Device and method for recovering heat of mother liquor tail gas in methoxyamine production

Abstract

The invention discloses a mother liquor tail gas heat recovery device and method in methoxyamine production. The mother liquor tail gas heat recovery device comprises a mother liquor kettle, a waste heat exchanger, an efficient gas-liquid separation tank, a liquid caustic soda temporary storage tank, a liquid caustic soda circulating pump and a distillation kettle, an outlet of the mother liquor kettle is communicated with a gas phase inlet of the waste heat exchanger through a pipeline, a gas phase outlet of the waste heat exchanger is communicated with an inlet of the efficient gas-liquid separation tank through a pipeline, and a gas phase outlet of the efficient gas-liquid separation tank is connected into a tail gas system through a pipeline. According to the process, heat in the mother liquor tail gas can be recycled to the maximum extent, the initial temperature of fed caustic soda liquid can be effectively increased, the amount of steam used in the heating process in the earlier stage of methoxyamine distillation is reduced, a low-temperature gas phase at an outlet of the waste heat exchanger enters the efficient gas-liquid separation tank, liquid drops entrained in the low-temperature gas phase can be effectively recycled, and the quality of the methoxyamine is improved. And meanwhile, the tail gas subjected to efficient separation is relatively modified, so that subsequent further treatment on the tail gas is facilitated.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of methoxylamine production, and particularly relates to a mother liquor tail gas heat recovery device and method in methoxylamine production. BACKGROUND

[0002] Furan ammonium salt (English name: SMIA) is currently the main raw material for the production of cephalosporin antibiotics cefuroxime and cefuroxime ester. Cefuroxime was first developed by Glaxo William Company and was first listed in the United Kingdom, Ireland, Germany and Italy in 1978, and then sold in many countries around the world. The trade name is "Cefuroxime". After being approved by the FDA in the United States in 1987, it was listed in the United States. Due to its exact efficacy, it is widely used to resist various infections caused by sensitive bacteria. In the 1990s, the drug has become a best-selling anti-infective drug in the world, with good efficacy. Furan ammonium salt, as a new type of pharmaceutical intermediate, is a key intermediate for the synthesis of the second-generation cephalosporin cefuroxime drug. Its property state is white or white crystalline powder, the molecular weight is 186.17, the boiling point is 284.7℃ at 760mmHg, the trans-isomer is less than or equal to 0.5%, and the chemical name is (z)-2-methoxymethylamino-2-(furan-2-yl) ammonium acetate.

[0003] The production process of furan ammonium salt is as follows: acetyl furan, sodium nitrite, water, phosphoric acid, hydrochloric acid and the like are mixed to generate ketonic acid, the ketonic acid is reacted with methoxylamine to generate oxime acid, and finally the oxime acid is reacted with ammonia to obtain crude furan ammonium salt. The crude furan ammonium salt is decolorized by activated carbon and then fed into a concentration kettle. After concentration, the product furan ammonium salt is obtained by centrifugation and drying.

[0004] In the industrial production of furan ammonium salt, the main raw material of furan ammonium salt is methoxylamine, which accounts for a large proportion of the total cost. Therefore, the production cost of methoxylamine is the key to determine the production cost of furan ammonium salt. The current production process mainly includes oximation, methylation, hydrolysis and distillation. A large amount of mother liquor is generated in the production process. Finally, the mother liquor is desalted by pressure filtration. A large amount of high-temperature tail gas is generated in the pressure filtration process. The high-temperature characteristics of the tail gas increase the treatment difficulty and lead to an increase in treatment cost, and also result in a large amount of heat loss. In order to utilize the heat in the methoxylamine mother liquor tail gas and reduce the production cost of methoxylamine, thereby further reducing the production cost of furan ammonium salt, it is urgent to provide a new methoxylamine production mother liquor tail gas heat recovery device and method for process research and application. Therefore, the research is imminent. SUMMARY

[0005] In order to solve the problems mentioned in the background, the present application provides a mother liquor tail gas heat recovery device and method in methoxylamine production.

