A continuous flow photoelectrochemical reactor with an exhaust device

Abstract

The present invention discloses a continuous flow photoelectrochemical reactor with an exhaust device, comprising an electric reactor, a photoreactor and a conveying pipeline connecting the electric reactor and the photoreactor, wherein an exhaust device is provided on the conveying pipeline, and the exhaust device comprises a buffer chamber and a breathable membrane. The continuous flow photoelectrochemical reactor of the present invention is provided with an exhaust device on the conveying pipeline connecting the electric reactor and the photoreactor, so that bubbles mixed into the reaction liquid generated during the reaction of the electric reactor can be removed before it is transferred to the photoreactor, thereby avoiding the influence of bubbles on subsequent photoreactions. In addition, the bubble removal process does not require increasing the liquid pressure of the reaction liquid, but only needs to follow the normal flow rate. When the reaction liquid flows through the exhaust device, the bubbles naturally float up and are discharged from the breathable membrane. In addition, the entire exhaust device has a simple structure, does not require adding a lot of costs, and is easy to disassemble and maintain.

Description

Technical Field

[0001] The present invention relates to the technical field of photoelectrochemical technology, in particular to a continuous flow photoelectrochemical reactor with an exhaust device. Background Art

[0002] In the past few decades, the energy and environmental crises have become increasingly prominent, and the emergence of green organic chemical methods is urgently needed. As green and pollution-free methods, photocatalysis and electrocatalysis have attracted more and more attention from chemists in organic synthesis. Recently, with the development of modern organic electrochemistry, unique photocatalytic synergistic catalysis methods have attracted widespread attention from scientists. Several research groups have carried out systematic work in organic synthesis based on photocatalysis and developed a series of efficient catalytic redox and coupling reactions based on photocatalytic synergistic catalysis ([1] Barham, JP; Konig, B. Angew. Chem. Int. Ed. 2020, 59, 11732; [2] Liu, JJ; Lu, LX; Wood, D.; Lin, S. ACS Cent. Sci. 2020, 6, 1317; [3] Yu, Y.; Guo, P.; Zhong, J.-S.; Yuan, Y.; Ye, K.-Y. Org. Chem. Front. 2020, 7, 131.]). However, due to the limitations of the reaction equipment and the characteristics of the photoelectric reaction itself, there are problems such as difficulty in amplification that need to be solved.

[0003] In recent years, flow chemistry has flourished in laboratories and industry. Several reviews on flow chemical synthesis have summarized the potential advantages of this technology. External current and light, as easily controllable reaction conditions, combined with flow chemistry can solve the problems existing in traditional photoelectrochemical reactors ([1] Malet-Sanz, L.; Susanne, FJ Med. Chem. 2012, 55, 4062; [2] Britton, J.; Raston, CLChem. Soc. Rev. 2017, 46, 1250; [3] Cambie, D.; Bottecchia, C.; Straathof, NJW; Hessel, V.; Noel, T. Chem. Rev. 2016, 116, 10276.). Recently, some research groups have applied flow synthesis to photoelectrocatalytic reactions. However, the electrode half-reaction is often accompanied by the generation of gas, which generates bubbles in the flow line, which may cause problems such as pipeline blockage and uneven illumination, limiting the development of flow photoelectrochemistry ([1] Qiu, YA; Scheremetjew, A.; Finger, LH; Ackermann, L.Chem.-Eur.J.2020, 26, 3241; [2] Yan, H.; Zhu, S.; Xu, H.-C.Org.Process Res.Dev.2021, 25, 2608; [3] Yan, H.; Song, J.; Zhu, S.; Xu, H.-C.CCS Chem.2021, 3, 317.]). In existing flow chemistry technology methods, the gas dissolution can be promoted by increasing the liquid pressure to avoid the generation of bubbles in the flow path, but this will make the reaction device more complicated and not conducive to the screening of reaction conditions. Therefore, it is of great significance to develop a device to remove the gas generated by the electroreaction during the reaction process. Summary of the Invention

[0004] In view of the above-mentioned deficiencies in the prior art, the present invention provides a continuous flow photoelectrochemical reactor with an exhaust device.

