Solvent-free extraction system for supercritical fluids

Abstract

A solvent-free supercritical fluid extraction system (1) suitable for plant extraction at low and medium temperature and with a high nutrient extraction rate, comprising: a pre-processing unit (10) comprising a cleaning device (11); a supercritical fluid extraction unit (20) connected to the preprocessing unit (10) and comprising a fluid storage tank (21), a supercritical extraction reaction tank (22), a temperature adjusting device (23) and a pressure adjusting device (24), wherein the supercritical extraction reaction tank (22) is equipped with a pressure pump (221) for extracting a supercritical fluid to obtain a primary extract (E0), wherein the temperature adjusting device (23) is connected to the supercritical extraction reaction tank (22) and the pressure adjusting device (24) is connected to the supercritical extraction reaction tank (22); a separation device (30) connected to the supercritical extraction reaction vessel (22); and a recycling unit (40) comprising a first circulation pump (41) and a second circulation pump (42) which return the supercritical fluid to the supercritical fluid extraction unit (20).

Description

Field of the InventionThe present invention relates to an extraction system for extraction of Chinese Bocksdorn pigments and, more particularly, to a supercritical fluid extraction system for extraction of Chinese Bocksdorn pigments without the use of solvents.Prior ArtSupercritical carbon dioxide extraction is an efficient and advanced technique for separating materials developed in the chemical industry over the past decades. The basic principle of supercritical extraction is to dissolve the required chemical composition by means of a supercritical fluid at temperatures and pressures above the critical values. Subsequently, the pressure of the fluid solution is reduced or the temperature is raised, whereby the solutes in the supercritical fluid are precipitated and extracted due to the decrease in their density and solubility, thus achieving extraction of specific solutes. Supercritical fluids are high density fluids that exist at temperatures and pressures above the critical values.In conventional methods for extraction of Chinese bock seed oils, the active ingredients are generally first extracted with organic solvents by steam distillation, vacuum distillation, direct compression or extraction methods and then recovered by filtration, evaporation or other separation methods.In Chinese Patents CN1237618A and CN1272417C, it is stated that the effects of a short extraction time and a high yield of the final product without propane residues are obtained. However, these conventional techniques still cannot overcome the difficulties in extraction of Chinese bock mandrels pigments and the lack of impairment of the activity of Chinese bock mandrels by the use of solvents. Further, when no solvents are used and Chinese bock seeds are introduced directly into the supercritical extraction system, the polysaccharides contained in Chinese bock seeds tend to join in the extraction chamber into lumps which can reach the hardness of bricks and stones. This leads to blockage of the pipes, distortion of the extraction chamber and a rise in pressure to the maximum permissible values of the equipment. Therefore, if emergency measures are not taken, this may lead to work accidents in which equipment is damaged or, in the worst case, people are injured.Therefore, a solvent-free supercritical fluid extraction system which not only eliminates the problem of blockage in piping caused by polysaccharides, but also solves the problems of extraction of Chinese bockdorn pigments and enables efficient extraction without using solvents is being earnestly sought in industry.Object of the InventionIn view of the above problems and deficiencies, the inventor has devoted himself to solving the problem by his many years of occupation and, after several alterations, attempts and improvements, has finally created this solvent-free supercritical fluid extraction system.It is the main object of the present invention to provide a solventless supercritical fluid extraction system comprising a preprocessing unit, a supercritical fluid extraction unit, a separator and a recycling unit, the preprocessing unit comprising a cleaner for purifying Chinese bock mandrel raw materials and removing unnecessary impurities to obtain a plurality of clean Chinese bock mandrel raw materials to be extracted, the supercritical fluid extraction unit being connected to the preprocessing unit and comprising at least an extractant storage container, a supercritical extraction reaction container, a temperature adjuster and a pressure adjuster. First, the extractant is pressurized by a pressure pump to form a supercritical fluid. In the supercritical extraction reaction vessel, the supercritical fluid permeates, dissolves and extracts nutrients from Chinese bockworm raw materials to be extracted, such as Chinese bockworm seeds and Chinese bockworm fruits, to obtain a primary extract. The separation device is connected to the supercritical extraction reaction vessel and serves to feed the primary extract after the supercritical extraction into the separation device to separate the plurality of Chinese bocksdorn extracts, the residues, and the supercritical fluid. The recycling unit comprises at least a first circulation pump and a second circulation pump, wherein the first circulation pump serves to return the supercritical fluid to the supercritical fluid extraction unit and the second circulation pump serves to return the residues serving as diluents to the supercritical fluid extraction unit.Brief Description of the DrawingsFIG. 1 is a schematic structural diagram of the solvent-free supercritical fluid extraction system of the present invention; FIG. 2 is a schematic block diagram showing the arrangement of the solvent-free supercritical fluid extraction system of the present invention; Fig. 3 is a schematic view showing the structure of the heater and the cooling apparatus according to the present invention.DETAILED DESCRIPTION OF THE EMBODIMENTReference is made to Figs. 1 and 2, each showing a schematic structural diagram and a schematic block diagram of the arrangement of the solvent-free supercritical fluid extraction system of the present invention. The solvent-free supercritical fluid extraction system according to the present invention includes primarily a preprocessing unit 10, a supercritical fluid extraction unit 20, a separator 30, a recycling unit 40, and a control unit 50.The preprocessing unit 10 comprises a cleaning device 11, a drying device 12 and a comminution device 13, wherein the cleaning device 11 serves for cleaning the Chinese bock mandrel raw materials and for removing unnecessary impurities in order to obtain a plurality of clean Chinese bock mandrel raw materials to be extracted, wherein the cleaning device 11 is connected to the drying device 12 and the drying device 12 is connected to the comminution device 13. In the present invention, the Chinese bockworm raw material may be at least one of Chinese bockworm seed and Chinese bockworm fruit, or a combination thereof.The drying device 12 serves for drying the plurality of Chinese jackkhorn raw materials in order to reduce the moisture content. The comminution device 13 serves for comminution of the plurality of dried Chinese bock mandrel raw materials into pulverulent particles in order to enlarge the extraction surface and thus to improve the extraction efficiency.The supercritical fluid extraction unit 20 is connected to the