Ceramic membrane filtration system and method for removing 6-methyl-2-ethylaniline magnetic foreign matters

Abstract

The invention discloses a ceramic membrane filtration system and method for removing 6-methyl-2-ethylaniline magnetic foreign matters, and belongs to the technical field of chemical separation and purification. The system comprises a circulating tank, a CIP tank, a delivery pump, a security filter, a circulating pump, a ceramic membrane assembly, a heat exchanger and a dialysate tank. According to the system, a complete circulating filtration and on-line cleaning loop is formed through specific pipeline connection and valve control. The method comprises the following steps: carrying out ceramic membrane cross-flow filtration on a 6-methyl-2-ethylaniline solution containing 85% of ethanol at 80-90 DEG C under the filtration pressure of 1-3 bar and the surface flow velocity of 3-5 m / s, so as to effectively remove the magnetic foreign matters. The high-temperature-resistant and solvent-resistant ceramic membrane and a non-metal liquid receiving material are adopted, so that secondary pollution is fundamentally avoided, and the filter has the advantages of high filtering precision, stable operation, easiness in cleaning and regeneration and the like, and is particularly suitable for high-purification production of high-end electronic chemicals and medical intermediates.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of chemical separation and purification, and particularly relates to a ceramic membrane filtration system and method for removing magnetic foreign matters from 6-methyl-2-ethyl aniline. BACKGROUND

[0002] 6-methyl-2-ethyl aniline is an important chemical intermediate and is widely used in the synthesis of medicines, high-performance dyes and electronic chemicals (such as liquid crystals and OLED materials). These high-end application fields have extremely high requirements for the purity of intermediates and final products. The presence of trace amounts of magnetic foreign matters (such as metal particles) can cause serious risks.

[0003] Specifically, the presence of magnetic foreign matters can cause the following problems: in a synthesis reaction, the active sites of a noble metal catalyst are contaminated, leading to catalyst poisoning, a decrease in catalytic efficiency, and even reaction failure; metal ions can catalyze unnecessary side reactions, affecting the yield and selectivity of the main reaction; the magnetic foreign matters themselves as extraneous impurities can affect the color and purity specifications of the final product; hard metal particles can also cause wear and scratches to process equipment such as pumps and valves, shorten the service life of the equipment, and even cause leaks or blockages.

[0004] Currently, the commonly used methods for removing magnetic foreign matters or solid particles from liquids in industry mainly include filter core filtration, plate and frame filtration, and filter bag filtration. However, when dealing with 6-methyl-2-ethyl aniline and other specific materials, these traditional methods have obvious defects. First, 6-methyl-2-ethyl aniline is usually purified in an 85% ethanol solution at a high temperature of 80-90°C. Conventional filter cores, filter bags and other polymer materials can easily swell, age or decrease in precision in this high-temperature and high-concentration organic solvent environment, leading to leakage of magnetic substances, poor filtration stability, and inability to meet the strict requirements of downstream applications for near-zero tolerance of magnetic substances. Second, once the traditional filtration medium (such as filter cores and filter bags) is clogged, it usually needs to be replaced frequently, which not only increases the operating cost and maintenance workload, but also generates secondary solid waste.

[0005] Therefore, there is an urgent need in the art to develop a technology and system that can adapt to high-temperature and high-concentration organic solvent environments, has high filtration precision, good stability, is not prone to introducing secondary pollution, and is easy to clean and regenerate, in order to achieve efficient and reliable removal of magnetic foreign matters from 6-methyl-2-ethyl aniline. SUMMARY

[0006] The present application aims to overcome the deficiencies of the prior art, and provides a ceramic membrane filtration system and method for removing 6-methyl-2-ethyl aniline magnetic foreign matter. The system uses high-temperature-resistant and organic solvent-resistant ceramic membranes as the core filter element, and combines specific system configuration and process flow, which can stably and efficiently remove magnetic foreign matter in the material, and effectively avoid secondary pollution.

