A microchannel reactor and system

Abstract

The present invention relates to a microchannel reactor and system, comprising a first middle plate and a second middle plate stacked together, and a mixing flow channel is formed between the first middle plate and the second middle plate, the mixing flow channel comprises a plurality of flow channel units connected in sequence, and the flow channel unit comprises an input flow channel, a full mixed flow micro-reaction unit, a connecting flow channel and a buffer flow channel, wherein the input flow channel is connected to the full mixed flow micro-reaction unit at the head end, the buffer flow channel is connected to the full mixed flow micro-reaction unit at the end, adjacent full mixed flow micro-reaction units are connected through corresponding connecting flow channels, the first material inlet and the second material inlet are both connected to the input flow channel of the head end flow channel unit, the mixed liquid outlet is connected to the buffer flow channel of the end flow channel unit, and the buffer flow channel of any flow channel unit is connected to the input flow channel of the adjacent flow channel unit. The present invention achieves the purpose of rapid, multiple and uniform mixing of fluids by alternating high speed and buffering, and can realize accurate control of reaction temperature.

Description

Technical Field

[0001] The present invention relates to the technical field of reaction equipment, and particularly to a microchannel reactor and system. Background Art

[0002] In the chemical industry, most raw material mixing reactions require a certain temperature, pressure, or the provision of a specified catalyst to proceed. Especially in the field of microreaction systems, after the raw materials transported by volumetric conveying equipment enter the reactor, due to the initial mixing of the raw materials not reaching the required degree, the residence time of the raw materials in the reactor often increases, affecting the reaction efficiency. Experiments show that in a microreaction system, the addition of a front-end mixer can significantly promote the reaction efficiency, product conversion rate, and yield.

[0003] The existing micro mixer has two fluid input devices and one fluid output device on its outer shell. And the existing micro mixer usually includes multiple mixing plates stacked on top of each other. The inlet holes of the mixing plates form secondary channels for input products, and the mixing areas of the mixing plates form the main channels for output products. The main channels between the multiple mixing areas of the multiple mixing plates are connected in sequence, and the secondary channels are also connected in sequence. By adopting the above scheme, two different fluids can be respectively input into two different secondary channels through the two fluid input devices, and then enter the mixing area through the secondary channels. After mixing and reacting in the mixing area, they flow out from the main channel of the mixing area. However, when this structure works, the materials can only be mixed once in one mixing area. When the primary mixing is uneven, the product after the primary mixing cannot be mixed again, and the mixing effect is not ideal. In addition, each mixing plate is fixed by the outer shell, and only a fixed number of mixing plates can be placed in one outer shell, so the flexibility of use is poor and the applicable range is relatively narrow.

[0004] In addition, during the chemical reaction process, precise control of the reaction temperature, good mixing state of the materials, etc. all play important roles in the reaction effect. Currently, the reaction channels and heat dissipation channels of the plate-type microreactors used are processed on two substrates respectively, and then fixed together by corresponding fastening methods. The reaction channels and heat dissipation channels of this structure are not in direct contact, and the heat in the reaction channels needs to be transferred to the heat dissipation channels through the two substrates, resulting in low heat transfer efficiency. This structure also requires additional fastening and sealing, which not only increases the cost, volume, and weight, but also brings the risk of heat dissipation channel seal failure. Summary of the Invention

[0005] The purpose of the present invention is to provide a microchannel reactor and system, which achieve the purpose of rapid, multiple, and uniform mixing of fluids in the form of alternating high speed and buffering, and the heat exchange flow channels are in direct contact with the flow channel units to take away heat, enabling precise control of the reaction temperature.