[0005] A continuous flow photoelectrochemical reactor with an exhaust device, comprising:

[0006] An electric reactor, comprising a reaction sleeve and a metal rod passing through the reaction sleeve, wherein the reaction sleeve has a first liquid inlet and a first liquid outlet;

[0007] A photoreactor comprising a light source and a coiled transparent pipe located outside the light source, wherein the transparent pipe has a second liquid inlet and a second liquid outlet;

[0008] A delivery pipeline is used to connect the first liquid outlet and the second liquid inlet, and is used to deliver the product after the reaction of the electric reactor to the photoreactor;

[0009] The continuous flow photoelectrochemical reactor further comprises an exhaust device provided on the delivery pipeline, the exhaust device comprising:

[0010] The buffer chamber is provided with an opening on the top surface, and the buffer chamber has a third liquid inlet and a third liquid outlet for connecting the exhaust device to the delivery pipeline.

[0011] A breathable membrane covers the top opening of the buffer chamber and is used for gas discharge.

[0012] The fixing mechanism is used to fix the breathable membrane at the top opening of the buffer chamber.

[0013] The metal rods in the electric reactor and the reaction sleeve are nested with each other to form the anode and cathode of the electric reactor, and are connected to the positive and negative electrodes of the DC power supply as needed.

[0014] The breathable membrane only allows gas to pass through but not liquid. The breathable membrane can be made of materials such as expanded polytetrafluoroethylene membrane, polyethylene membrane, and polyvinylidene fluoride.

[0015] Preferably, the third liquid inlet and the third liquid outlet are located on either side of the buffer chamber, and the third liquid inlet is located higher than the third liquid outlet. More preferably, the inner cavity of the buffer chamber is tapered, with a smaller bottom and a larger top, and the third liquid outlet is connected to the lowest point of the inner cavity of the buffer chamber.

[0016] Preferably, the buffer chamber is provided with a first convex edge at the top opening; the fixing mechanism includes a hollow ground-edge cover for pressing the breathable membrane from above, the hollow ground-edge cover is vertically opened at both ends, and a second convex edge is provided at the bottom opening, the second convex edge cooperates with the first convex edge to clamp the breathable membrane, and the fixing mechanism also includes a spring clip for clamping the second convex edge and the first convex edge.

[0017] Preferably, the reaction sleeve is cylindrical with openings at both ends, and insulating plugs are provided at the openings at both ends. The insulating plugs have a mounting hole in the middle for the metal rod to pass through. The openings at both ends of the reaction sleeve may be internally threaded, and the insulating plugs may be externally threaded, and the two may be fixed together by threaded engagement.

[0018] Preferably, the photoreactor further comprises a pipeline supporting device, wherein the pipeline supporting device is a transparent beaker, the light source is located in the transparent beaker, and the transparent pipeline is coiled around the outer circumference of the transparent beaker.

[0019] The present invention also provides a continuous flow photoelectrochemical reaction method, which uses the continuous flow photoelectrochemical reactor with an exhaust device.

[0020] Preferably, during the reaction, the flow rate of the liquid flowing out of the third liquid outlet is less than the rising speed of the bubbles in the buffer chamber.

[0021] The continuous flow photoelectrochemical reactor of the present invention incorporates an exhaust device on the transport pipeline connecting the electroreactor and the photoreactor. This allows for the removal of bubbles that are generated during the electroreactor reaction and are mixed into the reaction liquid before it is transferred to the photoreactor, thus preventing the bubbles from affecting the subsequent photoreaction. Furthermore, the bubble removal process does not require increasing the liquid pressure of the reaction liquid; it only requires a normal flow rate. As the reaction liquid flows through the exhaust device, the bubbles naturally float upward and are removed from the breathable membrane. Furthermore, the exhaust device has a simple structure, does not require significant additional costs, and is easy to disassemble and maintain. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 Schematic diagram of the explosion structure of the electric reactor.

[0023] Figure 2 Schematic diagram of the explosion structure of the photoreactor.

[0024] Figure 3 Schematic diagram of the explosion structure of the exhaust device.

[0025] Figure 4 This is a schematic structural diagram of a continuous flow photoelectrochemical reactor with an exhaust device for this application.

