Guanidinoacetic acid production system

Abstract

According to the guanidinoacetic acid production system, the mother liquor concentration device is used for concentrating, crystallizing and separating the mother liquor separated by the guanidinoacetic acid separation device, then the concentrated liquor is conveyed to the guanidinoacetic acid reaction kettle for recycling, guanidinoacetic acid and dicyandiamide crystals are conveyed to the guanidinoacetic acid recovery device, and after dicyandiamide in the guanidinoacetic acid is separated, the guanidinoacetic acid is recycled. The separated guanidinoacetic acid is recycled and reused, so that the utilization rate of raw materials is increased. A triple-effect evaporation concentrator is adopted in the mother liquor concentration device, the crystallization rate and the crystallization rate can be effectively increased compared with a copious cooling technology adopted in traditional freezing concentration, and due to the fact that the triple-effect evaporation technology is mature, compared with the copious cooling technology, the number of process control points is small, automatic control is simple, and the process control difficulty is low. Meanwhile, water vapor discharged by the triple-effect evaporation concentrator is recycled and reused in preparation of guanidinoacetic acid, so that waste is avoided, and raw materials are saved.

Description

Technical Field

[0001] The utility model relates to the technical field of chemical systems, in particular to a guanidinoacetic acid production system. Background Art

[0002] Guanidinoacetic acid is a white or slightly yellowish crystalline powder, soluble in water, very slightly soluble in ethanol and ether. Guanidinoacetic acid is mainly used as an intermediate in organic synthesis of medicine, and can also be used as a food and feed additive, which plays an important role in improving production performance, improving meat quality and promoting energy metabolism. In addition, it can prevent bacterial infection, enhance the immune function of animals, and reduce the impact of heat stress on animals, thereby correspondingly reducing the mortality rate of animals in high-temperature environments.

[0003] According to relevant literature reports, the main production process of guanidinoacetic acid is as follows: S-ethylthiourea hydrobromide is formed by reacting thiourea with bromoethane, and then guanidinoacetic acid is prepared by reacting with glycine. The specific steps are as follows: Thiourea, bromoethane and absolute ethanol are mixed and warmed in a water bath for 3 h to completely dissolve the thiourea; then ethanol and excessive bromoethane are distilled off under reduced pressure, and the residue is crystallized and dried to obtain S-ethylthiourea hydrobromide. Then, a sodium hydroxide solution is added to the obtained S-ethylthiourea hydrobromide, and a hot solution prepared by glycine and water is quickly added under cooling. After crystallization, ether is added, and the mixture is left overnight and cooled in an ice bath for 2 h, and the ether layer is separated. The ether layer is suction filtered, and the obtained solid product is washed successively with ice water, cold ethanol and low-temperature ether, and dried in air to obtain the finished product. This method has a complex process, low yield and poor product quality, and is obviously not suitable for large-scale industrial production.

[0004] In this regard, a guanidinoacetic acid production system disclosed in the Chinese utility model patent with the application number 202321311887.7 first adds glycine, sodium hydroxide and purified water into a dissolution reaction kettle through a glycine feed pipe, a sodium hydroxide feed pipe and a purified water feed pipe, adds cyanamide into a cyanamide metering tank through a cyanamide feed pipe, after heating up the dissolution reaction kettle, glycine and sodium hydroxide are clarified in the dissolution reaction kettle, glycine, sodium hydroxide and cyanamide are simultaneously transported into a reactor, and guanidinoacetic acid crude product is generated after reaction in the reactor. After the guanidinoacetic acid is subjected to crystallization separation, guanidinoacetic acid finished product and mother liquor are obtained. The mother liquor is frozen by a freezing concentrator, and dicyandiamide is separated and recycled. A large amount of cold source is required during the freezing concentration process, and the process control is difficult. If the temperature of the chilled water is too high, the crystallization rate is low; if the temperature of the chilled water is too low, the equipment and pipelines are easily frozen; at the same time, limited by the concentration of the mother liquor, the crystallization rate is low. Summary of the Invention

[0005] Based on this, the present application provides a guanidinoacetic acid production system to solve the technical problems of large process control difficulty, low crystallization rate and low crystallization speed in the existing freezing concentration technology.

