Membrane integration system for purifying herbicide mother liquor

Abstract

The invention relates to the technical field of herbicide mother liquor purification, and discloses a membrane integration system for herbicide mother liquor purification, which comprises a mother liquor box, the mother liquor box is connected with a primary membrane assembly pipeline, the primary membrane assembly is used for treating mother liquor in the mother liquor box, the primary membrane assembly is connected with a secondary membrane assembly pipeline, and the secondary membrane assembly is used for treating mother liquor in the mother liquor box. The second-stage membrane assembly is used for treating permeate of the first-stage membrane assembly, the second-stage membrane assembly is in pipeline connection with the electrodialysis device, the electrodialysis device is used for treating permeate of the second-stage membrane assembly, the electrodialysis device is respectively in pipeline connection with the third-stage membrane assembly and the first evaporator, and the third-stage membrane assembly is used for treating thin liquid of the electrodialysis device. According to the invention, the membrane technology is integrated into the recovery treatment of the herbicide mother liquor, and impurities in the herbicide mother liquor are removed in a physical separation manner, so that the complexity of the traditional process is reduced, and herbicide components with higher purity are recovered; a cleaner and more efficient method is explored for separation and extraction of herbicides.

Description

Technical Field

[0001] The invention relates to the technical field of herbicide mother liquor purification, and in particular to a membrane integrated system for herbicide mother liquor purification. Background Art

[0002] Herbicides are agents that can kill weeds completely or selectively. They are also called weed killers. They are a type of substance used to eliminate or inhibit plant growth.

[0003] For example, glyphosate (N-(phosphonoformic acid) glycine) is a highly effective, low-toxic, broad-spectrum, and safe herbicide. It has good systemic and conductive properties and is very effective in preventing and controlling perennial deep-rooted malignant weeds. It is also extremely easy to decompose and will not accumulate or remain in animals or other organisms. It is relatively safe for humans, animals, aquatic organisms, and the environment. Therefore, glyphosate is currently the most widely used herbicide in the world.

[0004] Patent CN113072580A discloses a method for recovering glyphosate from a glycine-based glyphosate acid mother liquor. The glyphosate acid mother liquor is concentrated and applied to effectively increase the crystal concentration of glyphosate. No additional water and acid are added during the entire process, which reduces the evaporation energy consumption and acid-base consumption of the entire system. However, the recovery method disclosed in the patent uses a concentrated crystallization filtration method to remove salt. Although most of the salt in the glyphosate mother liquor is removed, the salt in the desalted concentrated mother liquor used for subsequent hydrolysis is still in a saturated state, affecting the purity of the recovered glyphosate.

[0005] Another example is glufosinate, which is a natural amino acid herbicide containing a CPC structure. Its green, safe and environmentally friendly significance is significantly superior to chemical synthetic herbicides such as diquat, glyphosate and ordinary glufosinate. The biocatalytic method for producing glufosinate has the advantages of strict stereoselectivity, mild reaction conditions and high yield. It is an advantageous method for producing L-glufosinate. In the prior art, publication number "CN116143834" discloses a method for purifying and stabilizing the crystal form of L-glufosinate, which can effectively separate inorganic substances such as sulfate and oxalate, and can also efficiently remove protein organic impurities in the biological reaction solution to obtain a high-purity L-glufosinate product. However, the purification method disclosed in the patent requires the use of a variety of organic solvents, and the separation and recovery of organic solvents requires the use of a series of equipment, which invisibly increases the production cost. Summary of the invention

[0006] In order to solve the technical problems mentioned in the above background technology, a membrane integrated system for purifying herbicide mother liquor is proposed, which integrates membrane technology into the recovery and treatment of herbicide mother liquor, removes impurities in the herbicide mother liquor by physical separation, reduces the complexity of traditional processes, recovers higher purity herbicide components, and explores a cleaner and more efficient method for the separation and extraction of herbicides.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions:

