Method for increasing yield of artemisinin crude product

Abstract

A method for increasing the yield of an artemisinin crude product belongs to the technical field of artemisinin extraction, and comprises the following steps: an extraction step: adding artemisia apiacea leaves into a petroleum ether solvent, and extracting by combining heating stirring, ultrasonic waves or microwaves; a separation step: carrying out liquid-solid separation by adopting a filtering or centrifuging mode to obtain an artemisinin extracting solution containing artemisinin; a concentration step: evaporating and concentrating the artemisinin extracting solution to obtain an artemisinin concentrated solution; a crystallization step: putting the artemisinin concentrated solution into a crystallization tank for crystallization, and filtering after crystallization to obtain a mother solution and an artemisinin crude product; the crystallizing tank is a cold and hot crystallizing tank provided with a refrigerant ring cavity and a heating medium ring cavity at the same time, the artemisinin extracting solution on the upper portion can be rapidly cooled, meanwhile, the artemisinin extracting solution on the lower portion is kept at the constant temperature, impurities attached to low-temperature crystals can be reduced, the crystallizing speed is increased, and the crystallizing recovery rate of the artemisinin crude product is increased.

Description

Technical Field

[0001] The invention belongs to the technical field of artemisinin extraction, in particular to a method for increasing the yield of crude artemisinin. Background Art

[0002] Artemisinin is mainly extracted from plants, and its active ingredients are extracted based on the solubility differences of various components in Chinese herbal medicines in different solvents. How to extract artemisinin more efficiently and ensure the purity of the product is a technical problem that needs to be solved in this field.

[0003] An existing artemisinin extraction process includes (1) drying treatment of raw materials; (2) primary preparation of artemisinin: extracting the treated raw materials with petroleum ether and then separating them, eluting the supernatant with a silica gel column, concentrating the obtained eluent until crystals precipitate, crystallizing in a crystallization tank for 15-20 hours, and filtering to obtain a crude artemisinin product after the crystallization is completed; (3) refining artemisinin: placing the crude artemisinin product obtained in step (2) in an alcohol precipitation tank for dissolution and standing, taking the supernatant for coarse and dense filtration, concentrating the filtrate, and removing the mother liquor after crystallization for 15-20 hours to obtain a fine artemisinin product. Although this method saves energy and reduces consumption, the recovery rate of artemisinin is not high, especially the recovery rate of crude artemisinin is not high, and its recovery rate is only about 80%, which seriously affects the economic benefits. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a method for improving the recovery rate of crude artemisinin and the purity of fine artemisinin by rapidly cooling and maintaining a constant temperature at the crystallization position in view of the above-mentioned defects.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is a method for increasing the yield of crude artemisinin, comprising: an extraction step: putting Artemisia annua leaves into a petroleum ether solvent, and extracting them by combining heating, stirring, ultrasound or microwave; a separation step: performing liquid-solid separation by filtering or centrifugation to obtain an artemisinin extract containing artemisinin; a concentration step: evaporating and concentrating the artemisinin extract to obtain an artemisinin concentrate; a crystallization step: putting the artemisinin concentrate into a crystallization tank for crystallization, and filtering after the crystallization is completed to obtain a mother liquor and a crude artemisinin;

