IDA method glyphosate freezing crystallization residual liquid recovery system

Abstract

The utility model discloses an IDA method glyphosate freezing crystallization residual liquid recovery system, and relates to the technical field of glyphosate production wastewater recovery. During use, freezing crystallization residual liquid to be recovered is introduced into a first-stage membrane separation device to form first-stage membrane concentrated liquid and first-stage membrane permeation liquid, the first-stage membrane concentrated liquid serves as impurity-containing residual liquid to be discharged and treated, and the second-stage membrane permeation liquid serves as impurity-containing residual liquid to be discharged and treated; the first-stage membrane permeate enters the second-stage membrane separation device to form a second-stage membrane concentrated solution and a second-stage membrane permeate, the second-stage membrane concentrated solution is reused in a glyphosate freezing crystallization system to recycle glyphosate, the purpose of recycling and extracting powder is achieved, the second-stage membrane permeate enters the third-stage membrane separation device to form a third-stage membrane concentrated solution and a third-stage membrane permeate, and the third-stage membrane permeate enters the third-stage membrane separation device to form a third-stage membrane permeate. A third-stage membrane concentrated solution is returned to the second-stage membrane separation device through a circulating pipeline, and a third-stage membrane permeate is used as production water to be reused in a glyphosate production system, so that the purpose of reuse of reclaimed water of the wastewater is achieved, the recovery rate of the glyphosate is improved, meanwhile, the water quantity of discharged residual liquid is reduced, and resource recovery of the wastewater is realized.

Description

TECHNICAL FIELD

[0001] The utility model relates to glyphosate production wastewater recovery technical field especially, it is a kind of IDA method glyphosate freeze crystallization residual liquid recovery system. BACKGROUND

[0002] Glyphosate production process route is mainly divided into glycine method and IDA method.

[0003] The main raw material of glyphosate production process route of glycine method is glycine, polyformaldehyde and (phosphite) dimethyl ester, the above three raw materials are finally produced glyphosate after synthesis, hydrolysis, crystallization separation, drying and other procedures.

[0004] IDA method is the abbreviation of iminodiacetic acid (IDA), and iminodiacetic acid is the key intermediate for synthesizing glyphosate, and compared with traditional glycine method, the method has the advantages of low raw material cost and high product quality.The raw materials of glyphosate production process route of IDA method mainly include phosphorus trichloride, formaldehyde and iminodiacetic acid, and the method is finally oxidized to synthesize glyphosate mother liquor at a temperature of 80-90 DEG C, the glyphosate mother liquor is cooled to below 12 DEG C by brine cooling, and a large amount of glyphosate crystal is obtained by freeze crystallization treatment, and 95% of glyphosate crystal powder and freeze crystallization residual liquid are obtained by centrifugation.Among them, freeze crystallization residual liquid is concentrated to about 10% by evaporation system, and sold as water agent.However, freeze crystallization residual liquid is complex and difficult to handle, and the economic benefit of 10% glyphosate water agent is low compared with glyphosate powder. UTILITY MODEL CONTENT

[0005] The utility model aims at providing a kind of IDA method glyphosate freeze crystallization residual liquid recovery system to solve the problems of above-mentioned related techniques, can improve the recovery rate of glyphosate, and reach the purpose of wastewater reuse, realize the resource recovery of wastewater.

[0006] To achieve the above object, the utility model provides the following scheme:

