A solvent-free hydrogenation process for the production of m-aminotrifluorotoluene

Abstract

This invention belongs to the field of m-aminotrifluorotoluene production technology, specifically a solvent-free hydrogenation process for producing m-aminotrifluorotoluene, comprising: S1: Introducing nitrogen gas at 80℃-85℃ into the reactor through a nitrogen inlet to replace and purge the air inside the reactor; S2: Adding raw materials and catalyst into the reactor; maintaining nitrogen purging during the process and raising the temperature to 80℃; S3: First stopping the nitrogen gas supply, then introducing hydrogen gas to start the reaction; the hydrogen temperature is 80℃-90℃, the pressure is 2.5-5 MPa, and the reaction time is 6 hours; S4: After the reaction is completed, cooling to 65℃, and recovering the product filtrate and catalyst sequentially under normal pressure. Then, the filtrate is recovered by negative pressure distillation to obtain the product. This invention employs a solvent-free process, reducing production costs and methanol wastewater. Simultaneously, rotating, raising, impacting, and agitating the catalyst inside the reactor prevents catalyst aggregation, increases the contact area between the catalyst and raw materials, and improves reaction efficiency.

Description

Technical Field

[0001] This invention belongs to the field of m-aminotrifluorotoluene production technology, specifically a solvent-free hydrogenation process for producing m-aminotrifluorotoluene. Background Technology

[0002] m-Aminotrifluorotoluene, also known as 3-aminotrifluorotoluene or m-trifluoromethylaniline, is an important raw material for chemical pharmaceuticals. It can be used to synthesize a series of fluorinated drugs, exhibiting lower toxicity and better physiological activity compared to traditional medicines. For example, fluphenazine has an antiemetic effect 200 times stronger than chlorpromazine, with a faster onset and longer duration of action. Based on these advantages of fluorinated drugs, the development and utilization of m-trifluoromethylaniline is still under further research, and its applications are increasingly evident. It can serve as an upstream raw material for many drugs, including the anti-ulcer drug monifluethyl ester, the anti-inflammatory and analgesic drugs flufenamic acid and niflufenic acid, the diuretic drugs hydrofluorothiazide and benzflufenic acid, the analgesic drugs trifluoperazine and fluphenazine, the skin bactericide trifluorodiphenylurea, the anti-prostate cancer drugs flutamide and niflumetedin, and the potent tranquilizers and antipsychotics flufenoxuronide and flufenoxuronide.

[0003] Existing methods for synthesizing m-aminotrifluorotoluene mainly include amination, dehalogenation reduction, and nitro reduction.

[0004] The ammoniation method involves reacting m-chlorotrifluorotoluene and sodium amino in liquid ammonia to produce m-aminotrifluorotoluene. The raw material is usually prepared by chlorination of trifluorotoluene. The chlorination product is a mixture of three isomers: ortho-, m-, and para-chlorotrifluorotoluene. The m- and para-isomers have very low melting points and the same boiling point, making them difficult to separate. In addition, the chlorination yield is only 52%.

[0005] The nitro reduction method is used to reduce m-nitrotrifluorotoluene to prepare m-aminotrifluorotoluene. It mainly includes the iron powder reduction method, the electrochemical reduction method, and the catalytic hydrogenation method. However, the iron powder reduction method and the electrochemical reduction method have problems such as large amount of "three wastes", environmental pollution, high energy consumption, and immature technology, which make it difficult to carry out industrial production.

[0006] The catalytic hydrogenation method uses trifluorotoluene as a raw material, which is nitrated with mixed acid, washed and distilled under reduced pressure to obtain ortho-, meta-, and para-trifluoromethylnitrobenzene, respectively. Then, under Pd / C catalysis and anhydrous ethanol as a solvent, hydrogenation reduction is carried out at atmospheric pressure to obtain the target compound.

[0007] Meanwhile, the catalytic hydrogenation reduction method requires the use of solvents such as methanol and ethanol as reaction media, which poses certain hazards to the surrounding environment and personnel. In addition, the reaction of methanol and other solvents with the reduced amino group produces amine toluene as a byproduct, affecting the purity of the product. Furthermore, the synthesized product is mixed with methanol, requiring further distillation to separate the product from the methanol. This adds a methanol distillation recovery step, reduces production efficiency, and increases energy consumption during the production process. Moreover, the added methanol distillation recovery step requires the use of dedicated methanol wastewater treatment equipment, leading to increased equipment investment costs. Summary of the Invention

[0008] To overcome the shortcomings of existing technologies, a solvent-free process is adopted to reduce production costs and methanol wastewater. At the same time, the catalyst in the reactor is rotated and raised to promote contact between the catalyst and the raw materials, thereby improving the reaction efficiency. Furthermore, the catalyst in the reactor is impacted and stirred to prevent catalyst aggregation and accumulation. This invention proposes a solvent-free hydrogenation process for the production of m-aminotrifluorotoluene.

[0009] The technical solution adopted by this invention to solve its technical problem is: a solventless hydrogenation process for producing m-aminotrifluorotoluene, the method comprising the following steps:

[0010] S1: Nitrogen gas is introduced into the reactor through the nitrogen port to replace and purge the air inside the reactor; the temperature of the nitrogen gas used for air replacement is 80℃-85℃;

[0011] S2: Add raw material m-nitrotrifluorotoluene and catalyst Raney nickel to the reactor; during the process, maintain nitrogen purging and use the reactor's heating mechanism to heat the reactor, so that the raw material is rapidly heated to 80°C;

[0012] S3: First stop the nitrogen gas supply to the reactor, then introduce hydrogen gas into the reactor to start the reaction; the hydrogen temperature is 80℃-90℃, the pressure inside the reactor is 2.5-5Mpa, and the reaction time is 6 hours.