[0007] To achieve the above object, the present application adopts the following technical solutions:

[0008] In a first aspect, the present application provides a ceramic membrane filtration system for removing 6-methyl-2-ethyl aniline magnetic foreign matter, comprising a circulating tank, a CIP tank, a feed pump, a safety filter, a circulating pump, a ceramic membrane assembly, a heat exchanger and a dialysate tank, and a plurality of valves arranged on the pipeline;

[0009] The circulating tank is used for storing and circulating the 6-methyl-2-ethyl aniline ethanol solution to be treated;

[0010] The CIP tank (online cleaning tank) is used for storing cleaning agents and for internal circulation and circulating cleaning of the system;

[0011] The bottoms of the circulating tank and the CIP tank are respectively connected to the inlet end of the feed pump through pneumatic valves XV01 and XV02;

[0012] The outlet end of the feed pump is connected to the inlet end of the safety filter;

[0013] The outlet end pipeline of the safety filter is divided into three paths: the first path is connected to the inlet end of the circulating pump, the second path is connected to the outlet end of the ceramic membrane assembly, and the third path is connected to the inlet end of the regulating valve PV01;

[0014] The outlet end of the circulating pump is connected to the inlet end of the ceramic membrane assembly;

[0015] The outlet end of the ceramic membrane assembly is connected back to the inlet end of the circulating pump, forming a circulating loop;

[0016] The outlet end of the regulating valve PV01 is connected to the inlet end of the heat exchanger;

[0017] The outlet end pipeline of the heat exchanger is divided into three paths: the first path is connected to the top of the CIP tank through pneumatic valve XV03, the second path is connected to the top of the circulating tank through pneumatic valve XV04, and the third path is connected to the discharge port through pneumatic valve XV13;

[0018] A dialysate outlet is provided on the ceramic membrane assembly, which is connected to the CIP tank through pneumatic valve XV06 and / or connected to the dialysate tank through pneumatic valve XV07;

[0019] The dialysate tank is used for storing the filtered 6-methyl-2-ethyl aniline clear liquid.

[0020] Preferably, the ceramic membrane module is internally filled with a ceramic membrane core, the ceramic membrane core has a filtering accuracy of 20 nm, 50 nm or 100 nm, and is made of alumina or zirconia.

[0021] Preferably, the material of the liquid receiving parts of the circulation tank, the feed pump, the safety filter, the circulation pump, the membrane shell of the ceramic membrane module, the heat exchanger and the dialysate tank is FRPP (glass fiber reinforced polypropylene) or fluoroplastic; the feed pump and the circulation pump are fluoroplastic pumps.

[0022] Preferably, the top end of the outlet of the circulation pump and the top end of the U-shaped tube connected to the ceramic membrane module are respectively connected to pneumatic valve XV09 and pneumatic valve XV10.

[0023] Preferably, the bottom of the ceramic membrane module is connected to the drain ditch through pneumatic valve XV11 and pneumatic valve XV12.

[0024] Preferably, the bottom of the CIP tank is connected to the drain ditch through pneumatic valve XV08.

[0025] In a second aspect, the present application provides a method for removing 6-methyl-2-ethyl aniline magnetic foreign matter using any of the above systems, comprising the following steps:

[0026] S1, preparation step: adding 6-methyl-2-ethyl aniline ethanol solution into the circulation tank, wherein the 6-methyl-2-ethyl aniline ethanol solution contains 85% ethanol, and the temperature is maintained at 80-90℃;

[0027] S2, start-up and exhaust step: opening pneumatic valve XV01, pneumatic valve XV04, pneumatic valve XV07, pneumatic valve XV09, pneumatic valve XV10, adjusting valve PV01 maintaining full open state, starting the feed pump and the circulation pump in turn, performing system large circulation exhaust for 3-5 minutes, and then closing pneumatic valve XV09 and pneumatic valve XV10;

[0028] S3, filtration step: adjusting the regulating valve PV01 to a specified opening degree, so that the system filtration pressure is maintained at 1-3 bar, and performing constant opening degree filtration, wherein cross-flow filtration is adopted, the surface flow rate is controlled at 3-5 m / s, and the filtration flux is 200-400 L / m 2 h, using the ceramic membrane module to filter the magnetic foreign matter;

[0029] S4, stop step: adjusting valve PV01 maintaining full open state, stopping the circulation pump and the feed pump in turn, and closing pneumatic valve XV01, pneumatic valve XV04 and pneumatic valve XV07 after the circulation pump and the feed pump are completely stopped.

