Microwave-enhanced liquid-liquid heterogeneous extraction device

Abstract

The invention discloses a microwave enhanced liquid-liquid heterogeneous extraction device which comprises a microwave cavity and an extraction tube nest arranged in the microwave cavity, and the extraction tube nest is divided into three parts from top to bottom, namely a light phase layering area, a filler area and a heavy phase layering area in sequence; a light phase outlet in the top of the light phase layering area and a heavy phase inlet in the middle of the light phase layering area are connected with a light phase discharging pipe and a heavy phase feeding pipe through pipelines respectively, a light phase inlet is formed between the filler area and the heavy phase layering area and connected with the light phase feeding pipe through a pipeline, and a heavy phase outlet in the bottom of the heavy phase layering area is connected with the heavy phase discharging pipe through a pipeline. According to the extraction device disclosed by the invention, by utilizing the selective heating characteristic of microwaves, the microwave action range of the materials is increased and the heat and mass transfer among liquid-liquid heterogeneous systems is accelerated by dividing the materials to be separated in a tube array form and arranging the filler in the tube array, and the extraction efficiency is improved by utilizing the coalescence effect of the microwaves on liquid drops in the liquid-liquid heterogeneous systems. The liquid-liquid heterogeneous layering process is enhanced, and the extraction efficiency is improved.

Description

Technical Field

[0001] The invention relates to the field of liquid-liquid heterogeneous extraction, and in particular to a microwave-enhanced liquid-liquid heterogeneous extraction device. Background Art

[0002] Extraction is a common separation and purification technology, widely used in chemistry, chemical industry, pharmaceuticals, food, environmental science and other fields. It uses the difference in solubility of substances in different solvents to separate the target substance from the mixture. The extraction tower is a device that realizes multi-stage extraction. Common extraction towers include the following types: such as packed extraction tower, sieve plate extraction tower, rotary disk extraction tower, pulsating extraction tower, etc.

[0003] Traditional extraction towers break liquid into droplets by adding external energy (pulses, stirring, etc.) or changing structures (such as sieve plates, fillers, etc.), thereby achieving full contact between the two phases and improving separation efficiency. However, for low interfacial tension extraction systems, the introduction of pulse energy with strong drag or stirring energy with strong shear force can easily cause over-crushing or even emulsification of dispersed phase droplets (CN118389825A); fillers play an important role in the extraction process, but when the density difference between the two phases is relatively small and the viscosity of the continuous phase is relatively large, the axial backmixing in the packed extraction tower is very serious, especially the axial backmixing of the continuous phase, which not only restricts the production capacity of the extraction tower, but also seriously affects the separation efficiency of the extraction tower (CN102698465A). Summary of the invention

[0004] In view of the above technical problems existing in the prior art, the object of the present invention is to provide a microwave enhanced liquid-liquid heterogeneous extraction device. The device of the present invention shortens the sedimentation time between liquid-liquid heterogeneous phases, enhances mass transfer efficiency, and improves extraction efficiency through efficient energy transfer of microwave field.

[0005] The technical solution adopted by the present invention is as follows: A microwave enhanced liquid-liquid heterogeneous extraction device comprises a microwave cavity and an extraction tube array arranged in the microwave cavity, wherein the extraction tube array is divided into three parts from top to bottom, namely a light phase stratification zone, a packing zone and a heavy phase stratification zone in sequence; a light phase outlet at the top of the light phase stratification zone and a heavy phase inlet in the middle are respectively connected to a light phase discharge pipe and a heavy phase feed pipe by pipelines, a light phase inlet is arranged between the packing zone and the heavy phase stratification zone and is connected to the light phase feed pipe by pipeline, and a heavy phase outlet at the bottom of the heavy phase stratification zone is connected to the heavy phase discharge pipe by pipeline.

[0006] Furthermore, the material of the filler in the filler zone is ceramic or glass, and the material of the extraction tubes is quartz.

[0007] Furthermore, a waveguide and a temperature sensor are provided on the microwave cavity. There are at least two waveguides disposed on opposite sides of the microwave cavity. The waveguide is connected to a microwave generator. The microwave generated by the microwave generator enters the microwave cavity through the waveguide.

[0008] Furthermore, the radius of the extraction tubes is not greater than the penetration depth of the microwaves generated by the microwave generator into the light phase solution or the heavy phase solution in the extraction tubes.