[0013] S4: After the reaction is complete, cool to 65°C, stop the hydrogen flow and purge with nitrogen. Then, recover the product filtrate under normal pressure, then recover the catalyst. After that, the filtrate is distilled under negative pressure at 0.1-0.12 MPa and 115-125°C to recover m-aminotrifluorotoluene.

[0014] In step S2, the mass ratio of raw material to catalyst is 1:0.001-0.0025, and the raw material and catalyst in the reactor are kept separate before the reaction begins.

[0015] Preferably, in step S1, nitrogen is first introduced to purge and replace the air, and the nitrogen after replacement is stored separately. In steps S1 and S2, nitrogen purging is performed continuously, and the nitrogen generated by purging is heated and then recycled. In step S4, nitrogen is introduced to replace the residual hydrogen in the reactor, and the nitrogen generated after replacement is stored separately.

[0016] Preferably, the reactor includes a vessel body, on which a motor and a rotating shaft are mounted. A connecting ring is mounted on the rotating shaft, and a nitrogen port and a hydrogen port are mounted on the connecting ring. A distribution rod is mounted on the rotating shaft, and a communicating cavity is formed inside the rotating shaft. The connecting ring and the distribution rod are interconnected through the communicating cavity. Micropores are formed on the distribution rod, and a scraper is installed between the distribution rod and the bottom surface of the vessel body.

[0017] The upper end of the vessel body is equipped with an exhaust port and a feed port, the lower end of the vessel body is equipped with a discharge port and a discharge outlet, a lifting guide rail is installed on the inner wall of the vessel body, a lifting ring is installed on the rotating shaft via a spline, a mesh frame box is installed on the lifting ring via a fixing rod, and the end of the fixing rod is in contact with the lifting guide rail;

[0018] A movable plate is installed on the bottom surface of the mesh frame box. The movable plate is connected to the inner wall of the mesh frame box by a spring. A tube is installed on the vessel body. An insertion tube is installed inside the installation tube. The lower end of the insertion tube is inserted into the mesh frame box. A lifting rod is installed inside the installation tube. The lifting rod and the insertion tube are connected by a thread. A catalyst port is installed on the installation tube.

[0019] Preferably, the inner wall of the wire mesh frame box is equipped with protruding plates, the protruding plates are installed in pairs, and multiple sets of the pairs of protruding plates are arranged inside the wire mesh frame box.

[0020] Preferably, the upper surface of the movable plate is arc-shaped, and there is a magnetic attraction between the movable plate and the raised plate.

[0021] Preferably, the wire mesh frame box has through holes, and the outlet of the through holes is inclined upward.

[0022] Preferably, a rotating ring is rotatably installed below the lifting ring, a swing rod is installed on the rotating ring, and an impact plate is installed on the swing rod. The impact plate corresponds to the mesh frame box, and the impact plate is located behind the mesh frame box in the direction of rotation within the reactor.

[0023] A damping block is provided on the lifting guide rail. The damping block is elastic. The end of the swing rod is in contact with the damping block. An elastic plate is installed on the end of the swing rod and the fixed rod near the inner wall of the vessel.

[0024] Preferably, a restraining net is installed between the impact plate and the wire mesh box.

[0025] The beneficial effects of this invention are as follows:

[0026] 1. The solventless hydrogenation process for producing m-aminotrifluorotoluene described in this invention reduces the reaction temperature and energy consumption by adopting a solventless process. The quality, conversion rate, and yield of the obtained pharmaceutical intermediate m-aminotrifluorotoluene are equal to or better than those of traditional processes. At the same time, the solventless process does not generate methanol wastewater, and the pharmaceutical intermediate products after the reaction are easy to separate, thereby improving production efficiency and reducing production costs.

[0027] 2. The solventless hydrogenation process for producing m-aminotrifluorotoluene described in this invention, by setting up a mesh frame box, fixing rods, and upgraded guide rails, allows the catalyst to be added synchronously with the raw materials. Furthermore, the added raw materials and catalyst are separated before the reaction, facilitating the replacement and removal of impurities such as air and moisture introduced during the addition of raw materials before the reaction. This ensures stable reaction and product quality. Simultaneously, the catalyst rotates and moves up and down within the reactor during the reaction, increasing the contact between the catalyst and the raw materials, improving reaction efficiency, and facilitating rapid separation of the catalyst and reaction products after the reaction, thus enabling catalyst separation, recovery, and reuse.

[0028] 3. The solventless hydrogenation process for producing m-aminotrifluorotoluene described in this invention, by setting up a swing rod, damping block, impact plate and limiting net, allows the impact plate to periodically move away from the mesh frame box and quickly approach and impact the mesh frame box during rotation. This causes the raw material between the impact plate and the mesh frame box to be rapidly squeezed and impacted into the mesh frame box, agitating and impacting the catalyst inside the mesh frame box, reducing the possibility of catalyst aggregation and accumulation, increasing the mutual contact between the catalyst and the raw material, and improving the reaction efficiency.