[0006] The technical solution for this application to solve the above technical problems is as follows:

[0007] A guanidine acetic acid production system, comprising:

[0008] A guanidine acetic acid reaction kettle;

[0009] A guanidine acetic acid separation device, the outlet of the guanidine acetic acid reaction kettle is connected to the inlet of the guanidine acetic acid separation device, and the guanidine acetic acid separation device is provided with a mother liquor discharge pipe;

[0010] A mother liquor concentration device, the mother liquor concentration device includes a triple-effect evaporation concentrator, a first crystallization reaction kettle and a first centrifuge; the mother liquor discharge pipe is connected to the inlet of the triple-effect evaporation concentrator, the discharge port of the triple-effect evaporation concentrator is connected to the inlet of the first crystallization reaction kettle, the outlet of the first crystallization reaction kettle is connected to the inlet of the first centrifuge; the liquid phase outlet of the first centrifuge is connected to the inlet of the guanidine acetic acid reaction kettle.

[0011] Preferably, the above guanidine acetic acid production system further includes a steam recovery device, the steam recovery device includes a condenser and a heat exchanger, the steam outlet of the triple-effect evaporation concentrator is connected to the inlet of the condenser, the outlet of the condenser is connected to the cold medium inlet of the heat exchanger, the heating outlet of the triple-effect evaporation concentrator is connected to the hot medium inlet of the heat exchanger, and the cold medium outlet of the heat exchanger is connected to the inlet of the guanidine acetic acid reaction kettle.

[0012] Preferably, the above guanidine acetic acid production system further includes a steam recovery device, the steam recovery device includes a condenser and a heat exchanger, the steam outlet of the triple-effect evaporation concentrator is connected to the inlet of the condenser, the outlet of the condenser is connected to the cold medium inlet of the heat exchanger, the discharge port of the triple-effect evaporation concentrator is connected to the hot medium inlet of the heat exchanger, the hot medium outlet of the heat exchanger is connected to the inlet of the first crystallization reaction kettle, and the cold medium outlet of the heat exchanger is connected to the inlet of the guanidine acetic acid reaction kettle.

[0013] Preferably, in the above guanidine acetic acid production system, the guanidine acetic acid separation device includes a second crystallization reaction kettle and a second centrifuge, the outlet of the guanidine acetic acid reaction kettle is connected to the second crystallization reaction kettle, the outlet of the second crystallization reaction kettle is connected to the second centrifuge, the solid phase outlet of the second centrifuge is the guanidine acetic acid finished product outlet, and the liquid phase outlet of the centrifuge is connected to the mother liquor discharge pipe.

[0014] Preferably, the above-mentioned guanidine acetic acid production system further includes a guanidine acetic acid recovery device. The guanidine acetic acid recovery device is provided with a dicyandiamide dissolution reaction kettle. The solid-phase outlet of the first centrifuge is connected to the inlet of the dicyandiamide dissolution reaction kettle, and the dicyandiamide dissolution reaction kettle is provided with an ethanol feed pipe.

[0015] Preferably, in the above-mentioned guanidine acetic acid production system, the guanidine acetic acid recovery device further includes a third centrifuge. The outlet of the dicyandiamide dissolution reaction kettle is connected to the inlet of the third centrifuge, and the solid-phase outlet of the third centrifuge is connected to the inlet of the second crystallization reaction kettle.

[0016] Preferably, in the above-mentioned guanidine acetic acid production system, the guanidine acetic acid recovery device further includes a de-alcoholization device. The solid-phase outlet of the third centrifuge is connected to the inlet of the de-alcoholization device, and the outlet of the de-alcoholization device is connected to the inlet of the second crystallization reaction kettle.

[0017] Preferably, in the above-mentioned guanidine acetic acid production system, the dicyandiamide dissolution reaction kettle is further connected to a distillation reaction kettle. The liquid-phase outlet of the third centrifuge is connected to the inlet of the distillation reaction kettle.