[0006] In order to achieve the above-mentioned purpose, the present application adopts the following technical scheme:

[0007] A mother liquor tail gas heat recovery device in methanolamine production, comprising a mother liquor tank, a waste heat exchanger, a high-efficiency gas-liquid separation tank, a liquid alkali temporary storage tank, a liquid alkali circulating pump and a distillation tank;

[0008] The outlet of the mother liquor tank is communicated with the gas phase inlet of the waste heat exchanger through a pipeline, the gas phase outlet of the waste heat exchanger is communicated with the inlet of the high-efficiency gas-liquid separation tank through a pipeline, the gas phase outlet of the high-efficiency gas-liquid separation tank is connected to a tail gas system through a pipeline, and the liquid phase outlet of the high-efficiency gas-liquid separation tank is connected to a methanolamine production system through a pipeline;

[0009] The outlet of the liquid alkali temporary storage tank is communicated with the inlet of the liquid alkali circulating pump, and the outlet of the liquid alkali circulating pump is communicated with the liquid phase inlet of the waste heat exchanger through a pipeline.

[0010] The waste heat exchanger is provided with a baffle, the high-efficiency gas-liquid separation tank is provided with a special baffle, and the waste heat exchanger is provided with an on-line temperature monitor.

[0011] Preferably, the pressure control regulating valve is used to control the gas phase pressure of the mother liquor in the waste heat exchanger at 0.02-0.03 MPa.

[0012] Preferably, the visual frequency converter is used to adjust the frequency of the liquid alkali circulating pump, so that the frequency of the liquid alkali circulating pump is controlled at 20-50 Hz; and the liquid alkali flow meter is used to monitor the circulating flow of the liquid alkali, so that the circulating flow of the liquid alkali is controlled at 2.5-12.5 m³ / h.

[0013] Preferably, the special baffle in the high-efficiency gas-liquid separation tank has a cyclone separation effect, is used to separate the condensed liquid in the low-temperature gas phase after heat exchange, and the separated condensed liquid enters the methanolamine production system through the liquid phase outlet pipeline of the high-efficiency gas-liquid separation tank for reuse.

[0014] Preferably, the baffle in the waste heat exchanger is used to control the flow rate of the mother liquor tail gas in the waste heat exchanger, prolong the contact time of the mother liquor tail gas and the liquid alkali, and improve the heat exchange efficiency between the mother liquor tail gas and the liquid alkali.

[0015] Preferably, the waste heat exchanger is provided with a pressure control regulating valve on the gas phase outlet pipeline, the liquid alkali circulating pump is provided with a visual frequency converter, and the liquid alkali circulating pump is provided with a liquid alkali flow meter on the outlet pipeline.

[0016] Preferably, the liquid alkali storage tank and the distillation kettle are connected by a pipe with a discharge shut-off valve. A bracket is fixed to the top of the liquid alkali storage tank, and a hydraulic cylinder is fixed on the bracket. A limit sleeve is fixed to the inner wall of the top of the liquid alkali storage tank, and a limit groove is formed on the limit sleeve. The limit groove extends along a spiral. A lifting drive rod is movably installed inside the liquid alkali storage tank. The top of the lifting drive rod extends movably to the outside of the liquid alkali storage tank and is connected to the output shaft of the hydraulic cylinder. The bottom end of the lifting drive rod passes through the limit sleeve, and a mounting bracket is fixed to the bottom end of the lifting drive rod. A support ring is fixed to the top of the mounting bracket. A stirring shaft is rotatably installed at the bottom end of the support ring. A gear is fixed on the stirring shaft. A gear ring is rotatably installed at the bottom end of the support ring. The gear meshes with the gear ring. A limit bar is fixed to the inner wall of the gear ring, and the end of the limit bar away from the gear ring extends into the limit groove.