[0006] The object of the present invention is achieved by the following technical solutions:

[0007] A microchannel reactor includes a first intermediate plate and a second intermediate plate stacked together, and a mixing channel is formed between the first intermediate plate and the second intermediate plate. The mixing channel includes a plurality of sequentially connected channel units, and each channel unit includes an input channel, a continuous stirred tank microreaction unit, a connecting channel, and a buffer channel. The input channel is connected to the continuous stirred tank microreaction unit at the head end, the buffer channel is connected to the continuous stirred tank microreaction unit at the tail end, adjacent continuous stirred tank microreaction units are connected through corresponding connecting channels, a first material inlet and a second material inlet are both connected to the input channel of the head-end channel unit, a mixed liquid outlet is connected to the buffer channel of the tail-end channel unit, and the buffer channel of any channel unit is communicated with the input channel of the adjacent channel unit.

[0008] A first spoiler, a second spoiler, and a flow splitting module are provided in the unit cavity of the continuous stirred tank microreaction unit. The first spoiler and the second spoiler are symmetrically arranged on both sides of the flow splitting module. A first channel is formed between the first spoiler and the unit cavity, and a second channel is formed between the first spoiler and the flow splitting module. The second channel is narrow at both ends and wide in the middle, and the inlet end of the second channel is narrower than the outlet end. A third channel is formed between the flow splitting module and the second spoiler. The third channel is narrow at both ends and wide in the middle, and the outlet end of the third channel is narrower than the inlet end. A fourth channel is formed between the second spoiler and the unit cavity. The middle parts of the second channel and the third channel form a reaction cavity for the material to stay.

[0009] The diameters of the input channel and the connecting channel are both smaller than the diameter of the buffer channel.

[0010] The microreactor further includes fixed side plates on both sides, and heat exchange channels are formed between the first intermediate plate and the corresponding fixed side plate and between the second intermediate plate and the corresponding fixed side plate. The input end of the heat exchange channel is communicated with a heat exchange fluid inlet, and the output end of the heat exchange channel is communicated with a heat exchange fluid outlet.

[0011] The shape of the heat exchange channel matches the shape of the mixing channel.

[0012] The first intermediate plate, the second intermediate plate, and the fixed side plates form a microreactor plate group.

[0013] A microchannel reactor system according to the above description includes a first storage tank, a second storage tank, a cooling and heating integrated machine, a splitting valve, a plurality of delay reactors, and a plurality of microchannel reactors as described in claim 1. The first storage tank is connected to the input end of the splitting valve through a first pipeline. The first material inlets on each microchannel reactor are respectively connected to the corresponding output ends on the splitting valve through corresponding connection branches, and control valves for controlling the on-off of the pipeline are provided on each connection branch. The second storage tank is connected to the second material inlet on the first microchannel reactor through a second pipeline. The mixed liquid outlet of any microchannel reactor is connected to the second material inlet of the adjacent microchannel reactor through an intermediate pipeline, and a delay reactor is provided on the intermediate pipeline. The last microchannel reactor is connected to a connection pipeline, and a delay reactor is also provided on the connection pipeline. One end of the cooling and heating integrated machine is connected to the heat exchange flow inlet of the first microchannel reactor, and the other end is connected to the heat exchange flow outlet of the last microchannel reactor. The heat exchange flow outlet of any microchannel reactor is connected to the heat exchange flow inlet of the adjacent microchannel reactor through a pipeline.

[0014] A first metering pump, a first one-way valve, a first heat exchanger, a first temperature sensor, and a first pressure sensor are successively provided on the first pipeline; a second metering pump, a second one-way valve, a second heat exchanger, a second temperature sensor, and a second pressure sensor are successively provided on the second pipeline.

[0015] The advantages and positive effects of the present invention are as follows:

[0016] 1. The microchannel reactor of the present invention includes a plurality of flow channel units, and each flow channel unit includes a plurality of continuous stirred tank microreaction units. The continuous stirred tank microreaction units achieve forced mixing of materials in the form of alternating high speed and buffering. Moreover, a reaction cavity with a certain volume will be formed in the wide part between the second flow channel and the third flow channel in the continuous stirred tank microreaction unit, enabling the materials to stay in the channel for 0.01 - 10 seconds for reaction. In addition, the diameters of the input flow channel and the connection flow channel of the flow channel unit are both smaller than that of the buffer flow channel, and the mixed liquid in the input flow channel and the connection flow channel flows out in a high-speed jet shape, while the flow rate of the mixed liquid in the buffer flow channel slows down, thereby further forming the form of alternating high speed and buffering to achieve the purpose of rapid, multiple, and uniform mixing of the fluid.