[0009] Furthermore, the number of the extraction tubes is at least 2, and a first intelligent liquid stratification instrument for monitoring the state of the light phase after stratification is arranged on the upper part of the light phase stratification zone of the extraction tubes. A heavy phase inlet in the middle of the light phase stratification zone is connected to a heavy phase diversion pipe, which passes through the microwave cavity and then merges with the main pipe and is connected to the heavy phase feed pipe. A first solenoid valve is arranged on the heavy phase diversion pipe, and the first solenoid valve is connected to the first intelligent liquid stratification instrument signal through a PLC control system. The liquid separation state signal monitored by the first intelligent liquid stratification instrument is transmitted to the PLC control system, and then the flow rate of the input heavy phase solution is regulated by adjusting the opening of the first solenoid valve.

[0010] Furthermore, the number of the extraction tubes is at least 2, and a second intelligent liquid stratification instrument for monitoring the status after heavy phase stratification is arranged at the lower part of the heavy phase stratification zone of the extraction tubes. The light phase inlet on the extraction tubes is connected to a light phase diversion pipe, which passes through the microwave cavity and then merges with the main pipe and is connected to the light phase feed pipe. A second solenoid valve is arranged on the light phase diversion pipe, and the second solenoid valve is connected to the second intelligent liquid stratification instrument signal through a PLC control system. The liquid separation status signal monitored by the second intelligent liquid stratification instrument is transmitted to the PLC control system, and then the flow rate of the input light phase solution is regulated by adjusting the opening of the second solenoid valve.

[0011] Furthermore, the light phase discharge pipe, heavy phase feed pipe, light phase feed pipe, and heavy phase discharge pipe are all provided with flow meters and valves.

[0012] Furthermore, the microwave cavity is provided with pipeline through holes so that corresponding pipelines can penetrate into the microwave cavity and be connected with the light phase outlet, heavy phase inlet, light phase inlet and heavy phase outlet on the extraction tube array respectively.

[0013] Compared with the prior art, the present invention has the following beneficial effects: The present invention divides the materials to be separated in the form of tube arrays to increase the microwave action volume, increase the heat exchange area, make microwave heating more uniform, and improve the heat transfer rate; built-in fillers in the tube arrays promote the droplet breakup, aggregation and re-breakup process of the liquid-liquid heterogeneous system, increase the mass transfer and microwave action area between the liquid-liquid heterogeneous system, and improve the liquid-liquid extraction efficiency; the selective heating characteristics of microwaves are utilized to strengthen the heating of liquids with strong polarity in the heterogeneous liquid-liquid system, reduce the viscosity of the droplets, strengthen the aggregation of the droplets, and accelerate the sedimentation and stratification of the heterogeneous liquid-liquid system. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic structural diagram of a microwave-enhanced liquid-liquid heterogeneous extraction device of the present invention; Figure 2 This is a schematic diagram of the structure of a single extraction tube in the present application; Figure markings: 1-microwave cavity, 2-light phase discharge pipe, 3-extraction tube array, 31-light phase stratification area, 32-filling area, 33-heavy phase stratification area, 34-light phase outlet, 35-heavy phase outlet, 36-light phase inlet, 37-heavy phase inlet, 4-temperature sensor, 5-heavy phase feed pipe, 61-first intelligent liquid stratifier, 62-second intelligent liquid stratifier, 7-light phase feed pipe, 8-heavy phase discharge pipe, 10-waveguide. DETAILED DESCRIPTION

[0015] The present invention will be further described below in conjunction with specific embodiments, but the protection scope of the present invention is not limited thereto.

[0016] Example: Control Figure 1-Figure 2 A microwave enhanced liquid-liquid heterogeneous extraction device comprises a microwave cavity 1 and an extraction tube array 3 arranged in the microwave cavity 1, wherein the extraction tube array 3 is divided into three parts from top to bottom, namely a light phase stratification zone 31, a packing zone 32 and a heavy phase stratification zone 33. A light phase outlet 34 at the top of the light phase stratification zone 31 and a heavy phase inlet 37 in the middle are respectively connected to a light phase discharge pipe 2 and a heavy phase feed pipe 5 by pipelines, a light phase inlet 36 is arranged between the packing zone 32 and the heavy phase stratification zone 33 and is connected to a light phase feed pipe 7 by a pipeline, and a heavy phase outlet 35 at the bottom of the heavy phase stratification zone 33 is connected to a heavy phase discharge pipe 8 by a pipeline.

[0017] The material of the filler in the filler area 32 is a wave-transmitting material such as ceramic or glass, and the material of the extraction tube array 3 is quartz.