[0018] Preferably, in the above-mentioned guanidine acetic acid production system, the distillation reaction kettle is further connected to an ethanol recovery kettle, and the ethanol recovery kettle is used to recover ethanol.

[0019] Compared with the prior art, the present utility model has at least the following advantages:

[0020] The guanidine acetic acid production system of the present application. After the mother liquor concentration device concentrates, crystallizes and separates the mother liquor separated by the guanidine acetic acid separation device, the concentrated solution is transported to the guanidine acetic acid reaction kettle for reuse. The guanidine acetic acid and dicyandiamide crystals are transported to the guanidine acetic acid recovery device. After separating the dicyandiamide therein, the separated guanidine acetic acid is recycled and reused, improving the utilization rate of raw materials. In the mother liquor concentration device, a triple-effect evaporation concentrator is adopted. Compared with the cryogenic technology used in traditional freeze concentration, since the concentration of the mother liquor in triple-effect evaporation continuously increases, it is beneficial to crystallization. At the same time, because the change in temperature has a greater impact on solubility, cooling crystallization is carried out when the temperature of the mother liquor is relatively high. After the high-temperature mother liquor is cooled, the solubility drops significantly, and the amount of crystals formed is large, that is, the crystallization rate and crystallization yield can be improved. In the prior art, further cryogenic crystallization is carried out when the temperature of the mother liquor is relatively low. Even though the solubility decreases to some extent as the temperature of the mother liquor decreases, the solubility only decreases slightly, and at this time the mother liquor is not saturated, resulting in a very small amount of crystallization. That is to say, the amplitude of the solubility decrease brought about by cryogenic cooling is much smaller than the amplitude of the decrease when the mother liquor is at a high temperature. Therefore, by heating and concentrating the mother liquor and then cooling it for crystallization, on the one hand, it can make the mother liquor in a saturated state, which is more conducive to crystal precipitation; on the other hand, when cooling at a high temperature, the amplitude of the solubility decrease is large, and a large amount of solute will crystallize out when the solubility of the solution decreases greatly. In summary of the above two points, by replacing the freeze concentration in the prior art with the triple-effect evaporation in the present application, the crystallization rate and crystallization yield can be effectively improved.

[0021] At the same time, since the triple-effect evaporation technology is mature, compared with the cryogenic technology, the process control points are relatively fewer, and it is relatively simple to adopt automatic control, with low process control difficulty. Of course, from the perspective of energy conversion, the cryogenic technology needs to convert energy such as electric energy into cold energy, while the triple-effect evaporation technology converts energy such as electric energy into heat. In the prior art, the conversion efficiency of converting energy into cold energy is much lower than the conversion efficiency of converting energy into heat. Therefore, from this perspective, by replacing the freeze concentration in the prior art with the triple-effect evaporation in the present application, the energy utilization efficiency can be effectively improved, avoiding waste due to low conversion rate and high power consumption.

[0022] Furthermore, the steam outlet of the triple-effect evaporation concentrator is also connected to a condenser, the outlet of the condenser is connected to a heat exchanger, the heating outlet / discharge port of the triple-effect evaporation concentrator is connected to the heat medium inlet of the heat exchanger, and the cold medium outlet of the heat exchanger is connected to the inlet of the guanidine acetic acid reaction kettle. In this way, the steam discharged from the triple-effect evaporation concentrator is recycled and reused in the preparation of guanidine acetic acid, avoiding waste and saving raw materials. At the same time, the heating outlet / discharge port of the triple-effect evaporation concentrator is connected to the heat medium inlet of the heat exchanger to heat the condensed water in the condenser, effectively utilizing the heat energy of the live steam / mother liquor and avoiding waste of heat energy. Brief Description of the Drawings

[0023] Figure 1 It is a schematic structural diagram of an implementation mode of a guanidinoacetic acid production system.

[0024] Figure 2 It is a schematic structural diagram of another implementation mode of a guanidinoacetic acid production system.