[0029] 4. The solventless hydrogenation process for producing m-aminotrifluorotoluene described in this invention uses a mesh frame box and raised plates to separate the catalysts within the mesh frame box, forming a columnar shape, and to increase the possibility of the catalysts moving radially along the reactor body within the mesh frame box, thereby avoiding catalyst accumulation and affecting reaction efficiency. Attached Figure Description

[0030] The invention will now be further described with reference to the accompanying drawings.

[0031] Figure 1 This is a flowchart of the production method of the present invention;

[0032] Figure 2 This is a perspective view of the reaction vessel used in the production method of the present invention; wherein, the supporting structure and heating mechanism are not shown.

[0033] Figure 3This is a schematic diagram of the reactor used in the production method of the present invention;

[0034] Figure 4 This is a schematic diagram of the structure of the reactor vessel of the present invention when the impact plate and the wire mesh box are separated from each other;

[0035] Figure 5 This is a schematic diagram of the structure when a catalyst is added inside the mesh frame box in the reactor of the present invention;

[0036] Figure 6 This is a schematic diagram of the structure of the mesh frame box in the reactor;

[0037] Figure 7 This is a schematic diagram of the distribution plate, scraper, and rotating shaft in the reactor.

[0038] In the diagram: 1. Reactor body; 11. Motor; 12. Nitrogen port; 13. Hydrogen port; 14. Exhaust port; 15. Discharge port; 16. Inlet port; 17. Installation pipe; 2. Lifting rod; 21. Catalyst port; 22. Insertion pipe; 23. Rotating shaft; 3. Connecting cavity; 31. Lifting guide rail; 4. Damping block; 41. Lifting ring; 5. Rotating ring; 51. Fixed rod; 53. Swinging rod; 54. Wire mesh box; 55. Movable plate; 551. Spring; 552. Protruding plate; 553. Impact plate; 56. Restriction net; 57. Elastic plate; 58. Distribution rod; 6. Scraper; 61. Detailed Implementation

[0039] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below in conjunction with specific embodiments.

[0040] like Figures 1 to 7 As shown, the present invention discloses a solventless hydrogenation process for producing m-aminotrifluorotoluene, the method comprising the following steps:

[0041] S1: Nitrogen gas is introduced into the reactor through nitrogen port 12 to replace and purge the air inside the reactor; the temperature of the nitrogen gas used for air replacement is 80℃-85℃;

[0042] S2: Add raw material m-nitrotrifluorotoluene and catalyst Raney nickel to the reactor; during the process, maintain nitrogen purging and use the reactor's heating mechanism to heat the reactor, so that the raw material is rapidly heated to 80°C;

[0043] S3: First stop the nitrogen gas supply to the reactor, then introduce hydrogen gas into the reactor to start the reaction; the hydrogen temperature is 80℃-90℃, the pressure inside the reactor is 2.5-5Mpa, and the reaction time is 6 hours.

[0044] S4: After the reaction is complete, cool to 65°C, stop the hydrogen flow and purge with nitrogen. Then, recover the product filtrate under normal pressure, then recover the catalyst. After that, the filtrate is distilled under negative pressure at 0.1-0.12 MPa and 115-125°C to recover m-aminotrifluorotoluene.

[0045] In step S2, the mass ratio of raw material to catalyst is 1:0.001-0.0025, and the raw material and catalyst in the reactor are kept separate before the reaction begins.

[0046] Nitrogen gas is heated to 80℃-85℃. Then, the heated nitrogen gas is used to replace and purge the air inside the reactor, thereby removing air and moisture from the reactor, ensuring that the reaction proceeds normally and safely, and avoiding the generation of by-products that could affect product quality.

[0047] Meanwhile, solvent-free process conditions are often used, which reduces the emission of organic matter in traditional production processes, making it relatively safe and friendly to the environment and workers. At the same time, the reaction requires a relatively low temperature, which reduces production energy consumption and production costs, and is conducive to energy conservation and emission reduction.

[0048] Meanwhile, after adding raw materials and catalysts into the reactor, nitrogen purging continues to remove newly introduced impurities such as air and moisture, ensuring the stable progress of the hydrogenation reduction reaction within the reactor. Simultaneously, the nitrogen purging process, combined with the reactor's own heating mechanism, rapidly heats the raw materials and catalysts, shortening the time required to reach the reaction temperature and accelerating production efficiency. Furthermore, since the raw materials and catalysts are kept separate before the reaction, the purged nitrogen can heat both materials and catalysts separately, and purge the catalyst, accelerating the temperature rise within the reactor. The higher-temperature nitrogen also dries any moisture present in the catalyst, reducing the likelihood of moisture presence, ensuring stable reaction progress, and minimizing reaction byproducts.

[0049] Meanwhile, by separating the raw materials and catalysts, the raw materials and catalysts can be added simultaneously, reducing preparation time in the production process and accelerating production efficiency.

[0050] In one embodiment of the present invention, when nitrogen is introduced in step S1, purging is performed first to replace the air, and the nitrogen after replacement is stored separately. In steps S1 and S2, nitrogen purging is performed continuously, and the nitrogen generated by purging is heated and then recycled. In step S4, nitrogen is introduced to replace the hydrogen remaining in the reactor, and the nitrogen generated after replacement is stored separately.

[0051] The purging nitrogen is recycled to improve the efficiency of nitrogen heating inside the reactor, accelerate the rate of temperature rise inside the reactor, and at the same time reduce the amount of nitrogen used in the production process.

[0052] Meanwhile, when replacing the air, nitrogen is introduced through nitrogen port 12 and discharged through exhaust port 14. During the reaction, hydrogen is introduced through hydrogen port 13 and discharged through exhaust port 14.

