Negative pressure rectification treatment device for amino acetic acid methanol mother liquor

Abstract

The utility model discloses a glycine methanol mother liquor negative pressure rectification treatment device which comprises a pretreatment system and a negative pressure rectification system, the pretreatment system comprises a mother liquor feeding pipeline, a plate frame filtering device and an intermediate tank, and the pretreatment system is mainly used for removing precipitated crystals, impurity particles and the like in glycine methanol mother liquor; the introduction of impurities is reduced, and subsequent negative pressure rectification is convenient to implement; wherein the negative pressure rectification system comprises a negative pressure rectification tower, a reboiler, a condenser, a vacuum unit, an extraction reflux tank and a methanol storage tank, the negative pressure rectification system is mainly used for carrying out negative pressure rectification separation treatment on a material filtered by the plate and frame filtering device, methanol is separated out under the condition of relatively low temperature, and a catalyst urotropine is not damaged; both the two can be recycled continuously, and meanwhile, energy consumption is reduced; the device has the advantages of being good in separation effect, capable of reducing production cost, energy-saving and efficient.

Description

Technical Field

[0001] The utility model belongs to the technical field of aminoacetic acid methanol mother liquor processing equipment, and specifically relates to a negative pressure distillation processing device for aminoacetic acid methanol mother liquor. Background Art

[0002] The structural formula of aminoacetic acid is NH2CH2COOH, commonly known as glycine, gum, white monoclinic or hexagonal crystals, or white crystalline powder, odorless, with a special sweet taste, easily soluble in water, slightly soluble in methanol and ethanol, and almost insoluble in acetone and ether. Aminoacetic acid is mainly used for non-toxic decarbonation of fertilizers, medicine and pesticides. It is one of the raw materials for synthesizing glyphosate by the alkyl ester method. It can also be used as a raw material and preservative for cosmetics. It has a relatively broad market and application prospects, so the market demand for aminoacetic acid is increasing.

[0003] The main method for synthesizing aminoacetic acid in China now is the chloroacetic acid ammoniation method, which uses a urotropine aqueous solution as a catalyst, is synthesized in an aqueous phase or an alcohol phase at normal temperature and pressure, and then is obtained by alcohol analysis, centrifugation, refining, and drying to obtain the product aminoacetic acid. In the production process, a large amount of aminoacetic acid methanol mother liquor is produced in the centrifugal section, which also contains the catalyst urotropine and some crystalline impurities. When the catalyst urotropine is separated by atmospheric distillation, the high temperature will destroy the catalyst urotropine and cannot be used for production. Therefore, recovering methanol and urotropine from the aminoacetic acid mother liquor produced in the centrifugal section in the aminoacetic acid production process has become a difficult problem for the treatment of aminoacetic acid methanol mother liquor. And with the increase in domestic demand for aminoacetic acid, the output of aminoacetic acid has been promoted to increase, but at the same time, the output of methanol mother liquor has also been promoted to be larger and larger, and the production cost consumption of methanol and catalyst urotropine has also been promoted to increase. Therefore, in order to solve the above problems, it is necessary to develop a negative pressure distillation treatment device for aminoacetic acid methanol mother liquor. Utility Model Content

[0004] The utility model aims to overcome the deficiencies of the prior art and to provide a negative pressure distillation treatment device for aminoacetic acid methanol mother liquor which has good separation effect, can reduce production cost, and is energy-saving and efficient.