[0007] The utility model provides a kind of IDA method glyphosate frozen crystallization residual liquid recovery system, including primary membrane separation device, secondary membrane separation device and tertiary membrane separation device, the import of primary membrane separation device is used to pass in the frozen crystallization residual liquid to be recycled, one-stage separation membrane is provided in the primary membrane separation device, the molecular weight cut-off of the one-stage separation membrane is at 2500 Dalton-5000 Dalton, to form primary membrane concentrated solution and primary membrane permeate with the frozen crystallization residual liquid to be recycled being separated, the concentrated solution outlet of primary membrane separation device is used to pass out the primary membrane concentrated solution, the primary membrane concentrated solution is discharged as impurity-containing residual liquid, the permeate outlet of primary membrane separation device is used to pass out the primary membrane permeate;The import of secondary membrane separation device is communicated with the permeate outlet of primary membrane separation device, secondary separation membrane is provided in the secondary membrane separation device, the molecular weight cut-off of the secondary separation membrane is at 150 Dalton-400 Dalton, to form secondary membrane concentrated solution and secondary membrane permeate with the primary membrane permeate being separated, the concentrated solution outlet of secondary membrane separation device is used to pass out the secondary membrane concentrated solution, the secondary membrane concentrated solution is sent to glyphosate frozen crystallization system and recycles glyphosate, the permeate outlet of secondary membrane separation device is used to pass out the secondary membrane permeate;The import of tertiary membrane separation device is communicated with the permeate outlet of secondary membrane separation device, tertiary separation membrane is provided in the tertiary membrane separation device, the molecular weight cut-off of the tertiary separation membrane is at 50 Dalton-300 Dalton, to form tertiary membrane concentrated solution and tertiary membrane permeate with the secondary membrane permeate being separated, the concentrated solution outlet of tertiary membrane separation device is used to pass out the tertiary membrane concentrated solution, and the concentrated solution outlet of tertiary membrane separation device is communicated with the import of secondary membrane separation device by circulation pipeline, the permeate outlet of tertiary membrane separation device is used to pass out the tertiary membrane permeate, and the tertiary membrane permeate is recycled as production water.

[0008] Preferably, the one-stage separation membrane is nanofiltration membrane.

[0009] Preferably, the secondary separation membrane is nanofiltration membrane.

[0010] Preferably, the tertiary separation membrane is nanofiltration membrane.

[0011] Preferably, the IDA method glyphosate frozen crystallization residual liquid recovery system further includes heat exchanger, the import of heat exchanger is communicated with the permeate outlet of primary membrane separation device, the heat exchanger can heat the primary membrane permeate, and the outlet of heat exchanger is communicated with the import of secondary membrane separation device.

[0012] Preferably, the heat exchanger can heat the primary membrane permeate to 35-42 DEG C.

[0013] The utility model discloses relative to relevant technology has obtained following technical effect:

[0014] The IDA method glyphosate freeze crystallization residual liquid recovery system provided by the utility model includes a first membrane separation device, a second membrane separation device and a third membrane separation device, when in use, the freeze crystallization residual liquid to be recovered (that is, the residual liquid after taking powder by the IDA method glyphosate freeze crystallization, the glyphosate content in the residual liquid is 0.6%-1.2%, and the impurity content including the glyphosate content is 0.5%-1.2%) is separated from impurities by the first membrane separation device, the freeze crystallization residual liquid to be recovered is separated by a first separation membrane with a molecular weight cut-off of 2500-5000 daltons in the first membrane separation device to form a first membrane concentrated liquid and a first membrane permeate, wherein the first membrane concentrated liquid is discharged as an impurity-containing residual liquid, and the first membrane permeate (the glyphosate content is 0.5%-1%, and the impurity content is 0.3%-0.8%) is concentrated 4-6 times in the second membrane separation device, the first membrane permeate is separated by a second separation membrane with a molecular weight cut-off of 150-400 daltons in the second membrane separation device to form a second membrane concentrated liquid and a second membrane permeate, wherein the second membrane concentrated liquid (the glyphosate content is greater than 2.8%) is sent to a glyphosate freeze crystallization system (that is, the IDA method glyphosate freeze crystallization system) to recover glyphosate, and the second membrane permeate (the glyphosate content is less than 0.2%) is separated and recovered in the third membrane separation device, the second membrane permeate is separated by a third separation membrane with a molecular weight cut-off of 50-300 daltons in the third membrane separation device to form a third membrane concentrated liquid and a third membrane permeate, wherein the third membrane concentrated liquid is returned to the second membrane separation device through a circulation pipeline, and the third membrane permeate (the glyphosate content is less than 0.02%) is reused as production water.

