Supercritical Extraction of Essential Oil from Elaeagnus angustifolia
Elaeagnus angustifolia is the flower of Elaeagnus angustifolia, which is mainly produced in Northwest China. According to the Chronicle of Chinese Medicine in Ningxia, Elaeagnus angustifolia mainly contains kaempferol, anthocyanin, fat oil and a small amount of volatile oil, which has the function of relieving cough and asthma and can be used to treat chronic tracheitis.
The extraction method of volatile oil from Elaeagnus angustifolia is usually steam distillation. The characteristics of steam distillation method are simple equipment and low cost, but the extraction rate is relatively low, and its process is easy to cause damage to thermal instability and oxidizable components, resulting in low quality products, which will affect the efficacy of drugs and cause losses to enterprises.
Supercritical fluid extraction technology has been widely used in food, medicine, spices and natural pigments. Supercritical CO2 fluid technology as a solvent has the advantages of no pollution, no solvent residue and no damage to the effective components of the volatile oil of Elaeagnus angustifolia, which makes the volatile oil of Elaeagnus angustifolia safe, reliable and of higher value.
Compared with steam distillation, supercritical CO2 extraction has the advantages of less time-consuming, high efficiency and avoidance of pyrolysis and volatilization of volatile oil components. It is suitable for batch production and is convenient for subsequent preparation of preparations. Therefore, it can reduce costs, save time and bring greater economic benefits for enterprises.
Recently, the laboratory has carried out a pilot study on the industrial process of extracting volatile oil from Elaeagnus angustifolia L. by supercritical CO2, and has made some achievements. The laboratory combines supercritical CO2 fluid technology with other technologies and develops a set of technological route suitable for industrial production of volatile oil from Elaeagnus angustifolia L. through small-scale experiments, which effectively improves the quality of volatile oil from Elaeagnus angustifolia L. and reduces the cost. The extraction process is reasonable, the results are reliable and the repeatability is good, which can provide a basis for the industrialized production of volatile oil from Elaeagnus angustifolia.
Brief Introduction -
Supercritical fluid CO₂extraction equipment is composed of CO2 supply system, extraction and separation system, CO2 circulation system, clean system, co-solvent system, cold water circulation system, hot water circulation system, steel platform, control system, tail gas recovery system, and so on.
CO2 supply system
Put liquid CO2 by delivery pump to condenser before or during operation. The CO2 supply system contains: outside CO2 delivery pump, outside tank.
Extraction and separation
The liquid CO2 flow through pre-heater to heat after pump by CO2 high pressure pump, then flow to extractor, the outlet temperature will be controlled automatic.
CO2 circulation system
The CO2 will back to middle storage tank after finish extraction, waiting the pressure balance between extractor and middle tank at 50bar, then put the left CO2 of extractor to the next extractor
Clean system working
Pump the clean agent to pipes from clean tank when finish extraction working.The clean system is composed of clean storage tank, clean pump.
Cold water circulation system
Pump tap water to purified water equipment, it flows to cold water tank after purifying. Pump cold purified water to refrigerator, the water will back to cold water tank after cooling.
Hot water circulation system
Put soften water to hot water tank, start hot water circulation pump and heated by electro-boiler(or heated by vapor), then distribute the hot water to extractor, separator, heat exchanger by the use of hot water circulation pump.
Steel platform description
The steel platform is for device fix and operation.With carbon steel, and antirust paint, the plane and stair is stainless steel riffled plate.
Tail gas recovery system
When extraction finish, close CO2 high pressure pump, the CO2 of extractor and separator will flow back to middle tank, when pressure balance, let the CO2 of extractor to another extractor, and pump the residual CO2 by compressor when pressure balance between two extractors.
Control system description
The control system is composed of low voltage switch box, PLC control cabinet, extractor quick-open chain control cabinet, control computer, cooling unit control cabinet, and so on.