[0008] A membrane integrated system for purifying herbicide mother liquid, comprising a mother liquid tank, the mother liquid tank being connected to a first-stage membrane module pipeline, the first-stage membrane module being used to process the mother liquid in the mother liquid tank;

[0009] The first-level membrane assembly is connected to the second-level membrane assembly pipeline, and the second-level membrane assembly is used to process the permeate of the first-level membrane assembly;

[0010] The secondary membrane assembly is connected to a pipeline of an electrodialysis device, and the electrodialysis device is used to process the permeate of the secondary membrane assembly;

[0011] The electrodialysis device is connected to the three-stage membrane assembly and the first evaporator pipeline respectively. The three-stage membrane assembly is used to treat the dilute liquid of the electrodialysis device, and the first evaporator performs evaporation and crystallization treatment on the electrodialysis concentrated liquid.

[0012] The first evaporator is connected to a bipolar membrane electrodialysis device pipeline, and the bipolar membrane electrodialysis device is used to process the inorganic salt of the first evaporator.

[0013] As a further description of the above technical solution:

[0014] The three-stage membrane assembly is connected to the second evaporator pipeline, and the second evaporator is used to process the concentrated liquid of the three-stage membrane assembly.

[0015] As a further description of the above technical solution:

[0016] The mother liquor in the mother liquor tank is L-phosphinothricin ammonium bioreactor liquid, and the L-phosphinothricin ammonium bioreactor liquid is connected by a primary membrane assembly, a secondary membrane assembly, and a tertiary membrane assembly to purify L-phosphinothricin ammonium, wherein the primary membrane assembly is a ceramic membrane device, the secondary membrane assembly is an ultrafiltration membrane device, and the tertiary membrane assembly is a nanofiltration membrane device.

[0017] As a further description of the above technical solution:

[0018] The ceramic membrane is designed to have a pressure of 0-4 bar and is made of aluminum oxide;

[0019] The ultrafiltration membrane in the ultrafiltration membrane device uses a pressure of 0-8 bar and is made of PA;

[0020] The electrodialysis membrane in the electrodialysis device uses a pressure of 0.1-2 bar, a rated voltage of 400 V, a rated current of 350 A, and the membrane is an anion and cation membrane;

[0021] The nanofiltration membrane in the nanofiltration membrane device uses a pressure of 0-35 bar and is made of aluminum oxide;

[0022] The bipolar membrane electrodialysis membrane in the bipolar membrane electrodialysis device adopts a pressure of 0.1-1.5 bar, a rated voltage of 480V, a rated current of 400A, and the membrane material is a bipolar membrane.

[0023] As a further description of the above technical solution:

[0024] The permeate and condensate of the nanofiltration membrane device are transported through pipelines and flow back to the mother liquid tank.

[0025] As a further description of the above technical solution:

[0026] The mother liquid in the mother liquid tank is glyphosate mother liquid, and the glyphosate mother liquid is purified by using a primary membrane assembly, a secondary membrane assembly, and a tertiary membrane assembly. The primary membrane assembly is a ceramic membrane device, the secondary membrane assembly is a reverse osmosis membrane device, and the tertiary membrane assembly is a nanofiltration membrane device.

[0027] As a further description of the above technical solution:

[0028] The ceramic membrane adopts a pressure of 0-4 bar and is made of aluminum oxide;

[0029] The reverse osmosis membrane in the reverse osmosis membrane device uses a pressure of 0.1-2 bar and is made of PA;

[0030] The electrodialysis membrane in the electrodialysis device uses a pressure of 0.1-2 bar, a rated voltage of 400 V, a rated current of 350 A, and the membrane is an anion and cation membrane;

[0031] The nanofiltration membrane in the nanofiltration membrane device uses a pressure of 0-35 bar and is made of PA;

[0032] The bipolar membrane electrodialysis membrane in the bipolar membrane electrodialysis device adopts a pressure of 0.1-1.5 bar, a rated voltage of 480V, a rated current of 400A, and the diaphragm is a cathode bipolar membrane.