[0025] In the figure: guanidinoacetic acid reaction kettle 100, glycine feed pipe 110, sodium hydroxide feed pipe 120, purified water feed pipe 130, monocyanamide feed pipe 140, mother liquor discharge pipe 210, second crystallization reaction kettle 220, second centrifuge 230, guanidinoacetic acid discharge pipe 240, triple-effect evaporation concentrator 310, first crystallization reaction kettle 320, first centrifuge 330, discharge port 311, heating outlet 312, heating inlet 313, steam outlet 314, condenser 410, heat exchanger 420, electric heater 430, dicyandiamide dissolution reaction kettle 510, ethanol feed pipe 511, third centrifuge 520, alcohol removal device 530, distillation reaction kettle 540, ethanol recovery kettle 550. Specific implementation mode

[0026] For the convenience of understanding this application, the following will describe this application more comprehensively with reference to the relevant drawings. The preferred implementation mode of this application is given in the drawings. However, this application can be implemented in many different forms and is not limited to the implementation modes described herein. On the contrary, the purpose of providing these implementation modes is to make the disclosure of this application understood more thoroughly and comprehensively.

[0027] It should be noted that when an element is referred to as "disposed on" another element, it can be directly on the other element or there may also be an intermediate element. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be an intermediate element at the same time. The terms "vertical", "horizontal", "left", "right", "top", "bottom", "bottom end", "top end" and similar expressions used herein are only for the purpose of illustration and do not represent the only implementation mode.

[0028] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which this application belongs. The terms used in the specification herein are only for the purpose of describing specific implementation modes and are not intended to limit this application. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0029] Please refer to Figures 1 to 2 , in a specific implementation mode of this application, a guanidinoacetic acid production system includes:

[0030] Guanidinoacetic acid reactor 100; a guanidinoacetic acid separation device, the outlet of the guanidinoacetic acid reactor 100 is connected to the inlet of the guanidinoacetic acid separation device, and the guanidinoacetic acid separation device is provided with a mother liquor discharge pipe 210; a mother liquor concentration device, the mother liquor concentration device includes a triple-effect evaporation concentrator 310, a first crystallization reactor 320 and a first centrifuge 330; the mother liquor discharge pipe 210 is connected to the inlet of the triple-effect evaporation concentrator 310, the discharge port 311 of the triple-effect evaporation concentrator 310 is connected to the inlet of the first crystallization reactor 320, and the outlet of the first crystallization reactor 320 is connected to the inlet of the first centrifuge 330; the liquid phase outlet of the first centrifuge 330 is connected to the inlet of the guanidinoacetic acid reactor 100. Specifically, glycine, sodium hydroxide, purified water and monocyanamide are added into the guanidinoacetic acid reactor 100 through a glycine feed pipe 110, a sodium hydroxide feed pipe 120, a purified water feed pipe 130 and a monocyanamide feed pipe 140, and guanidinoacetic acid crude product is generated by reaction. The guanidinoacetic acid crude product is transported to the guanidinoacetic acid separation device to separate the guanidinoacetic acid finished product and the mother liquor. Since the mother liquor still contains unreacted glycine, monocyanamide, as well as the reaction product guanidinoacetic acid and the by-product dicyandiamide, the mother liquor needs to be further processed to separate the reusable substances and by-products therein. Therefore, the mother liquor is transported to the triple-effect evaporation concentrator 310 through the mother liquor discharge pipe 210 for evaporation and concentration. The triple-effect evaporation concentrator is an efficient evaporation and concentration device, and its main working principle is to utilize the principle of evaporation, and through multiple utilization of steam, adopt a multi-effect evaporation process to evaporate and concentrate the solution. This device is usually composed of three evaporators combined together, and each evaporator is connected in series in turn to form an overall evaporation operation process.