[0017] Preferably, the liquid alkali storage tank has an inlet at the top and a drain at the bottom, and a support leg at the bottom. A guide sleeve is fixed at the top of the liquid alkali storage tank, and a lifting drive rod moves through the guide sleeve. Multiple stirring shafts are provided, and the multiple stirring shafts are arranged in a ring array around the toothed ring.

[0018] Preferably, multiple sets of stirring blades are fixed on the stirring shaft, and the multiple sets of stirring blades are equidistantly distributed in the axial direction of the stirring shaft. The stirring blades on the multiple stirring shafts are staggered and do not contact each other.

[0019] A method for recovering heat from the tail gas of the mother liquor in methoxyamine production includes the following steps:

[0020] Step S1: The high-temperature gas phase generated in the mother liquor reactor enters the gas phase channel of the waste heat exchanger through the pipeline. The tail gas temperature is monitored in real time by the online temperature monitoring instrument on the inlet and outlet pipes of the mother liquor gas phase of the waste heat exchanger. At the same time, the pressure of the mother liquor gas phase in the waste heat exchanger is controlled at 0.02-0.03MPa by the pressure control regulating valve on the gas phase outlet pipe of the waste heat exchanger.

[0021] Step S2: The low-temperature gas phase after heat exchange in the waste heat exchanger enters the high-efficiency gas-liquid separator through the pipeline. The separated condensate enters the methoxyamine production system through the liquid phase outlet pipeline of the high-efficiency gas-liquid separator. The low-temperature gas phase without liquid enters the tail gas system through the gas phase outlet pipeline of the high-efficiency gas-liquid separator.

[0022] Step S3: The cold liquid alkali in the liquid alkali storage tank is pumped into the liquid phase channel of the waste heat exchanger by the liquid alkali circulation pump. After being heated, it returns to the liquid alkali storage tank. The frequency of the liquid alkali circulation pump is controlled at 20-50Hz by the visual frequency converter of the liquid alkali circulation pump, and the liquid alkali circulation flow rate is controlled at 2.5-12.5m³ / h by the liquid alkali flow meter on the liquid alkali circulation pump outlet pipe. When the hot liquid alkali in the liquid alkali storage tank reaches a certain temperature, the discharge shut-off valve on the pipe between the liquid alkali storage tank and the distillation kettle is opened, and the hot liquid alkali is put into the distillation kettle for use through the pipe.

[0023] Compared with the prior art, the beneficial effects of the present invention are:

[0024] 1. The original process lacked a waste heat recovery step, resulting in the complete loss of heat in the mother liquor tail gas, and the treatment cost and difficulty of the mother liquor tail gas were relatively high. The process of this invention can recover heat from the mother liquor tail gas to the maximum extent, effectively increase the initial temperature of the feed alkali, and reduce the amount of steam used in the early heating process of methoxyamine distillation;

[0025] 2. The low-temperature gas phase at the outlet of the waste heat heat exchanger enters the high-efficiency gas-liquid separator, which can effectively recover the liquid droplets entrained in the low-temperature gas phase. At the same time, the tail gas after high-efficiency separation is modified to facilitate further treatment of the tail gas.

[0026] 3. This process has a high degree of automation. The inlet and outlet pipes of the waste heat heat exchanger are equipped with thermometers. In addition, pressure control valves are used to control the tail gas flow rate, which improves the heat recovery effect. At the same time, the liquid alkali discharge is changed from manual to discharge shut-off valve, which makes the operation more convenient and greatly improves the degree of automation. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is a schematic diagram of the process of the present invention;

[0029] Figure 2 This is a perspective view of the liquid alkali temporary storage tank of the present invention;

[0030] Figure 3 This is a three-dimensional sectional view of the liquid alkali storage tank of the present invention;

[0031] Figure 4 This is a front-view sectional view of the liquid alkali storage tank of the present invention;

