Organic electrochemical reactor and continuous reaction device thereof

Abstract

The utility model discloses an organic electrochemical reactor and a continuous reaction device thereof, the organic electrochemical reactor comprises a reactor and three electrode plates which are sequentially arranged in the reactor in parallel, the two electrode plates on the two sides are anode plates, and the electrode plate in the middle is a cathode plate; the three electrode plates are parallel to each other, the projections of the two anode plates on the cathode plate are at least partially overlapped, and a gap is formed between the adjacent electrode plates. The combination of the three electrode plates in the organic electrochemical reactor disclosed by the utility model can effectively increase the electrolysis area of a single reaction device, increase the anode reaction speed and improve the conversion of products, and a plurality of organic electrochemical reactors are connected in series, so that the productivity can be effectively increased, and meanwhile, the amplification effect of the reaction cannot be increased.

Description

Technical Field

[0001] The utility model relates to an organic electrochemical reactor and a continuous reaction device thereof. Background Art

[0002] Previously developed electrochemical amplification devices, such as flow cell equipment, have low flux and are prone to clogging. Although the parallel electrode plate reactor has a large electrolysis area, the flow rate is low, and the reaction solution needs to be circulated for electrolysis, resulting in low production capacity. There are also problems such as leakage, gas production, and solid blockage, which limit its application in electrochemical organic synthesis. Both flow cell equipment and parallel electrode plate reactors cannot achieve kilogram-level amplification reactions. Although reactor equipment can effectively avoid problems such as gas production and solid blockage, it is difficult to achieve proportional amplification due to the small specific surface area of ​​the equipment. Therefore, there is currently a lack of modular equipment that can be used for amplification in electrochemical organic synthesis. Utility Model Content

[0003] The technical problem to be solved by the utility model is to overcome the problem of easy clogging and low production capacity of the existing electrochemical reaction device during the amplified reaction. Provided is an organic electrochemical reactor and a continuous reaction device thereof, the utility model can effectively increase the electrolysis area of ​​a single reaction device and improve the production capacity without increasing the amplified effect of the reaction.

[0004] The utility model solves the above technical problems through the following technical solutions:

[0005] The utility model discloses an organic electrochemical reactor, which comprises a reactor and three electrode plates arranged in sequence in parallel in the reactor, wherein two electrode plates on both sides are anode plates, and the middle electrode plate is a cathode plate; the three electrode plates are parallel to each other, the projections of two anode plates on the cathode plate at least partially overlap, and a spacing is arranged between adjacent electrode plates.

[0006] In the present invention, the distance between two adjacent electrode plates is preferably 1 / 2 to 1 / 5 of the inner diameter of the reactor, and more preferably 1 / 3 to 1 / 5.

[0007] When the spacing is too large, it is conducive to full mixing with the electrolyte, rapid and uniform mass and heat transfer, and fast electrolysis rate. However, the voltage is high and the power loss is large; when the spacing is too small, the mass and heat transfer is uneven, local overheating occurs, the electrolysis rate is slow, and the positive electrode will undergo physical deformation during the reaction. If the spacing is too small, the electrode will be damaged.

[0008] In some preferred embodiments, the distance between two adjacent electrode plates is 1-5 cm, for example, 2 cm.

[0009] In the utility model, the three electrode plates are preferably distributed at equal intervals, which increases the rapidity and uniformity of mass and heat transfer and the safety of the electrodes, and reduces the energy consumption of the equipment.

[0010] In the present invention, preferably, the projections of the two anode plates on the cathode plate completely overlap. When the projections of the three electrode plates have no overlapping parts, no electrolysis reaction occurs.

[0011] In the utility model, preferably, the reactor is provided with a top cover, the top cover includes a cover body and a plug arranged on the cover body, the plug is used to be detachably sealed and connected with the reactor; the top cover is provided with three notches for correspondingly inserting the three electrode plates, the three notches are sequentially arranged in parallel on the cover body, and the three notches all pass through the plug. By providing a plug having a certain thickness, the electrode plates can be stably supported while the top cover is connected to the reactor.

[0012] More preferably, the cover body includes a cover plate and an edge arranged on the outer side of the cover plate, the edge extends in the direction of the plug rod, an annular gap is arranged between the inner wall of the edge and the side wall of the plug rod, and the annular gap matches the wall thickness of the reactor. The edge is arranged to fix the position of the top cover to prevent the top cover from moving back and forth and affecting the test process.