[0018] Comparison Figure 1 In the figure, a waveguide 10 and a temperature sensor 4 are provided on the microwave cavity 1. There are at least two waveguides 10 disposed on opposite sides of the microwave cavity 1. The waveguide 10 is connected to a microwave generating device. The microwave generated by the microwave generating device enters the microwave cavity 1 through the waveguide 10.

[0019] Comparison Figure 1 In the embodiment, the number of the extraction tubes 3 is at least 2. The radius of each extraction tube 3 is not greater than the penetration depth of the microwave generated by the microwave generator into the light phase solution or the heavy phase solution in the extraction tube 3. By increasing the number of the extraction tubes 3 and reducing the inner diameter of the extraction tubes 3, the liquid separation effect under the action of microwaves can be significantly improved.

[0020] A first intelligent liquid stratification instrument 61 for monitoring the state of the light phase after stratification is arranged on the upper part of the light phase stratification zone 31 of the extraction tube array 3. The heavy phase inlet 37 in the middle of the light phase stratification zone 31 is connected to a heavy phase diversion pipe, which passes through the microwave cavity 1 and is merged into the main pipe and then connected to the heavy phase feed pipe 5. A first solenoid valve is arranged on the heavy phase diversion pipe, and the first solenoid valve is connected to the first intelligent liquid stratification instrument 61 through a PLC control system. The liquid separation state signal monitored by the first intelligent liquid stratification instrument 61 is transmitted to the PLC control system, and then the flow rate of the input heavy phase solution is regulated by adjusting the opening of the first solenoid valve.

[0021] A second intelligent liquid stratification instrument 62 for monitoring the status after heavy phase stratification is arranged at the lower part of the heavy phase stratification zone 33 of the extraction tube array 3. The light phase inlet 36 on the extraction tube array 3 is connected to a light phase shunt pipe, which passes through the microwave cavity 1 and is merged into the main pipe and then connected to the light phase feed pipe 7. A second solenoid valve is arranged on the light phase shunt pipe, and the second solenoid valve is connected to the second intelligent liquid stratification instrument 62 through a PLC control system. The liquid separation status signal monitored by the second intelligent liquid stratification instrument 62 is transmitted to the PLC control system, and then the flow rate of the input light phase solution is regulated by adjusting the opening of the second solenoid valve.

[0022] In the present invention, both the first intelligent liquid stratification instrument 61 and the second intelligent liquid stratification instrument 62 can adopt commercially available intelligent liquid stratification instruments, and their detection principle is: the response values ​​of conductivity, capacitance, inductance and impedance are compounded and output as a numerical value of 0-100, and the difference in physical properties of light components and heavy components is used to realize interface detection, which can reflect the stratification effect of light components and heavy components.

[0023] The light phase discharge pipe 2, the heavy phase feed pipe 5, the light phase feed pipe 7 and the heavy phase discharge pipe 8 are all provided with flow meters and valves.

[0024] Comparison Figure 1 In the embodiment, the microwave cavity 1 is provided with pipeline through holes so that the corresponding pipelines penetrate into the microwave cavity 1 and are respectively connected with the light phase outlet 34, the heavy phase inlet 37, the light phase inlet 36 and the heavy phase outlet 35 on the extraction tube array 3.

[0025] Application Implementation Case Will be like Figure 1The microwave-enhanced liquid-liquid heterogeneous extraction device shown is used in the process of removing homogeneous catalysts in the preparation of ricinoleic acid methyl ester. Castor oil and methanol react for 1 hour under the catalytic action of the homogeneous catalyst KOH. After removing methanol and glycerol, a raw material liquid 1 to be extracted is obtained. The raw material liquid 1 mainly contains ricinoleic acid methyl ester, glycerol and KOH. In terms of mass percentage, the raw material liquid 1 contains 5% glycerol and 0.03% KOH.

[0026] In order to remove KOH, pure glycerol was used as an extractant to extract KOH from the raw material solution 1, thereby achieving efficient removal of KOH and rapid separation of methyl ester and glycerol during the preparation of ricinoleic acid methyl ester. The following application examples 1 to 3 all performed extraction treatment on the raw material solution 1.