[0030] Further preferably, the method further comprises: during the filtration process of step S3, supplementing ethanol into the circulation tank.

[0031] Further preferably, the method further comprises a step of CIP cleaning the ceramic membrane module, the CIP cleaning step comprising:

[0032] After the process liquid in the system is emptied, a cleaning liquid with a concentration of 0.2%-2% is added to the CIP tank;

[0033] The pneumatic valves XV02, XV03, XV06, XV09, and XV10 are opened, and the feed pump and the circulation pump are started to circulate the cleaning liquid for 1-4 hours;

[0034] After the cleaning is completed, the circulation pump and the feed pump are stopped in sequence, and the cleaning waste liquid is emptied through the pneumatic valves XV08, XV11, and XV12;

[0035] The operation of circulating and emptying is repeated using purified water until the system is thoroughly cleaned.

[0036] Further preferably, in step S3, the operating temperature of the filtration step is controlled at 85°C.

[0037] In summary, compared with the prior art, the ceramic membrane filtration system and method for removing 6-methyl-2-ethyl aniline magnetic foreign matter provided by the present application have the following beneficial effects:

[0038] (1) The ceramic membrane with a filtration precision of 20-100 nm is used as the core filtration element in the present application, which can effectively intercept micron-level or even nanometer-level magnetic foreign matter particles. Combined with a specific cross-flow filtration mode (surface flow rate of 3-5 m / s) and a relatively low filtration pressure (1-3 bar), the embedding and penetration of particles on the membrane surface are effectively prevented, the precision decline and magnetic foreign matter leakage problems caused by material swelling and aging of traditional filter cartridges and filter bags in a high-temperature ethanol environment are avoided, and the content of magnetic foreign matter in the cleaned liquid after filtration is stably reduced to a very low level, meeting the extreme requirements of high-end downstream applications for product purity.

[0039] (2) The ceramic membrane element and its support layer material (alumina, zirconia) and the preferred non-metallic material (FRPP, fluoroplastic, etc.) of the liquid connection part of the system together give the entire system excellent high-temperature resistance (80-90°C) and high-concentration organic solvent resistance (85% ethanol). This enables the system to operate stably directly under the actual purification process conditions of 6-methyl-2-ethyl aniline, avoiding the risk of changing process parameters or causing equipment damage due to the intolerance of equipment materials.

[0040] (3) By limiting the material of all parts in the system that come into contact with materials (tank, pump, pipeline, membrane, etc.) to non-metallic materials such as FRPP or fluoroplastics, and using fluoroplastic pumps, the introduction of magnetic foreign objects such as iron filings that may be generated by corrosion or friction of traditional stainless steel equipment into the system is completely avoided, thus eliminating secondary pollution from the source. It is particularly suitable for the production of electronic chemicals and pharmaceutical intermediates that have zero tolerance for magnetic foreign objects.

[0041] (4) Ceramic membranes are hard and wear-resistant, and have a service life much longer than polymer filter cartridges or filter bags. When their flux decreases due to long-term operation, they can be restored to their performance by high-temperature CIP (online cleaning) with strong acid or alkali cleaning agents. This eliminates the need for frequent replacement of the membrane cartridge, significantly reduces the generation of solid waste, and lowers operating and maintenance costs.

[0042] (5) The method of this invention ensures the controllability and reproducibility of the entire filtration and demagnetization process through clear steps (preparation, venting, constant pressure cross-flow filtration, and shutdown) and precise control of key process parameters (temperature, pressure, surface flow rate, and filtration flux). In particular, by maintaining an operating temperature of 85°C and adding ethanol, the precipitation of 6-methyl-2-ethylaniline due to temperature fluctuations or ethanol evaporation during the filtration process is effectively prevented, thus ensuring the continuity and stability of the filtration process.

[0043] (6) The present invention integrates functions such as circulation, filtration, heat exchange, cleaning and venting. Through the coordinated control of various pneumatic valves and regulating valves, it is easy to achieve fully automated operation, reduce human error, and improve production efficiency and process stability. Attached Figure Description

[0044] Other features, objects, and advantages of the invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0045] Figure 1 This is a process flow diagram of the ceramic membrane filtration system for removing magnetic foreign matter from 6-methyl-2-ethylaniline according to the present invention;

[0046] Figure 2 This is a flowchart illustrating the usage method of the ceramic membrane filtration system for removing magnetic foreign matter from 6-methyl-2-ethylaniline according to the present invention.