[0013] The top cover is preferably also provided with a feed port for feeding and a discharge port for discharging, the feed port is arranged on the outside of one of the anode plates, and the discharge port is arranged on the outside of the other anode plate, and the outside of the anode plate refers to the side of the anode plate close to the inner wall of the reactor. By arranging the feed port and the discharge port, feeding and discharging are facilitated, and by arranging the feed port and the discharge port on the outside of the anode plate, the influence of feeding and discharging on electrolysis can be avoided or reduced.

[0014] Preferably, the discharge port and the feed port are arranged on the plug column and pass through the plug column, and when a pipe is inserted into the discharge port and the feed port, the pipe is firmly supported by the plug column having a certain thickness.

[0015] In the present invention, the reactor is a conventional kettle reactor in the art, such as a glass reactor.

[0016] In the present invention, the organic electrochemical reactor may further include a heat exchanger, and heat is exchanged with the system in the reactor by passing a heat exchange medium into the heat exchanger.

[0017] Wherein, an annular cavity sandwich is formed between the shell of the reactor and the inner wall of the reactor, the annular cavity sandwich is used to pass a heat exchange medium, the shell is provided with a heat exchange medium inlet and a heat exchange medium outlet for the heat exchange medium to flow, and the heat exchange system formed by the annular cavity sandwich, the heat exchange medium inlet and the heat exchange medium outlet and the required heat exchange pipelines constitutes the heat exchanger. When the reaction system needs to be cooled, the heat exchange medium is a cooling medium, and when the reaction system needs to be heated, the heat exchange medium is a heating medium.

[0018] Of course, the heat exchanger may also be other structures, such as a coil structure, but the above-mentioned sandwich structure is preferred, which can improve the uniformity of heat exchange.

[0019] In the utility model, the organic electrochemical reactor may further include a power supply, the two electrode plates on both sides are connected in parallel to the positive electrode of the power supply, and the middle electrode plate is connected to the negative electrode of the power supply.

[0020] In the utility model, the organic electrochemical reactor may further include a stirring system, and the stirring system is preferably a magnetic stirring system.

[0021] The organic electrochemical reactor also includes a control system, which is connected to a power supply and a pump system and is used to control the voltage, current and flow of the reaction liquid.

[0022] In the present invention, the electrode plate is made of conventional material in the art, such as graphite.

[0023] In the utility model, the length, width and thickness of the electrode plate can be adjusted according to the size of the reactor and the feed amount, for example, the length can be 200-350 mm, the width can be 70-80 mm, and the thickness can be 3-5 mm.

[0024] The utility model also discloses a continuous reaction device, which comprises at least three of the above-mentioned organic electrochemical reactors, wherein the plurality of organic electrochemical reactors are sequentially connected in series;

[0025] Each of the reactors is provided with a feed end and a discharge end, and along the material flow direction, the discharge end of the previous reactor is connected to the feed end of the next reactor;

[0026] The anode plate, the cathode plate and the cathode plate in each reactor are arranged in sequence from the feed end to the discharge end.

[0027] In the utility model, the feed end of the reactor includes a feed pipe, one end of which is inserted into the reactor and located on the outside of the anode plate close to the feed end, and the other end of the feed pipe is located outside the reactor, and the outside of the anode plate refers to the side of the anode plate close to the inner wall of the reactor.

[0028] In the utility model, the feed end of the reactor includes a discharge pipe, one end of which is inserted into the reactor and located outside the anode plate near the discharge end, and the other end of the discharge pipe is located outside the reactor.

[0029] Wherein, a metering pump is arranged on the feed pipe and / or the discharge pipe, and the feed flow rate of each organic electrochemical reactor is controlled by the metering pump.

[0030] In the present invention, the number of the organic electrochemical reactors can be adjusted according to the actual feed amount and the reaction time requirement. In one embodiment, the number of the organic electrochemical reactors is 5.

[0031] The utility model also discloses an electrolytic reaction method, which comprises the following steps: adding a mixture formed by an electrolyte and a substrate into the aforementioned organic electrochemical reactor or the aforementioned continuous reaction device to carry out an electrolytic reaction to obtain a product;

[0032] When the substrate is 3-furoic acid methyl ester and the product is 2,5-dimethoxy-2,5-dihydro-furan-3-carboxylic acid methyl ester, the temperature of the electrolysis reaction is -10 to 5°C, the amount of electricity of the electrolysis reaction is 4 to 5F / mol, and in each of the reactors, the ratio of the concentration of the electrolyte to the concentration of the substrate is (1 to 5):1.