[0032] Figure 5 This is a magnified detail view of the position of the limiting sleeve inside the liquid alkali storage tank of the present invention;

[0033] Figure 6 This is a front-view sectional view of the position of the limiting sleeve inside the liquid alkali storage tank of the present invention;

[0034] In the diagram: 1. Liquid alkali storage tank; 101. Inlet; 102. Outlet; 103. Support; 104. Support leg; 105. Guide sleeve; 2. Hydraulic cylinder; 201. Lifting drive rod; 202. Mounting frame; 3. Limiting sleeve; 301. Limiting slide; 4. Support ring; 401. Stirring shaft; 402. Stirring blade; 403. Gear; 404. Gear ring; 405. Limiting rod; 7. Mother liquor tank; 8. Waste heat exchanger; 9. High-efficiency gas-liquid separator; 10. Liquid alkali circulation pump; 11. Distillation kettle. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0036] Example 1

[0037] Reference Figures 1-6 A device and method for recovering heat from the tail gas of mother liquor in the production of methoxyamine, comprising a mother liquor tank 7, a waste heat exchanger 8, a high-efficiency gas-liquid separator 9, a liquid alkali storage tank 1, a liquid alkali circulation pump 10, and a distillation kettle 11.

[0038] The outlet of the mother liquor reactor 7 is connected to the gas phase inlet of the waste heat heat exchanger 8 through a pipeline. The gas phase outlet of the waste heat heat exchanger 8 is connected to the inlet of the high-efficiency gas-liquid separator 9 through a pipeline. The gas phase outlet of the high-efficiency gas-liquid separator 9 is connected to the tail gas system through a pipeline. The liquid phase outlet of the high-efficiency gas-liquid separator 9 is connected to the methoxyamine production system through a pipeline.

[0039] The high-efficiency gas-liquid separator 9 has a cyclone separation effect to separate low-temperature gas phase moisture, and the waste heat exchanger 8 is used to recover heat from the high-temperature gas phase of the mother liquor, increasing profits and reducing the difficulty of tail gas treatment.

[0040] The outlet of the liquid alkali storage tank 1 is connected to the inlet of the liquid alkali circulation pump 10. The outlet of the liquid alkali circulation pump 10 is connected to the liquid phase inlet of the waste heat exchanger 8 through a pipe. The liquid phase outlet of the waste heat exchanger 8 is connected to the liquid alkali storage tank 1 through a pipe.

[0041] The waste heat exchanger 8 is equipped with baffles, and the high-efficiency gas-liquid separator 9 is equipped with special baffles. The mother liquid gas phase inlet and outlet pipes of the waste heat exchanger 8 are equipped with online temperature monitoring instruments.

[0042] The pressure control regulating valve is used to control the mother liquor gas phase pressure in the waste heat exchanger 8 at 0.025 MPa.

[0043] The visible frequency converter is used to adjust the frequency of the liquid alkali circulation pump 10, so that the frequency of the liquid alkali circulation pump 10 is controlled at 30Hz; the liquid alkali flow meter is used to monitor the liquid alkali circulation flow rate, so that the liquid alkali circulation flow rate is controlled at 10m³ / h.

[0044] The specially designed baffle inside the high-efficiency gas-liquid separator 9 has a cyclone separation effect, which is used to separate the condensate in the low-temperature gas phase after heat exchange. The separated condensate enters the methoxyamine production system through the liquid phase outlet pipe of the high-efficiency gas-liquid separator 9.

[0045] Among them, the baffle plate in the waste heat exchanger 8 is used to control the flow rate of the mother liquor tail gas in the waste heat exchanger 8, prolong the contact time between the mother liquor tail gas and the liquid alkali, and improve the heat exchange efficiency between the mother liquor tail gas and the liquid alkali.