[0033] As a further description of the above technical solution:

[0034] Part of the clear liquid and condensed water of the reverse osmosis membrane device flows back to the electrodialysis device, and the other part flows back to the nanofiltration membrane device.

[0035] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0036] 1. In the present invention, membrane technology is a pure physical separation technology. Compared with traditional processes, it has the advantages of simple process route, small investment, high equipment integration, high degree of automation, and easy operation.

[0037] 2. In the present invention, the ceramic membrane is an inorganic membrane with good acid and alkali resistance and low requirements on material water quality. It is an ideal choice for material pretreatment. Adding a ceramic membrane as a pretreatment reduces the pollution of impurities such as suspended matter to the subsequent membrane system and optimizes the inlet water quality of the membrane system.

[0038] 3. In the present invention, the by-product inorganic salt is treated by salt separation and then treated by a bipolar membrane electrodialysis device to obtain the corresponding acid and base. The acid and base, as commonly used chemical raw materials, can be recycled to other process sections, which not only solves the dilemma that the miscellaneous salt can only be treated as solid waste, but also recovers chemical raw materials such as acid and base, further achieving zero emissions and reducing the impact on the ecological environment.

[0039] 4. In the present invention, compared with a single evaporation crystallization desalination method, the combination of reverse osmosis membrane and electrodialysis membrane can greatly reduce the inorganic salt content in the concentrated mother liquor. At the same time, the reverse osmosis is moved before the electrodialysis to avoid the situation where the inorganic salts that are not completely removed by electrodialysis are also concentrated during the material concentration by reverse osmosis, thereby greatly improving the purity of the herbicide component. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 The figure shows a purification process flow chart of glyphosate mother solution using a membrane integrated system according to the first embodiment of the present invention;

[0041] Figure 2 The process flow chart of purifying L-glufosinate-ammonium mother liquor using a membrane integrated system according to the second embodiment of the present invention is shown;

[0042] Figure 3 A process flow chart of the purification of L-glufosinate ammonium mother liquor using a membrane integrated system according to Example 2 of the present invention is shown. DETAILED DESCRIPTION

[0043] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0044] Embodiment 1

[0045] In this embodiment 1, a membrane integrated system is applied to the recovery and treatment of L-glufosinate bioreactor liquid produced by biocatalysis, and impurities in the L-glufosinate bioreactor liquid are removed by physical separation, which greatly reduces the complexity of the traditional process and explores a cleaner and more efficient method for the separation and extraction of L-glufosinate.

[0046] like Figure 1-2 As shown, a membrane integrated system for purifying herbicide mother liquor includes a mother liquor tank, wherein the L-glufosinate bioreactor reaction liquid in the mother liquor tank is transported to a primary membrane assembly manufactured by a ceramic membrane device through a pipeline, the ceramic membrane device separates different types of enzymes in the solution, recovers the different types of enzymes and transports them to a biocatalytic process, so as to achieve resource recycling and reuse, and then the permeate of the ceramic membrane device is transported to a secondary membrane assembly manufactured by an ultrafiltration membrane device through a pipeline, the ultrafiltration membrane device removes small molecular protein organic impurities and substrates in the permeate, and then the ultrafiltration permeate is transported to an electrodialysis device through a pipeline, and the electrodialysis device separates sulfuric acid from the permeate of the ultrafiltration membrane device. Salt, oxalate and other inorganic substances and electrodialysis light liquid, the electrodialysis light liquid is L-glufosinate solution, to achieve the effect of purifying L-glufosinate solution, then the L-glufosinate solution (electrodialysis light liquid) is transported to the three-stage membrane assembly manufactured by the nanofiltration membrane device through a pipeline, the nanofiltration membrane device concentrates and separates the electrodialysis light liquid to obtain a concentrated liquid, the concentrated liquid is L-glufosinate concentration, thereby achieving the maximum increase of L-glufosinate concentration without affecting the purity, and at the same time, the electrodialysis concentrated liquid is transported to the first evaporator through a pipeline, and is subjected to evaporation and crystallization treatment to obtain by-product inorganic salts and condensed water, the condensed water and the permeate of the nanofiltration membrane device can be reused in the biocatalysis method to maximize the recovery rate of the system;