[0017] 2. The present invention also provides a heat exchange flow channel matching the mixing flow channel. The heat exchange flow channel directly contacts and takes away heat in cooperation with the flow channel unit in the form of high-speed buffering, enabling precise control of the reaction temperature. Moreover, the heat exchange flow channel is arranged between two intermediate plates and the corresponding fixed side plates. This design enables the heat in the reaction channel to be directly transferred to the heat exchange flow channel through the intermediate plate itself, with the heat exchange efficiency increased by more than 30% and not easily blocked, and better sealing performance.

[0018] 3. The microchannel reactor of the present invention can be combined with a delay reactor or the like to form a system, which can be used in liquid-liquid (nitration reaction) and gas-liquid reactions. It has the advantages of fast reaction speed, high continuous efficiency, accurate control of reaction temperature and high product selectivity. It can also be used in liquid-liquid reactions with the advantages of fast reaction speed, high continuous efficiency, high accurate reaction yield and few side reactions. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic structural diagram of the present invention.

[0020] Figure 2 is Figure 1 the schematic external view of the present invention in

[0021] Figure 3 is Figure 1 the schematic diagram of the mixing flow channel in

[0022] Figure 4 is Figure 3 the schematic structural diagram of the continuous stirred tank microreaction unit in

[0023] Figure 5 is Figure 1 the schematic diagram of the heat exchange flow channel in

[0024] Figure 6 is a schematic diagram of a device system adopting the present invention.

[0025] Among them, 1 is the first storage tank, 2 is the second storage tank, 3 is the first pipeline, 301 is the first metering pump, 302 is the first one-way valve, 303 is the first heat exchanger, 4 is the second pipeline, 401 is the second metering pump, 402 is the second one-way valve, 403 is the second heat exchanger, 5 is the sampling valve, 6 is the splitting valve, 7 is the cooling and heating integrated machine, 801 is the mixed liquid outlet, 802 is the second material inlet, 803 is the first material inlet, 804 is the heat exchange flow inlet, 805 is the heat exchange flow outlet, 806 is the input flow channel, 807 is the continuous stirred tank microreaction unit, 8071 is the first spoiler, 8072 is the second spoiler, 8073 is the splitting module, 8074 is the first flow channel, 8075 is the second flow channel, 8076 is the third flow channel, 8077 is the fourth flow channel, 808 is the connecting flow channel, 809 is the buffer flow channel, 810 is the first intermediate plate, 811 is the second intermediate plate, 812 is the fixed side plate, and 9 is the delay reactor. DETAILED DESCRIPTION OF THE INVENTION

[0026] The present invention will be further described in detail below with reference to the drawings.

[0027] As Figures 1 to 5As shown, the present invention includes a first intermediate plate 810 and a second intermediate plate 811 stacked together, and a mixing channel is formed between the first intermediate plate 810 and the second intermediate plate 811. As Figure 3 shown, the mixing channel includes a plurality of sequentially connected channel units, and each channel unit includes an input channel 806, a complete mixing micro-reaction unit 807, a connecting channel 808, and a buffer channel 809. The input channel 806 is connected to the complete mixing micro-reaction unit 807 at the head end, the buffer channel 809 is connected to the complete mixing micro-reaction unit 807 at the tail end, adjacent complete mixing micro-reaction units 807 are connected by corresponding connecting channels 808, the first material inlet 803 and the second material inlet 802 are both connected to the input channel 806 of the channel unit at the head end, the mixed liquid outlet 801 is connected to the buffer channel 809 of the channel unit at the tail end, and the buffer channel 809 of any intermediate channel unit is communicated with the input channel 806 of the adjacent channel unit.

