An oscillating flow device and process for improving liquid-liquid extraction efficiency

Abstract

This invention relates to an oscillating flow device and process for improving liquid-liquid extraction efficiency. The oscillating flow device for improving liquid-liquid extraction efficiency is characterized by comprising, in sequence, a first container for holding a first solution, a first feeding device, a first tee, a sleeve-type reactor, a second tee, and a first collection tank, connected by pipelines. The sleeve-type reactor consists of a hollow fiber membrane inner tube, an outer tube, and a spiral internal component disposed between the inner and outer tubes. Both ends of the outer tube are connected to the second port of the first tee and the first port of the second tee, respectively. The first pipeline near the output end of the first feeding device is connected to the first port of the first tee and extends into the first tee. The extended end of the first pipeline extends to the second port of the first tee and is connected to the first end of the hollow fiber membrane inner tube. This oscillating flow device and process for improving liquid-liquid extraction efficiency utilizes a lower oscillation intensity to enhance the radial mixing effect of the fluid in the outer tube, reduce the concentration gradient difference, and improve the extraction efficiency.

Description

Technical Field

[0001] This invention belongs to the field of reactor technology, specifically relating to an oscillating flow device and process for improving liquid-liquid extraction efficiency. Background Technology

[0002] Liquid-liquid extraction is one of the most common operations in chemical processes. It utilizes the difference in solubility of a solute in two solvent phases to achieve the enrichment and separation of the solute between the two phases. That is, it is a method that uses the difference in solubility or partition coefficient of a substance in two immiscible (or slightly soluble) solvents to transfer the solute from one solvent to another, thereby achieving the purpose of separation.

[0003] Shell-and-tube reactors offer numerous advantages in liquid-liquid extraction processes, such as small size, high mass transfer efficiency, and fast reaction rates, making them a growing research and application focus. Liquid-liquid extraction in shell-and-tube reactors enables more efficient mass transfer and reaction process control, contributing to improved product purity and yield. The compact design of shell-and-tube reactors, with their high specific surface area and excellent mass transfer characteristics, facilitates thorough mixing and contact between the liquid phases, thereby accelerating the mass transfer rate and reaction speed. Furthermore, shell-and-tube reactors allow for flexible control of operating conditions, such as temperature, pressure, and flow rate, enabling precise control and optimization of the extraction process. Liquid-liquid extraction in shell-and-tube reactors not only reduces reactant consumption and waste generation but also improves product quality and reduces energy consumption, demonstrating significant engineering application potential. Therefore, the application of shell-and-tube reactors in liquid-liquid extraction has broad development prospects and is expected to bring more innovation and breakthroughs to chemical production and laboratory research.

[0004] For example, the Chinese patent "A Method for Continuous Extraction of Epichlorohydrin" (publication number CN104072446B) was found, which includes: (1) feeding the liquid to be extracted into the extraction system from any one or more of the extraction devices; feeding extractant A and extractant B into the extraction system from the inlet of the first extraction device and the inlet of the nth extraction device of the extraction system, respectively, and extracting them in contact with the liquid to be extracted; (2) making the flow direction of extractant A sequentially from the first extraction device to the nth extraction device, and making the flow direction of extractant B sequentially from the nth extraction device to the first extraction device, thereby obtaining raffinate from the outlet of the nth extraction device and extractant from the outlet of the first extraction device. This invention can efficiently and continuously extract and separate epichlorohydrin and methanol, but its structure is complex and the extraction rate is low. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of the prior art by providing an oscillating flow device and process for improving liquid-liquid extraction efficiency. This oscillating flow device and process for improving liquid-liquid extraction efficiency utilizes a lower oscillation intensity to enhance the radial mixing effect of the fluid in the outer tube, reduce the concentration gradient difference, and improve the extraction efficiency.

[0006] The solution adopted by this invention to solve the technical problem is as follows:

[0007] The present invention provides an oscillating flow device for improving the efficiency of liquid-liquid extraction, characterized in that it comprises, in sequence, a first container for holding a first solution, a first feeding device, a first tee, a sleeve reactor, a second tee, and a first collection tank connected by pipelines.

[0008] The shell-and-tube reactor consists of an inner tube, an outer tube, and an internal component located between the inner and outer tubes. The two ends of the outer tube are respectively connected to the second port of the first tee and the first port of the second tee.