[0033] In the present invention, the substrate is preferably a substrate solution.

[0034] The substrate solution is generally formed by dissolving the substrate in a solvent. The solvent is conventional in the art, such as MeOH.

[0035] Wherein, the concentration of the substrate in the substrate solution may be 50 g / L.

[0036] In the present invention, the concentration of the electrolyte and the concentration of the substrate are preferably 2:1.

[0037] In the utility model, the electrolysis reaction is a conventional organic electrolysis reaction in the art.

[0038] Wherein, the substrate is a conventional organic compound, such as a furan compound. The furan compound is preferably methyl 3-furoate.

[0039] Wherein, the product is a conventional α-oxidation product, such as a dihydrofuran compound. Dihydrofuran The compound is preferably 2,5-dimethoxy-2,5-dihydro-furan-3-carboxylic acid methyl ester.

[0040] In the utility model, the time of the electrolytic reaction is related to the feed amount of the reaction system and the number of the organic electrochemical reactors. The reaction termination time is monitored by gas chromatography to monitor the product content, and the reaction is stopped when the desired content is reached.

[0041] In the utility model, the electrolysis reaction may further include a stirring step, wherein the stirring speed is preferably 800-1000 rpm.

[0042] In the present invention, the feed flow rate of each reactor is preferably 10-20 mL / min, for example 15 mL / min.

[0043] In the present invention, the temperature of the electrolysis reaction is preferably -10 to 0°C or 0 to 5°C, more preferably -8 to 0°C.

[0044] In the present invention, the electrolyte is conventional in the art, such as H2SO4.

[0045] In the utility model, in each reactor, the volume ratio of the total effective electrolysis area to the mixture in the reactor is 0.05-0.2 cm 2 / mL, for example 0.18 cm 2 / mL; Preferably, the volume ratio of the effective electrolysis area of ​​each anode plate to the mixture in the reactor is 0.01 to 0.1 cm 2 / mL, for example 0.09cm 2 / mL, the effective electrolysis area refers to the area of ​​the anode plate immersed in the electrolyte and overlapping and opposite to the projection of the cathode plate.

[0046] In the present invention, the electric quantity is the total electric quantity. For example, when one organic electrochemical reactor is used, the electric quantity is 4 to 5 F / mol. When the continuous reaction device is used, the electric quantity of each organic electrochemical reactor is the ratio of the total electric quantity to the organic electrochemical reactor.

[0047] In the utility model, after the electrolysis reaction is completed, a post-treatment step of the electrolyte may be included.

[0048] The post-treatment step of the electrolyte preferably includes: adding the electrolyte after the electrolysis reaction is completed into a mixture of ice water and DCM to reduce or avoid the product from becoming impure.

[0049] The positive and progressive effects of the utility model are:

[0050] (1) The three-electrode plate combination in the organic electrochemical reactor of the utility model can effectively increase the electrolysis area of ​​a single reaction device, increase the speed of the anode plate reaction, and improve the conversion of the product.

[0051] (2) The continuous reaction device of the utility model uses multiple organic electrochemical reactors connected in series, which can effectively increase the production capacity without increasing the amplification effect of the reaction.

[0052] (3) The organic electrochemical reactor and the continuous reaction device of the utility model can obtain a good product conversion rate in the scaled-up production of the reaction, especially in the electrolysis of 3-furoic acid methyl ester to synthesize 2,5-dimethoxy-2,5-dihydro-furan-3-carboxylic acid methyl ester. GC IPC shows that the 2,5-dimethoxy-2,5-dihydro-furan-3-carboxylic acid methyl ester in the reaction system can reach 95%, and the production capacity can reach 1500g / day. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 This is a schematic diagram of the structure of the organic electrochemical reactor described in Example 1.

[0054] Figure 2 This is an axonometric view of the top cover of the organic electrochemical reactor described in Example 1.

[0055] Figure 3 This is a side view of the top cover of the organic electrochemical reactor described in Example 1.

[0056] Figure 4 This is a schematic diagram of the structure of the electrodes in the organic electrochemical reactor of Comparative Example 1.