[0026] Figure annotation:

[0027] Electroreactor 1, reaction sleeve 11, metal rod 12, first liquid inlet 13, first liquid outlet 14, insulating cock 15,

[0028] Photoreactor 2, light source 21, transparent pipe 22, second liquid inlet 23, second liquid outlet 24, transparent beaker 25,

[0029] Delivery pipeline 3,

[0030] Exhaust device 4 , buffer chamber 41 , breathable membrane 42 , hollow ground cover 43 , third liquid inlet 44 , third liquid outlet 45 , first convex edge 46 , second convex edge 47 . DETAILED DESCRIPTION

[0031] like Figures 1 to 4 As shown, a continuous flow photoelectrochemical reactor with an exhaust device includes an electric reactor 1, a photoreactor 2, and a delivery pipeline 3 connecting the electric reactor 1 and the photoreactor 2, and an exhaust device 4 is provided on the delivery pipeline 3.

[0032] The electroreactor 1 is used to perform an electroreaction. Figure 1As shown, the electroreactor 1 includes a reaction sleeve 11 and a metal rod 12 extending through the reaction sleeve 11. The reaction sleeve 11 has a first liquid inlet 13 and a first liquid outlet 14. The reaction sleeve 11 is cylindrical with two openings. Insulating plugs 15 are provided at each opening. The insulating plug 15 has a mounting hole in the middle for the metal rod 12 to pass through. The openings at both ends of the reaction sleeve 11 can be internally threaded, while the insulating plug 15 can be externally threaded, with the two being secured together by a threaded fit.

[0033] The photoreactor 2 is used to carry out a photoreaction. Figure 2 As shown, the photoreactor 2 includes a light source 21 and a coiled transparent tube 22 located outside the light source 21. The transparent tube 22 has a second liquid inlet 23 and a second liquid outlet 24. The photoreactor 2 also includes a tube support device, which is a transparent beaker 25. The light source 21 is located in the transparent beaker 25, and the transparent tube 22 is coiled around the outer circumference of the transparent beaker 25.

[0034] like Figure 3 As shown, the exhaust device 4 includes a buffer chamber 41, a breathable membrane 42, and a hollow ground cover 43. The top surface of the buffer chamber 41 is open, and the inner cavity is tapered, narrow at the bottom and wide at the top. The buffer chamber 41 has a third liquid inlet 44 and a third liquid outlet 45, which connect the exhaust device 4 to the delivery pipeline 3. The third liquid inlet 44 and the third liquid outlet 45 are located on either side of the buffer chamber 41. This facilitates the liquid entering the buffer chamber 41 through the third liquid inlet 44 to fully enter the inner cavity of the buffer chamber 41, thereby giving bubbles sufficient time to float. The third liquid inlet 44 is also located higher than the third liquid outlet 45, thereby minimizing the risk of bubbles entering the buffer chamber 41 through the third liquid inlet 44 and then entering the downstream photoreactor 2 through the third liquid outlet 45. In the most preferred embodiment, the third liquid outlet 45 is connected to the lowest point of the inner cavity of the buffer chamber 41. Since bubbles float upward, connecting the third liquid outlet 45 to the lowest point of the inner cavity of the buffer chamber 41 can avoid bubbles from entering the downstream photoreactor 2 from the third liquid outlet 45 as much as possible.

[0035] The breathable membrane 42 covers the top opening of the buffer chamber 41 and is used for gas discharge. The breathable membrane 42 only allows gas to pass through but not liquid. The breathable membrane 42 can be made of expanded polytetrafluoroethylene membrane, polyethylene membrane, polyvinylidene fluoride, etc.

[0036] The buffer chamber 41 has a first flange 46 at its top opening. The hollow ground cover 43 is vertically open at both ends and has a second flange 47 at its bottom opening. The hollow ground cover 43 presses against the breathable membrane 42 from above, and the second flange 47 cooperates with the first flange 46 to clamp the breathable membrane 42. The second flange 47 and the first flange 46 are clamped together and secured together by a spring clip (not shown).

[0037] A continuous flow photoelectrochemical reaction method using the continuous flow photoelectrochemical reactor with an exhaust device. The specific steps are as follows:

[0038] Step 1) First, pass the metal rod 12 through the insulating cock 15, and then fix the metal rod 12 to the reaction sleeve 11 through the insulating cock 15. The other end of the reaction sleeve 11 is also fixed with the insulating cock 15. The metal rod 12 and the reaction sleeve 11 in the electroreactor 1 are nested with each other to form the anode and cathode of the electroreactor 1. Use wires to connect the metal rod 12 and the reaction sleeve 11 to the positive and negative poles of the power supply respectively;

[0039] Step 2) Fixing the breathable membrane 42 between the buffer chamber 41 and the hollow ground cover 43;