[0027] Application Example 1: A glass extraction tube with a tube radius of 10 cm and a tube length of 20 cm is placed in the microwave cavity of the microwave enhanced liquid-liquid heterogeneous extraction device. No filler is placed in the packing area of ​​the extraction tube. First, the extraction tube is filled with raw liquid 1, and then the microwave generator (microwave frequency is 2450 MHz) is turned on. The microwave generated by the microwave generator enters the microwave cavity through the waveguide, and the material in the extraction tube is heated by microwave radiation, and the liquid temperature in the extraction tube is controlled at 40°C. The raw liquid 1 is pumped into the light phase feed pipe 7, and the pure glycerol is pumped into the heavy phase feed pipe 5. The flow rate of the light phase into the extraction tube is 10 ml / min, and the volume flow ratio of the light phase and the heavy phase feed is 10:1. After countercurrent and stratification, the raffinate is obtained from the heavy phase discharge pipe 9, and the product is obtained from the light phase discharge pipe 2.

[0028] According to the above method, samples were taken at 2 locations of the light phase discharge pipe after running for 20 minutes. After titration analysis, the KOH content in the product was 0.03%, and the glycerol content was 5%; the second sample was taken after running for 40 minutes. After titration analysis, the KOH content in the product was 0.01%, and the glycerol content was 3%; the third sample was taken after running for 60 minutes. After analysis, the KOH content in the product was 0.002%, and the glycerol content was 2.5%; the fourth sample was taken after running for 80 minutes. After analysis, the KOH content in the product was 10 ppm, and the glycerol content was 2%; subsequent sampling and analysis showed that the product content was basically stable.

[0029] Application Example 2: A glass extraction tube with a tube radius of 10 cm and a tube length of 20 cm is placed in the microwave cavity of the microwave enhanced liquid-liquid heterogeneous extraction device. Ceramic Raschig ring fillers are placed in the packing area of ​​the extraction tube. First, the extraction tube is filled with raw liquid 1, and then the microwave generator (microwave frequency is 2450 MHz) is turned on. The microwave generated by the microwave generator enters the microwave cavity through the waveguide, and the material in the extraction tube is heated by microwave radiation, and the liquid temperature in the extraction tube is controlled at 40°C. The raw liquid 1 is pumped into the light phase feed pipe 7, and the pure glycerol is pumped into the heavy phase feed pipe 5. The flow rate of the light phase into the extraction tube is 10 ml / min, and the volume flow ratio of the light phase and the heavy phase feed is 10:1. After countercurrent and stratification, the raffinate is obtained from the heavy phase discharge pipe 9, and the product is obtained from the light phase discharge pipe 2.

[0030] According to the above method, samples were taken at 2 locations of the light phase discharge pipe after running for 20 minutes. After titration analysis, the KOH content in the product was 0.01%, and the glycerol content was 4.5%; the second sample was taken after running for 40 minutes. After titration analysis, the KOH content in the product was 0.003%, and the glycerol content was 3%; the third sample was taken after running for 60 minutes. After analysis, the KOH content in the product was 8ppm, and the glycerol content was 2%; subsequent sampling and analysis showed that the product content was basically stable.

[0031] Application Example 3: Two glass extraction tubes with a tube radius of 5 cm and a tube length of 20 cm were placed in the microwave cavity of the microwave enhanced liquid-liquid heterogeneous extraction device. The tube diameter was determined according to the penetration depth of 2450 MHz microwaves in each material. Ceramic Raschig ring fillers were placed in the packing area of ​​the extraction tube. First, the extraction tube was filled with raw liquid 1, and then the microwave generator (microwave frequency was 2450 MHz) was turned on. The microwave generated by the microwave generator entered the microwave cavity through the waveguide, and the material in the extraction tube was heated by microwave radiation, and the liquid temperature in the extraction tube was controlled at 40°C. The raw material liquid is pumped into the light phase feed pipe 7 and then split into two extraction tubes. The pure glycerol is pumped into the heavy phase feed pipe 5 and then split into two extraction tubes. The flow rate of the light phase entering the two extraction tubes is 5 ml / min. The volume flow ratio of the light phase and the heavy phase feed is 10:1. After the material is split in the two extraction tubes, it is countercurrent and stratified to obtain the raffinate from the heavy phase discharge pipe 9, and the product is obtained from the light phase discharge pipe 2.

[0032] According to the above method, samples were taken at 2 locations of the light phase discharge pipe after running for 20 minutes. After titration analysis, the KOH content in the product was 0.003%, and the glycerol content was 3%; samples were taken for the second time after running for 40 minutes. After titration analysis, the KOH content in the product was 0.001%, and the glycerol content was 2%; samples were taken for the third time after running for 60 minutes. After analysis, the KOH content in the product was 4ppm, and the glycerol content was 2%; subsequent sampling and analysis showed that the product content was basically stable.