[0057] Figure 5 This is a schematic diagram of the structure of the electrodes in the organic electrochemical reactor of Comparative Example 2.

[0058] Figure 6 This is a schematic diagram of the structure of the electrodes in the organic electrochemical reactor of Comparative Example 3.

[0059] Figure 7 This is a schematic diagram of the structure of the electrodes in the organic electrochemical reactor of Comparative Example 4.

[0060] Figure 8 This is a schematic diagram of the structure of the continuous reaction device described in Example 2.

[0061] Fig. 9 The figure shows the variation of the product content of Example 2 in each reactor.

[0062] Description of Reference Numerals

[0063] Reactor 1

[0064] Annular cavity sandwich 11

[0065] Top cover 12

[0066] Cover 121

[0067] Plug 122

[0068] Edge 123

[0069] Notch 124

[0070] Feed port 125

[0071] Discharge port 126

[0072] Electrode plate 2

[0073] Power Supply 3

[0074] Metering pump 4

[0075] Electrode rod 5

[0076] Feed pipe 6

[0077] Discharge pipe 7 DETAILED DESCRIPTION

[0078] The present invention is further described below by way of embodiments, but the present invention is not limited to the scope of the embodiments.

[0079] The 3-furoic acid methyl ester in the following examples and comparative examples was purchased from LabNetwork.

[0080] Example 1

[0081] This embodiment discloses an organic electrochemical reactor, which includes a reactor 1, three electrode plates 2, a stirring system and a control system.

[0082] like Figure 1 As shown, three electrode plates 2 are arranged in parallel in the reactor 1, the two electrode plates 2 on both sides are anode plates, the middle electrode plate 2 is a cathode plate, the three electrode plates 2 are parallel to each other, and the projections of the two anode plates on the cathode plate completely overlap, and there is a spacing between adjacent electrode plates 2, the spacing is 2cm, the two anode plates are connected in parallel to the positive pole of the power supply 3, and the cathode plate is connected to the negative pole of the power supply 3. The material of the electrode plate is graphite, and the effective electrolysis area of ​​each anode plate is 72cm 2 , where the effective electrolysis area refers to the area of ​​each anode plate immersed in the electrolyte and overlapping and opposite to the projection of the cathode plate. Therefore, the total effective electrolysis area of ​​this embodiment is 144cm 2 .

[0083] Reactor 1 is a jacketed glass reactor, comprising an inner shell and an outer shell sleeved on the inner shell, an annular cavity interlayer 11 is formed between the shell wall of the inner shell and the shell wall of the outer shell, a coolant inlet and a coolant outlet are arranged on the annular cavity interlayer 11, the annular cavity interlayer 11 is used for the flow of coolant, and the annular cavity interlayer 11 is connected to the TCU circulating cooling system.

[0084] The reactor is provided with a top cover 12, such as Figure 2 and Figure 3 As shown, the top cover includes a cover body and a plug 122 arranged on the cover body. The cover body includes a cover plate 121 and an edge 123 arranged on the outer side of the cover plate 121, the edge 123 extends toward the setting direction of the plug 122, and an annular gap is arranged between the inner wall of the edge 123 and the side wall of the plug 122, and the annular gap matches the wall thickness of the reactor 1.

[0085] The cover body 121 is a disc-shaped structure, and the plug 122 is a cylindrical structure. The plug 122 is arranged in the middle of the cover body 121. The top cover 12 is provided with three notches 124 for correspondingly inserting three electrode plates, a feed port 125 for feeding, and a discharge port 126 for discharging. The three notches 124 are arranged in parallel on the cover body 121 in sequence, and the three notches 124, the feed port 125, and the discharge port 126 all pass through the plug 122. The feed port 125 is arranged on the outside of one of the anode plates, and the discharge port 126 is arranged on the outside of the other anode plate. The outside of the anode plate refers to the side of the anode plate close to the inner wall of the reactor 1.

[0086] The stirring system is a magnetic stirring system.

[0087] The control system is connected with the power supply and the pump system and is used for controlling the voltage, current and flow of the reaction liquid of the reaction.

[0088] The feed amount in this example is 50 g, the reactor volume is 2 L, and the volume ratio of the total effective electrolysis area to the mixture in the reactor is 0.18 cm 2 / mL.