[0006] The crystallization tank is a cold and hot crystallization tank, which includes a tank body and a support frame. The tank body is fixedly installed on the support frame. The tank body is provided with a motor, a transmission, a rotating shaft, a feed port, an exhaust port, a solvent inlet, a stirring blade, a crystallization screen plate, a drain port, a material outlet, a refrigerant ring cavity and a heat medium ring cavity. The tank body is vertically installed on the support frame. The middle part of the tank body is a cylindrical shell. The upper and lower ends of the cylindrical shell are both dome-shaped protruding shells, which are respectively called an upper shell and a lower shell; the rotating shaft passes through the center of the upper shell and is located on the axis line inside the tank body. The upper end of the rotating shaft is installed on the transmission, and the transmission is installed on the outer surface of the upper shell. The transmission is connected to the motor, and the motor is installed on a separately arranged bracket. The feed port, the exhaust port and the solvent inlet are arranged on the upper shell. The stirring blade is installed on the rotating shaft inside the tank body. The stirring blade is a U-shaped single-layer stirring blade. The bottom of the U-shaped single-layer stirring blade is a straight horizontal stripe blade, and the two sides are straight vertical stripe blades. The straight horizontal stripe blade and the lower shell are connected. The straight vertical leaves are connected in an arc-shaped transition. The middle upper surface of the straight horizontal leaves of the stirring leaves is provided with a mounting frame, which is mounted on the bottom end of the rotating shaft inside the tank body; the crystallization screen plate is a disc plate, which is mounted on the lower shell body below the straight horizontal leaves, so that the straight horizontal leaves and the crystallization screen plate together constitute a crystallization space, and the crystallization screen plate and the central part of the lower shell body protruding downward together constitute a filtrate space; the drain port is arranged at the center of the lower shell body for discharging the filtered filtrate, and the material outlet is arranged on the lower shell body between the straight horizontal leaves and the crystallization screen plate for discharging crystals; the refrigerant annular cavity is arranged on the outer surface of the middle and lower part of the cylindrical shell body in a surrounding and wrapping shape, and a refrigerant inlet and a refrigerant outlet are arranged on the refrigerant annular cavity for quickly cooling the Artemisia annua extract in the tank body, and the heat medium annular cavity is arranged on the lower shell body in an annular attachment shape and leaves the central position of the lower shell body, and a heat medium inlet and a heat medium outlet are arranged on the heat medium annular cavity for keeping the Artemisia annua extract in the lower part of the tank body at a constant temperature without the temperature being too low.

[0007] This crystallization tank body, which is provided with both a refrigerant ring cavity and a heat medium ring cavity, can quickly cool the artemisinin extract in the upper part while maintaining a constant temperature of the artemisinin extract in the lower part, thereby reducing the adhesion of impurities to the low-temperature crystals, accelerating the crystallization speed and improving the crystallization recovery rate of the crude artemisinin.

[0008] The refrigerant in the refrigerant ring cavity is chilled water, and its temperature is 5-10°C.

[0009] The heat medium in the heat medium ring cavity is hot water, and its temperature is 60-80°C.

[0010] The crystallization temperature of the artemisinin extract in the crystallization tank is N, 10°C < N < 20°C, and the crystallization time is 6 hours.

[0011] Furthermore, a secondary crystallization step is provided: the secondary crystallization step is to heat the temperature in the crystallization tank, filter the mother liquor, add 5-20L petroleum ether solvent, transfer them to the crystallization tank for secondary crystallization, filter after the crystallization is completed, and obtain the secondary crystallized artemisinin crude product.

[0012] Compared with the prior art, the present invention has the following beneficial effects:

[0013] (1) The crystallization tank body is provided with a cooling medium annular cavity and a heating medium annular cavity, so that the artemisinin extract in the upper part can be cooled quickly while the artemisinin extract in the lower part can be kept at a constant temperature, thereby reducing the adhesion of impurities to the low-temperature crystals, accelerating the crystallization speed and improving the crystallization recovery rate of the crude artemisinin.

[0014] (2) A U-shaped single-layer stirring blade is used, so that the straight horizontal blade at the bottom and the crystallization screen plate installed on the lower shell together form a crystallization space. The crystallization space is located in the middle and lower part of the heat medium ring cavity, which can keep the position at a constant temperature.

[0015] (3) A U-shaped single-layer stirring blade is used, so that the straight vertical blades on both sides are close to the inner wall of the cylindrical shell, which can stir the artemisinin extract more fully.

[0016] (4) Secondary crystallization was carried out using hot and cold crystallization tanks, which further improved the crystallization recovery rate of crude artemisinin.

[0017] (5) The crystallization recovery rate of crude artemisinin can reach more than 98%, and after the crude artemisinin is purified by crystallization, An artemisinin product with a purity of more than 96% can be obtained, and the artemisinin recovery rate reaches more than 97%. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a side perspective structural schematic diagram of the cold and hot crystallization tank in the present invention.

[0019] Figure 2 It is a schematic diagram of the top view of the cold and hot crystallization tank in the present invention.

[0020] Figure 3 It is a schematic diagram of the front structure of the crystallization screen plate in the present invention.