[0040] Step 3) Connect the electroreactor 1, the exhaust device 4, and the photoreactor 2 through the delivery pipeline 3; at the same time, the first liquid inlet 13 on the electroreactor 1 is connected to the pre-reaction liquid flow bottle through a pipeline for providing the pre-reaction reaction liquid to the continuous flow photoelectrochemical reactor of the present application, and the connection pipeline of the pre-reaction liquid flow bottle also has a hydraulic pump that provides liquid flow driving force; the second liquid outlet 24 on the photoreactor 2 is connected to the post-reaction liquid flow bottle through a pipeline for collecting the reaction liquid after the reaction of the continuous flow photoelectrochemical reactor of the present application;

[0041] Step 4) Turn on the hydraulic pump to allow the reaction liquid to flow out of the pre-reaction liquid flow bottle, flow through the electroreactor 1, the exhaust device 4, the photoreactor 2 in sequence, and finally flow into the post-reaction liquid flow bottle;

[0042] Step 5) Power on the electrodes and turn on the light until the reaction is complete, then disconnect all power supplies and end use.

[0043] Table 1

[0044] solvent Maximum flow rate (cm / s) Acetonitrile 25 water 18 Methanol 25 Ethylene dichloride 20 Hexafluoroisopropanol 25 Toluene 25 N,N-dimethylformamide 20 Dimethyl sulfoxide 20

[0045] During the reaction, the flow rate of the liquid out of the third liquid outlet 45 is set to be less than the rising speed of the bubbles in the buffer chamber 41. The upper limit of the flow rate varies with different solvents. After testing, the comparison data of some commonly used solvents and flow rates are shown in Table 1.

Claims

1. A continuous flow photoelectrochemical reactor with an exhaust device, comprising: An electric reactor, comprising a reaction sleeve and a metal rod passing through the reaction sleeve, wherein the reaction sleeve has a first liquid inlet and a first liquid outlet; A photoreactor comprising a light source and a coiled transparent pipe located outside the light source, wherein the transparent pipe has a second liquid inlet and a second liquid outlet; A delivery pipeline is used to connect the first liquid outlet and the second liquid inlet, and is used to deliver the product after the reaction of the electric reactor to the photoreactor; It is characterized in that the continuous flow photoelectrochemical reactor further includes an exhaust device provided on the delivery pipeline, and the exhaust device includes: The buffer chamber is provided with an opening on the top surface, and the buffer chamber has a third liquid inlet and a third liquid outlet for connecting the exhaust device to the delivery pipeline. A breathable membrane covers the top opening of the buffer chamber and is used for gas discharge. A fixing mechanism, used for fixing the breathable membrane at the top opening of the buffer chamber; The third liquid inlet and the third liquid outlet are respectively located on both sides of the buffer chamber, and the position of the third liquid inlet is higher than that of the third liquid outlet; The inner cavity of the buffer chamber is tapered with a smaller bottom and a larger top, and the third liquid outlet is connected to the lowest point of the inner cavity of the buffer chamber; The buffer chamber is provided with a first convex edge at the top opening. The fixing mechanism includes a hollow ground-edge cover for pressing the breathable membrane from above. The hollow ground-edge cover is vertically opened at both ends, and a second convex edge is provided at the bottom opening. The second convex edge cooperates with the first convex edge to clamp the breathable membrane. The fixing mechanism also includes a spring clip for clamping the second convex edge and the first convex edge.

2. The continuous flow photoelectrochemical reactor with an exhaust device according to claim 1, characterized in that: The reaction sleeve is cylindrical with openings at both ends. Insulating cocks are provided at the openings at both ends. A mounting hole is provided in the middle of the insulating cock for the metal rod to pass through.

3. The continuous flow photoelectrochemical reactor with an exhaust device according to claim 1, characterized in that: The photoreactor further includes a pipeline supporting device, which is a transparent beaker. The light source is located in the transparent beaker, and the transparent pipeline is coiled around the outer periphery of the transparent beaker.

4. A continuous flow photoelectrochemical reaction method, characterized in that: A continuous flow photoelectrochemical reactor with an exhaust device according to any one of claims 1 to 3 is used.

5. The continuous flow photoelectrochemical reaction method according to claim 4, characterized in that: During the reaction, the flow rate of the liquid flowing out of the third liquid outlet is less than the rising speed of the bubbles in the buffer chamber.

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