Glufosinate-ammonium mother liquor desalting device

Abstract

The utility model provides a glufosinate-ammonium mother liquor desalting device which comprises an electrodialysis device, the electrodialysis device is connected with the thin liquid storage tank through a first circulating pump to form a first loop, the electrodialysis device is connected with the thick liquid storage tank through a second circulating pump to form a second loop, and the electrodialysis device is connected with the polar liquid storage tank through a third circulating pump to form a third loop; the electrodialysis device is connected with the mother liquor storage tank through a valve; the thin liquid storage tank is connected with the crystallization kettle, and the thick liquid storage tank is connected with the cooling crystallization kettle. According to the device disclosed by the invention, the glufosinate-ammonium mother liquor is desalted through matched use of the equipment, and the defects of low efficiency and poor desalting effect when the glufosinate-ammonium mother liquor is desalted by adopting a traditional cooling crystallization desalting mode are overcome.

Description

Technical Field

[0001] This application relates to the field of pesticide production technology, and in particular to a glufosinate mother liquor desalination device. Background Technology

[0002] Glufosinate is a highly effective, broad-spectrum, contact herbicide belonging to the organophosphorus herbicide class. Its main mechanism of action is to interfere with the metabolic pathway of glutamine synthase in plants. It has the advantages of low toxicity, harmlessness, and easy degradation.

[0003] There are two main process routes for the industrial production of glufosinate: the thermal cracking ACA process and the Strecker process. Among them, the Strecker process is more mature due to its related technologies, so it is the most common method for producing glufosinate in China. This process uses diethyl methylphosphonite as raw material. First, the acetal generated from acrolein and ethanol undergoes a Michael addition reaction with diethyl methylphosphonite. After acidification, 3-ethoxymethylphosphonopropionaldehyde is obtained. Sodium cyanide, ammonium chloride, and ammonia are added to undergo the Strecker reaction to obtain aminonitrile. Finally, hydrolysis, ammoniation, and purification are performed to obtain the glufosinate product. The purity of glufosinate obtained by this process can reach 95%, and the total yield is over 30%. In the purification process of glufosinate, crystallization is an essential method due to its ease of operation and large processing capacity. After crystallization, a large amount of organophosphorus salts remain in the glufosinate mother liquor. Therefore, it is necessary to remove the salts from the mother liquor and then return it to the crystallization section for reuse. Otherwise, the high salt and impurities in the mother liquor will result in low purity and yield of the crystallized product, affecting production. The existing desalination method is to remove salt by cooling crystallization. However, since the salt concentration in the mother liquor does not reach the saturation concentration, this method has low desalination efficiency and poor desalination effect. Utility Model Content

[0004] This application provides a glufosinate mother liquor desalination device to solve the problems of low efficiency and poor desalination effect in existing methods for desalinating glufosinate mother liquor.

[0005] This application provides a glufosinate mother liquor desalination device, including an electrodialysis device;

[0006] The electrodialysis device is connected to the dilute solution storage tank via a first circulation pump to form a first loop, the electrodialysis device is connected to the concentrated solution storage tank via a second circulation pump to form a second loop, and the electrodialysis device is connected to the electrode solution storage tank via a third circulation pump to form a third loop.

[0007] The electrodialysis unit is connected to the mother liquor storage tank via valves;

[0008] The dilute liquid storage tank is connected to the crystallization kettle, and the concentrated liquid storage tank is connected to the cooling crystallization kettle.

[0009] Optionally, the crystallization vessel is connected to the cooling crystallization vessel.

[0010] Optionally, the crystallization vessel and the cooling crystallization vessel are connected by a filter.

[0011] Optionally, a first heat exchanger is provided between the first circulating pump and the electrodialysis device, and the two devices are connected through the tube side of the first heat exchanger.

[0012] A second heat exchanger is provided between the second circulating pump and the electrodialysis device, and the two heat exchangers are connected through the tube side of the second heat exchanger.

[0013] The cooling crystallization vessel is connected to the shell-side input terminals of the first heat exchanger and the second heat exchanger, respectively.