[0021] In the figure: 1. tank body, 2. motor, 3. transmission, 4. rotating shaft, 5. feed port, 6. exhaust port, 7. solvent inlet, 8. stirring blade, 9. crystallization screen plate, 10. drain port, 11. material outlet, 12. refrigerant ring cavity, 13. heat medium ring cavity, 14. support frame, 15. cylindrical shell, 16. upper shell, 17. lower shell, 18. straight horizontal strips, 19. straight vertical strips, 20. refrigerant inlet, 21. refrigerant outlet, 22. heat medium inlet, 23. heat medium outlet. DETAILED DESCRIPTION

[0022] The present invention will be further described below in conjunction with examples. The following examples are intended to illustrate the present invention rather than to further limit the present invention, and should not be used to limit the scope of protection of the present invention.

[0023] Example 1.

[0024] The key of the present invention is to quickly cool down the artemisinin extract in the crystallization tank and keep the crystallization position at a constant temperature. The specific operation method is: a method for increasing the yield of crude artemisinin, comprising:

[0025] S1: Extraction: Dry and crush the Artemisia annua leaves, pass through a 40-mesh sieve to obtain Artemisia annua leaf powder; take 1 kg of Artemisia annua leaf powder and put it into 10-20 L of petroleum ether solvent, place it in a microwave ultrasonic synthesis extractor, and stir and extract in an environment with a microwave frequency of 10-20 GHz, an ultrasonic frequency of 20-25 kHz, and a temperature of 30-40°C.

[0026] S2: Separation: Filter with a filter to obtain an artemisinin extract containing artemisinin.

[0027] S3: Concentration: The artemisinin extract is evaporated and concentrated to obtain artemisinin concentrate.

[0028] S4: Crystallization: The artemisinin concentrate is put into a crystallization tank for crystallization. After the crystallization is completed, the mother liquor and the crude artemisinin are obtained by filtering. This is the key to the present invention. The existing crystallization tank can only be cooled quickly. If the cooling temperature is too low, impurities are easily attached to the crystals. If the cooling temperature is too high, the crystallization speed is slow and the crystallization rate is not high. Therefore, this scheme develops a hot and cold crystallization tank, which allows the upper part of the tank to be cooled quickly and the lower part to maintain the constant temperature required for the crystallization temperature, thereby avoiding impurities and achieving fast and efficient crystallization.

[0029] As shown in the figure, the cold and hot crystallization tank includes a tank body 1 and a support frame 14, the tank body 1 is fixedly installed on the support frame 14, and the tank body 1 is provided with a motor 2, a transmission 3, a rotating shaft 4, a feed port 5, an exhaust port 6, a solvent inlet 7, a stirring blade 8, a crystallization screen plate 9, a drain port 10, a material outlet 11, a refrigerant ring cavity 12 and a heat medium ring cavity 13, the tank body 1 is vertically installed on the support frame 14, the middle part of the tank body 1 is a cylindrical shell 15, and the upper and lower ends of the cylindrical shell 15 are both dome-shaped protruding shells, respectively referred to as an upper shell 16 and a lower shell 17; the rotating shaft 4 passes through the center of the upper shell 16 and is located on the axis line inside the tank body 1, and the upper end of the rotating shaft 4 is installed on the transmission 3, and the transmission The device 3 is installed on the outer surface of the upper shell 16, the transmission device 3 is connected to the motor 2, the motor 2 is installed on a separately arranged bracket, the feed port 5, the exhaust port 6 and the solvent inlet 7 are arranged on the upper shell 16, the stirring blade 8 is installed on the rotating shaft 4 inside the tank body 1, and the existing stirring blades are stirring blades of multiple layers installed at different positions on the rotating shaft, so that the stirring speed is very frequent, which is not conducive to crystallization. Here, the stirring blade 8 is made into a U-shaped single-layer stirring blade, the bottom of the U-shaped single-layer stirring blade is a straight horizontal strip blade 18, and the two sides are straight vertical strip blades 19. The straight horizontal strip blade 18 and the straight vertical strip blade 19 are connected in an arc-shaped transition, and the middle upper surface of the straight horizontal strip blade 18 of the stirring blade 8 is provided with a mounting frame, which is installed The mounting frame is installed on the bottom end of the rotating shaft 4 inside the tank body 1; the crystallization screen plate 9 is a disc plate, which is installed on the lower shell body 17 below the straight horizontal strip leaves 18, so that the straight horizontal strip leaves 18 and the crystallization screen plate 9 together constitute a crystallization space, and the crystallization screen plate 9 and the central part of the lower shell body 17 protruding downward together constitute a filtrate space; the drain port 10 is arranged at the center of the lower shell body 17 for discharging the filtered filtrate, and the material outlet 11 is arranged on the lower shell body 17 between the straight horizontal strip leaves 18 and the crystallization screen plate 9 for discharging crystals; the refrigerant annular cavity 12 is arranged on the outer surface of the lower middle part of the cylindrical shell body 15 in a surrounding and wrapped shape, and the refrigerant annular cavity 12 is provided with a refrigerant inlet 20 and a refrigerant outlet 21, which adjusts the refrigerant liquid temperature The temperature of the artemisinin concentrate is set to 10-20°C, the crystallization time is changed to 6 hours, and then filtered to separate the mother liquor and the crude artemisinin. It has been measured that the method of using the cold and hot crystallization tank crystallization method can produce 2-4% more crude artemisinin from the artemisinin concentrate each time, and the crystallization recovery rate is high.