[0031] The mother liquor concentrated by the third-effect heater and the separation chamber is the concentrated mother liquor. The concentrated mother liquor is transported to the first crystallization reactor 320 for crystallization, and then enters the first centrifuge 330 for centrifugal separation. The solid phase after centrifugal separation is guanidinoacetic acid and dicyandiamide, and the liquid phase is the concentrated solution, containing glycine and monocyanamide. The liquid phase outlet of the first centrifuge 330 is connected to the inlet of the guanidinoacetic acid reactor 100, and the concentrated solution is transported to the guanidinoacetic acid reactor 100 to participate in the reaction for preparing guanidinoacetic acid again, avoiding waste and realizing the efficient utilization of raw materials. Moreover, the triple-effect evaporation concentrator 310 utilizes steam multiple times, and the amount of live steam required by the system is less. Compared with a single-effect evaporator, it can save about 70% of the evaporation amount; the system operates under a relatively high vacuum condition, the boiling point is reduced, and thus the evaporation speed is accelerated.

[0032] In this application, the solid phase after centrifugal separation is guanidinoacetic acid and dicyandiamide. It should be noted that the solubility of guanidinoacetic acid and dicyandiamide in water is related to temperature, and the solubility is higher at higher temperatures.

[0033] In the guanidine acetate production system of the present application, after the mother liquor concentration device concentrates, crystallizes, and separates the mother liquor separated by the guanidine acetate separation device, the concentrated liquid is transported to the guanidine acetate reaction kettle 100 for reuse. The guanidine acetate and dicyandiamide crystals are transported to the guanidine acetate recovery device. After separating the dicyandiamide therein, the separated guanidine acetate is recovered and recycled, improving the utilization rate of raw materials. A triple-effect evaporation concentrator 310 is used in the mother liquor concentration device. Compared with the cryogenic technology used in traditional freeze concentration, since the concentration of the mother liquor in triple-effect evaporation continuously increases, it is beneficial to crystallization. At the same time, because the change in temperature has a greater impact on solubility, cooling crystallization is carried out when the temperature of the mother liquor is relatively high. After the high-temperature mother liquor is cooled, the solubility drops significantly, and the amount of crystals formed is relatively large, that is, the crystallization rate and crystallization yield can be improved. In the prior art, further cryogenic crystallization is carried out when the temperature of the mother liquor is relatively low. Even if the temperature of the mother liquor drops and the solubility also drops, the solubility only drops slightly, and at this time the mother liquor is not saturated, resulting in a very small amount of crystallization. That is to say, the amplitude of the solubility drop brought about by cryogenic cooling is much smaller than the amplitude of the drop when the mother liquor is at a high temperature. Therefore, by heating and concentrating the mother liquor and then cooling it for crystallization, on the one hand, the mother liquor can be in a saturated state, which is more conducive to crystal precipitation; on the other hand, when the temperature drops at a high temperature, the amplitude of the solubility drop is relatively large, and a large amount of solute will crystallize out when the solubility of the solution drops significantly. In summary of the above two points, by replacing the freeze concentration in the prior art with the triple-effect evaporation in the present application, the crystallization rate and crystallization yield can be effectively improved.

[0034] At the same time, since the triple-effect evaporation technology is mature, compared with the cryogenic technology, the process control points are relatively fewer, and it is relatively simple to adopt automatic control, with low process control difficulty. Of course, from the perspective of energy conversion, the cryogenic technology needs to convert energy such as electric energy into cold energy, while the triple-effect evaporation technology converts energy such as electric energy into heat. In the prior art, the conversion efficiency of converting energy into cold energy is much lower than the conversion efficiency of converting energy into heat. Therefore, from this perspective, by replacing the freeze concentration in the prior art with the triple-effect evaporation in the present application, the energy utilization efficiency can be effectively improved, avoiding waste due to low conversion rate and high power consumption.

[0035] As described above, the triple-effect evaporation concentrator 310 will generate secondary steam during the working process. If this part of the secondary steam is not reused, it needs to be condensed with condensed water, resulting in a certain amount of heat energy waste.