[0046] The waste heat exchanger 8 is equipped with a pressure control regulating valve on its gas phase outlet pipe, the liquid alkali circulation pump 10 is equipped with a visual frequency converter, and the liquid alkali circulation pump 10 is equipped with a liquid alkali flow meter on its outlet pipe.

[0047] The liquid alkali storage tank 1 is connected to the distillation kettle 11 via a pipe with a discharge shut-off valve. A bracket 103 is fixed to the top of the liquid alkali storage tank 1, and a hydraulic cylinder 2 is fixed on the bracket 103. A limit sleeve 3 is fixed to the inner wall of the top of the liquid alkali storage tank 1, and a limit groove 301 is formed on the limit sleeve 3. The limit groove 301 extends along a spiral. A lifting drive rod 201 is movably installed inside the liquid alkali storage tank 1. The top of the lifting drive rod 201 extends movably to the outside of the liquid alkali storage tank 1 and is connected to the output shaft of the hydraulic cylinder 2. Next, the bottom end of the lifting drive rod 201 passes through the limiting sleeve 3, and the bottom end of the lifting drive rod 201 is fixed with a mounting bracket 202. The top end of the mounting bracket 202 is fixed with a support ring 4. The bottom end of the support ring 4 is rotatably mounted with a stirring shaft 401. A gear 403 is fixed on the stirring shaft 401. The bottom end of the support ring 4 is rotatably mounted with a toothed ring 404. The gear 403 meshes with the toothed ring 404. A limiting rod 405 is fixed on the inner wall of the toothed ring 404. The end of the limiting rod 405 away from the toothed ring 404 extends into the limiting groove 301.

[0048] If the liquid alkali storage tank 1 lacks stirring, the hot liquid alkali (returning from the waste heat exchanger 8) tends to accumulate on the upper layer of the storage tank due to its lower density, while the cold liquid alkali (newly added or insufficiently heated liquid alkali) settles on the lower layer due to its higher density, forming a "hot on top, cold on the bottom" temperature stratification. This stratification will result in: the overall average temperature of the liquid alkali in the storage tank being lower than expected, requiring additional steam to be consumed for heating when entering the distillation kettle; the liquid alkali pump may draw liquid alkali from the lower layer of cold alkali, causing the heat exchange temperature difference between the liquid alkali and the mother liquor tail gas in the waste heat exchanger to decrease, further reducing the heat recovery efficiency.

[0049] Hydraulic cylinder 2, acting as a power source, is connected to lifting drive rod 201 via its output shaft. This allows it to move the support ring 4 up and down, which in turn moves the stirring shaft 401 up and down, thus increasing the stirring area. During the movement of the support ring 4, the limiting rod 405 on the gear ring 404 is engaged in the limiting groove 301. The limiting rod 405 slides along the limiting groove 301. Since the limiting groove 301 extends along a spiral, it can cause the gear ring 404 to rotate relative to the support ring 4. This rotation is achieved through the meshing of the gear ring 404 and the gear 403. The stirring shaft 401 is rotated to stir the alkali solution, thereby breaking up the temperature stratification of the liquid alkali and ensuring maximum heat recovery efficiency. With only a hydraulic cylinder 2 as the power input, the stirring shaft 401 can be rotated and stirred during the lifting and lowering process, which can greatly improve the stirring coverage and the stirring effect. Through stirring, the liquid alkali in the tank can be forcibly pushed to convect, so that the hot liquid alkali and the cold liquid alkali can be fully mixed, ensuring that the temperature deviation of the liquid alkali in the temporary storage tank 1 is controlled within a small range, and maximizing the use of the heat recovered from the mother liquor tail gas to raise the initial temperature of the liquid alkali.

[0050] The liquid alkali storage tank 1 has an inlet 101 at its top and a drain 102 at its bottom. A support leg 104 at the bottom of the liquid alkali storage tank 1 supports the entire tank and ensures stable placement. A guide sleeve 105 is fixed to the top of the liquid alkali storage tank 1 to guide the vertical movement of the lifting drive rod 201. The lifting drive rod 201 moves through the guide sleeve 105. Multiple stirring shafts 401 are arranged in a circular array around the toothed ring 404 to increase the horizontal area covered by the stirring and reduce dead zones.