[0047] After the byproduct inorganic salt is treated by salt separation, it is treated by bipolar membrane electrodialysis device to obtain the corresponding acid and alkali. Acids and alkalis, as common chemical raw materials, can be reused in other process sections, which not only solves the dilemma that miscellaneous salts can only be treated as solid waste, but also recycles chemical raw materials such as acids and alkalis, further achieving zero emissions and reducing the impact on the ecological environment;

[0048] The L-glufosinate concentrated solution (concentrated solution) is adjusted to be an L-glufosinate aqueous solution, and the L-glufosinate aqueous solution is transported to a second evaporator through a pipeline, and subjected to evaporation and crystallization treatment to obtain an L-glufosinate powder. Compared with the aqueous solution, the L-glufosinate powder has the advantages of small volume and easy transportation and storage;

[0049] In the present application, the ceramic membrane in the ceramic membrane device adopts a pressure of 0-4 bar and is made of aluminum oxide; the ultrafiltration membrane in the ultrafiltration membrane device adopts a pressure of 0-8 bar, the composite membrane is made of PA, the electrodialysis membrane in the electrodialysis membrane device adopts a pressure of 0.1-2 bar, a rated voltage of 400 V, a rated current of 350 A, and the diaphragm is an anionic and cationic membrane, the nanofiltration membrane in the nanofiltration membrane device adopts a pressure of 0-35 bar, and the composite membrane is made of aluminum oxide. The pH value of the L-glufosinate bioreactor is 5-9, and the temperature is 5-40°C. The bipolar membrane electrodialysis membrane in the bipolar membrane electrodialysis device adopts a pressure of 0.1-1.5 bar, a rated voltage of 480 V, a rated current of 400 A, and the diaphragm is a bipolar membrane;

[0050] In summary, membrane technology is a pure physical separation technology. Compared with traditional processes, it has the advantages of simple process route, low investment, high equipment integration, high degree of automation, and easy operation. In addition, the L-glufosinate biological reaction liquid does not need to be diluted and then concentrated, which greatly saves energy consumption.

[0051] Embodiment 2

[0052] In the second embodiment, the membrane integrated system is applied to the recovery and treatment of the glyphosate mother liquor produced by the glycine method, and glyphosate with higher purity is recovered, and a cleaner and more efficient method for the recovery and utilization of the glyphosate mother liquor is explored.

[0053] like Figure 1 , 3 As shown, a membrane integrated system for purifying herbicide mother liquor comprises a mother liquor tank, wherein the glyphosate mother liquor in the mother liquor tank is transported to a primary membrane assembly manufactured by a ceramic membrane device through a pipeline, wherein the ceramic membrane device pre-treats the glyphosate mother liquor to remove suspended solids and large particle impurities and reduce membrane pollution, and then the ceramic permeate is transported to a secondary membrane assembly manufactured by a reverse osmosis membrane device through a pipeline, wherein the reverse osmosis membrane device pre-concentrates the ceramic permeate to reduce the volume of the mother liquor and increase the glyphosate concentration, wherein the reverse osmosis concentrated liquid is transported to an electrodialysis device through a pipeline, wherein the electrodialysis device separates inorganic substances such as sodium chloride and sulfite from the reverse osmosis concentrated liquid to obtain an electrodialysis dilute liquid, wherein the electrodialysis dilute liquid is a desalted concentrated mother liquor, wherein the desalted concentrated mother liquor is transported to a tertiary membrane assembly manufactured by a nanofiltration membrane device through a pipeline, wherein the nanofiltration membrane device performs concentration and separation, wherein the separated concentrated liquid is glyphosate, and the permeate participates in subsequent hydrolysis, crystallization, and separation processes to obtain glyphosate;