[0028] As Figure 4 shown, the unit cavity of the complete mixing micro-reaction unit 807 is provided with a first flow disturbing plate 8071, a second flow disturbing plate 8072, and a flow splitting module 8073. The first flow disturbing plate 8071 and the second flow disturbing plate 8072 are symmetrically arranged on both sides of the flow splitting module 8073. A first channel 8074 is formed between the first flow disturbing plate 8071 and the unit cavity, and a second channel 8075 is formed between the first flow disturbing plate 8071 and the flow splitting module 8073. The second channel 8075 is in the shape of narrow at both ends and wide in the middle, and the inlet end of the second channel 8075 is narrower than the outlet end. A third channel 8076 is formed between the flow splitting module 8073 and the second flow disturbing plate 8072. The third channel 8076 is in the shape of narrow at both ends and wide in the middle, and the outlet end of the third channel 8076 is narrower than the inlet end. A fourth channel 8077 is formed between the second flow disturbing plate 8072 and the unit cavity. After the mixed liquid is output from the first channel 8074, since the inlet end of the second channel 8075 is the narrow end, part of the mixed liquid first flows into the second channel 8075 at a high speed and then the flow rate slows down. Another part of the mixed liquid first enters the third channel 8076 and then flows out from the outlet end of the third channel 8076 at a high speed and is mixed with the mixed liquid in the second channel 8075 again and then input into the fourth channel 8077, so as to realize the forced mixing of the materials in the form of high speed and buffering. Moreover, a reaction cavity with a certain volume will be formed in the wide part in the middle of the second channel 8075 and the third channel 8076, so that the materials stay in the channel for 0.01 - 10 seconds for reaction.

[0029] As Figures 3 to 4As shown, the diameters of the input flow channel 806 and the connecting flow channel 808 are both smaller than the diameter of the buffer flow channel 809. The mixed liquid in the input flow channel 806 and the connecting flow channel 808 flows out in a high-speed jet shape, while the flow rate of the mixed liquid in the buffer flow channel 809 slows down, so as to further form an alternating form of high speed and buffering, achieving the purpose of rapid, multiple and uniform mixing of the fluid.

[0030] As Figure 1 shown, the present invention further includes fixed side plates 812 on both sides. Heat exchange flow channels are formed between the first intermediate plate 810 and the corresponding fixed side plate 812, and between the second intermediate plate 811 and the corresponding fixed side plate 812. As Figure 5 shown, the shape of the heat exchange flow channel matches the mixed flow channel and is in direct contact with the mixed flow channel. In this embodiment, the mixed flow channel is in a reciprocating bending shape, and the heat exchange flow channel is also in a reciprocating bending shape to correspondingly cover each flow channel unit of the mixed flow channel. The input end of the heat exchange flow channel is communicated with the heat exchange flow inlet 804, and the output end of the heat exchange flow channel is communicated with the heat exchange flow outlet 805. The present invention uses the heat exchange flow channel to cooperate with the flow channel unit in the form of high-speed buffering to take away heat, and can achieve precise control of the reaction temperature.

[0031] As Figure 1 shown, the first intermediate plate 810, the second intermediate plate 811 and the fixed side plate 812 form a microreactor plate group. When the present invention is used, one or more microreactor plate groups can be adopted according to needs. Adjacent microreactor plate groups are separated by the fixed side plate 812, and the fixed side plate 812 has a heat conduction effect.

[0032] The present invention can be made by traditional processing methods (chemical etching, subtractive manufacturing) or 3D printing (additive manufacturing is sintered from metal powder with extremely high precision). The number of flow channel units and the number of perfect mixing microreaction units 807 in each flow channel unit are designed according to actual needs.

