Recycling device for carbazide production mother liquor

Abstract

The utility model discloses a recycling device for mother liquor in carbazide production, and relates to the technical field of carbazide production, an inlet of a distillation kettle is communicated with a mother liquor tank, an outlet of the distillation kettle is communicated with a crystallizing tank through a pipeline, and an outlet of the crystallizing tank is communicated with a first centrifugal machine; and a solid phase outlet of the first centrifugal machine is communicated with a hydrazine crystal tank. The mother liquor is distilled by the distillation kettle, and moisture and low-boiling-point impurities in the mother liquor are evaporated by heating, so that primary concentration and component separation of the mother liquor are realized, and a proper concentration condition is created for subsequent crystallization. And the concentrated mother liquor in the crystallizing tank is cooled and the like, and the carbazide reaches a supersaturated state so as to be crystallized and separated out. The first centrifugal machine is used for separating carbazide crystals formed in the crystallizing tank from mother liquor, and the solid phase outlet is connected with the carbazide crystal tank, so that the carbazide crystals are preliminarily recovered, the whole process is coherent, and basic operation from mother liquor to preliminary recovery of the carbazide crystals is reasonably realized.

Description

Technical Field

[0001] This utility model relates to the field of carbazine production technology, specifically to a device for recycling carbazine production mother liquor. Background Technology

[0002] Carbazine is widely used in chemical production, which generates a large amount of mother liquor. This mother liquor contains unreacted raw materials, such as urea and hydrazine hydrate, as well as carbazine products and other byproducts. Currently, most companies treat the carbazine production mother liquor in a relatively simple way, directly discharging it, which not only wastes a great deal of resources but also causes serious environmental pollution. If conventional methods such as evaporation and crystallization are used to recover the useful components, there are problems such as high energy consumption, low recovery efficiency, and difficulty in guaranteeing product purity. Summary of the Invention

[0003] The technical problem to be solved by this utility model is to provide a device for recycling carbazide production mother liquor, which reduces the waste of raw materials and improves the economic benefits of the product, in order to address the shortcomings of the existing technology.

[0004] To solve the above-mentioned technical problems, the technical solution of this utility model is as follows:

[0005] A device for recycling mother liquor from carbazide production includes a distillation kettle, the inlet of which is connected to a mother liquor tank, the outlet of which is connected to a crystallization tank via a pipeline, the outlet of which is connected to a first centrifuge, and the solid phase outlet of the first centrifuge is connected to a carbazide crystal tank.

[0006] As an improved technical solution, the outlet of the mother liquor tank is connected to a decolorization tank via a pipeline, the inlet of the decolorization tank is connected to an activated carbon tank, the outlet of the decolorization tank is connected to a plate and frame filter press via a pipeline, and the liquid phase outlet of the plate and frame filter press is connected to the distillation kettle via a pipeline.

[0007] As an improved technical solution, the solid phase outlet of the first centrifuge is connected to a water washing tank, the inlet of the water washing tank is connected to a deionized water tank, the outlet of the water washing tank is connected to a second centrifuge, the solid phase outlet of the second centrifuge is connected to a dryer, and the outlet of the dryer is connected to the bazine crystal tank.

[0008] As an improved technical solution, the liquid phase outlets of the first centrifuge and the second centrifuge are respectively connected to a regulating tank. The inlet of the regulating tank is connected to a sodium hydroxide solution tank. The outlet of the regulating tank is connected to an extraction tank through a pipe. The inlet of the extraction tank is connected to a n-butanol tank through a pipe. The outlet of the extraction tank is connected to a separatory tank through a pipe. The outlet of the separatory tank is connected to an evaporator through a pipe. The upper outlet of the evaporator is connected to a n-butanol recovery tank.

[0009] As an improved technical solution, the bottom outlet of the evaporator is connected to an ion exchange resin column via a pipe, the inlet of the ion exchange resin column is connected to an eluent tank, and the outlet of the ion exchange resin column is connected to an eluent tank.