[0015] The system separates 10%-20% of the freeze crystallization residual liquid to be recovered by the first membrane separation device as a first membrane concentrated liquid, discharges the first membrane concentrated liquid as an impurity-containing residual liquid, and separates 80%-90% of the freeze crystallization residual liquid to be recovered as a first membrane permeate, the first membrane permeate is concentrated 4-6 times in the second membrane separation device to form a second membrane concentrated liquid, and the second membrane concentrated liquid is used to recover glyphosate in the glyphosate freeze crystallization system to achieve the purpose of recycling and taking powder, the second membrane permeate is separated by the third membrane separation device to form 10%-20% of a third membrane concentrated liquid, the third membrane concentrated liquid is returned to the second membrane separation device through a circulation pipeline, and 80%-90% of the second membrane permeate is a third membrane permeate, which is reused as production water in the glyphosate production system to achieve the purpose of wastewater reuse, improve the glyphosate recovery rate, reduce the water volume of the discharged residual liquid, and realize the resource recovery of wastewater. BRIEF DESCRIPTION OF DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the related art, the drawings needed in the embodiments will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained based on these drawings without creative labor.

[0017] Figure 1 The IDA method glyphosate freeze crystallization residual liquid recovery system provided by the embodiments of the present application is shown in the schematic diagram.

[0018] In the figure: 1 - first membrane separation device, 2 - second membrane separation device, 3 - third membrane separation device, 4 - circulating pipeline, 5 - heat exchanger. DETAILED DESCRIPTION

[0019] The technical solutions in the embodiments of the present application will be described clearly and completely in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0020] The purpose of the present application is to provide an IDA method glyphosate freeze crystallization residual liquid recovery system to solve the problems in the related art, improve the recovery rate of glyphosate, achieve the purpose of wastewater reuse, and realize the recycling of wastewater resources.

[0021] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the present application will be further described in detail in combination with the drawings and specific embodiments.

[0022] As Figure 1As shown, the embodiment provides an IDA glyphosate frozen crystallization residue recovery system, which comprises a first membrane separation device 1, a second membrane separation device 2 and a third membrane separation device 3. The inlet of the first membrane separation device 1 is used to pass in the frozen crystallization residue to be recovered (i.e. the residue after powder collection in the IDA glyphosate frozen crystallization system). The first membrane separation device 1 is provided with a first separation membrane. The molecular weight cut-off of the first separation membrane is 2500-5000 Dalton, so as to separate the frozen crystallization residue to be recovered to form a first membrane concentrated liquid and a first membrane permeate. The concentrated liquid outlet of the first membrane separation device 1 is used to pass out the first membrane concentrated liquid. The first membrane concentrated liquid is discharged as an impurity-containing residue for treatment. The permeate outlet of the first membrane separation device 1 is used to pass out the first membrane permeate. The inlet of the second membrane separation device 2 is communicated with the permeate outlet of the first membrane separation device 1. The second membrane separation device 2 is provided with a second separation membrane. The molecular weight cut-off of the second separation membrane is 150-400 Dalton, so as to separate the first membrane permeate to form a second membrane concentrated liquid and a second membrane permeate. The concentrated liquid outlet of the second membrane separation device 2 is used to pass out the second membrane concentrated liquid. The second membrane concentrated liquid is sent to the glyphosate frozen crystallization system (i.e. the IDA glyphosate frozen crystallization system) to recover glyphosate. The permeate outlet of the second membrane separation device 2 is used to pass out the second membrane permeate. The inlet of the third membrane separation device 3 is communicated with the permeate outlet of the second membrane separation device 2. The third membrane separation device 3 is provided with a third separation membrane. The molecular weight cut-off of the third separation membrane is 50-300 Dalton, so as to separate the second membrane permeate to form a third membrane concentrated liquid and a third membrane permeate. The concentrated liquid outlet of the third membrane separation device 3 is used to pass out the third membrane concentrated liquid. The concentrated liquid outlet of the third membrane separation device 3 is communicated with the inlet of the second membrane separation device 2 through a circulating pipeline 4. The permeate outlet of the third membrane separation device 3 is used to pass out the third membrane permeate. The third membrane permeate is reused as production water.