[0033] The contents described in this specification are merely an enumeration of implementation forms of the inventive concept, and the protection scope of the present invention should not be regarded as being limited to the specific forms described in the embodiments.

Claims

1. A microwave-enhanced liquid-liquid heterogeneous extraction device, characterized in that: The invention comprises a microwave cavity (1) and an extraction tube array (3) arranged in the microwave cavity (1), wherein the extraction tube array (3) is divided into three parts from top to bottom, namely a light phase stratification zone (31), a packing zone (32) and a heavy phase stratification zone (33); a light phase outlet (34) at the top of the light phase stratification zone (31) and a heavy phase inlet (37) in the middle are respectively connected to a light phase discharge pipe (2) and a heavy phase feed pipe (5) by pipelines; a light phase inlet (36) is arranged between the packing zone (32) and the heavy phase stratification zone (33) and is connected to the light phase feed pipe (7) by pipelines; and a heavy phase outlet (35) at the bottom of the heavy phase stratification zone (33) is connected to a heavy phase discharge pipe (8) by pipelines.

2. The microwave enhanced liquid-liquid heterogeneous extraction device according to claim 1, characterized in that: The material of the filler in the filler area (32) is ceramic or glass, and the material of the extraction tube array (3) is quartz.

3. The microwave enhanced liquid-liquid heterogeneous extraction device according to claim 1, characterized in that: A waveguide (10) and a temperature sensor (4) are provided on the microwave cavity (1); the number of the waveguides (10) is at least two and they are arranged on two opposite sides of the microwave cavity (1); the waveguide (10) is connected to a microwave generating device; microwaves generated by the microwave generating device enter the microwave cavity (1) through the waveguide (10).

4. The microwave enhanced liquid-liquid heterogeneous extraction device according to claim 1, characterized in that: The radius of the extraction tube array (3) is no greater than the penetration depth of the microwaves generated by the microwave generating device into the light phase solution or the heavy phase solution in the extraction tube array (3).

5. The microwave enhanced liquid-liquid heterogeneous extraction device according to claim 1, characterized in that: The number of the extraction tube array (3) is at least 2. A first intelligent liquid stratification instrument (61) for monitoring the state of the light phase after stratification is arranged on the upper part of the light phase stratification zone (31) of the extraction tube array (3). A heavy phase inlet (37) in the middle of the light phase stratification zone (31) is connected to a heavy phase diverter pipe. The heavy phase diverter pipe passes through the microwave cavity (1) and then merges with the main pipe and is connected to the heavy phase feed pipe (5). A first solenoid valve is arranged on the heavy phase diverter pipe. The first solenoid valve is connected to the first intelligent liquid stratification instrument (61) through a PLC control system. The liquid separation state signal monitored by the first intelligent liquid stratification instrument (61) is transmitted to the PLC control system, and then the flow rate of the input heavy phase solution is regulated by regulating the opening of the first solenoid valve.

6. The microwave enhanced liquid-liquid heterogeneous extraction device according to claim 1, characterized in that: The number of the extraction tubes (3) is at least 2. A second intelligent liquid stratification instrument (62) for monitoring the status of the heavy phase after stratification is provided at the lower part of the heavy phase stratification zone (33) of the extraction tubes (3). The light phase inlet (36) on the extraction tubes (3) is connected to a light phase diversion pipe. The light phase diversion pipe passes through the microwave cavity (1) and then merges with the main pipe and is connected to the light phase feed pipe (7). A second electromagnetic valve is provided on the light phase diversion pipe, and the second electromagnetic valve is connected to the second intelligent liquid stratification instrument (62) through a PLC control system. The liquid separation status signal monitored by the second intelligent liquid stratification instrument (62) is transmitted to the PLC control system, and then the flow rate of the input light phase solution is regulated by regulating the opening of the second electromagnetic valve.

7. The microwave enhanced liquid-liquid heterogeneous extraction device according to claim 1, characterized in that: The light phase discharge pipe (2), the heavy phase feed pipe (5), the light phase feed pipe (7), and the heavy phase discharge pipe (8) are all provided with flow meters and valves.

8. The microwave enhanced liquid-liquid heterogeneous extraction device according to claim 1, characterized in that: The microwave cavity (1) is provided with a pipeline through hole so that a corresponding pipeline can penetrate into the microwave cavity (1) and be respectively connected to the light phase outlet (34), the heavy phase inlet (37), the light phase inlet (36) and the heavy phase outlet (35) on the extraction tube array (3).

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