[0089] The electrolysis effect of the organic electrochemical reactor of this embodiment was tested, and the electrolysis parameters were as follows:

[0090] 2,5-dimethoxy-2,5-dihydro-furan-3-carboxylic acid methyl ester (product) was synthesized using 3-furoic acid methyl ester as substrate, MeOH as solvent, and H2SO4 as electrolyte. Among them, 3-furoic acid methyl ester was 50g, and its concentration after dissolving in MeOH was 50g / L, the molar ratio of H2SO4 to 3-furoic acid methyl ester was 2:1, the volume of the mixture formed by the electrolyte, substrate and solvent was 800mL, the temperature of the electrolytic reaction was -8 to 0℃, the amount of electricity was 4F / mol, and the electrolytic reaction time was 180min.

[0091] Gas chromatography (GC) IPC was used to monitor the contents of methyl 3-furoate and methyl 2,5-dimethoxy-2,5-dihydro-furan-3-carboxylate in the reaction solution after the electrolysis reaction. The results are shown in Table 1.

[0092] Comparative Example 1

[0093] The difference between this comparative example and Example 1 is that this comparative example has two electrode plates, such as Figure 4 As shown, the two electrode plates are an anode plate and a cathode plate. Figure 2 The distance between the two electrode plates is 6 cm, and the effective electrolysis area of ​​the electrode plates is 72 cm 2 , the rest are the same as in Example 1.

[0094] The electrolysis effect testing method and process parameters of this comparative example are the same as those of Example 1.

[0095] Gas chromatography (GC) IPC was used to monitor the contents of methyl 3-furoate and methyl 2,5-dimethoxy-2,5-dihydro-furan-3-carboxylate in the reaction solution after the electrolysis reaction. The results are shown in Table 1.

[0096] Comparative Example 2

[0097] The difference between this comparative example and Example 1 is that this comparative example has four electrode plates, such as Figure 5 As shown, four electrode plates are arranged in parallel in the reactor. Figure 3 As shown, from left to right are the first electrode plate, the second electrode plate, the third electrode plate and the fourth electrode plate. The first electrode plate and the third electrode plate are both anode plates, connected in parallel to the positive pole of the power supply. The second electrode plate and the fourth electrode plate are both cathode plates, connected in parallel to the negative pole of the power supply. The distance between each two adjacent electrode plates is 1 cm, and the effective electrolysis area of ​​a single electrode plate is 72 cm 2 The total effective electrolysis area is 144 cm 2 , the rest are the same as in Example 1.

[0098] The electrolysis effect testing method and process parameters of this comparative example are the same as those of Example 1.

[0099] Gas chromatography (GC) IPC was used to monitor the contents of methyl 3-furoate and methyl 2,5-dimethoxy-2,5-dihydro-furan-3-carboxylate in the reaction solution after the electrolysis reaction. The results are shown in Table 1.

[0100] Comparative Example 3

[0101] The difference between this comparative example and Example 1 is that this comparative example has four electrode plates and two sets of power supplies. Figure 6 As shown, four electrode plates are arranged in parallel in the reactor. Figure 4 As shown, from left to right are the first electrode plate, the second electrode plate, the third electrode plate and the fourth electrode plate. The first electrode plate and the second electrode plate are connected to the positive and negative electrodes of one power source respectively, and the third electrode plate and the fourth electrode plate are connected to the positive and negative electrodes of the other power source respectively. The distance between each two adjacent electrode plates is 1 cm, and the effective electrolysis area of ​​a single electrode plate is 72 cm2 The total effective electrolysis area is 144 cm 2 , the rest are the same as in Example 1.

[0102] The electrolysis effect testing method and process parameters of this comparative example are the same as those of Example 1.

[0103] Gas chromatography (GC) IPC was used to monitor the contents of methyl 3-furoate and methyl 2,5-dimethoxy-2,5-dihydro-furan-3-carboxylate in the reaction solution after the electrolysis reaction. The results are shown in Table 1.

[0104] Comparative Example 4

[0105] The difference between this comparative example and Example 1 is that the three-electrode system is replaced with electrode rods, such as Figure 7 As shown, 12 electrode rods 5 are arranged in the reactor 1 in a circular shape around the circumference of the reactor. The 12 electrode rods are distributed alternately as anodes and cathodes. The anode electrode rods are connected in parallel to the positive electrode of the power supply, and the cathode electrode rods are connected in parallel to the negative electrode of the power supply. Figure 5 The figure shows a top view of 12 electrode rods in the reactor. The spacing between adjacent electrode rods is 0.5 to 1 cm, and the total effective electrolysis area of ​​all electrode rods is 171 cm. 2 , the electrode rod is made of graphite.