[0047] Reference numerals: 14, circulation tank; 15, CIP tank; 16, feed pump; 17, security filter; 18, circulation pump; 19, ceramic membrane module; 20, heat exchanger; 21, dialysate tank. Detailed Implementation

[0048] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.

[0049] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0050] Example 1: Construction of a ceramic membrane filtration system

[0051] This embodiment describes in detail a ceramic membrane filtration system for removing magnetic foreign matter from 6-methyl-2-ethylaniline according to the present invention, and its process flow is as follows: Figure 1 As shown.

[0052] The system mainly consists of the following components connected by pipes and valves:

[0053] Circulation tank 14: preferably with a volume of 500L, made of FRPP material, used for storing and circulating the 6-methyl-2-ethylaniline ethanol solution to be treated.

[0054] CIP tank 15: Preferably with a volume of 200L, made of FRPP material, used to store cleaning agents and for internal circulation and circulating cleaning of the system.

[0055] Material pump 16: A fluoroplastic magnetic pump is used to transport materials from circulation tank 14 or CIP tank 15 to downstream systems.

[0056] Security Filter 17: The filtration accuracy is 5μm. The housing is made of FRPP material and contains a polypropylene filter element. It is used to intercept large solid particles in the feed liquid or cleaning agent, prevent large particles from causing irreversible damage to the membrane system, and protect the downstream ceramic membrane module.

[0057] Circulation pump 18: A fluoroplastic magnetic pump is used to power the main circulation loop and ensure that the required membrane surface flow rate is achieved.

[0058] Ceramic membrane module 19: Composed of two identical membrane modules, each filled with a ceramic membrane core for filtering magnetic foreign objects. The outer shell has two inlets / outlets, and each ceramic membrane module 19 has two dialysate outlets on the side of its shell: an upper dialysate outlet and a lower dialysate outlet. The specifications of a single ceramic membrane core are: diameter Φ30mm, length 1200mm, 19 channels, each channel with a diameter of 4mm. The ceramic membrane support layer is made of alumina, and the filter membrane layer is made of zirconium oxide. Filtration precision of 20nm, 50nm, or 100nm can be selected as needed.

[0059] Heat exchanger 20: A graphite heat exchanger is used, which is connected to the steam pipeline through manual valves at its inlet and outlet to control the temperature of the system materials.

[0060] Dialysis fluid tank 21: preferably with a volume of 300L, made of FRPP material, used to collect and store filtered 6-methyl-2-ethylaniline solution.

[0061] The specific piping connections of the system are as follows:

[0062] The bottoms of the circulation tank 14 and the CIP tank 15 are connected to the inlet of the feed pump 16 via pneumatic valves XV01 and XV02, respectively. The outlet of the feed pump 16 is connected to the inlet of the security filter 17.

[0063] The outlet pipe of the security filter 17 is connected to the inlet of the circulating pump 18, the outlet of the ceramic membrane module 19, and the inlet of the regulating valve PV01, respectively, forming three pipes. One pipe connects to the inlet of the membrane module 19 through the circulating pump 18 and then returns to the inlet of the circulating pump 18 through the outlet to form a circulation loop. Another pipe connects to the inlet of the heat exchanger 20 through the outlet of the regulating valve PV01.

[0064] The outlet of the circulating pump 18 is connected to the inlet of the ceramic membrane module 19. The outlet of the ceramic membrane module 19 is connected back to the inlet of the circulating pump 18, forming the main circulation loop. The outlet of the regulating valve PV01 is connected to the inlet of the heat exchanger 20.

[0065] The outlet piping of heat exchanger 20 is divided into three lines:

[0066] The first path is connected to the top of CIP tank 15 via pneumatic valve XV03; the second path is connected to the top of circulation tank 14 via pneumatic valve XV04; and the third path is connected to the system discharge port via pneumatic valve XV13.