[0051] The stirring shaft 401 has multiple sets of stirring blades 402 fixed on it. The multiple sets of stirring blades 402 are equidistantly distributed in the axial direction of the stirring shaft 401. The stirring blades 402 on the multiple stirring shafts 401 are staggered and do not contact each other. The stirring blades 402 that rotate synchronously on the multiple stirring shafts 401 will not interfere with each other.

[0052] Example 2

[0053] ReferenceFigure 1 A method for recovering heat from the tail gas of the mother liquor in methoxyamine production includes the following steps:

[0054] Step S1: The high-temperature gas phase generated in the mother liquor reactor 7 enters the gas phase channel of the waste heat exchanger 8 through the pipeline. The tail gas temperature is monitored in real time by the online temperature monitoring instrument on the inlet and outlet pipes of the mother liquor gas phase of the waste heat exchanger 8. At the same time, the pressure of the mother liquor gas phase in the waste heat exchanger 8 is controlled at 0.02~0.025MPa by the pressure control regulating valve on the gas phase outlet pipe of the waste heat exchanger 8.

[0055] Step S2: The low-temperature gas phase after heat exchange in the waste heat exchanger 8 enters the high-efficiency gas-liquid separator 9 through the pipeline. The separated condensate enters the methoxyamine production system through the liquid phase outlet pipeline of the high-efficiency gas-liquid separator 9. The low-temperature gas phase without liquid enters the tail gas system through the gas phase outlet pipeline of the high-efficiency gas-liquid separator 9.

[0056] Step S3: The cold liquid alkali in the liquid alkali storage tank 1 is pumped into the liquid phase channel of the waste heat exchanger 8 by the liquid alkali circulation pump 10, and after being heated, it returns to the liquid alkali storage tank 1; the frequency of the liquid alkali circulation pump 10 is controlled at 30Hz by the visual frequency converter of the liquid alkali circulation pump 10, and the liquid alkali circulation flow rate is controlled at 10m³ / h by the liquid alkali flow meter on the outlet pipe of the liquid alkali circulation pump 10; when the hot liquid alkali in the liquid alkali storage tank 1 reaches a certain temperature, the discharge shut-off valve on the pipe between the liquid alkali storage tank 1 and the distillation kettle 11 is opened, and the hot liquid alkali is put into the distillation kettle 11 for use through the pipe.

[0057] After three months of continuous and stable operation, the original process, by adding a heat recovery step to the existing tail gas, recovers and utilizes the heat in the mother liquor tail gas, increasing the initial temperature of the liquid alkali and reducing the steam required for heating in the early stage of methoxyamine distillation. Simultaneously, after this step, the final mother liquor tail gas, after waste heat exchange and efficient gas-liquid separation, is low in temperature and dry, making it easier to handle. Experiments have shown that the treatment cost of the mother liquor tail gas after waste heat recovery and efficient separation is significantly reduced, decreasing the cost of mother liquor tail gas treatment. Furthermore, the separated condensate can be reused in the oxime formulation of methoxyamine, further demonstrating the process's considerations in tail gas treatment, energy conservation, and environmental protection, achieving good results.

[0058] Since the start-up, there have been multiple instances of high-temperature exhaust gas causing deformation of the exhaust gas treatment system pipelines. This is mainly due to the excessively high temperature of the mother liquor exhaust gas. During the operation of the new process, the final mother liquor exhaust gas produced is lower in temperature and drier, making it easier to treat and reducing the risks in the treatment process.