[0009] The first pipe near the output end of the first feeding device is connected to the first port of the first tee and extends into the first tee. The extension end of the first pipe extends to the second port of the first tee and is connected to the first end of the inner pipe.

[0010] The second pipe near the first collection tank is connected to the second port of the second tee and extends into the second tee. The end of the second pipe extends to the first port of the second tee and is connected to the second end of the inner pipe.

[0011] The third port of the first three-way valve is connected to the second collection tank; the third port of the second three-way valve is connected in sequence to the oscillation device, the back pressure valve, the pressure sensor, the second feeding device, and the second container for holding the second solution through a pipeline;

[0012] The space between the inner and outer tubes of the shell-and-tube reactor is connected to the third port of the first tee and the third port of the second tee.

[0013] Preferably, the first feeding device and the second feeding device are horizontal flow pumps.

[0014] Preferably, the above-mentioned oscillation device is a pulse pump.

[0015] Preferably, the first solution is an organic phase solution and the second solution is an aqueous phase solution.

[0016] Preferably, the first collecting tank is an organic phase solution collecting tank, and the second collecting tank is an aqueous phase solution collecting tank.

[0017] Preferably, the outer tube is a transparent circular tube with a constant diameter and an inner diameter of 1-10 mm; the inner tube is a hollow fiber membrane tube, a membrane tube with micropores, or a hollow tube formed by porous media, with an inner diameter of 0.5-1 mm, and the inner component is a spiral inner component.

[0018] Preferably, the aforementioned spiral internal component is in the form of a single spiral, double spiral, or multiple spirals.

[0019] Preferably, when the oscillation amplitude of the above-mentioned oscillation device is 0-20 mm, the oscillation frequency is 0-3 Hz.

[0020] The present invention describes a liquid-liquid extraction process using the aforementioned oscillating flow device, characterized in that:

[0021] The first step is to prepare an aqueous phase solution of a certain concentration for the experiment and place it in the second container, and to prepare an organic phase solution of a certain concentration for the experiment and place it in the first container.

[0022] The second step is to set the flow rate of the first and second feeding devices to 0.03-0.3 mL / min, the oscillation frequency of the oscillation device to 0-3 Hz, the amplitude to 1-10 mm, the back pressure valve pressure to 10 kPa, and then turn on the oscillation device.

[0023] The third step is to take a certain volume of aqueous effluent from the second collection tank after the extraction has stabilized, dilute it, measure the absorbance, and calculate the extraction rate and the overall mass transfer coefficient.

[0024] In existing technologies, the radial mixing effect and extraction rate of liquid-liquid extraction using a shell-and-tube reactor are poor. The oscillating flow device of this invention, which improves the efficiency of liquid-liquid extraction, has a simple structure and low cost. Under oscillation conditions, it can induce strong disturbances. It can improve the radial mixing effect of the fluid in the outer tube and significantly improve the liquid-liquid extraction efficiency even at a low oscillation intensity. At the same time, no phase separation step is required after liquid-liquid extraction, and the extraction rate is significantly improved. It has important research and application significance. Attached Figure Description

[0025] The present invention will be further described below with reference to the accompanying drawings.

[0026] Figure 1 This is a schematic diagram of one embodiment of the oscillating flow sleeve reactor of the present invention;

[0027] Figure 2 This is a schematic diagram of the overall structure of a shell-and-tube reactor;

[0028] Figure 3 This is a table of experimental results in the reactor under different flow rates and oscillation conditions.

[0029] In the diagram: 1-Reactor body; 101-Transparent outer tube; 102-Hollow fiber membrane inner tube; 103-Spiral inner component; 2-First container (for containing organic phase solution); 3-Second container (for containing aqueous phase solution); 401-First feed device; 402-Second feed device; 5-Pressure sensor; 6-Back pressure valve; 7-Oscillating device (specifically a pulse pump); 8-Pressure sensor; 13-Second collection tank (aqueous phase solution collection tank); 10-First collection tank (organic phase solution collection tank). Detailed Implementation

[0030] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0031] The present invention provides an oscillating flow device for improving the efficiency of liquid-liquid extraction, comprising a first container 2 for holding a first solution (which may be an organic phase solution), a first feeding device 401, a first three-way valve 8, a sleeve reactor 1, a second three-way valve 9, and a first collection tank 10, which are connected in sequence by pipelines.