[0106] The electrolysis effect testing method and process parameters of this comparative example are the same as those of Example 1.

[0107] Gas chromatography (GC) IPC was used to monitor the contents of methyl 3-furoate and methyl 2,5-dimethoxy-2,5-dihydro-furan-3-carboxylate. The results are shown in Table 1.

[0108] Comparative Example 5

[0109] The difference between this comparative example and Example 1 is that the amount of electricity in the electrolysis parameters of this comparative example is 1 F / mol. The rest is the same as Example 1.

[0110] The electrolysis effect testing method and process parameters of this comparative example are the same as those of Example 1.

[0111] Gas chromatography (GC) IPC was used to monitor the contents of methyl 3-furoate and methyl 2,5-dimethoxy-2,5-dihydro-furan-3-carboxylate in the reaction solution after the electrolysis reaction. The results are shown in Table 1.

[0112] Comparative Example 6

[0113] The difference between this comparative example and Example 1 is that the amount of electricity in the electrolysis parameters of this comparative example is 2F / mol. The rest is the same as Example 1.

[0114] The electrolysis effect testing method and process parameters of this comparative example are the same as those of Example 1.

[0115] Gas chromatography (GC) IPC was used to monitor the contents of methyl 3-furoate and methyl 2,5-dimethoxy-2,5-dihydro-furan-3-carboxylate in the reaction solution after the electrolysis reaction. The results are shown in Table 1.

[0116] Comparative Example 7

[0117] The difference between this comparative example and Example 1 is that the amount of electricity in the electrolysis parameters of this comparative example is 3F / mol. The rest is the same as Example 1.

[0118] The electrolysis effect testing method and process parameters of this comparative example are the same as those of Example 1.

[0119] Gas chromatography (GC) IPC was used to monitor the contents of methyl 3-furoate and methyl 2,5-dimethoxy-2,5-dihydro-furan-3-carboxylate in the reaction solution after the electrolysis reaction. The results are shown in Table 1.

[0120] Table 1

[0121]

[0122]

[0123] When the charge is 5 F / mol, the contents of substrate and product in the reaction solution after the electrolysis reaction is monitored by gas chromatography GC IPC are close to those in Example 1.

[0124] Example 2

[0125] This embodiment discloses a continuous reaction device, such as Figure 8 As shown, it includes five organic electrochemical reactors described in Example 1, which are connected in series in sequence through pipelines to form a primary, secondary, tertiary, quaternary and fifth organic electrochemical reactor in sequence, with the primary stage feeding and the fifth stage discharging liquid.

[0126] Each reactor 1 is provided with a feed pipe 6 and a discharge pipe 7. Along the material flow direction, the feed pipe 6 of the previous reactor is connected to the discharge pipe 7 of the next reactor. The anode plate, cathode plate, and anode plate in each reactor are arranged in sequence from the feed pipe 6 to the discharge pipe 7.

[0127] A metering pump 4 is provided on the pipeline between adjacent reactors 1, and the feed flow rate of each reactor is controlled by the metering pump 4 to be 15 mL / min.

[0128] The volume of each reactor 1 is 2L, and the total effective electrolysis area is 144cm 2 The total effective electrolysis area in each reactor and the volume ratio of the mixture in the reactor is 0.18 cm 2 / mL.

[0129] The electrolysis effect of the continuous reaction device of this embodiment was tested, and the electrolysis parameters were as follows:

[0130] 2,5-Dimethoxy-2,5-dihydro-furan-3-carboxylic acid methyl ester (product) was synthesized using 3-furoic acid methyl ester as substrate, MeOH as solvent, and H2SO4 as electrolyte.

[0131] Among them, when 3-furoic acid methyl ester is 325g, the concentration after it is dissolved in MeOH is 50g / L, the molar ratio of H2SO4 to 3-furoic acid methyl ester is 2:1, the temperature of the electrolysis reaction is -8~0℃, and the amount of electricity is 4F / mol. After 7h of stable flow, gas chromatography GC IPC is used to monitor the contents of substrate 3-furoic acid methyl ester and product 2,5-dimethoxy-2,5-dihydro-furan-3-carboxylic acid methyl ester, respectively, and the results are shown in Group A in Table 2.