[0033] As Figure 6As shown in the figure, the microchannel reactor of the present invention can be combined with a delay reactor 9, etc. to form a system. The system includes a first storage tank 1, a second storage tank 2, a cooling and heating integrated machine 7, a splitting valve 6, a plurality of delay reactors 9, and a plurality of microchannel reactors of the present invention. Among them, the first storage tank 1 is connected to the input end of the splitting valve 6 through a first pipeline 3, and a first metering pump 301, a first one-way valve 302, a first heat exchanger 303, a first temperature sensor, and a first pressure sensor are sequentially arranged on the first pipeline 3. The first material inlets 803 on each microchannel reactor are respectively connected to the corresponding output ends on the splitting valve 6 through corresponding connecting branches, and a control valve for controlling the on-off of the pipeline is arranged on each connecting branch. The second storage tank 2 is connected to the second material inlet 802 on the first microchannel reactor through a second pipeline 4, and a second metering pump 401, a second one-way valve 402, a second heat exchanger 403, a second temperature sensor, and a second pressure sensor are sequentially arranged on the second pipeline 4. The mixed liquid outlet 801 of any microchannel reactor is connected to the second material inlet 802 of the adjacent microchannel reactor through an intermediate pipeline, and a delay reactor 9 is arranged on the intermediate pipeline. The last microchannel reactor is connected to the next unit through a connecting pipeline, and a delay reactor 9 is also arranged on the connecting pipeline. One end of the cooling and heating integrated machine 7 is connected to the heat exchange flow inlet 804 of the first microchannel reactor, and the other end is connected to the heat exchange flow outlet 805 of the last microchannel reactor. The heat exchange flow outlet 805 of any microchannel reactor is connected to the heat exchange flow inlet 804 of the adjacent microchannel reactor through a pipeline. The cooling and heating integrated machine and the splitting valve are both well-known technologies in the art and are commercially available products. The delay reactor 9 can adopt a coiled tubular and cylindrical reactor with a heat exchange jacket, which is also a well-known technology in the art and is a commercially available product.

[0034] The working principle of the present invention is as follows:

[0035] As Figures 1 to 5As shown, when the present invention is working, material A enters the mixing channel from the first material inlet 803, and material B enters the mixing channel from the second material inlet 802. The mixing channel includes a plurality of channel units, each of which includes a plurality of full-mixed flow micro-reaction units 807. The full-mixed flow micro-reaction unit 807 realizes forced mixing of logistics A and material B in the form of alternating high speed and buffering, and the wide part between the second channel 8075 and the third channel 8076 in the full-mixed flow micro-reaction unit 807 will form a reaction cavity of a certain volume, so that the material stays in the channel for 0.01- 10 seconds reaction, in addition, the diameters of the input channel 806 and the connecting channel 808 of the channel unit are smaller than the buffer channel 809, and the mixed liquids in the input channel 806 and the connecting channel 808 flow out in a high-speed jet shape, while the mixed liquid in the buffer channel 809 slows down, thereby further forming a high-speed and buffered form, achieving the purpose of rapid, multiple and uniform mixing of fluids, and the microchannel reactor is also provided with a heat exchange channel matching the mixing channel, which directly contacts the mixing channel to take away the heat, and can achieve precise control of the reaction temperature.

[0036] The present invention uses chemical probe technology to characterize the mixing performance, as follows:

[0037] The reaction system used in the present invention is:

[0038] H 2 BO 3 - +H + →H 3 BO 3 ;

[0039] 5I - +IO 3 - +6H + →3I 2 +3H 2 O;

[0040] The resulting iodine will react with I - Reaction I 3 - :

[0041]

[0042] Ultraviolet absorption spectroscopy can detect I 3 - concentration, and then calculate Xs:

[0043]

[0044] ​​In the above formula, Xs is the separation index. The smaller its value, the better the mixing performance. When it is ideal mixing, Xs is 0, and when the mixing performance is very poor, Xs is 1.