[0032] The sleeve-type reactor 1 is composed of a hollow fiber membrane inner tube 102, an outer tube 101, and a spiral inner component 103 disposed between the hollow fiber membrane inner tube and the outer tube. The outer surface of the spiral inner component 103 is attached to the inner surface of the outer tube. The two ends of the outer tube 101 are respectively connected to and sealed to the second port 8B of the first tee 8 and the first port 9A of the second tee 9.

[0033] The first pipe 11, which is close to the output end of the first feeding device 401, is connected to the first port 8A of the first tee 8 and extends into the first tee (the contact position between the first pipe 11 and the first port 8A is sealed). The extension end of the first pipe 11 extends to the second port 8B of the first tee 8 and is connected to the first end of the hollow fiber membrane inner tube 102.

[0034] The second pipe 12, which is close to the first collection tank, is connected to the second port 9B of the second tee 9 and extends into the second tee (the contact position between the second pipe 12 and the second port 9B is sealed). The extension end of the second pipe 12 extends to the first port 9A of the second tee 9 and is connected to the second end of the hollow fiber membrane inner tube.

[0035] The third port 8C of the first three-way valve 8 is connected to the second collection tank 13, and the third port 9C of the second three-way valve 9 is connected in sequence to the oscillation device 7, the back pressure valve 6, the pressure sensor 5, the second feeding device 402 and the second container 3 for holding the second solution through the pipeline;

[0036] The space between the inner and outer tubes of the hollow fiber membrane in the sleeve reactor is connected to the third port 8C of the first tee 8 and the third port 9C of the second tee 9.

[0037] During operation, the aqueous phase solution in the second container flows into the second collection tank 13 after passing through the second feeding device 402, pressure sensor 5, back pressure valve 6, oscillation device 7, second three-way valve 9, sleeve reactor 1, and first three-way valve 8 in sequence; the organic phase solution in the first container flows into the first collection tank 10 after passing through the first feeding device 401, first pipeline 11, first three-way valve 8, hollow fiber membrane inner tube 102, and second pipeline 12 in sequence. During this process, substances in the aqueous phase solution are extracted through the hollow fiber membrane inner tube 102.

[0038] The first feeding device 401 and the second feeding device 402 are parallel flow pumps; the above-mentioned oscillation device is a pulse pump. When the oscillation amplitude of the oscillation device is 0mm-20mm, the oscillation frequency is 0-3Hz. The oscillation device is used to generate regular oscillations of fluid with variable frequency and amplitude, thereby triggering oscillating flow; the back pressure valve can ensure that the operation of the pulse pump does not affect the flow rate of the parallel flow pump, thus improving the accuracy of the data.

[0039] The first solution is an organic phase solution, and the second solution is an aqueous phase solution; the first collection tank is an organic phase solution collection tank, and the second collection tank is an aqueous phase solution collection tank.

[0040] The outer tube is a transparent circular tube with a constant diameter and an inner diameter of 1-10 mm; the inner tube is a hollow fiber membrane tube, a membrane tube filled with micropores, or a hollow tube formed by porous media, preferably a hollow fiber membrane tube (the hollow fiber membrane tube serves as the site of the extraction reaction, i.e., after the organic phase solution fills the membrane pores of the hollow fiber membrane tube, the aqueous phase solution comes into contact with the organic phase solution in the membrane pores and extraction occurs. The biggest advantage of using a hollow fiber membrane tube for extraction is that no phase separation step is required after extraction. In the following embodiments, the hollow fiber membrane tube can extract phenol from phenol-aqueous solution), and it has an inner diameter of 0.5-1 mm. The inner component is a spiral inner component.

[0041] The aforementioned helical internal components can be in the form of a single helix, double helix, or multiple helixes; the helical internal components have a wire diameter of 0.1-0.4 mm and a turn pitch of 0.7-3 mm.