[0030] Example 2.

[0031] The key of the present invention is to quickly cool down the artemisinin extract in the crystallization tank and keep the crystallization position at a constant temperature. The specific operation method is: a method for increasing the yield of crude artemisinin, comprising:

[0032] S1: Extraction: Dry and crush the Artemisia annua leaves, pass through a 40-mesh sieve to obtain Artemisia annua leaf powder; take 1 kg of Artemisia annua leaf powder and put it into 20-30 L of petroleum ether solvent, place it in a microwave ultrasonic synthesis extractor, and stir and extract in an environment with a microwave frequency of 15-25 GHz, an ultrasonic frequency of 23-28 kHz, and a temperature of 40-50°C.

[0033] S2: Separation: Filter with a filter to obtain an artemisinin extract containing artemisinin.

[0034] S3: Concentration: The artemisinin extract is evaporated and concentrated to obtain artemisinin concentrate.

[0035] S4: Crystallization: The artemisinin concentrate is put into a crystallization tank for crystallization. After the crystallization is completed, the mother liquor and the crude artemisinin are obtained by filtering.

[0036] S5: Secondary crystallization: Heat the temperature in the tank to 25-30°C, filter the mother liquor, add 10-15L petroleum ether solvent, and transfer them to the crystallization tank for secondary crystallization. After the crystallization is completed, filter to obtain the secondary crystallized artemisinin crude product. It has been measured that the secondary crystallization method can crystallize 1-2% more crude artemisinin from the artemisinin concentrate each time.

[0037] Example 3.

[0038] The key of the present invention is to quickly cool down the artemisinin extract in the crystallization tank and keep the crystallization position at a constant temperature. The specific operation method is: a method for increasing the yield of crude artemisinin, comprising:

[0039] S1: Extraction: Dry and crush the Artemisia annua leaves, pass through a 40-mesh sieve to obtain Artemisia annua leaf powder; take 1 kg of Artemisia annua leaf powder and put it into 30-40 L of petroleum ether solvent, place it in a microwave ultrasonic synthesis extractor, and stir and extract in an environment with a microwave frequency of 20-30 GHz, an ultrasonic frequency of 25-30 kHz, and a temperature of 50-60°C.

[0040] S2: Separation: Filter with a filter to obtain an artemisinin extract containing artemisinin.

[0041] S3: Concentration: The artemisinin extract is evaporated and concentrated to obtain artemisinin concentrate.

[0042] S4: Crystallization: The artemisinin concentrate is put into a crystallization tank for crystallization. After the crystallization is completed, the mother liquor and the crude artemisinin are obtained by filtering.

[0043] S5: Secondary crystallization: Heat the temperature in the tank to 25-30°C, filter the mother liquor, add 15-20L petroleum ether solvent, and transfer them to the crystallization tank for secondary crystallization. After the crystallization is completed, filter to obtain the secondary crystallized crude artemisinin.

