CO2 utilization technology
Supercritical CO2 extraction equipment-a CO2 utilization technology.
This technology can produce high value-added products, extract substances that cannot be extracted by chemical methods in the past, and is cheap, non-toxic, safe and efficient.
It is suitable for chemical, pharmaceutical, food and other industries. Carbon dioxide is a very common gas, but excessive carbon dioxide can cause the “greenhouse effect”, so it is important to make full use of carbon dioxide. Traditional carbon dioxide utilization technology is mainly used to produce dry ice (fire extinguishing) or as a food additive.
In the supercritical state, CO2 fluid has the dual characteristics of gas-liquid two-phase. It not only has the same high diffusion coefficient and low viscosity as gas, but also has similar density and good solubility as liquid. Its density is very sensitive to changes in temperature and pressure, and is proportional to the solubility within a certain pressure range, so the solubility of the substance can be changed by controlling the temperature and pressure.
When the temperature is higher than the critical temperature Tc=31.26℃ and the pressure is higher than the critical pressure Pc=7.2MPa, the properties of carbon dioxide will change. Its density is close to liquid, viscosity is close to gas, and its diffusion coefficient is 100 times that of liquid, so it has amazing solubility, can dissolve a variety of substances and extract effective ingredients.
It has a wide range of application prospects.
Supercritical CO2 is currently the commonly used extractant.
- The critical temperature of CO2 is 31.1C and the critical pressure is 7.2MPa. The critical conditions are easy to reach.
- CO2 is chemically inactive, colorless, tasteless, non-toxic and safe.
- The price is cheap, the purity is high, and it is easy to obtain.
The principle of the supercritical carbon dioxide extraction and separation process is that supercritical carbon dioxide has a special dissolving effect on some special natural products, and the relationship between the dissolving ability of supercritical carbon dioxide and its density, that is, the influence of pressure and temperature on dissolution, is used.
Supercritical carbon dioxide capacity. In the supercritical state, the supercritical carbon dioxide is in contact with the substance to be separated, and the components of different polarity, boiling point and molecular weight can be selectively extracted.
Of course, the extracts obtained under different pressure ranges cannot be single, but mixed components can be obtained under controlled conditions.
Then the supercritical fluid is converted into ordinary gas by decompression and heating, and the extract can be completely or substantially precipitated, so as to achieve the purpose of separation and purification.