[0014] The shell-side outputs of the first and second heat exchangers are connected to the mother liquor storage tank.

[0015] Optionally, a first conductivity sensor is installed in the desalination tank, and a second conductivity sensor is installed in the concentrate tank.

[0016] The first circulating pump, the second circulating pump, the third circulating pump, the first conductivity sensor, the second conductivity sensor, and the valves are all electrically connected to the controller.

[0017] Optionally, the filter includes a housing and end caps for sealing both ends of the housing; the housing is divided into a filter chamber and a buffer chamber by a perforated plate, and the filter chamber is provided with a filter medium.

[0018] Optionally, the volume ratio of the filter chamber to the buffer chamber is 3 to 4:1.

[0019] This application provides a glufosinate mother liquor desalination device, which includes an electrodialysis unit to desalinate the glufosinate mother liquor using the principle of electrodialysis, and a crystallization kettle followed by a cooling crystallization kettle to recover the desalinated dilute and then concentrated liquor. The device of this application, through the combined use of the above equipment, desalinates the glufosinate mother liquor, overcoming the shortcomings of the traditional cooling crystallization desalination method, which has low efficiency and poor desalination effect. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this application 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 some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of a glufosinate mother liquor desalination device provided in an embodiment of this application;

[0022] Figure 2 This is a schematic diagram of a glufosinate mother liquor desalination device provided in another embodiment of this application;

[0023] Figure 3 A schematic diagram of a glufosinate mother liquor desalination device provided in yet another embodiment of this application;

[0024] Figure 4 A schematic diagram of a glufosinate mother liquor desalination device provided in another embodiment of this application;

[0025] Figure 5 This is a schematic diagram of the structure of a filter provided in one embodiment of this application;

[0026] Figure 6 This is a schematic diagram of a glufosinate mother liquor desalination device provided in one embodiment of this application.

[0027] Explanation of reference numerals in the attached figures:

[0028] 1. Electrodialysis unit; 2. Dilute solution storage tank; 3. Concentrate solution storage tank; 4. Electrolyte storage tank; 5. Mother liquor storage tank; 6. Crystallization vessel; 7. Cooling crystallization vessel; 8. Filter; 9. Controller; 10. First circulation pump; 20. Second circulation pump; 21. First conductivity sensor; 30. Third circulation pump; 31. Second conductivity sensor; 71. First heat exchanger; 72. Second heat exchanger; 81. Shell; 82. End cap; 83. Orifice plate; 84. Filter medium; 100. Valve. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application are described clearly and completely below. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are also within the scope of protection of this application.

[0030] like Figure 1 As shown, this application provides a glufosinate mother liquor desalination device, including an electrodialysis device 1;

[0031] The electrodialysis device 1 is connected to the dilute liquid storage tank 2 through the first circulation pump 10 to form a first circuit, the electrodialysis device 1 is connected to the concentrated liquid storage tank 3 through the second circulation pump 20 to form a second circuit, and the electrodialysis device 1 is connected to the electrode liquid storage tank 4 through the third circulation pump 30 to form a third circuit.

[0032] Electrodialysis unit 1 is connected to mother liquor storage tank 5 via valve 100;

[0033] The dilute liquid storage tank 2 is connected to the crystallization kettle 6, and the concentrated liquid storage tank 3 is connected to the cooling crystallization kettle 7.

[0034] In this application, the function of each circuit is to allow the feed liquid in different areas to circulate during the electrodialysis process, thereby increasing the throughput.

[0035] During use, a certain amount of mother liquor is added to the dilute liquid storage tank 2 and the concentrated liquid storage tank 3 in advance (to ensure smooth circulation of the liquid; the mother liquor can come from the mother liquor storage tank 5). The valve 100 is opened to inject the glufosinate mother liquor stored in the mother liquor storage tank 5 into the corresponding area (i.e., the concentrated liquid area and the dilute liquid area in the electrodialysis device 1). At the same time, a certain amount of electrode liquid (an aqueous solution of sodium sulfate in this application) is added to the electrodialysis device 1 using the third circulation pump 30.

