is very interesting for extraction or reaction, or high diffusivity and low viscosity with a lot of application on highly porous materials processing, extraction impregnation, nano-particles formation etc….


Density
(kg/m3)
Viscosity
(µPa.sec)
Diffusivity
(mm2/s)
Gases 1 10 1–10
Supercritical fluids 100–1000 50–100 0.01–0.1
Liquids 1000 500–1000 0.001

Comparison of gases, supercritical fluids and liquids properties

The two most widely used Supercritical Fluids are carbon dioxide (CO2) and water (H2O). Both fluids are readily available and can be used in a pressurized formed to replace organic solvents or being alternative environment friendly processes.

Solvent Critical temperature (°C ) Critical pressure (Bar ) Critical density (g/cm3 )
Carbon dioxide (CO2) 31.1 73,8 0.469
Water (H2O) 374 220 0.322
Propane (C3H8) 96,7 42,5 0.162
Visualize critical point and supercritical media

Experiment to visualize and determine solubility of a compound

More on supercritical fluid on Wikipedia

Contact us to know more about supercritical fluid potential for your product