[0042] In existing technologies, the radial mixing effect and extraction rate of liquid-liquid extraction using a shell-and-tube reactor are poor. The oscillating flow device of this invention, which improves the efficiency of liquid-liquid extraction, has a simple structure and low cost, and can induce strong disturbances under oscillation conditions. It can not only improve the radial mixing effect of the fluid in the outer tube at a low oscillation intensity, but also significantly improve the liquid-liquid extraction efficiency, which has important research and application significance.

[0043] The following is a specific embodiment of an experiment using the oscillating flow device of the present invention to improve the efficiency of liquid-liquid extraction:

[0044] Example 1:

[0045] The first step is to prepare a phenol-water solution of a certain concentration as the aqueous phase solution for the experiment (contained in the second container 3), and a tributyl phosphate-kerosene solution of a certain concentration (contained in the first container 2) as the organic phase solution for the experiment.

[0046] The second step is to set the flow rate of the two parallel flow pumps to 0.05 mL / min, the oscillation frequency of the oscillation device to 2 Hz, the amplitude to 3 mm, the back pressure valve pressure to 10 kPa, and then turn on the oscillation device.

[0047] The third step is to take a certain volume of aqueous effluent from the second collection tank after the extraction has reached stability, dilute it, measure the absorbance, and calculate the extraction rate and the overall mass transfer coefficient.

[0048] Data analysis revealed that the extraction rate was 0.85% and the overall mass transfer coefficient was 1.28 × 10⁻⁶. -6 .

[0049] Example 2:

[0050] The first step is the same as in Example 1;

[0051] The second step is to set the flow rate of the two parallel flow pumps to 0.05 mL / min, the oscillation frequency of the oscillation device to 2 Hz, the amplitude to 7 mm, the back pressure valve pressure to 10 kPa, and then turn on the oscillation device.

[0052] The third step is to take a certain volume of aqueous effluent from the second collection tank after the extraction has reached stability, dilute it, measure the absorbance, and calculate the extraction rate and the overall mass transfer coefficient.

[0053] After data processing and analysis, the extraction rate was 0.87 and the overall mass transfer coefficient was 1.35 × 10⁻⁶. -6 .

[0054] Example 3:

[0055] The first step is the same as in Example 1;

[0056] The second step is to set the flow rate of the two parallel flow pumps to 0.2 mL / min, the oscillation frequency of the oscillation device to 2 Hz, the amplitude to 3 mm, the back pressure valve pressure to 10 kPa, and then turn on the oscillation device.

[0057] The third step is to take a certain volume of aqueous effluent from the second collection tank after the extraction has reached stability, dilute it, measure the absorbance, and calculate the extraction rate and the overall mass transfer coefficient.

[0058] After data processing and analysis, the extraction rate was 0.37 and the overall mass transfer coefficient was 1.13 × 10⁻⁶. -6 .

[0059] Example 4:

[0060] The first step is the same as in Example 1;

[0061] The second step is to set the flow rate of the two parallel flow pumps to 0.2 mL / min, the oscillation frequency of the oscillation device to 2 Hz, the amplitude to 3 mm, the back pressure valve pressure to 10 kPa, and then turn on the oscillation device.

[0062] The third step is to take a certain volume of aqueous effluent from the second collection tank after the extraction has reached stability, dilute it, measure the absorbance, and calculate the extraction rate and the overall mass transfer coefficient.

[0063] After data processing and analysis, the extraction rate was 0.41 and the overall mass transfer coefficient was 1.20 × 10⁻⁶. -6 .

[0064] Comparative Example 1:

[0065] The first step is the same as in Example 1;

[0066] The second step is to set the flow rate of the two parallel flow pumps to 0.05 mL / min, the back pressure valve pressure to 10 kPa, and not to turn on the oscillation device.

[0067] The third step is to take a certain volume of aqueous effluent from the second collection tank after the extraction has reached stability, dilute it, measure the absorbance, and calculate the extraction rate and the overall mass transfer coefficient.

[0068] After data processing and analysis, the extraction rate was 0.65 and the overall mass transfer coefficient was 7.01 × 10⁻⁶. -7 .

[0069] Comparative Example 2:

[0070] The first step is the same as in Example 1;

[0071] The second step is to set the flow rate of the two parallel flow pumps to 0.2 mL / min, the back pressure valve pressure to 10 kPa, and not to turn on the oscillation device.