[0023] In the embodiment, the first separation membrane, the second separation membrane and the third separation membrane are all nanofiltration membranes.

[0024] In the embodiment, the IDA glyphosate frozen crystallization residue recovery system further comprises a heat exchanger 5. The inlet of the heat exchanger 5 is communicated with the permeate outlet of the first membrane separation device 1. The heat exchanger 5 can heat the first membrane permeate to 35-42℃. The outlet of the heat exchanger 5 is communicated with the inlet of the second membrane separation device 2.

[0025] The working process of the IDA glyphosate frozen crystallization residue recovery system provided by the embodiment is as follows:

[0026] The content of glyphosate in the frozen crystallization residual liquid to be recovered is 0.9%, and the content of impurities is 0.61%. The frozen crystallization residual liquid to be recovered is separated from impurities by the first membrane separation device 1. Specifically, the first membrane separation device 1 in the embodiment adopts a first separation membrane with a molecular weight cutoff of 2500-3000 daltons, 15% of which is separated as a first membrane concentrated liquid, which is discharged as a residual liquid containing impurities, and 85% of which is a first membrane permeate liquid, which is heated to 40 DEG C by the heat exchanger 5 and then enters the second membrane separation device 2 for 5 times concentration. Specifically, the second membrane separation device 2 in the embodiment adopts a second separation membrane with a molecular weight cutoff of 200-300 daltons, and the first membrane permeate liquid after heating is separated into a second membrane concentrated liquid and a second membrane permeate liquid. The second membrane concentrated liquid (the content of glyphosate is 3%-3.2%) is used back to the glyphosate frozen crystallization system to recover glyphosate, and the second membrane permeate liquid (the content of glyphosate is 0.1%-0.15%) enters the third membrane separation device 3 for separation and recovery. Specifically, the third membrane separation device 3 in the embodiment adopts a third separation membrane with a molecular weight cutoff of 100-200 daltons, 15% of which is separated as a third membrane concentrated liquid, which is returned to the second membrane separation device 2 through the circulating pipeline 4, and 85% of which is a third membrane permeate liquid (the content of glyphosate is 0.01%-0.015%), which is used as production water and recycled to the glyphosate production system.

[0027] In summary, the system can effectively recover glyphosate in the IDA method glyphosate frozen crystallization residual liquid, improve the recovery rate of glyphosate, and achieve the effect of wastewater reuse, and realize the resource recovery of wastewater.

[0028] The principle and implementation mode of the specific examples are described in the utility model, and the above embodiment is only used to help understand the method and core idea of the utility model. Meanwhile, for the general technical personnel in the art, according to the idea of the utility model, the specific implementation mode and application range will be changed. In summary, the content of the specification should not be understood as the limitation of the utility model.

Claims

1. An IDA process glyphosate freeze crystallization raffinate recovery system characterized by: The IDA method glyphosate freeze crystallization residual recovery system further comprises a heat exchanger, the inlet of the heat exchanger is communicated with the permeate outlet of the first membrane separation device, the heat exchanger can heat the first membrane permeate, and the outlet of the heat exchanger is communicated with the inlet of the second membrane separation device.

2. The IDA process glyphosate freeze crystallization raffinate recovery system of claim 1, wherein: The heat exchanger can heat the first membrane permeate to 35-42 DEG C.

3. The IDA process glyphosate freeze crystallization raffinate recovery system of claim 1, wherein: The heat exchanger can heat the first membrane permeate to 35-42 DEG C.

4. The IDA process glyphosate freeze crystallization raffinate recovery system of claim 1, wherein: ​ 5. The IDA process glyphosate freeze crystallization raffinate recovery system of claim 1, wherein: ​ 6. The IDA process glyphosate freeze crystallization raffinate recovery system of claim 5, wherein: ​

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