[0132] When 3-furoic acid methyl ester is 450g, its concentration after dissolving in MeOH is 50g / L, the molar ratio of H2SO4 to 3-furoic acid methyl ester is 2:1, the temperature of the electrolysis reaction is -8~0℃, and the amount of electricity is 4F / mol. After 10.5h of stable flow, the contents of substrate 3-furoic acid methyl ester and product 2,5-dimethoxy-2,5-dihydro-furan-3-carboxylic acid methyl ester in the reaction solution are monitored by gas chromatography GC IPC, respectively. The results are shown in Group B in Table 2.

[0133] Table 2

[0134]

[0135] As can be seen from Table 2, after 7 hours of stable flow, the content of the product 2,5-dimethoxy-2,5-dihydro-furan-3-carboxylic acid methyl ester monitored by GC IPC at the 5th stage of discharge reached 89%. After 10.5 hours of stable flow, the content of the product 2,5-dimethoxy-2,5-dihydro-furan-3-carboxylic acid methyl ester monitored by GC IPC at the 5th stage of discharge reached 93%, and the production capacity reached 1080 g / day.

[0136] Fig. 9 The figure shows the variation of the product content in each reactor of Example 2. It can be seen that, as the electrolysis proceeds, the product content gradually increases from the 1st stage to the 5th stage.

[0137] Example 3

[0138] The difference between this embodiment and embodiment 2 is that the electrolysis temperature during the electrolysis process of this embodiment is 0-5° C. The rest is the same as embodiment 2.

[0139] After 10.5 h of stable flow, GC IPC of the fifth-stage effluent showed that the content of substrate 3-furoic acid methyl ester was 4.4%, and the content of product 2,5-dimethoxy-2,5-dihydro-furan-3-carboxylic acid methyl ester was 91%.

[0140] Comparative Example 8

[0141] The difference between this comparative example and Example 2 is that the electrolysis temperature of this comparative example is 5-10° C. The rest is the same as Example 2.

[0142] After 10.5 h of stable flow, GC IPC of the fifth-stage effluent showed that the content of substrate 3-furoic acid methyl ester was 3.3%, and the content of product 2,5-dimethoxy-2,5-dihydro-furan-3-carboxylic acid methyl ester was 49%.

[0143] Comparative Example 9

[0144] The difference between this example and Example 2 is that the electrolysis temperature of this comparative example is -15°C. The rest is the same as Example 2.

[0145] Because the electrode plates are frosted due to low temperature, the voltage is too high when power is turned on and electrolysis is impossible.

[0146] Comparative Example 10

[0147] The difference between this example and Example 2 is that the molar ratio of H2SO4 to 3-furoic acid methyl ester in this comparative example is 0.1:1. The rest is the same as Example 2.

[0148] Since the voltage of the reaction solution was very high, the electrolysis data could not be monitored because the process was only carried out for 30 minutes.

[0149] Comparative Example 11

[0150] The difference between this example and Example 2 is that the molar ratio of H2SO4 to 3-furoic acid methyl ester in this comparative example is 3:1. The rest is the same as Example 2.

[0151] When preparing the solution, a small amount of substrate carbonization can be seen, and electrolysis cannot be achieved.

[0152] Example 4: Kilogram-level scale-up experiment

[0153] The continuous reaction apparatus described in Example 2 is used, and the volume of each reactor, the volume of the mixture and the effective electrolysis area of ​​the electrode plate are the same as those in Example 2.

[0154] In this experiment, 3-furoic acid methyl ester is 3 kg, and its concentration after dissolving in MeOH is 50 g / L. The molar ratio of H2SO4 to 3-furoic acid methyl ester is 2:1. The temperature of the electrolysis reaction is -8 to 0°C, and the amount of electricity is 5F / mol.

[0155] After 48 hours of stable flow, the content of 3-furoic acid methyl ester was monitored by gas chromatography GC IPC. 3%, product 2,5- The content of dimethoxy-2,5-dihydro-furan-3-carboxylic acid methyl ester is 95%. The production capacity reaches 150 0g / day.