[0072] The third step is to take a certain volume of the aqueous effluent after the extraction reaches stability, dilute it, measure the absorbance, and calculate the extraction rate and the overall mass transfer coefficient.

[0073] After data processing and analysis, the extraction rate was 0.23 and the overall mass transfer coefficient was 6.42 × 10⁻⁶. -7 .

[0074] like Figure 3As shown, data analysis of the embodiments and comparative examples revealed that the oscillating flow sleeve reactor of the present invention can significantly improve the radial mixing effect of the fluid in the outer tube, increase the total mass transfer coefficient and extraction rate. The oscillating flow sleeve reactor of the present invention only changes the flow state of the fluid, generating eddies in the outer tube of the reactor, reducing the fluid concentration gradient difference and improving the extraction efficiency.

Claims

1. An oscillating flow device for improving liquid-liquid extraction efficiency, characterized in that: It includes a first container for holding a first solution, a first feeding device, a first tee, a sleeve reactor, a second tee, and a first collection tank, which are connected in sequence by pipelines. The shell-and-tube reactor consists of an inner tube, an outer tube, and an internal component located between the inner and outer tubes. The two ends of the outer tube are respectively connected to the second port of the first tee and the first port of the second tee. The first pipe near the output end of the first feeding device is connected to the first port of the first tee and extends into the first tee. The extension end of the first pipe extends to the second port of the first tee and is connected to the first end of the inner pipe. The second pipe near the first collection tank is connected to the second port of the second tee and extends into the second tee. The end of the second pipe extends to the first port of the second tee and is connected to the second end of the inner pipe. The third port of the first three-way valve is connected to the second collection tank; the third port of the second three-way valve is connected in sequence to the oscillation device, the back pressure valve, the pressure sensor, the second feeding device, and the second container for holding the second solution through a pipeline; The space between the inner and outer tubes of the shell-and-tube reactor is connected to the third port of the first tee and the third port of the second tee.

2. The oscillating flow device for improving liquid-liquid extraction efficiency according to claim 1, characterized in that: The first and second feeding devices are horizontal flow pumps.

3. The oscillating flow device for improving liquid-liquid extraction efficiency according to claim 1, characterized in that: The oscillation device is a pulse pump.

4. The oscillating flow device for improving liquid-liquid extraction efficiency according to claim 1, characterized in that: The first solution is an organic phase solution, and the second solution is an aqueous phase solution.

5. The oscillating flow device for improving liquid-liquid extraction efficiency according to claim 1, characterized in that: The first collection tank is an organic phase solution collection tank, and the second collection tank is an aqueous phase solution collection tank.

6. The oscillating flow device for improving liquid-liquid extraction efficiency according to claim 1, characterized in that: The outer tube is a transparent circular tube with a constant diameter and an inner diameter of 1-10 mm; the inner tube is a hollow fiber membrane tube, a membrane tube with micropores, or a hollow tube formed by porous media, with an inner diameter of 0.5-1 mm, and the inner component is a spiral inner component.

7. The oscillating flow device for improving liquid-liquid extraction efficiency according to claim 6, characterized in that: The spiral internal component can be in the form of a single spiral, double spiral, or multiple spirals.

8. The oscillating flow device for improving liquid-liquid extraction efficiency according to claim 1, characterized in that: When the oscillation amplitude of the oscillation device is 0-20 mm, the oscillation frequency is 0-3 Hz.

9. A process for liquid-liquid extraction using the oscillating flow apparatus according to any one of claims 1-8, characterized in that: The first step is to prepare an aqueous phase solution of a certain concentration for the experiment and place it in the second container, and to prepare an organic phase solution of a certain concentration for the experiment and place it in the first container. The second step is to set the flow rate of the first and second feeding devices to 0.03-0.3 mL / min, the oscillation frequency of the oscillation device to 0-3 Hz, the amplitude to 1-10 mm, the back pressure valve pressure to 10 kPa, and then turn on the oscillation device. The third step is to take a certain volume of aqueous effluent from the second collection tank after the extraction has stabilized, dilute it, measure the absorbance, and calculate the extraction rate and the overall mass transfer coefficient.

10. The liquid-liquid extraction process according to claim 9, characterized in that: The aqueous phase solution is a phenol-water solution, and the organic phase solution is a tributyl phosphate-kerosene solution.

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