[0010] Due to the adoption of the above technical solution, the beneficial effects of this utility model are:

[0011] This invention relates to a device for recovering and utilizing carbazide production mother liquor, comprising a distillation kettle, an inlet connected to a mother liquor tank, an outlet connected via a pipe to a crystallization tank, an outlet connected to a first centrifuge, and a solid phase outlet connected to a carbazide crystal tank. The distillation kettle performs distillation on the mother liquor, evaporating water and low-boiling-point impurities through heating, achieving preliminary concentration and component separation of the mother liquor, creating suitable concentration conditions for subsequent crystallization. The concentrated mother liquor in the crystallization tank undergoes cooling and other operations, causing carbazide to reach a supersaturated state and crystallize out. The first centrifuge separates the carbazide crystals formed in the crystallization tank from the mother liquor, and the solid phase outlet is connected to the carbazide crystal tank, achieving preliminary recovery of carbazide crystals. The entire process is coherent and rationally implements the basic operations from mother liquor to preliminary recovery of carbazide crystals.

[0012] The outlet of the mother liquor tank in this invention is connected to a decolorization tank via a pipeline. The inlet of the decolorization tank is connected to an activated carbon tank. The outlet of the decolorization tank is connected to a plate and frame filter press via a pipeline. The liquid phase outlet of the plate and frame filter press is connected to the distillation kettle via a pipeline. Activated carbon has strong adsorption properties and can effectively adsorb pigments, some organic impurities, and large molecules that may affect the subsequent recovery process in the mother liquor, thereby improving the purity of the mother liquor. The plate and frame filter press retains the activated carbon and other insoluble impurities after adsorption, and the filtered liquid phase (purified mother liquor) enters the distillation kettle. This improvement effectively removes impurities from the mother liquor, reduces the interference of impurities on subsequent distillation, crystallization, and other operations, helps to improve the purity of the final carbazine product, and also extends the service life of subsequent equipment and reduces the frequency of equipment maintenance due to impurity blockage.

[0013] The solid phase outlet of the first centrifuge is connected to a water washing tank, the inlet of the water washing tank is connected to a deionized water tank, and the outlet of the water washing tank is connected to a second centrifuge. The solid phase outlet of the second centrifuge is connected to a dryer, and the outlet of the dryer is connected to the carbazine crystal tank. Deionized water effectively washes away the mother liquor and other impurities adhering to the crystal surface, improving crystal purity. The second centrifuge further separates the washed crystals into solid and liquid phases to remove the water generated during washing. The dryer dries the crystals after the secondary separation to remove residual water, obtaining dried, high-purity carbazine crystals, which finally enter the carbazine crystal tank. This process significantly improves the quality of the carbazine crystals, ensuring that the product meets the stringent requirements for purity and other indicators in industrial production.

[0014] The liquid phase outlets of the first and second centrifuges are respectively connected to conditioning tanks. The inlet of the conditioning tank is connected to a sodium hydroxide solution tank, and the outlet of the conditioning tank is connected to an extraction tank via a pipeline. The inlet of the extraction tank is connected to a n-butanol tank via a pipeline, and the outlet of the extraction tank is connected to a separatory tank via a pipeline. The outlet of the separatory tank is connected to an evaporator via a pipeline, and the upper outlet of the evaporator is connected to a n-butanol recovery tank. Sodium hydroxide can react with some acidic impurities in the mother liquor, while promoting the separation of urea and hydrazine hydrate. The liquid phase after pH adjustment enters the extraction tank. The n-butanol tank provides n-butanol as the extractant. Utilizing the selective extraction effect of n-butanol on urea and hydrazine hydrate, they are transferred from the mother liquor to the n-butanol phase. The separatory tank separates the two phases after extraction, obtaining a n-butanol phase containing urea and hydrazine hydrate. The evaporator evaporates the n-butanol by heating, and the n-butanol recovery tank recovers the evaporated n-butanol, realizing the recycling of the extractant and reducing production costs. Meanwhile, this solution can effectively recover residual urea and hydrazine hydrate in the mother liquor, improve resource utilization, and reduce environmental pollution from waste emissions.