[0005] The purpose of the utility model is achieved as follows: a negative pressure distillation treatment device for aminoacetic acid methanol mother liquor, comprising a pretreatment system and a negative pressure distillation system;

[0006] The pretreatment system comprises a mother liquid feed pipeline, a plate-frame filter device and an intermediate tank, the mother liquid feed pipeline is equipped with a high-pressure feed pump, a liquid flow meter A and a liquid pressure gauge, the liquid flow meter A and the liquid pressure gauge measure and analyze the methanol mother liquid, and the analysis result is transmitted to a remote control system, the mother liquid feed pipeline is connected to the feed port of the plate-frame filter device, and the discharge port of the plate-frame filter device is connected to the liquid inlet of the intermediate tank;

[0007] The negative pressure distillation system includes a negative pressure distillation tower, a reboiler, a condenser, a vacuum unit, a production reflux tank and a methanol storage tank. The liquid outlet of the intermediate tank is connected to the feed port of the negative pressure distillation tower through an intermediate feed pump and a liquid flow meter B. The liquid flow meter B measures and analyzes the liquid flowing through, and the analysis result is transmitted to the remote control system. The gas phase outlet at the top of the negative pressure distillation tower is connected to the gas inlet of the condenser through a gas phase pipeline. A methanol content meter A, an online moisture meter, a gas flow meter and a gas pressure gauge are installed on the gas phase pipeline. The methanol content meter A, the online moisture meter, the gas flow meter and the gas pressure gauge measure and analyze the methanol gas, and the analysis result is transmitted to the remote control system. A control system is provided, wherein a reboiler is provided at the lower part of the negative pressure distillation tower, a discharge port is provided at the bottom of the reboiler, an online thermometer A and an online thermometer B are provided at the top of the negative pressure distillation tower and the top of the reboiler respectively, the discharge port of the condenser is connected to the feed port at the top of the extraction reflux tank, the gas outlet of the condenser is connected to the vacuum unit, the reflux outlet on one side of the extraction reflux tank is connected to the reflux inlet at the top of the negative pressure distillation tower, the methanol extraction port on the other side of the extraction reflux tank is connected to the liquid storage port of the methanol storage tank through a methanol extraction pipeline, a methanol content meter B is installed on the methanol extraction pipeline, and the methanol content meter B measures and analyzes the methanol liquid, and the analysis result is transmitted remotely to the remote control system.

[0008] Preferably, the packing layer of the negative pressure distillation tower is divided into two parts, an upper part and an lower part, grid plates are provided at the lower ends of the upper and lower packing layers, and the feed port is provided between the upper and lower packing layers.

[0009] Preferably, the negative pressure in the negative pressure distillation tower is controlled at -0.03 to -0.05 MPa, the top temperature of the negative pressure distillation tower is controlled at 45±2°C, and the top temperature of the reboiler is controlled at 160±2°C.

[0010] Preferably, the mother liquor feed pipe is a galvanized pipe.

[0011] Preferably, the filter cloth of the plate and frame filter device is made of polytetrafluoro fiber, and the pore size of the filter cloth is controlled to be above 800 meshes.

[0012] Preferably, the plate and frame filter device has at least 20 groups of filter plates.

[0013] Preferably, the intermediate tank is equipped with a liquid level meter, and the liquid level meter is connected to a remote control system.

[0014] Preferably, the condenser is a tubular condenser made of graphite.

[0015] Preferably, the feed port, the discharge port, the liquid inlet, the liquid outlet, the air inlet, the air outlet, the discharge port, the reflux outlet, the methanol production port, the liquid storage port and the discharge port are all provided with solenoid valves, and the solenoid valves are all connected to a remote control system.