[0036] Therefore, please refer to Figure 1, Preferably, the guanidine acetic acid production system of the present application further includes a steam recovery device, the steam recovery device includes a condenser 410 and a heat exchanger 420, a steam outlet 314 of the triple-effect evaporation concentrator 310 is connected to an inlet of the condenser 410, an outlet of the condenser 410 is connected to a cold medium inlet of the heat exchanger 420, a heating outlet 312 of the triple-effect evaporation concentrator 310 is connected to a hot medium inlet of the heat exchanger 420, and a cold medium outlet of the heat exchanger 420 is connected to an inlet of the guanidine acetic acid reaction kettle 100. The secondary steam concentrated and separated by the triple-effect evaporation concentrator 310 is sent to the condenser 410 through the steam outlet 314 and condensed into condensed water in the condenser 410. Since the temperature of the condensed water is relatively low, and the process temperature in the guanidine acetic acid reaction kettle 100 is usually 65 to 75 °C, if the condensed water is to be reused in the reaction process of guanidine acetic acid, it needs to be heated. The condensed water is transported to the heat exchanger 420 through the cold medium inlet of the heat exchanger 420 for heat exchange. At the same time, the live steam (heating steam) used by the triple-effect evaporation concentrator 310 is discharged from the heating outlet 312 of the triple-effect evaporation concentrator 310 and sent to the heat exchanger 420 through the hot medium inlet of the heat exchanger 420 to heat the condensed water. After being heated, the condensed water is reused in the guanidine acetic acid reaction kettle 100. On the one hand, the amount of water required for the reaction is saved, and the heated condensed water is more suitable for the reaction process of guanidine acetic acid; on the other hand, the live steam is effectively utilized, avoiding waste of heat energy. In actual production, an electric heater 430 can also be provided at the outlet of the heat exchanger 420. The outlet of the electric heater 430 is connected to the heating inlet 313 of the triple-effect evaporation concentrator 310, and is used to heat the live steam discharged from the heat exchanger 420 to the required process temperature, and then transport it to the triple-effect evaporation concentrator 310 for recycling.

[0037] Please refer to Figure 2, in another preferred embodiment, the guanidine acetic acid production system of the present application further includes a steam recovery device, and the steam recovery device includes a condenser 410 and a heat exchanger 420. The steam outlet 314 of the triple-effect evaporation concentrator 310 is connected to the inlet of the condenser 410. The outlet of the condenser 410 is connected to the cold medium inlet of the heat exchanger 420. The discharge port 311 of the triple-effect evaporation concentrator 310 is connected to the hot medium inlet of the heat exchanger 420. The hot medium outlet of the heat exchanger 420 is connected to the inlet of the first crystallization reactor 320. The cold medium outlet of the heat exchanger 420 is connected to the inlet of the guanidine acetic acid reactor 100. As described above, it is necessary to heat the condensed water. The condensed water is transported to the heat exchanger 420 through the cold medium inlet of the heat exchanger 420 for heat exchange. Since the concentrated mother liquor concentrated by the triple-effect evaporation concentrator 310 has a relatively high temperature, it can be used as a heating medium to heat the condensed water. The concentrated mother liquor is transported to the heat exchanger 420 through the hot medium inlet of the heat exchanger 420 via the discharge port 311. After the condensed water is heated, it is recycled to the guanidine acetic acid reactor 100. On the one hand, the amount of water required for the reaction is saved, and the heated condensed water is more suitable for the reaction process of guanidine acetic acid. On the other hand, the heat energy of the concentrated mother liquor is effectively utilized, avoiding heat energy waste. At the same time, the heating outlet 312 of the triple-effect evaporation concentrator 310 is also connected to an electric heater 430. The outlet of the electric heater 430 is connected to the heating inlet 313 of the triple-effect evaporation concentrator 310, which is used to heat the live steam after the operation of the triple-effect evaporation concentrator 310 to the required process temperature and then transport it to the triple-effect evaporation concentrator 310 for recycling.

[0038] It should be noted that the cold / hot medium inlets / outs of the heat exchanger 420 described in the text can be the tube-side inlets / outs of the heat exchanger 420 or the shell-side inlets / outs, which are specifically determined according to the actual working conditions and are not specifically limited in this solution.

