What is supercritical co2 extraction?
Supercritical fluid extraction is a technique that uses supercritical fluid as an extractant to separate an extract from a mixture matrix. Carbon dioxide (CO2) is the most commonly used supercritical fluid. Supercritical is a supercritical fluid, which is a non-gaseous and non-liquid state of matter between gas and liquid. This substance can exist when its pressure exceed and temperature the critical point. The density of supercritical fluid is higher, similar to that of liquid, and its viscosity is closer to that of gas. Therefore, supercritical fluid is a very ideal extraction agent.
The principle of supercritical co2 extraction machine
The principle of supercritical co2 extraction machine and separation process is based on the relationship between the dissolving ability of supercritical fluid and its density, that is, the effect of pressure and temperature on the dissolving ability of supercritical fluid. In the supercritical state, the supercritical fluid is contacted with the substance to be separated, it can selectively extract the components of polarity, boiling point and molecular weight in turn. Of course, the extract obtained corresponding to each pressure range cannot be single, but the conditions can be controlled to obtain the optimal proportion of mixed components, and then the supercritical fluid can be turned into ordinary gas by means of decompression and temperature rise, and the extracted material is Complete or basic precipitation, to achieve the purpose of separation and purification, the highly critical CO2 fluid extraction process is a combination of extraction and separation processes.
Models and components of supercritical co2 extraction equipment
There are currently four types of supercritical co2 extraction process, namely: SFE-5L, SFE-10L, SFE-25L, SFE-50L. The supercritical co2 extraction equipment consists of a refrigerator, a gas storage tank, a liquid carbon dioxide pump, a modifier pump, a raw material pump, a heat exchanger, an extractor, an unloader, a feed valve, a discharge valve, a pressure relief valve, a pressure gauge, Nitrogen cylinder, pressure gauge, raw material intermediate tank, raw material tank, modifier tank, modifier intermediate tank. High pressure CO2 pump composition.
Use supercritical co2 extraction equipment to extract essential oils
Take peony essential oil as an example
1. Cleaning: Wash the roots, stems, leaves and flowers of peony to remove impurities and soil, and drain the water for later use;
2. Drying: Send the roots, stems, leaves and flowers of the dried peony into the drying room of the drying room of the drying equipment. After closing the door on the side of the drying room, open the air outlet set on the door, The other side of the boiler room is provided with an inspection door to close, and open the fan set on the inspection door, so that the heat energy generated by the drying furnace in the boiler room can take away the water vapor generated by the roots, stems, leaves and flowers through the air outlet; A temperature sensor is provided to ensure that the drying temperature in the drying room is between 40 to 70 degrees, the drying time is 3 to 8 hours, and the moisture content is less than 7%;
3. Pulverization: The roots, stems, leaves and flowers of the dried peony are pulverized into chaff through a crop straw pulverizer to obtain peony scraps;
4. Put 300Kg of peony pieces into the extractor; then close the extractor, check to ensure that the seal is tight, pump the liquid from the storage tank into the vaporizer through a high-pressure pump, and enter the vaporizer into the extractor in a critical fluid state for extraction;
5. adjust the pressure and temperature in the extractor, be respectively 10Mpa～45 Mpa, 32 ℃～80 ℃; CO after extraction The mixed fluid input separator of peony essential oil carries out decompression separation, the pressure control in the separator Between 4MPa～10Mpa, the temperature range is 20 ℃～80 ℃;
6. During the extraction and separation process, prevent the pressure in the extractor from being too high. When the pressure in the extractor exceeds the design requirements, adjust the outlet valve of the extractor, increase the overflow in the extractor, and reduce the pressure in the extractor to ensure that the design requirements are met. , the fluid rich in peony quintessence oil enters the separator after the decompression of the outlet regulating valve in the extractor, and in the separator, the low pressure and high temperature are respectively under the conditions of 4Ml～10Pa, 20 ℃～80 ℃, the peony quintessence oil and ( X) 2 separates, and the pure essential oil after the separation is cooled by the liquefier, finally flows back to the liquid storage tank, and completes the cyclic process of extraction,
7. After the supercritical co2 extraction equipment, the CO2 gas in the tail gas tank can be recovered by the compressor during the extraction process and enter the liquid CO2 storage tank for further extraction. During the extraction process, the peony essential oil in the separator is regularly released into barrels. And measure, in order to track the extraction process, so that the oil content in the peony scraps can be accurately grasped; the extracted peony scraps are discharged from the bottom cover of the extractor.