preprocessing unit and includes at least a fluid storage tank 21, a supercritical extraction reaction tank 22, a temperature adjuster 23, and a pressure adjuster 24, the fluid storage tank 21 serving to store an extractant.Further, the supercritical extraction reaction vessel 22 pressurizes the extractant by a pressure pump 221 to form a supercritical fluid. The supercritical fluid permeates, dissolves and extracts nutrients from the Chinese bock seeds, Chinese bock seeds, or combinations thereof to obtain a primary extract E0.The number of supercritical extraction reaction vessels 22 is not particularly limited and may be one or more. In the case of using a plurality of supercritical extraction reaction vessels 22, these may be arranged in series or in parallel.Further, the temperature adjusting device 23 is connected to the supercritical extraction reaction vessel 22 to bring and maintain the temperature of the supercritical fluid above the critical point. The pressure adjusting device 24 is connected to the supercritical extraction reaction vessel 22 to bring and maintain the supercritical fluid pressure above the critical point.Further, the upper and lower temperature setting limits of the temperature adjusting device 23 are generally in the range of 190 K to 700 K as far as it is possible to maintain the density of the supercritical fluid in the range of 100 to 1000 (kg / m 3), the diffusion coefficient in the range of 0.01 to 0.1 (mm 2 / sec), and the viscosity in the range of 50 to 100 (μPa· sec).The recycling unit 40 further comprises at least a first circulation pump 41, a second circulation pump 42 and a storage device 43, wherein the first circulation pump 41 serves for returning the supercritical fluid to the supercritical fluid extraction unit 20 and the second circulation pump 42 serves for returning the residues serving as diluents to the supercritical fluid extraction unit 20.The number of the first circulation pumps 41 and the second circulation pumps 42 is not particularly limited, and may be, for example, one, two, or more. If a plurality of first circulation pumps 41 and second circulation pumps 42 are used, these can be arranged in series or in parallel.Further, the storage device 43 serves to store the residues in a suitable low temperature environment to properly store the residues formed after extraction of the Chinese jackkhorn raw materials at temperatures between 0° C. and room temperature.The control unit 50 is electrically connected to the supercritical fluid extraction unit 20, the temperature adjuster 23, and the pressure adjuster 24. The control unit 50 is used to control temperature, pressure and flow rate during the extraction process.The pressure adjusting device 24 comprises a compressor 241 and a pressure reducing valve 242, wherein the compressor 241 serves for pressure increase and the pressure reducing valve serves for pressure reduction. The main function of the pressure adjusting means in the supercritical extraction reaction vessel 22 is to increase the pressure of the extractant to reach or exceed the supercritical state. The upper and lower pressure setting limits of the pressure adjusting device 24 are usually in the range of 30 to 300 atmospheres as far as it is possible to maintain the density of the supercritical fluid in the range of 100 to 1000 (kg / m 3), the diffusion coefficient in the range of 0.01 to 0.1 (mm 2 / sec), and the viscosity in the range of 50 to 100 (μPa· sec).Further, the function of the pressure reducing valve 242 in the solvent-free supercritical fluid extraction system 1 is to control and decrease the fluid pressure to return the fluid from a supercritical state to a lower pressure. This is of decisive importance both for the separation of the extracted active ingredients and for the safe operation of the system.As shown in FIG. 3, the temperature adjusting device 23 includes a heater 231 and a cooling device 232, wherein the heater 231 is for providing a heating function and the cooling device 232 is for providing a cooling function. In particular, the function of heater 231 is to heat the extractant to the temperature required for the supercritical state.In this way, with the solvent-free supercritical fluid extraction system of the present invention, at least the following excellent advantageous effects can be obtained:1. Since the Chinese burdock pigment is extracted in a critical state, the problem of difficult extraction of Chinese burdock pigment can be effectively solved;2. Since the supercritical extraction of Chinese bock mandrel is carried out without using solvents, no solvent container is required. There is therefore also no need to remove solvents by heating. Therefore, the problem of residual solvent does not occur;3. Since the supercritical extraction of Chinese bock mandrel takes place at temperatures below 35° C., the activity of the Chinese bock mandrel is completely maintained;4. Since the residues after extraction are used as diluents, there are no problems such as blockage in the piping and deformation of the extraction chamber due to the formation of lumps by too high concentrations of polysaccharides.List of reference characters1 Solvent-free supercritical fluid extraction system 10 Preprocessing unit 11 Cleaning device 12 Drying device 13 Crushing device 20 Supercritical fluid extraction unit 21 Fluid storage container 22 Supercritical extraction reaction container 221 Pressure pump 23 Temperature adjustment device 231 Heater 232 Cooling device 24 Pressure adjustment device 30 Separation device 31 Decompression chamber 40 Recycling unit 41 First circulation pump 42 Second circulation pump 43 Storage device 50 Control unit E 0 Primary extract Ef Chinese horse extractThe present invention relates to a solvent-free supercritical fluid extraction system, characterized in that it comprises: a preprocessing unit comprising a purification device for purifying Chinese bock mandrel raw materials; a supercritical fluid extraction unit connected to the purification device and comprising a fluid storage container for storing an extractant; a supercritical extraction reaction container in which, for obtaining a primary extract, a supercritical fluid permeates, dissolves and extracts nutrients from Chinese bock mandrel seeds, Chinese bock mandrel fruits or combinations thereof; a temperature adjusting device connected to the supercritical extraction reaction container and for maintaining the temperature of the supercritical fluid; and a pressure adjusting device connected to the supercritical extraction reaction vessel and for providing and maintaining the pressure of the supercritical fluid.Representative Figure of the Present Invention:. 1[List of Reference Numerals of this Figure]1 Solvent-free supercritical fluid extraction system 10 Preprocessing unit 11 Cleaning device 12 Drying device 13 Comminution device 20 Supercritical fluid extraction unit 21 Fluid storage container 22 Supercritical extraction reaction container 221 Pressure pump 23 Temperature adjustment device 24 Pressure adjustment device 30 Separation device 31 Decompression chamber 40 Recycling unit 41 First circulation pump 42 Second circulation pump 43 Storage device 50 Control unit E 0 Primary extract Ef Chinese bock spike extractReferences included in the specificationThis list of documents cited by the applicant has been produced in an automated manner and is only included for the better information of the reader. The list is not part of the German patent application or utility model application. The DPMA does not take any adhesion for any faults or omissions.Patent Literature citedCN 1272417C