[0045] When the present invention was tested, two solutions were prepared: Solution B, containing sulfuric acid with a concentration of 0.02253 mol / L; in Solution A, it contained H 2 BO 3 - , 0.03 mol / L of I - , 0.006 mol / L of IO 3 - .

[0046] Test Experiment 1: Solution B flows in through the second material inlet 802, and Solution A flows in through the first material inlet 803. The two enter the microchannel reactor of the present invention simultaneously. After being mixed by the complete mixing micro-reaction unit 807 of each flow channel unit and the connecting flow channel 808, it is finally output from the mixed liquid outlet 801. In this test experiment, a total of six groups of flow channel units are provided, and each group of flow channel units includes five complete mixing micro-reaction units 807 to achieve the purpose of sufficient mixing and efficient mass transfer.

[0047] In this test experiment, the flow rate of Solution A is 2 L / h, and the flow rate of Solution B is 2 L / h. Finally, the measured Xs is 0.002.

[0048] Test Experiment 2: Solution B flows in through the second material inlet 802, and Solution A flows in through the first material inlet 803. The two enter the microchannel reactor of the present invention simultaneously. After being mixed by the complete mixing micro-reaction unit 807 of each flow channel unit and the connecting flow channel 808, it is finally output from the mixed liquid outlet 801. Similarly, this test experiment has a total of six groups of flow channel units, and each group of flow channel units includes five complete mixing micro-reaction units 807 to achieve the purpose of sufficient mixing and efficient mass transfer.

[0049] In this test experiment, the flow rate of Solution A is 1 L / h, and the flow rate of Solution B is 1 L / h. The measured Xs is 0.006.

[0050] As Figure 6 shown, the microchannel reactor of the present invention can be combined with a delay reactor 9, etc. to form a system. Several application examples are listed below to further illustrate the above system.

[0051] Application Example 1:

[0052] Using pure trifluoromethoxybenzene as Material B and a mixed acid of fuming nitric acid and concentrated sulfuric acid as nitrating agent Material A, where the mass concentration of nitric acid in nitrating agent Material A is 24.1%, and the mass concentration of water is 2%. As Figure 6As shown in the figure, material B (raw material) is input at a flow rate of 10 mL / min through the second metering pump 401, and nitrating agent material A is input at a flow rate of 11 mL / min through the first metering pump 301. That is, in terms of molar amount, the feed ratio of nitric acid to trifluoromethoxybenzene is 1.0. Material A and material B are strongly mixed and initially react in the reaction zone system composed of 3 - 5 microchannel reactors of the present invention and the delay reactor 9 (it is tested that the conversion of the reactants is 70% - 80%). The mixed material stays in the delay reactor ( Figure 6 not marked in the figure) for 180 seconds to obtain the product nitrotrifluoromethoxybenzene and waste acid. The two phases are separated, the upper-layer product is combined, and the product is washed alternately with water and alkaline water until it is neutral. It is detected by an Agilent 7890 gas chromatograph, the chromatographic column is DB-1701, and the concentrations of meta-, para-, ortho-mononitrates and dinitrates in the product are quantified by peak area. After analysis: the raw material conversion rate is 99.8%, the meta-, para-, and ortho-mononitrates are 0.02%, 92.7%, 7.08% respectively, and the dinitrate is 0.00%.

[0053] Comparative Example 1:

[0054] Trifluoromethoxybenzene with the same molar ratio as in Application Example 1 was added to a 500 ml four-necked flask. Fuming nitric acid and sulfuric acid with the same molar ratio as in Application Example 1 were mixed and slowly added dropwise to the 500 ml four-necked flask. The dropping time was controlled within 4.5 h, and then it was kept warm at 0 - 5 °C for 12 h to obtain the product nitrotrifluoromethoxybenzene and waste acid. The two phases were separated, the upper-layer product was combined, and the product was washed alternately with water and alkaline water until it was neutral. The post-treatment scheme was the same as that in Comparative Example 1. The batch reaction process took 18 h, the conversion rate was 99.0%, the meta-, para-, and ortho-mononitrates were 0.12%, 90.2%, 9.18% respectively, and the dinitrate was 0.50%

[0055] From the above Application Example 1 and Comparative Example 1, it can be shown that the system formed by the microchannel reactor of the present invention together with the delay reactor 9 has the advantages of fast reaction speed, high continuous efficiency, precise control of the reaction temperature, and high product selectivity in the liquid-liquid nitration reaction.