[0067] The ceramic membrane module 19 is provided with a dialysate outlet (clear liquid outlet). This outlet line can be selectively connected back to the CIP tank 15 via a pneumatic valve XV06 (for cleaning fluid return or dialysate misdirection), and is also connected to the dialysate tank 21 via a pneumatic valve XV07 (for collecting qualified clear liquid).

[0068] The top of the outlet of the circulating pump 18 and the top of the U-shaped tube connecting the ceramic membrane assembly 19 are respectively connected to the pneumatic valves XV09 and XV10 for exhaust before system startup.

[0069] The bottom of the ceramic membrane module 19 is connected to a drain via pneumatic valves XV11 and XV12 for draining residual liquid or cleaning fluid from the circulation side.

[0070] The bottom of CIP tank 15 is connected to a drain via pneumatic valve XV08 for emptying cleaning waste liquid. The top of CIP tank 15 is connected to a pure water pipeline via pneumatic valve XV05 for replenishing purified water for cleaning or top rinsing.

[0071] All components in this system that come into contact with process materials and cleaning agents, specifically including the circulation tank 14, CIP tank 15, feed pump 16, security filter 17 and its filter element, circulation pump 18, membrane housing and core of ceramic membrane module 19, heat exchanger 20, dialysate tank 21, all pipes, valves (including their internal components), and sealing elements (such as gaskets), are made of non-metallic corrosion-resistant materials such as FRPP or fluoroplastics; among them, feed pump 16 and circulation pump 18 are both fluoroplastic pumps. This system fundamentally avoids the introduction of magnetic foreign matter due to metal corrosion or wear, thereby eliminating secondary pollution.

[0072] Example 2: Method for removing 6-methyl-2-ethylaniline magnetic foreign matter using the system described in Example 1

[0073] This embodiment details the specific operation method for removing 6-methyl-2-ethylaniline magnetic foreign matter using the system constructed in Example 1, as follows: Figure 2 As shown.

[0074] S1. Preparation Steps: Add approximately 350L of a 6-methyl-2-ethylaniline ethanol solution to the circulating tank 14. This solution contains 85% (w / w) ethanol and approximately 35% (w / w) 6-methyl-2-ethylaniline. Start the heat exchanger 20 to heat the circulating material in the system with steam, stabilizing the liquid temperature at 85℃ (which can be adjusted within the range of 80-90℃ depending on the process).

[0075] S2. Start-up and Venting Procedure: Confirm that the relevant manual valves of the system are in the correct position (e.g., the dialysate outlet manual valve is open). Open pneumatic valves XV01, XV04, XV07, XV09, and XV10 in sequence. Adjust regulating valve PV01 to the fully open position. Start feed pump 16 and circulation pump 18 in sequence. The system performs a large circulation, venting gas from the pipeline and membrane module through pneumatic valves XV09 and XV10. After continuously venting for 3-5 minutes, close pneumatic valves XV09 and XV10.

[0076] S3. Filtration Steps: Slowly adjust the opening of regulating valve PV01, observe the system pressure, and stabilize the filtration pressure at 1 bar (this can be adjusted within the range of 1-3 bar depending on the process; 1 bar is preferred in this embodiment). The system begins constant-opening cross-flow filtration. During this process, control the flow velocity on the membrane surface within the range of 3-5 m / s, and maintain the filtration flux at 200-400 L / m³. 2•h. The ceramic membrane module 19 efficiently retains magnetic foreign matter in the feed solution, and the clear solution (dialysis fluid) continuously permeates through the membrane into the dialysate side and flows into the dialysate tank 21 for storage through the pneumatic valve XV07. The concentrated solution is continuously circulated within the system driven by the circulation pump 18.

[0077] During the filtration process, due to the high temperature causing ethanol to evaporate, ethanol needs to be added to the circulation tank 14 periodically to maintain the ethanol content in the solution at about 85% and prevent 6-methyl-2-ethylaniline from precipitating out due to changes in the solvent ratio.

[0078] S4. Stopping Procedure: When the liquid in the circulation tank 14 reaches the predetermined concentration ratio or the processing is complete, return the regulating valve PV01 to the fully open position. Stop the circulation pump 18 and the feed pump 16 in sequence. After both pumps have completely stopped operating, close the pneumatic valves XV01, XV04, and XV07. The system will then stop operating.