[0015] The bottom outlet of the evaporator is connected to an ion exchange resin column via a pipe. The inlet of the ion exchange resin column is connected to an eluent tank, and the outlet of the ion exchange resin column is connected to an eluent tank. The ion exchange resin selectively adsorbs urea and hydrazine hydrate. Using a suitable eluent, the two can be effectively separated and collected separately in the eluent tank. This method further improves the purity of recovered urea and hydrazine hydrate, meeting the requirements for reuse in the carbazine production system, truly realizing resource recycling, minimizing raw material waste, and reducing the company's production costs. Attached Figure Description

[0016] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0017] Figure 1 This is a structural schematic diagram of an embodiment of the present utility model;

[0018] The components are as follows: 1. Distillation kettle; 2. Mother liquor tank; 3. Crystallization tank; 4. First centrifuge; 5. Bazide crystallization tank; 6. Decolorization tank; 7. Activated carbon tank; 8. Plate and frame filter press; 9. Washing tank; 10. Deionized water tank; 11. Second centrifuge; 12. Dryer; 13. Adjustment tank; 14. Sodium hydroxide solution tank; 15. Extraction tank; 16. n-Butanol tank; 17. Separating tank; 18. Evaporation tank; 19. n-Butanol recovery tank; 20. Ion exchange resin column; 21. Eluent tank; 22. Eluent tank. Detailed Implementation

[0019] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0020] like Figure 1 As shown, a device for recovering and utilizing carbazide production mother liquor includes a distillation kettle 1. The inlet of the distillation kettle 1 is connected to a mother liquor tank 2, and the outlet of the distillation kettle 1 is connected to a crystallization tank 3 via a pipeline. The outlet of the crystallization tank 3 is connected to a first centrifuge 4, and the solid phase outlet of the first centrifuge 4 is connected to a carbazide crystal tank 5. The distillation kettle 1 performs distillation on the mother liquor, evaporating water and low-boiling-point impurities through heating, achieving preliminary concentration and component separation of the mother liquor, creating suitable concentration conditions for subsequent crystallization. The concentrated mother liquor in the crystallization tank 3 undergoes cooling and other operations, causing carbazide to reach a supersaturated state and crystallize out. The first centrifuge 4 separates the carbazide crystals formed in the crystallization tank 3 from the mother liquor, and the solid phase outlet is connected to the carbazide crystal tank 5, achieving preliminary recovery of carbazide crystals. The entire process is coherent and rationally realizes the basic operations from mother liquor to preliminary recovery of carbazide crystals.

[0021] The outlet of the mother liquor tank 2 is connected to a decolorization tank 6 via a pipeline. The inlet of the decolorization tank 6 is connected to an activated carbon tank 7. The outlet of the decolorization tank 6 is connected to a plate and frame filter press 8 via a pipeline. The liquid phase outlet of the plate and frame filter press 8 is connected to the distillation kettle 1 via a pipeline. Activated carbon has strong adsorption properties and can effectively adsorb pigments, some organic impurities, and macromolecules that may affect the subsequent recovery process in the mother liquor, thereby improving the purity of the mother liquor. The plate and frame filter press 8 retains the activated carbon and other insoluble impurities after adsorption, and the filtered liquid phase (purified mother liquor) enters the distillation kettle 1. This improvement effectively removes impurities from the mother liquor, reduces the interference of impurities on subsequent distillation, crystallization, and other operations, helps to improve the purity of the final carbazine product, and also extends the service life of subsequent equipment and reduces the frequency of equipment maintenance due to impurity blockage.

[0022] The solid phase outlet of the first centrifuge 4 is connected to a water washing tank 9, the inlet of the water washing tank 9 is connected to a deionized water tank 10, the outlet of the water washing tank 9 is connected to a second centrifuge 11, the solid phase outlet of the second centrifuge 11 is connected to a dryer 12, and the outlet of the dryer 12 is connected to the carbazide crystal tank 5. Deionized water effectively washes away the mother liquor and other impurities adhering to the crystal surface, improving crystal purity. The second centrifuge 11 further separates the washed crystals into solid and liquid phases to remove the water generated during washing. The dryer 12 dries the crystals after the secondary separation to remove residual water, obtaining dried, high-purity carbazide crystals, which finally enter the carbazide crystal tank 5. This process greatly improves the quality of the carbazide crystals, ensuring that the product meets the stringent requirements for purity and other indicators in industrial production.

