Supercritical carbon dioxide is used in large quantities for extraction because it has the following extraction characteristics:

A. supercritical CO2 fluid is colorless, tasteless non-toxic gas under normal, component separation and extraction, no solvent residue, can effectively avoid the traditional solvent extraction under the condition of residual solvent toxicity. Also prevents the extraction process of poison and pollution to the environment of the body, is A kind of the extraction technology of natural and environmental protection.

B. low extraction temperature, CO2 critical temperature of 31.265 ℃, the critical pressure is 72.9 ATM, can effectively prevent the oxidation of heat sensitive components, dissipation and reaction, completely retained the biologic activity of the biomass objects; It is also possible to extract substances with high boiling point, low volatility and pyrolysis below their boiling point temperature.

C. Extraction and separation are combined. When carbon dioxide supercritical fluid containing dissolved substances flows through the separator, the CO2 and the extract rapidly recover to be separated two phases (gas-liquid separation) due to pressure drop. Not only high extraction efficiency, but also less energy consumption, cost saving, and in line with the trend of environmental conservation.

D. extraction operation easy, pressure and temperature can be adjust the parameter of the extraction process. Near the critical point, the tiny change of temperature and pressure, will cause the CO2 density change significantly, thus cause changes in the solubility of object under extraction, can achieve extraction by using the method of controlling temperature or pressure. The pressure is fixed, change the temperature can separate the material; Conversely, the temperature is fixed, and the pressure is reduced to separate the extract. Therefore, the technological process is short, time consuming and small, and at the same time, it is really friendly to the environment. The extracted fluid CO2 can be recycled, which will not cause greenhouse effect due to waste carbon dioxide emissions. Become truly "green" production process.

E. the polarity of supercritical fluid can be changed. Under certain temperature conditions, materials of different polarity can be extracted by changing the pressure or adding appropriate entrainer.

Supercritical foaming equipment