[0079] CIP cleaning procedure (performed periodically or when filtration efficiency decreases):

[0080] The process liquid in the system is drained, and the system is top-washed with ethanol to recover residual products.

[0081] Open the pneumatic valve XV05, add an appropriate amount of purified water to CIP tank 15, and then prepare a 0.5% (w / w) NaOH solution as the cleaning solution (the concentration can be adjusted between 0.2% and 2% depending on the level of contamination, or an acidic cleaning agent can be used).

[0082] Open pneumatic valves XV02, XV03, XV06, XV09, and XV10 in sequence. Keep regulating valve PV01 fully open. Start material pump 16 and circulation pump 18 in sequence, perform large-scale circulation and exhaust for 3-5 minutes, then close XV09 and XV10.

[0083] Adjust PV01 to circulate the cleaning fluid under lower pressure. The cleaning temperature can be maintained at 60-80℃ through heat exchanger 20. The circulation cleaning time is about 2 hours (which can be adjusted within 1-4 hours depending on the degree of contamination).

[0084] After cleaning is complete, stop the circulation pump 18 and the feed pump 16 in sequence. Open the pneumatic valves XV08, XV11, and XV12 to discharge the cleaning waste liquid in the system into the drainage ditch.

[0085] Add purified water back into CIP tank 15 via XV05, and repeatedly start the feed pump and circulation pump for flushing, then drain. Repeat this flushing-draining operation 3-5 times until the cleaning agent in the system is completely rinsed out and the discharged flushing water is neutral.

[0086] Using the above system and method, multiple batches of 6-methyl-2-ethylaniline ethanol solution were treated under different process parameters, and the removal of magnetic foreign matter was significantly effective. Specific operating data are shown in the table below (initial magnetic material content in the solution was approximately 0.95 ppm):

[0087]

[0088] As shown in the table above, the system and method of this invention can stably reduce the content of magnetic materials in the feed solution from approximately 0.95 ppm to below 0.005 ppm, and under optimal conditions, it can reach 0.001 ppm, fully meeting the near-zero tolerance requirements of high-end applications for magnetic foreign matter. Simultaneously, the system operates stably, and the ceramic membrane can be effectively cleaned and its performance restored through CIP (Clean-In-Place) cleaning.

[0089] The above description is merely a preferred embodiment of the present invention and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention is not limited to the specific combination of the above-described technical features, but also includes other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. For example, technical solutions formed by substituting the above-described features with (but not limited to) technical features with similar functions disclosed in this invention.

Claims

1. A ceramic membrane filtration system for removing magnetic foreign matter from 6-methyl-2-ethylaniline, characterized in that, Includes a circulation tank (14), a CIP tank (15), a feed pump (16), a security filter (17), a circulation pump (18), a ceramic membrane module (19), a heat exchanger (20), and a dialysate tank (21), as well as multiple valves installed on the pipeline; The circulation tank (14) is used to store and circulate the 6-methyl-2-ethylaniline ethanol solution to be treated; The CIP tank (15) is used to store cleaning agent and for internal circulation and circulating cleaning of the system; The bottoms of the circulating tank (14) and the CIP tank (15) are connected to the inlet end of the feed pump (16) via pneumatic valves XV01 and XV02, respectively. The outlet end of the feed pump (16) is connected to the inlet end of the security filter (17); The outlet pipeline of the security filter (17) is divided into three paths: the first path is connected to the inlet of the circulating pump (18), the second path is connected to the outlet of the ceramic membrane module (19), and the third path is connected to the inlet of the regulating valve PV01. The outlet end of the circulating pump (18) is connected to the inlet end of the ceramic membrane module (19); The outlet end of the ceramic membrane module (19) is connected back to the inlet end of the circulating pump (18) to form a circulation loop; The outlet end of the regulating valve PV01 is connected to the inlet end of the heat exchanger (20); The outlet pipe of the heat exchanger (20) is divided into three paths: the first path is connected to the top of the CIP tank (15) through the pneumatic valve XV03, the second path is connected to the top of the circulation tank (14) through the pneumatic valve XV04, and the third path is connected to the discharge port through the pneumatic valve XV13. The ceramic membrane module (19) is provided with a dialysate outlet, which is connected to the CIP tank (15) via a pneumatic valve XV06 or to the dialysate tank (21) via a pneumatic valve XV07. The dialysate tank (21) is used to store the filtered 6-methyl-2-ethylaniline solution.