[0023] The liquid phase outlets of the first centrifuge 4 and the second centrifuge 11 are respectively connected to a regulating tank 13. The inlet of the regulating tank 13 is connected to a sodium hydroxide solution tank 14. The outlet of the regulating tank 13 is connected to an extraction tank 15 via a pipe. The inlet of the extraction tank 15 is connected to a n-butanol tank 16 via a pipe. The outlet of the extraction tank 15 is connected to a separating tank 17 via a pipe. The outlet of the separating tank 17 is connected to an evaporator 18 via a pipe. The upper outlet of the evaporator 18 is connected to a n-butanol recovery tank 19. Sodium hydroxide can react with some acidic impurities in the mother liquor, while promoting the separation of urea and hydrazine hydrate. The liquid phase after pH adjustment enters the extraction tank 15. The n-butanol tank 16 provides n-butanol as the extractant. Utilizing the selective extraction effect of n-butanol on urea and hydrazine hydrate, they are transferred from the mother liquor to the n-butanol phase. The separating tank 17 separates the two phases after extraction, obtaining a n-butanol phase containing urea and hydrazine hydrate. Evaporator 18 evaporates n-butanol through heating, and n-butanol recovery tank 19 recovers the evaporated n-butanol, realizing the recycling of the extractant and reducing production costs. At the same time, this scheme can effectively recover residual urea and hydrazine hydrate in the mother liquor, improve resource utilization, and reduce the pollution of the environment caused by waste discharge.

[0024] The bottom outlet of the evaporator 18 is connected to an ion exchange resin column 20 via a pipe. The inlet of the ion exchange resin column 20 is connected to an eluent tank 21, and the outlet of the ion exchange resin column 20 is connected to an eluent tank 22. The ion exchange resin selectively adsorbs urea and hydrazine hydrate. Eluting with dilute hydrochloric acid effectively separates the two substances, which are then collected separately in the eluent tank 22. The eluent is a mixture of urea and hydrazine hydrate. Through purification, it meets the requirements for reuse in the carbazine production system, truly realizing resource recycling, minimizing raw material waste, and reducing the company's production costs.

[0025] It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the present invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

Claims

1. A device for recycling a carbazide production mother liquor, characterized by: The distillation kettle is connected with a mother liquor tank at its inlet, and its outlet is connected with a crystallization tank through a pipeline, the outlet of the crystallization tank is connected with a first centrifuge, and the solid phase outlet of the first centrifuge is connected with a baraz crystal tank.

2. A device for recycling a carbazide production mother liquor according to claim 1, characterized in that: The outlet of the mother liquor tank is connected with a decolorization tank through a pipeline, the inlet of the decolorization tank is connected with an activated carbon tank, the outlet of the decolorization tank is connected with a plate-and-frame filter press through a pipeline, and the liquid phase outlet of the plate-and-frame filter press is connected with the distillation kettle through a pipeline.

3. A device for recycling a carbazide production mother liquor according to claim 1, characterized in that: The solid phase outlet of the first centrifuge is connected with a water washing tank, the inlet of the water washing tank is connected with a deionized water tank, the outlet of the water washing tank is connected with a second centrifuge, the solid phase outlet of the second centrifuge is connected with a dryer, and the outlet of the dryer is connected with the baraz crystal tank.

4. A device for recycling a carbazide production mother liquor according to claim 3, characterized in that: The liquid phase outlets of the first centrifuge and the second centrifuge are respectively connected with adjusting tanks, the inlets of the adjusting tanks are connected with sodium hydroxide solution tanks, the outlets of the adjusting tanks are connected with extraction tanks through pipelines, the inlets of the extraction tanks are connected with n-butanol tanks through pipelines, the outlets of the extraction tanks are connected with liquid separation tanks through pipelines, the outlets of the liquid separation tanks are connected with evaporation tanks through pipelines, and the upper outlets of the evaporation tanks are connected with n-butanol recovery tanks.

5. A device for recycling a carbazide production mother liquor according to claim 4, characterized in that: The bottom outlet of the evaporation tank is connected with an ion exchange resin column through a pipeline, the inlet of the ion exchange resin column is connected with an eluent tank, and the outlet of the ion exchange resin column is connected with an eluate tank.

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