[0056] Application Example 2: Preparation of fluorescent brightener 351.

[0057] Prepare material B: 500 g of 4,4'-bis(diethoxyphosphonomethyl)biphenyl, 500 g of sodium o-sulfonate benzaldehyde and an appropriate amount of N,N-dimethylformamide, and mix and preheat to 60 - 80 °C.

[0058] Prepare material A: 550 g of a 30% sodium methoxide methanol solution and 200 g of N,N-dimethylformamide, and mix and preheat to 30 °C.

[0059] The reaction equation is:

[0060]

[0061] As Figure 6 shown, material B is input into the reaction zone system through the second metering pump 401, and material A is input into the reaction zone system through the first metering pump 301. In each microchannel reactor in the reaction zone system, material B flows in through the second material inlet 802, and material A flows in through the first material inlet 803. The two enter the microchannel reactor of the present invention simultaneously. After mixing in the complete mixing micro-reaction unit 807 and the connecting channel 808 of each flow channel unit, finally, it is output from the mixed liquid outlet 801. After passing through Figure 6 the microchannel reactor and the delay reactor 9 as shown, the mixed material then passes through the subsequent reaction zone to obtain a reaction solution, and then distillation is carried out at 150 - 160 °C; after the distillation is completed, an aqueous solution of sodium chloride with a concentration of 3% is added, cooled, filtered, and dried to obtain the target product 4,4-bis(2-sulfonatostyryl)biphenyl. After testing, the raw material conversion rate reaches 100%, and the selectivity of the product is 99.99%.

[0062] Comparative Example 2:

[0063] 4,4'-bis(diethoxyphosphonomethyl) with the same molar ratio as in Application Example 2, sodium o-sulfobenzaldehyde, and dimethylformamide were added to a 500 ml four-necked flask. After the temperature was raised to 53 °C in a water bath, the materials were dissolved. Sodium methoxide was added dropwise to the four-necked flask, and the addition was completed in about 3 hours. Then, it was kept at 50 °C for 5 h. The sample in the four-necked flask was quenched with acetic acid, and the pH value was adjusted to about 7.5. Then, post-treatment was carried out, and the post-treatment scheme was the same as that in Application Example 2. The batch reaction process takes 8 h, the conversion rate is 99%, and the selectivity is 95%.

[0064] From the above Application Example 2 and Comparative Example 2, it can be shown that the system formed by connecting the microchannel reactor of the present invention and the delay reactor 9 has the advantages of fast reaction speed, high continuous efficiency, high accurate reaction yield, and few side reactions in liquid-liquid reactions.