[0036] After filling the electrodialysis unit 1, valve 100 is closed, and the first circulation pump 10 and the second circulation pump 20 are started. The electrodialysis unit 1 is then started for electrodialysis desalination. When the detected conductivity reaches a certain value, that is, when the electrodialysis endpoint is reached, circulation is stopped, and the desalination solution in the desalination tank 2 (at this time, the solution mainly contains glufosinate) is transferred to the crystallization kettle 6 for crystallization. The concentrated solution in the concentrated solution tank 3, that is, the high-salt solution, is transferred to the cooling crystallization kettle 7 for cooling and crystallization treatment.

[0037] This application provides a glufosinate mother liquor desalination device, which includes an electrodialysis device 1 to desalinate the glufosinate mother liquor using the principle of electrodialysis, and a crystallization kettle 6 and a cooling crystallization kettle 7 to recover the desalinated dilute and concentrated liquor. The device of this application desalinates the glufosinate mother liquor by using the above equipment in combination, overcoming the disadvantages of low efficiency and poor desalination effect of the traditional cooling crystallization desalination method for glufosinate mother liquor.

[0038] like Figure 2 As shown, optionally, the crystallization vessel 6 is connected to the cooling crystallization vessel 7.

[0039] In this application, the crystallization vessel 6 is connected to the cooling crystallization vessel 7, so that the mother liquor obtained after crystallization in the crystallization vessel 6 can be transferred to the cooling crystallization vessel 7 for preliminary desalination by cooling crystallization, and then the mother liquor after preliminary desalination can be further processed.

[0040] like Figure 3 As shown, optionally, the crystallization vessel 6 and the cooling crystallization vessel 7 are connected by a filter 8.

[0041] In this application, since the crystallization mother liquor output from the crystallization vessel 6 may contain fine crystal particles, a filter 8 is provided to trap the crystal particles mixed in the mother liquor, thereby reducing crystallization losses.

[0042] like Figure 4As shown, optionally, a first heat exchanger 71 is provided between the first circulating pump 10 and the electrodialysis device 1, and is connected through the tube side of the first heat exchanger 71.

[0043] A second heat exchanger 72 is provided between the second circulating pump 20 and the electrodialysis device 1, and is connected through the tube side of the second heat exchanger 72.

[0044] The cooling crystallization vessel 7 is connected to the shell-side input terminals of the first heat exchanger 71 and the second heat exchanger 72, respectively.

[0045] The shell-side output ends of the first heat exchanger 71 and the second heat exchanger 72 are connected to the mother liquor storage tank 5.

[0046] In this application, during the desalination process, the temperature of the circulating liquid will rise, which may lead to a decrease in desalination efficiency and is not conducive to the service life of the electrodialysis device 1. Therefore, the feed liquid circulated from the desalination tank 2 through the first circulation pump 10 is cooled down by exchanging heat with the low-temperature mother liquor in the first heat exchanger 71 (during the cooling crystallization process, the temperature of the mother liquor in the cooling crystallization vessel 7 is reduced to 5-10°C for crystallization, so the temperature of the crystallization mother liquor output from the cooling crystallization vessel 7 is low and can be used for heat exchange) before being input into the electrodialysis device 1; similarly, the feed liquid circulated from the concentrate tank 3 through the second circulation pump 20 is cooled down by exchanging heat with the low-temperature mother liquor in the second heat exchanger 72 before being input into the electrodialysis device 1.

[0047] After crystallization and desalination, the crystallizing liquid in the cooling crystallization vessel 7 is output and enters the shell side of the first heat exchanger 71 and the second heat exchanger 72, respectively, to exchange heat with the circulating liquid in the corresponding tube side, thus cooling the circulating liquid in the tube side. The crystallized liquid after heat exchange is then output from the shell side to the mother liquor storage tank 5 for temporary storage and used as the raw solution for electrodialysis desalination. Similarly, a filter can be installed at the output end of the crystallization mother liquor in the cooling crystallization vessel 7 to filter the crystallization mother liquor before it is fed to the first heat exchanger 71 and the second heat exchanger 72 for heat exchange.