2. The ceramic membrane filtration system for removing magnetic foreign matter from 6-methyl-2-ethylaniline according to claim 1, characterized in that, The ceramic membrane module (19) is filled with a ceramic membrane core, the ceramic membrane core having a filtration accuracy of 20nm, 50nm or 100nm, and being made of alumina or zirconium oxide.

3. The ceramic membrane filtration system for removing magnetic foreign matter from 6-methyl-2-ethylaniline according to claim 1, characterized in that, The membrane housings of the circulating tank (14), feed pump (16), security filter (17), circulating pump (18), ceramic membrane module (19), heat exchanger (20), and liquid receiving parts of dialysate tank (21) are made of FRPP or fluoroplastic; the feed pump (16) and circulating pump (18) are fluoroplastic pumps.

4. The ceramic membrane filtration system for removing magnetic foreign matter from 6-methyl-2-ethylaniline according to claim 1, characterized in that, The top of the outlet of the circulating pump (18) and the top of the U-shaped tube connecting the ceramic membrane assembly (19) are respectively connected to the pneumatic valve XV09 and the pneumatic valve XV10.

5. The ceramic membrane filtration system for removing magnetic foreign matter from 6-methyl-2-ethylaniline according to claim 1, characterized in that, The bottom of the ceramic membrane assembly (19) is connected to the drainage ditch via pneumatic valves XV11 and XV12.

6. The ceramic membrane filtration system for removing magnetic foreign matter from 6-methyl-2-ethylaniline according to claim 1, characterized in that, The bottom of the CIP tank (15) is connected to the drainage ditch via a pneumatic valve XV08.

7. A method for removing 6-methyl-2-ethylaniline magnetic foreign matter using the system described in any one of claims 1 to 6, characterized in that, Includes the following steps: S1. Preparation steps: Add 6-methyl-2-ethylaniline ethanol solution to the circulation tank (14), wherein the 6-methyl-2-ethylaniline ethanol solution contains 85% ethanol and the temperature is maintained at 80-90℃. S2. Start-up and exhaust procedure: Open pneumatic valves XV01, XV04, XV07, XV09, and XV10, keep regulating valve PV01 fully open, start the feed pump (16) and circulation pump (18) in sequence, perform system large circulation exhaust for 3-5 minutes, and then close pneumatic valves XV09 and XV10. S3. Filtration Procedure: Adjust the regulating valve PV01 to the specified opening to maintain the system filtration pressure at 1-3 bar, performing constant-opening filtration. Cross-flow filtration is employed, with the surface flow velocity controlled at 3-5 m / s and the filtration flux at 200-400 L / m³. 2 •h, using a ceramic membrane module (19) to filter magnetic foreign objects; S4. Stopping procedure: Keep regulating valve PV01 fully open, and stop circulating pump (18) and conveying pump (16) in sequence. After circulating pump (18) and conveying pump (16) have completely stopped, close pneumatic valve XV01, pneumatic valve XV04 and pneumatic valve XV07.

8. The method according to claim 7, characterized in that, Also includes: During the filtration process in step S3, ethanol is added to the circulation tank (14).

9. The method according to claim 7, characterized in that, The method further includes a CIP cleaning step of the ceramic membrane module (19), the CIP cleaning step including: After draining the process liquid in the system, add a cleaning solution with a concentration of 0.2%-2% to the CIP tank (15); Open pneumatic valves XV02, XV03, XV06, XV09, and XV10, and start the feed pump (16) and circulation pump (18) to circulate the cleaning solution for 1 to 4 hours. After cleaning is completed, stop the circulation pump (18) and the feed pump (16) in sequence, and drain the cleaning waste liquid through pneumatic valves XV08, XV11 and XV12. Repeat the rinsing and draining process using purified water until the system is thoroughly cleaned.

10. The method according to claim 7, characterized in that, In step S3, the operating temperature of the filtration step is controlled at 85°C.

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