[0053] In one embodiment of the present invention, the reaction vessel includes a vessel body 1, on which a motor 11 and a rotating shaft 3 are mounted. A connecting ring is mounted on the rotating shaft 3, and a nitrogen port 12 and a hydrogen port 13 are mounted on the connecting ring. A distribution rod 6 is mounted on the rotating shaft 3, and a communicating cavity 31 is formed inside the rotating shaft 3. The connecting ring and the distribution rod 6 are interconnected through the communicating cavity 31. Micropores are formed on the distribution rod 6, and a scraper 61 is installed between the distribution rod 6 and the bottom surface of the vessel body 1.

[0054] The upper end of the vessel body 1 is equipped with an exhaust port 14 and a feed port 17, the lower end of the vessel body 1 is equipped with a discharge port 15 and a discharge outlet 16, the inner wall of the vessel body 1 is equipped with a lifting guide rail 4, the rotating shaft 3 is equipped with a lifting ring 5 via a spline, the lifting ring 5 is equipped with a mesh frame box 55 via a fixing rod 53, and the end of the fixing rod 53 is in contact with the lifting guide rail 4;

[0055] A movable plate 551 is installed on the bottom surface of the mesh frame box 55. The movable plate 551 is connected to the inner wall of the mesh frame box 55 by a spring 552. A pipe 2 is installed on the vessel body 1. An insertion pipe 23 is installed inside the installation pipe 2. The lower end of the insertion pipe 23 is inserted into the mesh frame box 55. A lifting rod 21 is installed inside the installation pipe 2. The lifting rod 21 and the insertion pipe 23 are connected by a thread. A catalyst port 22 is installed on the installation pipe 2.

[0056] During the production process, heated nitrogen gas is first introduced into the vessel 1 through nitrogen port 12 to replace and purge the air inside the vessel 1. Then, the motor 11 is controlled to run, driving the rotating shaft 3, lifting ring 5, fixed rod 53, and mesh frame box 55 to rotate. Since the end of the fixed rod 53 is in contact with the lifting guide rail 4, when the rotating shaft 3 drives the fixed rod 53 to rotate, the fixed rod 53 is simultaneously acted upon by the lifting guide rail 4, causing the fixed rod 53 to gradually rise. This causes the fixed rod 53 and mesh frame box 55 to gradually rise within the vessel 1 until they reach the highest point of the lifting guide rail 4 within the vessel 1. The insertion tube 23 on the reactor body 1 is aligned with the inlet on the mesh frame box 55. The operator rotates the lifting rod 21 using a turntable, and then moves the insertion tube 23 towards each other through the threaded connection between the lifting rod 21 and the insertion tube 23 until the lower end of the insertion tube 23 is inserted into the mesh frame box 55. After that, the operator feeds the catalyst from the catalyst port 22, and after passing through the installation tube 2 and the insertion tube 23, it enters the mesh frame box 55. At the same time, the operator adds the raw material into the reactor from the feed port 17. Since the mesh frame box 55 is at a high position, the raw material and the catalyst are separated from each other.

[0057] Meanwhile, after adding raw materials and catalyst, the inside of the reactor body 1 is purged with nitrogen. Since the nitrogen port 12 is connected to the distribution rod 6 through the connecting ring and the connecting cavity 31, the nitrogen gas will be discharged from the distribution rod 6 at the bottom of the reactor body 1 and move from the bottom to the top of the raw materials in the reactor body 1, so that the nitrogen gas can fully contact the raw materials, heat the raw materials, improve the uniformity of temperature distribution in the raw materials, and accelerate the efficiency of subsequent reactions.

[0058] Meanwhile, after the temperature inside the vessel 1 reaches the reaction temperature, nitrogen purging is stopped, and hydrogen is introduced into the reactor through hydrogen port 13. Since both hydrogen port 13 and nitrogen port 12 are connected to the connecting ring, hydrogen is discharged from the micropores on the distribution rod 6, allowing hydrogen to fully contact the raw materials and react fully under the catalysis of the catalyst, thus accelerating the reaction efficiency.

[0059] Meanwhile, during the reaction, the mesh frame box 55 and the fixed rod 53 move up and down under the action of the lifting guide rail 4 and are driven to rotate by the rotating shaft 3, so that the catalyst in the mesh frame box 55 can move fully and contact the raw materials in the vessel body 1, increasing the contact area between the catalyst and the raw materials and improving the reaction efficiency. At the same time, as the mesh frame box 55 is driven by the rotating shaft 3, during the rotation of the mesh frame box 55, the liquid raw materials in the vessel body 1 will rush into the mesh frame box 55, thereby stirring the mesh frame box 55 and reducing the possibility of the catalyst agglomerating and accumulating in the mesh frame box 55. This avoids the catalyst in the middle position not contacting the raw materials sufficiently after relative accumulation, which would affect the effect of the catalyst and reduce the reaction efficiency.

[0060] Simultaneously, after the reaction is complete, the motor 11 is controlled by the controller to move the mesh frame box 55 to a higher position inside the reactor, separating the catalyst inside the mesh frame box 55 from the product inside the reactor body 1. Then, the outlet 15 on the reactor body 1 is opened to discharge the reaction product inside the reactor body 1, obtaining filtrate. The filtrate is then subjected to negative pressure distillation to obtain the product. At the same time, after the reaction product is discharged, the operator rotates the lifting rod 21 again to move the insertion tube 23 downward until the insertion tube 23 contacts and pushes the movable plate 551 at the bottom of the mesh frame box 55, causing the movable plate 551 to separate from the bottom of the mesh frame box 55, allowing the catalyst inside the mesh frame box 55 to fall into the reactor body 1. Then, the catalyst is discharged from the reactor for recovery or reuse, thus facilitating the separation of the catalyst during the production process and improving production efficiency.