[0039] In a specific embodiment of the present application, the guanidine acetic acid separation device includes a second crystallization reactor 220 and a second centrifuge 230. The outlet of the guanidine acetic acid reactor 100 is connected to the second crystallization reactor 220. The outlet of the second crystallization reactor 220 is connected to the second centrifuge 230. The solid phase outlet of the second centrifuge 230 is the guanidine acetic acid finished product outlet. The liquid phase outlet of the centrifuge is connected to the mother liquor discharge pipe 210. The crude guanidine acetic acid produced in the guanidine acetic acid reactor 100 is transported to the second crystallization reactor 220 for crystallization and then enters the second centrifuge 230 for centrifugal separation. The solid phase after centrifugal separation is the guanidine acetic acid finished product, which is discharged through the guanidine acetic acid discharge pipe 240. The liquid phase is the mother liquor, and the mother liquor is transported to the mother liquor concentration device through the mother liquor discharge pipe 210 for concentration.

[0040] In a preferred embodiment, the guanidine acetate production system of the present application further includes a guanidine acetate recovery device. The guanidine acetate recovery device is provided with a dicyandiamide dissolution reaction kettle 510. The solid-phase outlet of the first centrifuge 330 is connected to the inlet of the dicyandiamide dissolution reaction kettle 510, and the dicyandiamide dissolution reaction kettle 510 is provided with an ethanol feed pipe 511.

[0041] Since the solid phase after centrifugal separation by the first centrifuge 330 is guanidine acetate and dicyandiamide, to recover this part of guanidine acetate, the dicyandiamide therein needs to be removed. Therefore, the solid-phase outlet of the first centrifuge 330 is connected to the inlet of the dicyandiamide dissolution reaction kettle 510, and the solid phase is added to the dicyandiamide dissolution reaction kettle 510. At the same time, ethanol is also added to the dicyandiamide dissolution reaction kettle 510 through the ethanol feed pipe 511 to dissolve the dicyandiamide, and after dissolution, it becomes a dicyandiamide alcohol solution. At this time, the dicyandiamide dissolution reaction kettle 510 contains a dicyandiamide alcohol solution and guanidine acetate existing in the form of a solid phase, and they need to be separated.

[0042] Therefore, further, the guanidine acetate recovery device further includes a third centrifuge 520. The outlet of the dicyandiamide dissolution reaction kettle 510 is connected to the inlet of the third centrifuge 520, and the solid-phase outlet of the third centrifuge 520 is connected to the inlet of the second crystallization reaction kettle 220. After the dicyandiamide alcohol solution and guanidine acetate are separated by the third centrifuge 520, the guanidine acetate is discharged through the solid-phase outlet of the third centrifuge 520 and transported to the second crystallization reaction kettle 220 to continue participating in the reaction.

[0043] Further, the guanidine acetate recovery device further includes a de-alcoholization device 530. The solid-phase outlet of the third centrifuge 520 is connected to the inlet of the de-alcoholization device 530, and the outlet of the de-alcoholization device 530 is connected to the inlet of the second crystallization reaction kettle 220. Since there is still a small amount of ethanol in the guanidine acetate separated by the third centrifuge 520, a de-alcoholization device 530 is required for de-alcoholization, and any de-alcoholization equipment that meets the production process can be used.

[0044] In another specific embodiment of the present application, the dicyandiamide dissolution reaction kettle 510 is further connected to a distillation reaction kettle 540. The liquid-phase outlet of the third centrifuge 520 is connected to the inlet of the distillation reaction kettle 540. The distillation reaction kettle 540 is used to distill the dicyandiamide alcohol solution in the dicyandiamide dissolution reaction kettle 510. After the dicyandiamide alcohol solution is transported to the distillation reaction kettle 540 for distillation, an alcohol solution is obtained. Further, the distillation reaction kettle 540 is further connected to an ethanol recovery kettle 550, and the ethanol recovery kettle 550 is used to recover the ethanol distilled out in the distillation reaction kettle 540.