Claims

1. A microchannel reactor, characterized in that: The invention comprises a first middle plate (810) and a second middle plate (811) stacked together, wherein a mixing flow channel is formed between the first middle plate (810) and the second middle plate (811), wherein the mixing flow channel comprises a plurality of flow channel units connected in sequence, and wherein the flow channel units comprise an input flow channel (806), a full mixed flow micro-reaction unit (807), a connecting flow channel (808) and a buffer flow channel (809), wherein the input flow channel (806) is connected to the full mixed flow micro-reaction unit (807) at the head end, and the buffer flow channel (809) is connected to the input flow channel (806). The first material inlet (803) and the second material inlet (802) are both connected to the input flow channel (806) of the head flow channel unit, the mixed liquid outlet (801) is connected to the buffer flow channel (809) of the end flow channel unit, and the buffer flow channel (809) of any flow channel unit is connected to the input flow channel (806) of the adjacent flow channel unit; The unit cavity of the fully mixed flow micro-reaction unit (807) is provided with a first spoiler (8071), a second spoiler (8072) and a flow diversion module (8073), wherein the first spoiler (8071) and the second spoiler (8072) are symmetrically arranged on both sides of the flow diversion module (8073), a first flow channel (8074) is formed between the first spoiler (8071) and the unit cavity, and a second flow channel (8075) is formed between the first spoiler (8071) and the flow diversion module (8073), and the second flow channel (8075) is two The second flow channel (8075) has a narrow shape at the beginning and a wide shape in the middle, and the inlet end of the second flow channel (8075) is narrower than the outlet end. A third flow channel (8076) is formed between the diversion module (8073) and the second spoiler (8072). The third flow channel (8076) has a narrow shape at both ends and a wide shape in the middle, and the outlet end of the third flow channel (8076) is narrower than the inlet end. A fourth flow channel (8077) is formed between the second spoiler (8072) and the unit cavity. A reaction cavity for material retention is formed in the middle of the second flow channel (8075) and the middle of the third flow channel (8076).

2. The microchannel reactor according to claim 1, characterized in that: The diameter of the input flow channel (806) and the diameter of the connecting flow channel (808) are both smaller than the diameter of the buffer flow channel (809).

3. The microchannel reactor according to claim 1, characterized in that: It includes fixed side plates (812) on both sides, and heat exchange channels are formed between the first middle plate (810) and the fixed side plate (812) on the corresponding side, and between the second middle plate (811) and the fixed side plate (812) on the corresponding side. The input end of the heat exchange channel is connected to the heat exchange flow inlet (804), and the output end of the heat exchange channel is connected to the heat exchange flow outlet (805).

4. The microchannel reactor according to claim 3, characterized in that: The shape of the heat exchange flow channel matches that of the mixing flow channel.

5. The microchannel reactor according to claim 4, characterized in that: The first middle plate (810), the second middle plate (811) and the fixed side plate (812) form a microreactor plate set.

6. A microchannel reactor system according to claim 3, characterized in that: The invention comprises a first storage tank (1), a second storage tank (2), a hot and cold integrated machine (7), a stock splitting valve (6), a plurality of time-delay reactors (9) and a plurality of microchannel reactors as claimed in claim 3, wherein the first storage tank (1) is connected to the input end of the stock splitting valve (6) through a first pipeline (3), the first material inlet (803) on each microchannel reactor is connected to the corresponding output end on the stock splitting valve (6) through a corresponding connecting branch, and each connecting branch is provided with a control valve for controlling the on-off of the pipeline, the second storage tank (2) is connected to the second material inlet (802) on the first microchannel reactor through a second pipeline (4), and any The mixed liquid outlet (801) of a microchannel reactor is connected to the second material inlet (802) of an adjacent microchannel reactor through an intermediate pipeline, and a time delay reactor (9) is provided on the intermediate pipeline. The last microchannel reactor is connected to a connecting pipeline, and a time delay reactor (9) is also provided on the connecting pipeline. One end of the hot and cold integrated machine (7) is connected to the heat exchange flow inlet (804) of the first microchannel reactor and the other end is connected to the heat exchange flow outlet (805) of the last microchannel reactor. The heat exchange flow outlet (805) of any microchannel reactor is connected to the heat exchange flow inlet (804) of the adjacent microchannel reactor through a pipeline.

7. The microchannel reactor system according to claim 6, characterized in that: The first pipeline (3) is provided with a first metering pump (301), a first non-return valve (302), a first heat exchanger (303), a first temperature sensor and a first pressure sensor in sequence; the second pipeline (4) is provided with a second metering pump (401), a second non-return valve (402), a second heat exchanger (403), a second temperature sensor and a second pressure sensor in sequence.

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