[0061] As one embodiment of the present invention, a protruding plate 553 is installed on the inner wall of the wire mesh box 55. The protruding plates 553 are installed in pairs, and multiple sets of the pairs of protruding plates 553 are arranged inside the wire mesh box 55.

[0062] Because the inner wall of the mesh frame box 55 is provided with protruding plates 553, the mesh frame box 55 is divided into multiple small compartments by the protruding plates 553. When the catalyst falls into the mesh frame box 55 from the insertion tube 23, the catalyst can be restricted and guided by the protruding plates 553, so that the catalyst in the mesh frame box 55 is divided into multiple columnar shapes. This reduces the possibility of the catalyst moving radially along the vessel body 1 in the mesh frame box 55, thereby reducing the possibility of the catalyst agglomerating and accumulating in the mesh frame box 55. This makes the catalyst relatively dispersed and loose, which facilitates the catalyst to contact the raw materials during the reaction process, increases the contact area between the catalyst and the raw materials, and improves the reaction efficiency. At the same time, during the rotation of the mesh frame box 55, the liquid raw materials entering the mesh frame box 55 can also easily agitate the catalyst, promoting the relative dispersion of the catalyst.

[0063] In one embodiment of the present invention, the upper surface of the movable plate 551 is arc-shaped, and there is a magnetic attraction between the movable plate 551 and the protruding plate 553.

[0064] Because the upper surface of the movable plate 551 is arc-shaped, during the catalyst discharge process, the insertion tube 23 contacts and pushes the movable plate 551 downwards, creating a gap between the movable plate 551 and the lower end of the mesh frame box 55. The catalyst inside the mesh frame box 55 is affected by the shape of the upper surface of the movable plate 551, making it easier for the catalyst to fall off the movable plate 551, accelerating the discharge of the catalyst from the mesh frame box 55. This reduces or avoids catalyst residue in the mesh frame box 55, which could affect the subsequent use of the reactor. Simultaneously, the magnetic attraction between the movable plate 551 and the raised plate 553 creates a mutual attraction between the movable plate 551 and the lower end of the mesh frame box 55. The mesh frame box 55 and the movable plate 551 are kept close and tightly fitted to avoid gaps during the reaction process, which could cause the catalyst to fall to the bottom of the reactor body 1, making it difficult to separate the catalyst from the reaction products. At the same time, due to the magnetic attraction between the movable plate 551 and the raised plate 553, the force between the movable plate 551 and the lower end of the mesh frame box 55 is relatively uniform. When the movable plate 551 is pushed by the insertion tube 23, it is kept as vertical as possible to keep the movable plate 551 moving in the vertical direction, so that the gap between the movable plate 551 and the lower end of the mesh frame box 55 is of uniform size, which facilitates the catalyst to fall and be discharged, and avoids the catalyst getting stuck in the gap and leaving residue.

[0065] In one embodiment of the present invention, the wire mesh box 55 is provided with a through hole, and the outlet of the through hole is inclined upward.

[0066] Since the fixed rod 53 is in contact with the lifting guide rail 4, when the rotating shaft 3 rotates, it will drive the fixed rod 53 and the wire mesh box 55 to rise and fall. During this process, when the fixed rod 53 and the wire mesh box 55 move upward, they will be lifted by the lifting guide rail 4. When the fixed rod 53 and the wire mesh box 55 move downward, they will be subjected to gravity and descend along the lifting guide rail 4.

[0067] During the rotation of the mesh frame box 55, the raw materials that have entered the mesh frame box 55 from the vessel body 1 will be discharged from the through holes on the side of the mesh frame box 55 opposite to its rotation direction. During the discharge of the raw materials from the mesh frame box 55, the raw materials will be sprayed obliquely upward, thereby exerting a downward force on the mesh frame box 55. This downward force promotes close contact between the fixed rod 53 and the lifting guide rail 4, and ensures smooth downward movement of the fixed rod 53 and the mesh frame box 55 along the lifting guide rail 4. This prevents the lifting ring 5 from getting stuck on the rotating shaft 3. If catalyst particles accidentally detach from the spline between the lifting ring 5 and the rotating shaft 3, it will cause jamming and affect the rotation and vertical movement of the mesh frame box 55 in the vessel body 1.

[0068] In one embodiment of the present invention, a rotating ring 51 is rotatably installed below the lifting ring 5, a swing rod 54 is installed on the rotating ring 51, and an impact plate 56 is installed on the swing rod 54. The impact plate 56 corresponds to the mesh frame box 55, and the impact plate 56 is located behind the mesh frame box 55 in the rotation direction inside the reactor.

[0069] A damping block 41 is provided on the lifting guide rail 4. The damping block 41 is elastic. The end of the swing rod 54 is in contact with the damping block 41. An elastic plate 58 is installed on the end of the swing rod 54 and the fixed rod 53 near the inner wall of the vessel body 1.