[0004]

Claims

A solvent-free supercritical fluid extraction system (1) suitable for low and medium temperature and high nutrient extraction rate plant extraction, comprising: a pre-processing unit (10) comprising a cleaner (11); a supercritical fluid extraction unit (20) connected to the pre-processing unit (10) and comprising a fluid storage container (21), a supercritical extraction reaction container (22), a temperature adjuster (23), and a pressure adjuster (24), wherein the supercritical extraction reaction container (22) for obtaining a primary extract (E0) is equipped with a supercritical fluid extraction pressure pump (221), wherein the temperature adjuster (23) is connected to the supercritical extraction reaction container (22), and the pressure adjuster (24) is connected to the supercritical extraction reaction container (22); a separator (30) connected to the supercritical extraction reaction vessel (22); and a recycling unit (40) including a first circulation pump (41) and a second circulation pump (42) that return the supercritical fluid to the supercritical fluid extraction unit (20).The solventless supercritical fluid extraction system (1) according to claim 1, wherein the temperature adjusting means (23) comprises a heater (231) and a cooling device (232).The solventless supercritical fluid extraction system (1) of claim 1, wherein the pressure adjustment device (24) comprises a compressor and a pressure reducing valve.The solventless supercritical fluid extraction system (1) according to claim 1, wherein the separation means (30) further comprises a decompression chamber (31), and the recycling unit (40) further comprises a storage means (43).The solventless supercritical fluid extraction system (1) according to claim 1, further comprising a control unit (50) electrically connected to the supercritical fluid extraction unit (20), the temperature adjuster (23), and the pressure adjuster (24).The solvent-free supercritical fluid extraction system (1) according to claim 1, wherein the preprocessing unit (10) further comprises a drying device (12) and a crushing device (13), wherein the cleaning device (11) is connected to the drying device (12) and the drying device (12) is connected to the crushing device (13).

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