[0016] Due to the adoption of the above technical scheme, the beneficial effects of the utility model are as follows: the utility model adopts a pretreatment system to remove impurities from the aminoacetic acid methanol mother liquor, which is convenient for subsequent negative pressure distillation and reduces the introduction of impurities. The present invention adopts a negative pressure distillation system to carry out negative pressure distillation on the aminoacetic acid methanol mother liquor after impurities removal, the distillation temperature is low, the separation effect is good, the catalyst hexamethylenetetramine is not destroyed, and the energy consumption is less. A large amount of methanol and hexamethylenetetramine separated by negative pressure distillation can be continuously recycled and used in the production of aminoacetic acid, which greatly saves production cost consumption; the utility model adopts a reboiler to carry out cyclic heating and temperature control on the materials in the negative pressure distillation tower, and the temperature distribution is uniform and sufficient, further improving the negative pressure distillation efficiency. The utility model improves the separation effect of negative pressure distillation; the utility model adopts a production reflux tank to carry out cyclic cooling and temperature control on the materials in the negative pressure distillation tower, saves energy, maintains the heat balance in the tower, and purifies the separated materials so as to produce materials with high purity, thereby further improving the separation effect of negative pressure distillation; the utility model adopts flow meters, pressure gauges, methanol content measuring instruments and other detection instruments with remote information transmission functions to carry out real-time detection and remote monitoring of key process parameters of the entire device, and to understand the operation status of the entire device in real time so as to make timely adjustments and efficiently ensure the treatment effect of negative pressure distillation; in general, the utility model has the advantages of good separation effect, reduced production cost, energy saving and high efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the composition structure of the utility model.

[0018] In the figure: 1, high-pressure feed pump 2, liquid flow meter A 3, liquid pressure gauge 4, mother liquid feed pipeline 5, feed port 6, plate and frame filter device 7, discharge port 8, liquid inlet 9, intermediate tank 10, liquid level meter 11, liquid outlet 12, intermediate feed pump 13, liquid flow meter B 14, negative pressure distillation tower 15, feed port 16, packing layer 17, online thermometer A 18, gas phase outlet 19, gas phase pipeline 20, methanol content meter A 21, online moisture meter 22, gas flow meter 23, gas pressure gauge 24, air inlet 25, air outlet 26, vacuum unit 27, drain port 28, condenser 29, methanol content meter B 30, methanol production port 31, production reflux tank 32, reflux outlet 33, reflux inlet 34, online thermometer B 35. reboiler 36. discharge port 37. methanol storage tank 38. liquid storage port 39. methanol production pipeline. DETAILED DESCRIPTION

[0019] The technical solution of the utility model is further specifically described below in conjunction with the accompanying drawings.

[0020] like Figure 1 As shown, the utility model provides a negative pressure distillation treatment device for aminoacetic acid methanol mother liquor, comprising a pretreatment system and a negative pressure distillation system, which is used to solve the treatment problem of methanol mother liquor in the production process of aminoacetic acid, and is used to recycle methanol and catalyst urotropine in the production of aminoacetic acid, so as to achieve the purpose of recycling raw materials for aminoacetic acid production, reduce production costs and save resources.

[0021] The pretreatment system is mainly used to remove precipitated crystals, impurity particles, etc. in the aminoacetic acid methanol mother liquor, reduce the introduction of impurities, and facilitate the implementation of subsequent negative pressure distillation.

[0022] Specifically, the pretreatment system includes a mother liquor feed pipeline 4 , a plate and frame filter device 6 and an intermediate tank 9 .

[0023] A high-pressure feed pump 1, a liquid flow meter A2 and a liquid pressure gauge 3 are installed on the mother liquor feed pipeline 4. The liquid flow meter A2 and the liquid pressure gauge 3 measure and analyze the methanol mother liquor, and the analysis results are transmitted remotely to the remote control system. The remote control system can remotely adjust the feed amount of the plate and frame filter device 6 through the solenoid valve according to the flow and pressure data.

[0024] The mother liquor feed pipeline 4 is a galvanized pipeline, which is connected to the feed port 5 of the plate and frame filter device 6, and the discharge port 7 of the plate and frame filter device 6 is connected to the liquid inlet 8 of the intermediate tank 9. The intermediate tank 9 is used to temporarily store the methanol mother liquor after the impurities are filtered out. The intermediate tank 9 is equipped with a liquid level meter 10, which is used to detect the material liquid level height in the intermediate tank 9 and transmit the data to the remote control system.