[0070] When the wire mesh box 55 rotates, the swing rod 54 and the impact plate 56 are acted upon by the elastic plate 58, causing them to press tightly against the wire mesh box 55 and rotate synchronously. Because the lifting guide rail 4 is equipped with a damping block 41, when the swing rod 54 encounters the damping block 41 during its rotation with the fixed rod 53, it is blocked, causing the swing rod 54 to separate from the fixed rod 53 and the elastic plate 58 to undergo elastic deformation. This continues until the elastic force of the elastic plate 58 exceeds the elastic force of the damping block 41, at which point the damping block 41 stops rotating. The moving rod 54 deforms under the pressure, causing the swing rod 54 to pass through the damping block 41. This causes the swing rod 54 to drive the impact plate 56 to quickly approach and impact the mesh frame box 55. During this process, the rapid movement of the impact plate 56 will compress the liquid raw material between the impact plate 56 and the mesh frame box 55, causing the raw material to rush into the mesh frame box 55. This increases the impact and agitation effect of the raw material on the catalyst in the mesh frame box 55, increases the contact area between the catalyst and the raw material, avoids catalyst accumulation, and improves the reaction efficiency.

[0071] In one embodiment of the present invention, a limiting net 57 is installed between the impact plate 56 and the wire mesh box 55;

[0072] Because the gap between the impact plate 56 and the mesh frame box 55 is relatively large and the gap is directly open on all sides, when the impact plate 56 quickly approaches and impacts the mesh frame box 55, most of the material between the impact plate 56 and the mesh frame box 55 will be scattered from the open gap between the impact plate 56 and the mesh frame box 55 after being impacted and squeezed. This results in relatively less material entering the mesh frame box 55, which affects the stirring effect on the catalyst and increases the contact area between the catalyst and the material.

[0073] By installing a limiting net 57 between the impact plate 56 and the mesh frame box 55, the limiting net 57 guides and restricts the raw materials between the two. When the impact plate 56 quickly approaches the mesh frame box 55 and the raw materials are impacted and squeezed by the impact plate 56, most of the raw materials will be blocked by the limiting net 57, allowing most of the raw materials to impact into the mesh frame box 55, agitating the catalyst and increasing the contact area between the raw materials and the catalyst, thereby improving the reaction efficiency.

[0074] The specific workflow is as follows:

[0075] Nitrogen gas is heated to 80℃-85℃. Then, the heated nitrogen gas is used to replace and purge the air inside the reactor, thereby removing air and moisture from the reactor.

[0076] Meanwhile, solvent-free process conditions are often used, which reduces the emission of organic matter in traditional production processes. At the same time, the reaction temperature is relatively low, which reduces production energy consumption.

[0077] Meanwhile, after adding raw materials and catalysts into the reactor, nitrogen is used to purge the reactor to remove impurities such as air and moisture introduced during the addition of raw materials and catalysts. At the same time, the heating mechanism of the reactor itself can quickly heat the raw materials and catalysts during the nitrogen purging process. Since the raw materials and catalysts are kept separate before the reaction, the nitrogen is blown in to heat the raw materials and catalysts separately, and the higher temperature nitrogen purging can dry the moisture in the catalyst.

[0078] Meanwhile, by separating the raw materials and catalysts, the raw materials and catalysts can be added simultaneously, reducing the preparation time in the production process;

[0079] The purging nitrogen is recycled to improve the efficiency of nitrogen heating inside the reactor and reduce the amount of nitrogen used in the production process.

[0080] Meanwhile, when replacing the air, nitrogen is introduced through nitrogen port 12 and discharged through exhaust port 14. During the reaction, hydrogen is introduced through hydrogen port 13 and discharged through exhaust port 14.

[0081] During the production process, heated nitrogen gas is first introduced into the vessel 1 through nitrogen port 12 to replace and purge the air inside the vessel 1. Then, the motor 11 is controlled to run, driving the rotating shaft 3, lifting ring 5, fixed rod 53, and mesh frame box 55 to rotate. Since the end of the fixed rod 53 is in contact with the lifting guide rail 4, when the rotating shaft 3 drives the fixed rod 53 to rotate, the fixed rod 53 is simultaneously acted upon by the lifting guide rail 4, causing the fixed rod 53 to gradually rise. This causes the fixed rod 53 and mesh frame box 55 to gradually rise within the vessel 1 until they reach the highest point of the lifting guide rail 4 within the vessel 1. The insertion tube 23 on the reactor body 1 is aligned with the inlet on the mesh frame box 55. The operator rotates the lifting rod 21 using a turntable, and then moves the insertion tube 23 towards each other through the threaded connection between the lifting rod 21 and the insertion tube 23 until the lower end of the insertion tube 23 is inserted into the mesh frame box 55. After that, the operator feeds the catalyst from the catalyst port 22, and after passing through the installation tube 2 and the insertion tube 23, it enters the mesh frame box 55. At the same time, the operator adds the raw material into the reactor from the feed port 17. Since the mesh frame box 55 is at a high position, the raw material and the catalyst are separated from each other.

[0082] Meanwhile, after adding raw materials and catalyst, the inside of the vessel 1 is purged with nitrogen. Since the nitrogen port 12 is connected to the distribution rod 6 through the connecting ring and the connecting cavity 31, the nitrogen gas will be discharged from the distribution rod 6 at the bottom of the vessel 1 and move from the bottom to the top of the raw materials in the vessel 1.