[0054] The electrodialysis concentrate is transported to the first evaporator through a pipeline, and is subjected to evaporation and crystallization treatment to obtain byproduct inorganic salts and condensed water. Part of the condensed water and the clear liquid of the reverse osmosis membrane device is returned to the electrodialysis device, and the other part is returned to the nanofiltration membrane device to maximize the system recovery rate;

[0055] Furthermore, the byproduct inorganic salts are treated by salt separation and then treated by bipolar membrane electrodialysis to obtain the corresponding acids and bases. Acids and bases, as commonly used chemical raw materials, can be reused in other process sections, which not only solves the dilemma that miscellaneous salts can only be treated as solid waste, but also recycles chemical raw materials such as acids and bases, further achieving zero emissions and reducing the impact on the ecological environment;

[0056] In this application, the ceramic membrane uses a pressure of 0-4 bar and is made of aluminum oxide; the reverse osmosis membrane uses a pressure of 0-25 bar and the composite membrane is made of PA; the electrodialysis membrane uses a pressure of 0.1-2 bar, a rated voltage of 400 V, a rated current of 350 A, and the membrane is an anion and cation membrane; the nanofiltration membrane uses a pressure of 0-35 bar and the composite membrane is made of PA; the bipolar membrane electrodialysis uses a pressure of 0.1-1.5 bar, a rated pressure of 480 V, a rated current of 400 A, and the membrane is a bipolar membrane; the glyphosate content in the glyphosate mother liquor is about 0.8-2wt%, and the temperature is 5-40°C;

[0057] In the present application, the ceramic membrane is an inorganic membrane with good acid and alkali resistance and low requirements for material water quality. It is an ideal choice for material pretreatment. Compared with the single evaporation crystallization desalination method in the prior art, the combination of reverse osmosis membrane and electrodialysis membrane can greatly reduce the inorganic salt content in the concentrated mother liquor, greatly improving the purity of glyphosate. The inorganic salt in the mother liquor obtained by the single evaporation crystallization treatment method is still in a saturated state, which will affect the purity of glyphosate.

[0058] This application adds a ceramic membrane as a pretreatment, reduces the pollution of suspended matter and other impurities to the subsequent membrane system, and optimizes the water quality of the membrane system. At the same time, the reverse osmosis is moved before the electrodialysis to avoid the situation where the reverse osmosis concentrates the inorganic salts that are not completely removed by the electrodialysis during the material concentration, thereby affecting the purity of glyphosate.

[0059] Comparative Example 1

[0060] A method for recovering glyphosate from glyphosate acid mother liquor of the glycine process, the method steps are as follows:

[0061] (1) taking a portion of the glyphosate acid mother liquor as the first glyphosate acid mother liquor, and performing at least two stages of concentration, crystallization and filtration on the first glyphosate acid mother liquor;

[0062] (2) the desalted concentrated mother liquor obtained after at least two stages of concentration, crystallization and filtration in step (1) is mixed with the hydrolyzate and hydrolyzed to obtain a hydrolyzate;

[0063] (3) Crystallization treatment step: solid-liquid separation of the hydrolyzed liquid obtained in step (2) to obtain a glyphosate product and a glyphosate acid mother liquor;

[0064] The glyphosate acid mother liquor obtained in step (3) is recycled and used in step (1).