[0025] The plate and frame filter device 6 is a plate and frame filter of the prior art, which can filter out impurities and crystals and reduce impurities in the methanol mother liquor. It is mainly composed of a feed port 5, a hydraulic device, a filter plate, a filter frame, a guide rail and a discharge port 7. A pressure gauge for detecting hydraulic force data is installed on the hydraulic device. The number of filter plates is at least 20 groups, which can be easily disassembled and repaired individually. The hydraulic device is connected to a pressure rod, and the pressure rod is connected to an extrusion plate. The extrusion plate squeezes multiple groups of filter plates and multiple filter frames arranged therewith to move along the guide rail to the fixed plate on the other side. The extrusion makes the multiple groups of filter plates and the multiple filter frames arranged therewith squeezed together to form a filter, thereby effectively filtering out impurities in the methanol mother liquor. The filter plate is installed with a filter cloth, and the filter cloth is made of polytetrafluoroethylene fiber. The pore size of the filter cloth is controlled to be above 800 meshes, which is corrosion-resistant and has a good filtering effect.

[0026] The negative pressure distillation system is to perform negative pressure distillation separation treatment on the material filtered by the plate and frame filter device 6, and separate methanol at a relatively low temperature without destroying the catalyst hexamethylenetetramine, both of which can continue to be recycled and used, while saving energy consumption.

[0027] Specifically, the negative pressure distillation system includes a negative pressure distillation tower 14 , a reboiler 35 , a condenser 28 , a vacuum unit 26 , a production reflux tank 31 and a methanol storage tank 37 .

[0028] The liquid outlet 11 of the intermediate tank 9 is connected to the feeding port 15 of the negative pressure distillation tower 14 through the intermediate feed pump 12 and the liquid flow meter B13. The liquid flow meter B13 measures and analyzes the liquid flowing through, and the analysis result is transmitted to the remote control system. The remote control system can remotely adjust the feeding amount of the negative pressure distillation tower 14 through the solenoid valve according to the flow data.

[0029] The gas phase outlet 18 at the top of the negative pressure distillation tower 14 is connected to the air inlet 24 of the condenser 28 through the gas phase pipeline 19. The gas phase pipeline 19 is equipped with a methanol content meter A20, an online moisture meter 21, a gas flow meter 22 and a gas pressure gauge 23. The methanol content meter A20, the online moisture meter 21, the gas flow meter 22 and the gas pressure gauge 23 measure and analyze the methanol gas, and the analysis results are transmitted remotely to the remote control system. The remote control system can remotely adjust the air intake of the condenser 28 through the solenoid valve according to the methanol content, moisture content, flow and pressure data.

[0030] A reboiler 35 is provided at the lower part of the negative pressure distillation tower 14, and a discharge port 36 is provided at the bottom of the reboiler 35. The discharge port 36 is used to discharge the hexamethylenetetramine after the negative pressure distillation separation treatment. The reboiler 35 is equipped with a saturated hot steam inlet and outlet to provide a heat source for heating the material.

[0031] An online thermometer A17 and an online thermometer B34 are respectively provided at the top of the negative pressure distillation tower 14 and the top of the reboiler 35, which are respectively used to accurately detect the top temperature of the negative pressure distillation tower 14 and the top outlet heating material temperature of the reboiler 35, so as to facilitate the adjustment of the operating temperature of the negative pressure distillation tower 14.

[0032] The negative pressure in the negative pressure distillation tower is controlled at -0.03~-0.05Mpa, the top temperature of the negative pressure distillation tower is controlled at 45±2℃, and the top temperature of the reboiler is controlled at 160±2℃.