[0045] The above-disclosed is only the preferred embodiment of the present utility model. Of course, it cannot be used to limit the scope of rights of the present utility model. Those of ordinary skill in the art can understand all or part of the processes of implementing the above embodiments, and the equivalent changes made according to the claims of the present utility model still fall within the scope covered by the utility model.

Claims

1. A guanidinoacetic acid production system, characterized in that, Including: Guanidine acetate reactor; Guanidine acetate separation device, the outlet of the guanidine acetate reactor is connected to the inlet of the guanidine acetate separation device, and the guanidine acetate separation device is provided with a mother liquor discharge pipe; Mother liquor concentration device, the mother liquor concentration device includes a triple-effect evaporation concentrator, a first crystallization reactor and a first centrifuge; the mother liquor discharge pipe is connected to the inlet of the triple-effect evaporation concentrator, the discharge port of the triple-effect evaporation concentrator is connected to the inlet of the first crystallization reactor, and the outlet of the first crystallization reactor is connected to the inlet of the first centrifuge; the liquid phase outlet of the first centrifuge is connected to the inlet of the guanidine acetate reactor.

2. The guanidinoacetic acid production system according to claim 1, wherein It further includes a steam recovery device, the steam recovery device includes a condenser and a heat exchanger, the steam outlet of the triple-effect evaporation concentrator is connected to the inlet of the condenser, the outlet of the condenser is connected to the cold medium inlet of the heat exchanger, the heating outlet of the triple-effect evaporation concentrator is connected to the hot medium inlet of the heat exchanger, and the cold medium outlet of the heat exchanger is connected to the inlet of the guanidine acetate reactor.

3. The guanidinoacetic acid production system according to claim 1, characterized in that, It further includes a steam recovery device, the steam recovery device includes a condenser and a heat exchanger, the steam outlet of the triple-effect evaporation concentrator is connected to the inlet of the condenser, the outlet of the condenser is connected to the cold medium inlet of the heat exchanger, the discharge port of the triple-effect evaporation concentrator is connected to the hot medium inlet of the heat exchanger, the hot medium outlet of the heat exchanger is connected to the inlet of the first crystallization reactor, and the cold medium outlet of the heat exchanger is connected to the inlet of the guanidine acetate reactor.

4. The guanidinoacetic acid production system according to claim 1, wherein The guanidine acetate separation device includes a second crystallization reactor and a second centrifuge, the outlet of the guanidine acetate reactor is connected to the second crystallization reactor, the outlet of the second crystallization reactor is connected to the second centrifuge, the solid phase outlet of the second centrifuge is the guanidine acetate finished product outlet, and the liquid phase outlet of the centrifuge is connected to the mother liquor discharge pipe.

5. The guanidinoacetic acid production system according to claim 4, characterized in that, It further includes a guanidine acetate recovery device, the guanidine acetate recovery device is provided with a dicyandiamide dissolution reactor, the solid phase outlet of the first centrifuge is connected to the inlet of the dicyandiamide dissolution reactor, and the dicyandiamide dissolution reactor is provided with an ethanol feed pipe.

6. The guanidinoacetic acid production system according to claim 5, characterized in that, The guanidine acetate recovery device further includes a third centrifuge, the outlet of the dicyandiamide dissolution reactor is connected to the inlet of the third centrifuge, and the solid phase outlet of the third centrifuge is connected to the inlet of the second crystallization reactor.

7. The guanidinoacetic acid production system according to claim 6, characterized in that, The guanidine acetate recovery device further includes a de-alcoholization device, the solid phase outlet of the third centrifuge is connected to the inlet of the de-alcoholization device, and the outlet of the de-alcoholization device is connected to the inlet of the second crystallization reactor.

8. The guanidinoacetic acid production system according to claim 6, wherein, The dicyandiamide dissolution reactor is further connected to a distillation reactor, and the liquid phase outlet of the third centrifuge is connected to the inlet of the distillation reactor.

9. The guanidinoacetic acid production system according to claim 8, wherein The distillation reactor is further connected to an ethanol recovery kettle for recovering ethanol.

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