[0065] The purity of purified glyphosate in Comparative Example 1 and Implementation 2 are shown in the table below:

[0066]

[0067] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A membrane integrated system for purifying herbicide mother solution, comprising a mother solution tank, characterized in that: The mother liquid tank is connected to the first-stage membrane assembly pipeline, and the first-stage membrane assembly is used to process the mother liquid in the mother liquid tank; The first-level membrane assembly is connected to the second-level membrane assembly pipeline, and the second-level membrane assembly is used to process the permeate of the first-level membrane assembly; The secondary membrane assembly is connected to a pipeline of an electrodialysis device, and the electrodialysis device is used to process the permeate of the secondary membrane assembly; The electrodialysis device is connected to the three-stage membrane assembly and the first evaporator pipeline respectively. The three-stage membrane assembly is used to treat the dilute liquid of the electrodialysis device, and the first evaporator performs evaporation and crystallization treatment on the electrodialysis concentrated liquid. The first evaporator is connected to a bipolar membrane electrodialysis device pipeline, and the bipolar membrane electrodialysis device is used to process the inorganic salt of the first evaporator.

2. A membrane integrated system for purifying herbicide mother solution according to claim 1, characterized in that: The three-stage membrane assembly is connected to the second evaporator pipeline, and the second evaporator is used to process the concentrated liquid of the three-stage membrane assembly.

3. A membrane integrated system for purifying herbicide mother solution according to claims 1-2, characterized in that: The mother liquor in the mother liquor tank is L-phosphinothricin ammonium bioreactor liquid, and the L-phosphinothricin ammonium bioreactor liquid is connected by a primary membrane assembly, a secondary membrane assembly, and a tertiary membrane assembly to purify L-phosphinothricin ammonium, wherein the primary membrane assembly is a ceramic membrane device, the secondary membrane assembly is an ultrafiltration membrane device, and the tertiary membrane assembly is a nanofiltration membrane device.

4. A membrane integrated system for purifying herbicide mother solution according to claim 3, characterized in that: The ceramic membrane is designed to have a pressure of 0-4 bar and is made of aluminum oxide; The ultrafiltration membrane in the ultrafiltration membrane device uses a pressure of 0-8 bar and is made of PA; The electrodialysis membrane in the electrodialysis device uses a pressure of 0.1-2 bar, a rated voltage of 400 V, a rated current of 350 A, and the membrane is an anion and cation membrane; The nanofiltration membrane in the nanofiltration membrane device uses a pressure of 0-35 bar and is made of aluminum oxide; The bipolar membrane electrodialysis membrane in the bipolar membrane electrodialysis device adopts a pressure of 0.1-1.5 bar, a rated voltage of 480V, a rated current of 400A, and the membrane material is a bipolar membrane.

5. A membrane integrated system for purifying herbicide mother solution according to claim 4, characterized in that: The permeate and condensate of the nanofiltration membrane device are transported through pipelines and flow back to the mother liquid tank.

6. A membrane integrated system for purifying herbicide mother solution according to claim 1, characterized in that: The mother liquid in the mother liquid tank is glyphosate mother liquid, and the glyphosate mother liquid is purified by using a primary membrane assembly, a secondary membrane assembly, and a tertiary membrane assembly. The primary membrane assembly is a ceramic membrane device, the secondary membrane assembly is a reverse osmosis membrane device, and the tertiary membrane assembly is a nanofiltration membrane device.

7. A membrane integrated system for purifying herbicide mother solution according to claim 6, characterized in that: The ceramic membrane adopts a pressure of 0-4 bar and is made of aluminum oxide; The reverse osmosis membrane in the reverse osmosis membrane device uses a pressure of 0.1-2 bar and is made of PA; The electrodialysis membrane in the electrodialysis device uses a pressure of 0.1-2 bar, a rated voltage of 400 V, a rated current of 350 A, and the membrane is an anion and cation membrane; The nanofiltration membrane in the nanofiltration membrane device uses a pressure of 0-35 bar and is made of PA; The bipolar membrane electrodialysis membrane in the bipolar membrane electrodialysis device adopts a pressure of 0.1-1.5 bar, a rated voltage of 480V, a rated current of 400A, and the diaphragm is a cathode bipolar membrane.

8. A membrane integrated system for purifying herbicide mother solution according to claim 7, characterized in that: Part of the clear liquid and condensed water of the reverse osmosis membrane device flows back to the electrodialysis device, and the other part flows back to the nanofiltration membrane device.

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