[0033] The discharge port 27 of the condenser 18 is connected to the feed port at the top of the extraction reflux tank 31, the air outlet 25 of the condenser 28 is connected to the vacuum unit 26 that provides negative pressure, the reflux outlet 32 ​​on one side of the extraction reflux tank 31 is connected to the reflux inlet 33 at the top of the negative pressure distillation tower 14, and the methanol extraction port 30 on the other side of the extraction reflux tank 31 is connected to the liquid storage port 38 of the methanol storage tank 37 through the methanol extraction pipeline 39. The methanol storage tank 37 is used to store methanol after negative pressure distillation separation treatment. A methanol content meter B29 is installed on the methanol extraction pipeline. The methanol content meter B39 measures and analyzes the separated methanol liquid, and the analysis results are transmitted remotely to the remote control system.

[0034] The packing layer 16 of the negative pressure distillation tower 14 is divided into two parts, an upper and a lower part. The lower ends of the upper and lower packing layers 16 are provided with grid plates, and a feeding port 15 is provided between the upper and lower packing layers 16, that is, the feeding port 15 is arranged in the middle position of the negative pressure distillation tower 14. Feeding at this location can make the material evenly distributed in the tower body, reduce liquid accumulation, and improve the stability and separation efficiency of the tower body. The tower body is a negative pressure distillation. If material is added at the top of the tower, the material will be pumped away. If material is added at the bottom of the tower, liquid accumulation will occur. Therefore, it is most appropriate to add material in the middle position.

[0035] The condenser 28 is a tubular condenser made of graphite, which has good cooling effect and is corrosion-resistant.

[0036] Specifically, the feed port 5, the discharge port 7, the liquid inlet 8, the liquid outlet 11, the air inlet 24, the air outlet 25, the drain port 27, the reflux outlet 32, the methanol production outlet 30, the liquid storage port 38 and the discharge port 36 are all provided with solenoid valves, and the solenoid valves are all connected to the remote control system, which performs remote adjustments according to the actual operation conditions of the device.

[0037] After completing the above installation, the utility model can be put into use. When in use, the aminoacetic acid methanol mother liquor is pumped into the plate-frame filter device 6 through the mother liquor feed pipeline 4 by the high-pressure feed pump 1, and the material filtered by the plate-frame filter device 6 enters the intermediate tank 9 through the discharge port 7 and the liquid inlet 8; the material in the intermediate tank 9 is pumped out by the intermediate feed pump 12, and enters the negative pressure distillation tower 14 from the feed port 15 for negative pressure distillation separation treatment, and the separated methanol enters the condenser 28 from the gas phase outlet 18 through the gas phase pipeline 19, and the condensed methanol enters the production reflux tank 31 through the discharge port 27, and the production reflux tank 31 is used for the production reflux tank 31. Part of the material in the flow tank 31 refluxes from the reflux outlet 32 ​​to the top of the negative pressure distillation tower 14 for further purification, and part of the material in the reflux tank 31 is taken out and enters the methanol storage tank 37 from the methanol extraction outlet 30; during this period, the reboiler 35 performs cyclic heating on the material at the lower part of the negative pressure distillation tower 14 to separate methanol from the heated material; during this period, the vacuum unit 26 provides the negative pressure distillation tower 14 with working negative pressure; during this period, the remote control system coordinates as a whole, and adjusts the operating status of the entire device in time through the detection data sent back by various detection instruments, so that the negative pressure distillation treatment work can be completed normally.

[0038] In summary, by adopting the utility model to perform negative pressure distillation separation treatment on aminoacetic acid methanol mother liquor, methanol can be separated for further use in production, and the separated hexamethylenetetramine can also be continuously recycled, thereby saving energy and production costs at the same time.