[0083] Meanwhile, after the temperature inside the vessel 1 reaches the reaction temperature, nitrogen purging is stopped, and hydrogen is introduced into the reactor through hydrogen port 13. Since both hydrogen port 13 and nitrogen port 12 are connected to the connecting ring, hydrogen is discharged from the micropores on the distribution rod 6.

[0084] Meanwhile, during the reaction process, the mesh frame box 55 and the fixed rod 53 move up and down under the action of the lifting guide rail 4 and are driven to rotate by the rotating shaft 3, so that the catalyst in the mesh frame box 55 can move fully and contact the raw materials in the vessel body 1. At the same time, since the mesh frame box 55 is driven by the rotating shaft 3, during the rotation of the mesh frame box 55, the liquid raw materials in the vessel body 1 will rush into the mesh frame box 55, thereby agitating the mesh frame box 55 and reducing the possibility of the catalyst agglomerating and accumulating in the mesh frame box 55.

[0085] Meanwhile, after the reaction is complete, the motor 11 is controlled by the controller to move the mesh frame box 55 to a high position inside the reactor, so that the catalyst in the mesh frame box 55 is separated from the product in the reactor body 1. Then, the discharge port 15 on the reactor body 1 is opened to discharge the reaction product in the reactor body 1 and obtain filtrate. Then, the filtrate is subjected to negative pressure distillation to obtain the product. At the same time, after the reaction product is discharged, the operator rotates the lifting rod 21 again to move the insertion tube 23 downward until the insertion tube 23 contacts and pushes the movable plate 551 at the bottom of the mesh frame box 55, so that the movable plate 551 is separated from the bottom of the mesh frame box 55, so that the catalyst in the mesh frame box 55 falls into the reactor body 1. Then, the catalyst is discharged from the reactor for recovery or reuse.

[0086] Because the inner wall of the mesh frame box 55 is provided with a protruding plate 553, the mesh frame box 55 is divided into multiple small compartments by the protruding plate 553. When the catalyst falls into the mesh frame box 55 from the insertion tube 23, the catalyst can be restricted and guided by the protruding plate 553, so that the catalyst in the mesh frame box 55 is divided into multiple columnar shapes, reducing the possibility of the catalyst moving radially along the vessel body 1 in the mesh frame box 55. This makes the catalyst relatively dispersed and loose. At the same time, during the rotation of the mesh frame box 55, the liquid raw materials entering the mesh frame box 55 can also easily agitate the catalyst.

[0087] Because the upper surface of the movable plate 551 is arc-shaped, during the process of discharging the catalyst, the insertion tube 23 contacts and pushes the movable plate 551 downward, so that a gap appears between the movable plate 551 and the lower end of the mesh box 55. The catalyst in the mesh box 55 is affected by the shape of the upper surface of the movable plate 551, making it easier for the catalyst to fall off the movable plate 551, accelerating the discharge of the catalyst in the mesh box 55, and reducing or avoiding the residue of the catalyst in the mesh box 55. At the same time, through the magnetic attraction between the movable plate 551 and the protruding plate 553, the movable plate 551 and the lower end of the mesh box 55 are brought close together and pressed tightly. At the same time, due to the magnetic attraction between the movable plate 551 and the protruding plate 553, the force between the movable plate 551 and the lower end of the mesh box 55 is relatively uniform. When the movable plate 551 is pushed by the insertion tube 23, the movable plate 551 is kept moving vertically as much as possible, so that the gap between the movable plate 551 and the lower end of the mesh box 55 is of uniform size.

[0088] Since the fixed rod 53 is in contact with the lifting guide rail 4, when the rotating shaft 3 rotates, it will drive the fixed rod 53 and the wire mesh box 55 to rise and fall. During this process, when the fixed rod 53 and the wire mesh box 55 move upward, they will be lifted by the lifting guide rail 4. When the fixed rod 53 and the wire mesh box 55 move downward, they will be subjected to gravity and descend along the lifting guide rail 4.

[0089] During the rotation of the mesh frame box 55, the raw material that enters the mesh frame box 55 from the vessel body 1 will be discharged from the through hole on the side of the mesh frame box 55 opposite to its rotation direction. During the discharge of the raw material from the mesh frame box 55, the raw material will be sprayed obliquely upward, thereby exerting a downward force on the mesh frame box 55. This downward force promotes close contact between the fixed rod 53 and the lifting guide rail 4, and facilitates the smooth downward movement of the fixed rod 53 and the mesh frame box 55 along the lifting guide rail 4.

[0090] When the mesh frame box 55 rotates, the swing rod 54 and the impact plate 56 are acted upon by the elastic plate 58, and will be in close contact with the mesh frame box 55 and rotate synchronously. Since the lifting guide rail 4 is equipped with a damping block 41, when the swing rod 54 rotates with the fixed rod 53, it will be blocked by the damping block 41, causing the swing rod 54 and the fixed rod 53 to separate from each other and the elastic plate 58 to undergo elastic deformation. Until the elastic force of the elastic plate 58 is greater than the elastic force of the damping block 41, the damping block 41 will deform under the pressure of the swing rod 54, allowing the swing rod 54 to pass through the damping block 41, and then the swing rod 54 will drive the impact plate 56 to quickly approach and impact the mesh frame box 55. During this process, due to the rapid movement of the impact plate 56, the liquid raw material between the impact plate 56 and the mesh frame box 55 will be squeezed, causing the raw material to rush into the mesh frame box 55 quickly, increasing the impact and stirring effect of the raw material on the catalyst in the mesh frame box 55.