[0048] like Figure 5 As shown, optionally, a first conductivity sensor 21 is installed in the desalination tank 2, and a second conductivity sensor 31 is installed in the concentrate tank 3.

[0049] The first circulation pump 10, the second circulation pump 20, the third circulation pump 30, the first conductivity sensor 21, the second conductivity sensor 31, and the valve 100 are all electrically connected to the controller 9.

[0050] In this application, during the electrodialysis process, a first conductivity sensor 21 installed in the desalination tank 2 and a second conductivity sensor 31 installed in the concentrate tank 3 detect the conductivity in the corresponding tanks in real time and feed the data back to the controller 9 in real time. When the detected conductivity reaches a certain value, that is, when the electrodialysis endpoint is reached, the controller 9 controls the first circulation pump 10 and the second circulation pump 20 to stop working. The concentrate in the concentrate tank 3, that is, the high-salt feed liquid, is transferred to the cooling crystallization kettle 7 for processing.

[0051] like Figure 6 As shown, optionally, the filter 8 includes a housing 81 and end caps 82 for closing both ends of the housing 81; the housing 81 is divided into a filter chamber and a buffer chamber by a perforated plate 83, and a filter medium 84 is disposed in the filter chamber.

[0052] In this application, during use, the mother liquor first enters the buffer chamber of the shell 81 for buffering, and then enters the filter chamber through the holes on the perforated plate 83. After the fine crystals entrained in the mother liquor are filtered out by the filter medium 84 set in the filter chamber, it is transferred to the cooling crystallization kettle 7 for cooling and recrystallization to remove some of the salt in the mother liquor.

[0053] During use, the filtered crystals and other mechanical impurities will gradually accumulate in the buffer chamber of the filter 8. When the filtration pressure reaches the preset value, the end cover 82 near the buffer chamber can be opened to clean the buffer chamber.

[0054] During installation, the end of filter 8 near the buffer chamber is connected to the output end of crystallizer 6.

[0055] In this application, the filter medium is filter cloth or filter cotton, etc.

[0056] Optionally, the volume ratio of the filter chamber to the buffer chamber is 3 to 4:1.

[0057] In this application, the volume ratio of the filter chamber to the buffer chamber is 3 to 4:1, which can better achieve the functions of filtration, interception, and buffering.

[0058] A glufosinate mother liquor desalination device, the working process of which is as follows:

[0059] During use, a certain amount of mother liquor (which can come from mother liquor storage tank 5) is added to the dilute liquid storage tank 2 and the concentrated liquid storage tank 3 in advance. The valve 100 is opened by the controller 9 to inject the glufosinate mother liquor stored in the mother liquor storage tank 5 into the corresponding area (i.e., the concentrated liquid area and the dilute liquid area in the electrodialysis device 1). At the same time, the third circulation pump 30 is turned on by the controller 9 and a certain amount of electrode liquid (an aqueous solution of sodium sulfate in this application) is added to the electrodialysis device 1.

[0060] After filling the electrodialysis unit 1, valve 100 is closed, and the first circulation pump 10 and the second circulation pump 20 are turned on. Then, the electrodialysis unit 1 is started for electrodialysis desalination. During the desalination process, the temperature of the circulating liquid will rise, which may lead to a decrease in desalination efficiency and is not conducive to the service life of the electrodialysis unit 1. Therefore, the feed liquid circulated from the desalination tank 2 through the first circulation pump 10 is cooled by heat exchange with the low-temperature mother liquor in the first heat exchanger 71 before being fed into the electrodialysis unit 1. Similarly, the feed liquid circulated from the concentrate tank 3 through the second circulation pump 20 is cooled by heat exchange with the low-temperature mother liquor in the second heat exchanger 72 before being fed into the electrodialysis unit 1.

[0061] During the electrodialysis process, the first conductivity sensor 21 installed in the desalination tank 2 and the second conductivity sensor 31 installed in the concentrate tank 3 detect the conductivity in the corresponding tanks in real time and feed the data back to the controller 9 in real time. When the detected conductivity reaches a certain value, that is, when the electrodialysis endpoint is reached, the controller 9 controls the first circulation pump 10 and the second circulation pump 20 to stop working. The concentrate in the concentrate tank 3, that is, the high-salt feed liquid, is transferred to the cooling crystallization kettle 7.