[0039] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A negative pressure distillation treatment device for aminoacetic acid methanol mother liquor, characterized in that: Including pretreatment system and negative pressure distillation system; The pretreatment system comprises a mother liquid feed pipeline, a plate-frame filter device and an intermediate tank, the mother liquid feed pipeline is equipped with a high-pressure feed pump, a liquid flow meter A and a liquid pressure gauge, the liquid flow meter A and the liquid pressure gauge measure and analyze the methanol mother liquid, and the analysis result is transmitted to a remote control system, the mother liquid feed pipeline is connected to the feed port of the plate-frame filter device, and the discharge port of the plate-frame filter device is connected to the liquid inlet of the intermediate tank; The negative pressure distillation system includes a negative pressure distillation tower, a reboiler, a condenser, a vacuum unit, a production reflux tank and a methanol storage tank. The liquid outlet of the intermediate tank is connected to the feed port of the negative pressure distillation tower through an intermediate feed pump and a liquid flow meter B. The liquid flow meter B measures and analyzes the liquid flowing through, and the analysis result is transmitted to the remote control system. The gas phase outlet at the top of the negative pressure distillation tower is connected to the gas inlet of the condenser through a gas phase pipeline. A methanol content meter A, an online moisture meter, a gas flow meter and a gas pressure gauge are installed on the gas phase pipeline. The methanol content meter A, the online moisture meter, the gas flow meter and the gas pressure gauge measure and analyze the methanol gas, and the analysis result is transmitted to the remote control system. A control system is provided, wherein a reboiler is provided at the lower part of the negative pressure distillation tower, a discharge port is provided at the bottom of the reboiler, an online thermometer A and an online thermometer B are provided at the top of the negative pressure distillation tower and the top of the reboiler respectively, the discharge port of the condenser is connected to the feed port at the top of the extraction reflux tank, the gas outlet of the condenser is connected to the vacuum unit, the reflux outlet on one side of the extraction reflux tank is connected to the reflux inlet at the top of the negative pressure distillation tower, the methanol extraction port on the other side of the extraction reflux tank is connected to the liquid storage port of the methanol storage tank through a methanol extraction pipeline, a methanol content meter B is installed on the methanol extraction pipeline, and the methanol content meter B measures and analyzes the extracted methanol, and the analysis result is transmitted remotely to the remote control system.

2. The negative pressure distillation treatment device for aminoacetic acid methanol mother liquor according to claim 1, characterized in that: The packing layer of the negative pressure distillation tower is divided into two parts, an upper part and an lower part. The lower ends of the upper and lower packing layers are both provided with grid plates, and the feed port is provided between the upper and lower packing layers.

3. The negative pressure distillation treatment device for aminoacetic acid methanol mother liquor according to claim 1, characterized in that: The negative pressure in the negative pressure distillation tower is controlled at -0.03 to -0.05 MPa, the top temperature of the negative pressure distillation tower is controlled at 45±2°C, and the top temperature of the reboiler is controlled at 160±2°C.

4. The negative pressure distillation treatment device for aminoacetic acid methanol mother liquor according to claim 1, characterized in that: The mother liquor feed pipeline is a galvanized pipeline.

5. The negative pressure distillation treatment device for aminoacetic acid methanol mother liquor according to claim 1, characterized in that: The filter cloth of the plate and frame filter device is made of polytetrafluoro fiber, and the pore size of the filter cloth is controlled to be above 800 meshes.

6. The negative pressure distillation treatment device for aminoacetic acid methanol mother liquor according to claim 1, characterized in that: The plate-and-frame filter device has at least 20 groups of filter plates.

7. The negative pressure distillation treatment device for aminoacetic acid methanol mother liquor according to claim 1, characterized in that: The intermediate tank is equipped with a liquid level gauge, which is connected to a remote control system.

8. The negative pressure distillation treatment device for aminoacetic acid methanol mother liquor according to claim 1, characterized in that: The condenser is a tubular condenser made of graphite.

9. The negative pressure distillation treatment device for aminoacetic acid methanol mother liquor according to claim 1, characterized in that: The feed port, the discharge port, the liquid inlet, the liquid outlet, the air inlet, the air outlet, the discharge port, the reflux outlet, the methanol extraction port, the liquid storage port and the discharge port are all provided with solenoid valves, and the solenoid valves are all connected to a remote control system.

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