[0091] By installing a limiting net 57 between the impact plate 56 and the mesh frame box 55, the limiting net 57 guides and restricts the raw materials between the two. When the impact plate 56 quickly approaches the mesh frame box 55 and the raw materials are impacted and squeezed by the impact plate 56, most of the raw materials will be blocked by the limiting net 57, allowing most of the raw materials to impact into the mesh frame box 55, agitating the catalyst and increasing the contact area between the raw materials and the catalyst.

[0092] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A process for the production of m-aminobenzotrifluoride in a solvent-free hydrogenation process, characterized in that: The production device is a reaction kettle, the reaction kettle comprises a kettle body (1), a motor (11) and a rotating shaft (3) are installed on the kettle body (1), a connecting ring is installed on the rotating shaft (3), a nitrogen inlet (12) and a hydrogen inlet (13) are installed on the connecting ring, a distribution rod (6) is installed on the rotating shaft (3), a communication cavity (31) is formed in the rotating shaft (3), the connecting ring and the distribution rod (6) are communicated with each other through the communication cavity (31), a plurality of micropores are formed in the distribution rod (6), and a scraper (61) is installed between the distribution rod (6) and the bottom surface of the kettle body (1); An exhaust port (14) and a feeding port (17) are installed on the upper end of the kettle body (1), a discharging port (15) and a discharge port (16) are installed on the lower end of the kettle body (1), a lifting guide rail (4) is installed on the inner wall of the kettle body (1), a lifting ring (5) is installed on the rotating shaft (3) through a spline, a mesh box (55) is installed on the lifting ring (5) through a fixing rod (53), and the tail end of the fixing rod (53) is in contact with the lifting guide rail (4); A movable plate (551) is installed on the bottom surface of the mesh box (55), the movable plate (551) is connected to the inner wall of the mesh box (55) through a spring (552), a mounting pipe (2) is installed on the kettle body (1), an insertion pipe (23) is installed in the mounting pipe (2), the lower end of the insertion pipe (23) is inserted into the mesh box (55), a lifting rod (21) is installed in the mounting pipe (2), the lifting rod (21) and the insertion pipe (23) are connected through threads, and a catalyst port (22) is installed on the mounting pipe (2).

2. The apparatus according to claim 1, wherein the apparatus is characterized in that: A plurality of pairs of protruding plates (553) are installed on the inner wall of the mesh box (55).

3. The apparatus according to claim 2, wherein the apparatus is characterized by: The upper surface of the movable plate (551) is in a circular arc shape, and the movable plate (551) and the protruding plates (553) are magnetically attracted to each other.

4. The apparatus according to claim 1, wherein the apparatus is characterized by: A through hole is formed in the mesh box (55), and the outlet of the through hole is inclined upward.

5. The apparatus according to claim 4, wherein the apparatus is used for producing m-aminobenzotrifluoride by the solvent-free hydrogenation process. A rotating ring (51) is rotatably installed below the lifting ring (5), a swing rod (54) is installed on the rotating ring (51), an impact plate (56) is installed on the swing rod (54), the impact plate (56) corresponds to the mesh box (55), and the impact plate (56) is located behind the mesh box (55) in the rotating direction of the reaction kettle; A damping block (41) is arranged on the lifting guide rail (4), the damping block (41) is elastic, the tail end of the swing rod (54) is in contact with the damping block (41), and an elastic plate (58) is installed on the end of the swing rod (54) close to the inner wall of the kettle body (1).

6. The apparatus according to claim 5, wherein the apparatus is used for producing m-aminobenzotrifluoride by the solvent-free hydrogenation process. A limiting net (57) is installed between the impact plate (56) and the mesh box (55).

7. A process for the production of m-aminotolyltrifluoride by a solvent-free hydrogenation process, characterized by: The production method is carried out in the m-amino trifluoromethyl benzene production device in any one of claims 1-6, and the method comprises the following steps: S1: nitrogen is introduced into the reaction kettle through the nitrogen port (12) to replace and purge the air inside the reaction kettle; the temperature of the nitrogen for air replacement is 80-85°C; S2: raw material m-nitro-trifluorotoluene and catalyst Raney nickel are added into the reaction kettle; nitrogen is blown during the process, and the heating mechanism of the reaction kettle is used to heat the reaction kettle to rapidly heat the raw material to 80°C; S3: stop introducing nitrogen into the reaction kettle, and then introduce hydrogen into the reaction kettle to start the reaction; the temperature of the hydrogen is 80-90°C, the pressure in the reaction kettle is 2.5-5 MPa, and the reaction time is 6 hours; S4: after the reaction is completed, cooling to 65°C, stopping the introduction of hydrogen, and then purging with nitrogen, then recovering the product filtrate under normal pressure, and then recovering the catalyst, then, the filtrate is recovered by negative pressure rectification under the conditions of 0.1-0.12 MPa and 115-125°C to obtain m-aminotrifluorotoluene; In the S2 step, the mass ratio of the raw material to the catalyst is 1:0.001-0.0025, and the raw material and the catalyst in the reaction kettle are kept in a separated state before the reaction starts.

8. The process according to claim 7, wherein the process is characterized by: In the S1 step, the nitrogen is first purged to replace the air, and the replaced nitrogen is stored separately; the nitrogen blowing in the S1 and S2 steps is continuous and continuous, and the nitrogen produced by purging is heated and recycled; in the S4 step, nitrogen is introduced to replace the hydrogen remaining in the reaction kettle, and the nitrogen produced after replacement is stored separately.

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