[0044] According to the measurement, the cold and hot crystallization tank combined with the secondary crystallization method can crystallize 3-6% more crude artemisinin from the artemisinin concentrate each time, and the whole plant can crystallize 2-4kg more crude artemisinin from the artemisinin concentrate every day, and the product quality is qualified. The crystallization recovery rate of crude artemisinin is 98.3%. On this basis, the crude artemisinin is further crystallized and purified, and the purity of the obtained artemisinin product is 98.8%, and the artemisinin recovery rate reaches more than 97%.

Claims

1. A method for increasing the yield of crude artemisinin, comprising: Extraction steps: putting the Artemisia annua leaves into petroleum ether solvent, and extracting by heating, stirring, ultrasonic or microwave; Separation step: filtering or centrifuging to separate liquid from solid to obtain an artemisinin extract containing artemisinin; Concentration step: evaporating and concentrating the artemisinin extract to obtain an artemisinin concentrate; Crystallization step: putting the artemisinin concentrate into a crystallization tank for crystallization, and filtering after the crystallization is completed to obtain a mother liquor and a crude artemisinin product; The crystallization tank is a cold and hot crystallization tank, and the cold and hot crystallization tank comprises a tank body and a support frame, the tank body is fixedly mounted on the support frame, and the tank body is provided with a motor, a transmission, a rotating shaft, a feed port, an exhaust port, a solvent inlet, a stirring blade, a crystallization screen plate, a drain port, a material outlet, a refrigerant ring cavity and a heat medium ring cavity, the tank body is vertically mounted on the support frame, the middle part of the tank body is a cylindrical shell, and the upper and lower ends of the cylindrical shell are both dome-shaped protruding shells, respectively referred to as an upper shell and a lower shell; the rotating shaft passes through the center of the upper shell and is located on the axis line inside the tank body, the upper end of the rotating shaft is mounted on the transmission, and the transmission is mounted on the outer surface of the upper shell, the transmission is connected to the motor, and the motor is mounted on a separately arranged bracket, the feed port, the exhaust port and the solvent inlet are arranged on the upper shell, the stirring blade is mounted on the rotating shaft inside the tank body, and the stirring blade is a U-shaped single-layer stirring blade, the U The bottom of the single-layer stirring blade is a straight horizontal blade, and the two sides are straight vertical blades. The straight horizontal blades and the straight vertical blades are connected in an arc-shaped transition. A mounting frame is provided on the middle upper surface of the straight horizontal blade of the stirring blade, and the mounting frame is installed on the bottom end of the rotating shaft inside the tank body; the crystallization screen plate is a disc plate, which is installed on the lower shell body below the straight horizontal blade, so that the straight horizontal blade and the crystallization screen plate together constitute a crystallization space, and the crystallization screen plate and the central part of the lower shell body protruding downward together constitute a filtrate space; the drain port is arranged at the center of the lower shell body, and the material outlet is arranged on the lower shell body between the straight horizontal blade and the crystallization screen plate; the refrigerant annular cavity is arranged on the outer surface of the middle and lower part of the cylindrical shell body in a surrounding and wrapped shape, and a refrigerant inlet and a refrigerant outlet are provided on the refrigerant annular cavity, and the heat medium annular cavity is arranged on the lower shell body in an annular attachment shape and leaves the central position of the lower shell body, and a heat medium inlet and a heat medium outlet are provided on the heat medium annular cavity.

2. The method for increasing the yield of crude artemisinin according to claim 1, characterized in that The refrigerant in the refrigerant ring cavity is chilled water, and its temperature is 5-10°C.

3. The method for increasing the yield of crude artemisinin according to claim 1, characterized in that The heat medium in the heat medium ring cavity is hot water, and its temperature is 60-80°C.

4. The method for increasing the yield of crude artemisinin according to claim 1, characterized in that The crystallization temperature N of the artemisinin extract in the crystallization tank is 10°C < N < 20°C, and the crystallization time is 6 hours.

5. The method for increasing the yield of crude artemisinin according to claim 1, characterized in that The invention also includes a secondary crystallization step: the secondary crystallization step is to heat the temperature in the cold and hot crystallization tanks, then filter the mother liquor, add 5-20L petroleum ether solvent, transfer them to the crystallization tank for secondary crystallization, filter after the crystallization is completed, and obtain the secondary crystallized artemisinin crude product.

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