[0059] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0060] In this invention, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," "link," and "fix" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, a direct connection, or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0061] The control method of this invention is automatic control through a controller. The control circuit of the controller can be implemented by simple programming by those skilled in the art. The power supply is also common knowledge in the art. Furthermore, since this invention is mainly used to protect mechanical devices, the control method and circuit connection will not be explained in detail here.

[0062] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A heat recovery device for mother liquor tail gas in methoxyamine production, characterized in that: It includes a mother liquor tank (7), a waste heat exchanger (8), a high-efficiency gas-liquid separator (9), a liquid alkali storage tank (1), a liquid alkali circulation pump (10), and a distillation kettle (11). The outlet of the mother liquor tank (7) is connected to the gas phase inlet of the waste heat exchanger (8) through a pipeline. The gas phase outlet of the waste heat exchanger (8) is connected to the inlet of the high-efficiency gas-liquid separator (9) through a pipeline. The gas phase outlet of the high-efficiency gas-liquid separator (9) is connected to the tail gas system through a pipeline. The liquid phase outlet of the high-efficiency gas-liquid separator (9) is connected to the methoxyamine production system through a pipeline. The outlet of the liquid alkali storage tank (1) is connected to the inlet of the liquid alkali circulation pump (10), the outlet of the liquid alkali circulation pump (10) is connected to the liquid phase inlet of the waste heat exchanger (8) through a pipe, and the liquid phase outlet of the waste heat exchanger (8) is connected to the liquid alkali storage tank (1) through a pipe. The waste heat exchanger (8) is equipped with a baffle plate, and the high-efficiency gas-liquid separator (9) is equipped with a special baffle. The mother liquid gas phase inlet and outlet pipes of the waste heat exchanger (8) are equipped with online temperature monitoring instruments.

2. The heat recovery device for mother liquor tail gas in methoxyamine production according to claim 1, characterized in that: The pressure control regulating valve is used to control the mother liquor gas phase pressure in the waste heat exchanger (8) at 0.02 to 0.03 MPa.

3. The heat recovery device for mother liquor tail gas in methoxyamine production according to claim 1, characterized in that: The visual frequency converter is used to adjust the frequency of the liquid alkali circulation pump (10) so that the frequency of the liquid alkali circulation pump (10) is controlled at 20 to 50 Hz; the liquid alkali flow meter is used to monitor the liquid alkali circulation flow rate so that the liquid alkali circulation flow rate is controlled at 2.5 to 12.5 m³ / h.

4. The heat recovery device for mother liquor tail gas in methoxyamine production according to claim 1, characterized in that: The specially designed baffle inside the high-efficiency gas-liquid separator (9) has a cyclone separation effect, which is used to separate the condensate in the low-temperature gas phase after heat exchange, and the separated condensate enters the methoxyamine production system through the liquid phase outlet pipe of the high-efficiency gas-liquid separator (9).

5. The heat recovery device for mother liquor tail gas in methoxyamine production according to claim 1, characterized in that: The baffle plate in the waste heat exchanger (8) is used to control the flow rate of the mother liquor tail gas in the waste heat exchanger (8), prolong the contact time between the mother liquor tail gas and the liquid alkali, and improve the heat exchange efficiency between the mother liquor tail gas and the liquid alkali.

6. The heat recovery device for mother liquor tail gas in methoxyamine production according to claim 1, characterized in that: The gas phase outlet pipe of the waste heat exchanger (8) is equipped with a pressure control regulating valve, the liquid alkali circulation pump (10) is equipped with a visual frequency converter, and the outlet pipe of the liquid alkali circulation pump (10) is equipped with a liquid alkali flow meter.