Features of supercritical co2 extraction machine:
1. Supercritical co2 extraction machine can be carried out at room temperature (35-40°C) and under the cover of CO2 gas, which effectively prevents the oxidation and dissipation of heat-sensitive substances. Therefore, the active ingredients of medicinal plants are kept in the extract, and the substances with high boiling point, low volatility and easy pyrolysis can be extracted at a temperature far below its boiling point;
2. The use of SFE is the cleanest extraction method. Since no organic solvent is used in the whole process, the extract has no residual solvent substances, thus preventing the existence of harmful substances to the human body and the pollution to the environment during the extraction process, ensuring 100% of pure naturalness;
3. The extraction and separation are combined into one. When the CO2 fluid of the saturated dissolved substance enters the separator, due to the drop of pressure or the change of temperature, the CO2 and the extract quickly become two-phase (gas-liquid separation) and immediately separate. Not only the extraction efficiency is high, but also the energy consumption is less, which improves the production efficiency and reduces the cost;
4. CO2 is an inert gas that does not undergo a chemical reaction during the extraction process and is a non-flammable, odorless, odorless, non-toxic and highly safe gas;
5. CO2 gas is cheap, high purity, easy to prepare, and can be reused in production, thereby effectively reducing costs;
6. Both pressure and temperature can be used as parameters to adjust the extraction process. The purpose of extraction can be achieved by changing the temperature and pressure. The pressure can also be fixed by changing the temperature to separate the substances; on the contrary, the temperature can be fixed and the pressure can be reduced. Therefore, the process is simple and easy to master, and the extraction speed is fast.
Advantages of supercritical co2 fluid extraction machine
1. CO2 is inexpensive, non-flammable, non-explosive, sterilizing, bacteria-free, and has strong selectivity and mobility.
2. Gentle handling of heat-sensitive materials.
3. The product and residues are free of solvents.
4. Solubility can be changed.
5. Oil can achieve excellent flavor profile.
6. Produce pure extract with few process steps.
7. Fragrance and aroma stay the same.
8. Selective extraction and fractionation are possible.
9. CO2 is recycled in plants, which is harmless to physiology and will not cause environmental. problems such as some traditional solvents.
Application of supercritical co2 fluid extraction equipment
The characteristics of supercritical extraction determine its wide range of applications. For example,For example, in the pharmaceutical industry, it can be used for the extraction of CBD oil, the purification of heat-sensitive biological products, and the separation of lipid mixtures; in the food industry, the extraction of hops, the extraction of pigments, etc.; in the fragrance industry, natural and Refinement of synthetic fragrances; separation of mixtures in chemical industry, etc. Specialized applications can be divided into the following categories:
1. Extraction of biologically active molecules from medicinal plants, extraction and separation of alkaloids;
2. Lipid lipids from different microorganisms, or used for lipid lipid recovery, or removal of lipid lipids from glycosides and proteins;
3. Anti-cancer substances are extracted from various plants, especially paclitaxel is obtained from the bark and branches of Taxus chinensis to prevent and treat cancer;
4. Vitamins, mainly vitamin E extraction;
5. Purify various active substances (natural or synthetic) to remove unwanted molecules (such as pesticides from vegetable extracts) or "dregs" to obtain purified products;
6. Processing of various natural antibacterial or antioxidant extracts, such as basil, red string, thyme, garlic, onion, chamomile, chili powder, licorice and fennel seeds, etc.