[0062] The desalinated liquid (i.e., desalination feed liquid, which mainly contains glufosinate) in the desalination storage tank 2 is transferred to the crystallization kettle 6 for crystallization. The mother liquor obtained after crystallization in the crystallization kettle 6 is filtered through the filter 8.

[0063] During filtration in filter 8, the mother liquor first enters the buffer chamber of shell 81 for buffering, and then enters the filtration chamber through the holes on perforated plate 83. After the fine crystals entrained in the mother liquor are filtered out by the filter medium 84 in the filtration chamber, it is transferred to the cooling crystallization kettle 7 for cooling and recrystallization to remove some of the salt in the mother liquor. After crystallization and desalination, the crystallized liquid is output from the cooling crystallization kettle 7 and enters the shell side of the first heat exchanger 71 and the second heat exchanger 72 respectively to exchange heat with the circulating liquid in the corresponding tube side, cooling the circulating liquid in the tube side. The crystallized liquid after heat exchange is output from the shell side and temporarily stored in the mother liquor storage tank 5, and used as the raw solution for electrodialysis desalination treatment.

[0064] During use, the filtered crystals and other mechanical impurities will gradually accumulate in the buffer chamber of the filter 8. When the filtration pressure reaches the preset value, the end cover 82 near the buffer chamber can be opened to clean the buffer chamber.

[0065] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A desalination device for glufosinate mother liquor, characterized in that, Includes an electrodialysis device (1); The electrodialysis device (1) is connected to the dilute liquid storage tank (2) through the first circulation pump (10) to form a first circuit. The electrodialysis device (1) is connected to the concentrated liquid storage tank (3) through the second circulation pump (20) to form a second circuit. The electrodialysis device (1) is connected to the polar liquid storage tank (4) through the third circulation pump (30) to form a third circuit. The electrodialysis device (1) is connected to the mother liquor storage tank (5) via a valve (100); The dilute liquid storage tank (2) is connected to the crystallization kettle (6), and the concentrated liquid storage tank (3) is connected to the cooling crystallization kettle (7).

2. The glufosinate mother liquor desalination device according to claim 1, characterized in that, The crystallization vessel (6) is connected to the cooling crystallization vessel (7).

3. The glufosinate mother liquor desalination device according to claim 1, characterized in that, The crystallization vessel (6) and the cooling crystallization vessel (7) are connected by a filter (8).

4. The glufosinate mother liquor desalination device according to claim 1, characterized in that, A first heat exchanger (71) is provided between the first circulating pump (10) and the electrodialysis device (1), and is connected through the tube side of the first heat exchanger (71); A second heat exchanger (72) is provided between the second circulating pump (20) and the electrodialysis device (1), and is connected through the tube side of the second heat exchanger (72); The cooling crystallization vessel (7) is connected to the shell-side input terminals of the first heat exchanger (71) and the second heat exchanger (72), respectively. The shell-side output ends of the first heat exchanger (71) and the second heat exchanger (72) are connected to the mother liquor storage tank (5).

5. The glufosinate mother liquor desalination device according to claim 1, characterized in that, The desalination tank (2) is equipped with a first conductivity sensor (21), and the concentrate tank (3) is equipped with a second conductivity sensor (31). The first circulating pump (10), the second circulating pump (20), the third circulating pump (30), the first conductivity sensor (21), the second conductivity sensor (31), and the valve (100) are all electrically connected to the controller (9).

6. The glufosinate mother liquor desalination device according to claim 3, characterized in that, The filter (8) includes a housing (81) and end caps (82) for sealing both ends of the housing (81); the housing (81) is divided into a filter chamber and a buffer chamber by a perforated plate (83), and a filter medium (84) is provided in the filter chamber.

7. The glufosinate mother liquor desalination device according to claim 6, characterized in that, The volume ratio of the filter chamber to the buffer chamber is 3 to 4:1.

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