7. The heat recovery device for mother liquor tail gas in methoxyamine production according to claim 1, characterized in that: The liquid alkali storage tank (1) and the distillation kettle (11) are connected by a pipe with a discharge shut-off valve. A bracket (103) is fixed at the top of the liquid alkali storage tank (1), and a hydraulic cylinder (2) is fixed on the bracket (103). A limit sleeve (3) is fixed on the inner wall of the top of the liquid alkali storage tank (1), and a limit groove (301) is opened on the limit sleeve (3). The limit groove (301) extends along a spiral. A lifting drive rod (201) is movably installed inside the liquid alkali storage tank (1). The top of the lifting drive rod (201) extends movably to the outside of the liquid alkali storage tank (1) and is connected to the output shaft of the hydraulic cylinder (2). The bottom end of the lifting drive rod (201) passes through the limiting sleeve (3), and the bottom end of the lifting drive rod (201) is fixed with a mounting bracket (202). The top end of the mounting bracket (202) is fixed with a support ring (4). The bottom end of the support ring (4) is rotatably mounted with a stirring shaft (401). A gear (403) is fixed on the stirring shaft (401). The bottom end of the support ring (4) is rotatably mounted with a toothed ring (404). The gear (403) meshes with the toothed ring (404). A limiting rod (405) is fixed on the inner wall of the toothed ring (404). The end of the limiting rod (405) away from the toothed ring (404) extends into the limiting groove (301).

8. The heat recovery device for mother liquor tail gas in methoxyamine production according to claim 7, characterized in that: The liquid alkali storage tank (1) has an inlet (101) at the top and a drain (102) at the bottom. The liquid alkali storage tank (1) also has a support leg (104) at the bottom. A guide sleeve (105) is fixed at the top of the liquid alkali storage tank (1). A lifting drive rod (201) moves through the guide sleeve (105). There are multiple stirring shafts (401), and the multiple stirring shafts (401) are arranged in a ring array around the toothed ring (404).

9. A heat recovery device for mother liquor tail gas in methoxyamine production according to claim 7, characterized in that: Multiple sets of stirring blades (402) are fixed on the stirring shaft (401). The multiple sets of stirring blades (402) are equidistantly distributed in the axial direction of the stirring shaft (401). The stirring blades (402) on the multiple stirring shafts (401) are staggered and do not contact each other.

10. A method for recovering heat from the tail gas of mother liquor in methoxyamine production based on the apparatus of any one of claims 1-9, characterized in that, Includes the following steps: Step S1: The high-temperature gas phase generated in the mother liquor tank (7) enters the gas phase channel of the waste heat exchanger (8) through the pipeline. The tail gas temperature is monitored in real time by the online temperature monitoring instrument on the inlet and outlet pipelines of the mother liquor gas phase of the waste heat exchanger (8). At the same time, the pressure of the mother liquor gas phase in the waste heat exchanger (8) is controlled at 0.02~0.03MPa by the pressure control regulating valve on the gas phase outlet pipeline of the waste heat exchanger (8). Step S2: The low-temperature gas phase after heat exchange in the waste heat exchanger (8) enters the high-efficiency gas-liquid separator (9) through the pipeline. The separated condensate enters the methoxyamine production system through the liquid phase outlet pipeline of the high-efficiency gas-liquid separator (9). The low-temperature gas phase without liquid enters the tail gas system through the gas phase outlet pipeline of the high-efficiency gas-liquid separator (9). Step S3: The cold liquid alkali in the liquid alkali storage tank (1) is pumped into the liquid phase channel of the waste heat exchanger (8) by the liquid alkali circulation pump (10), and returns to the liquid alkali storage tank (1) after being heated; the frequency of the liquid alkali circulation pump (10) is controlled at 20-50Hz by the visual frequency converter of the liquid alkali circulation pump (10), and the liquid alkali circulation flow rate is controlled at 2.5-12.5m³ / h by the liquid alkali flow meter on the outlet pipe of the liquid alkali circulation pump (10); when the hot liquid alkali in the liquid alkali storage tank (1) reaches a certain temperature, the discharge shut-off valve on the pipe between the liquid alkali storage tank (1) and the distillation kettle (11) is opened, and the hot liquid alkali is put into the distillation kettle (11) for use through the pipe.

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