[0156] When a continuous reaction device is not used and five organic electrochemical reactors of this embodiment are used for parallel feeding, when the gas chromatography (GC) content of the substrate 3-furoic acid methyl ester in the reaction liquid is 3% and the gas chromatography (GC) content of the product 2,5-dimethoxy-2,5-dihydro-furan-3-carboxylic acid methyl ester is 95%, the production capacity is 100-200 g / day.

Claims

1. An organic electrochemical reactor, characterized in that: It includes a reactor and three electrode plates arranged in parallel in sequence in the reactor, the two electrode plates on both sides are anode plates, and the middle electrode plate is a cathode plate; the three electrode plates are parallel to each other, the projections of two anode plates on the cathode plate at least partially overlap, and a spacing is set between adjacent electrode plates.

2. The organic electrochemical reactor according to claim 1, characterized in that The distance between two adjacent electrode plates is 1 / 2 to 1 / 5 of the inner diameter of the reactor; And / or, the three electrode plates are distributed at equal intervals; And / or, the projections of the two anode plates on the cathode plate completely overlap.

3. The organic electrochemical reactor according to claim 2, characterized in that: The distance between two adjacent electrode plates is 1 / 3 to 1 / 5 of the inner diameter of the reactor.

4. The organic electrochemical reactor according to claim 2, characterized in that: The reactor is provided with a top cover, which includes a cover body and a plug arranged on the cover body, and the plug is used to be detachably sealed and connected to the reactor; the top cover is provided with three notches for correspondingly inserting the three electrode plates, and the three notches are opened in parallel on the cover body in sequence, and the three notches all pass through the plug.

5. The organic electrochemical reactor according to claim 4, characterized in that: The cover body includes a cover plate and an edge arranged on the outer side of the cover plate, the edge extends toward the setting direction of the plug column, an annular gap is arranged between the inner wall of the edge and the side wall of the plug column, and the annular gap matches the wall thickness of the reactor.

6. The organic electrochemical reactor according to claim 4, characterized in that: The top cover is also provided with a feed port for feeding and a discharge port for discharging. The feed port is arranged on the outside of one of the anode plates, and the discharge port is arranged on the outside of the other anode plate. The outside of the anode plate refers to the side of the anode plate close to the inner wall of the reactor.

7. The organic electrochemical reactor according to claim 1, characterized in that: The organic electrochemical reactor further comprises a heat exchanger, and heat is exchanged with the system in the reactor by passing a heat exchange medium into the heat exchanger; And / or, the organic electrochemical reactor further comprises a power supply, the two anode plates are connected in parallel to the positive electrode of the power supply, and the cathode plate is connected to the negative electrode of the power supply; And / or, the organic electrochemical reactor further comprises a stirring system, and the stirring system is a magnetic stirring system; And / or, the organic electrochemical reactor further comprises a control system, which is connected to a power supply and a pump system and is used to control the voltage, current and flow of the reaction liquid of the reaction.

8. The organic electrochemical reactor according to claim 7, characterized in that An annular cavity interlayer is formed between the outer shell of the reactor and the inner wall of the reactor, and the annular cavity interlayer is used to pass heat exchange medium. A heat exchange medium inlet and a heat exchange medium outlet for the flow of the heat exchange medium are provided on the shell. The heat exchange system formed by the annular cavity interlayer, the heat exchange medium inlet and the heat exchange medium outlet and the required heat exchange pipelines constitutes the heat exchanger.

9. A continuous reaction device, characterized in that: It comprises at least three organic electrochemical reactors according to any one of claims 1 to 8, wherein the plurality of organic electrochemical reactors are connected in series in sequence; Each of the reactors is provided with a feed end and a discharge end, and along the material flow direction, the discharge end of the previous reactor is connected to the feed end of the next reactor; The anode plate, the cathode plate and the cathode plate in each reactor are arranged in sequence from the feed end to the discharge end.

10. The continuous reaction device according to claim 9, characterized in that: The feed end of the reactor comprises a feed pipe, one end of which is inserted into the reactor and located on the outside of the anode plate close to the feed end, and the other end of which is located outside the reactor, and the outside of the anode plate refers to the side of the anode plate close to the inner wall of the reactor; And / or, the feed end of the reactor comprises a discharge pipe, one end of which is inserted into the reactor and located on the outside of the anode plate near the discharge end, and the other end of which is located outside the reactor; And / or, a metering pump is provided on the feed pipe; And / or, a metering pump is provided on the discharge pipe; And / or, the number of the organic electrochemical reactors is 5.

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