Device for recycling ammonium sulfate in glyphosate mother liquor treatment process

Abstract

The utility model discloses a device for recycling ammonium sulfate in a glyphosate mother liquor treatment process, which comprises an evaporation kettle, the evaporation kettle is communicated with a crystallization kettle through a pipeline, the top of the evaporation kettle is communicated with a condenser through a pipeline, and the top of the condenser is communicated with a vacuum pump through a pipeline. The evaporation kettle is provided with a tail gas wastewater inlet pipeline and a steam inlet pipeline, the crystallization kettle is provided with a dilute ammonia water inlet pipeline, and the condenser and the crystallization kettle are respectively provided with a circulating water inlet and a circulating water outlet. According to the utility model, tail gas generated in the wet oxidation process of the glyphosate mother liquor can be absorbed by dilute sulphuric acid to obtain tail gas absorption wastewater with higher COD (Chemical Oxygen Demand) and ammonia nitrogen content, and dilute ammonia water with higher COD and ammonium bicarbonate content generated in the evaporation process of oxidation liquid can be treated, so that nitrogen resources are recycled to obtain an ammonium sulfate product; produced evaporation condensate water is reused for production.

Description

Technical Field

[0001] The utility model belongs to the technical field of industrial wastewater treatment and relates to a device for recycling ammonium sulfate in the process of treating glyphosate mother liquor. Background Art

[0002] Glyphosate mother liquor is a type of wastewater generated during the production of glyphosate technical. Its composition is complex, primarily containing organic phosphorus, organic nitrogen, and sodium chloride. Our company currently uses wet oxidation technology to treat this organic wastewater. The organic matter in the wastewater undergoes an oxidation reaction under high temperature and high pressure to produce an oxidation liquid (organic amines are oxidized to ammonia, and large-molecule organic matter is oxidized to small-molecule organic matter and carbon dioxide). At high temperature, some low-molecular organic matter and ammonia enter the tail gas, where they are absorbed by dilute sulfuric acid to produce tail gas absorption wastewater with high COD and ammonia nitrogen content. The oxidation liquid then enters a steam stripping tower to further remove ammonia nitrogen, resulting in dilute ammonia water with high COD and ammonium carbonate content. This treatment is difficult, so a new technology is urgently needed to effectively treat both wastewaters to recover nitrogen resources and improve resource utilization. Utility Model Content

[0003] This utility model aims to provide a device for recycling ammonium sulfate during the treatment of glyphosate mother liquor, so as to solve the technical problem of difficulty in treating the high COD and high ammonia nitrogen tail gas absorption wastewater generated during the wet oxidation treatment of glyphosate mother liquor and the dilute ammonia water with high COD and ammonium carbonate content generated during the evaporation and stripping process. The device can effectively treat the tail gas absorption wastewater with high COD and ammonia nitrogen content obtained after the tail gas generated during the wet oxidation of glyphosate mother liquor is absorbed by dilute sulfuric acid, and the dilute ammonia water with high COD and ammonium carbonate content generated during the evaporation and stripping of the oxidation liquid, recover the nitrogen resources therein, obtain a high-purity ammonium sulfate product for external sale, and reuse the generated evaporation condensate for production. The centrifuge filtrate can be used to produce organic fertilizer. Unlike conventional methods for treating ammonia nitrogen wastewater, this device uses two difficult-to-treat industrial wastewaters and re-reuses them to obtain industrial products with high added value, turning waste into treasure.

[0004] A device for recycling ammonium sulfate in a glyphosate mother liquor treatment process comprises an evaporator, the evaporator being connected to a crystallizer via a pipeline, the top of the evaporator being connected to a condenser via a pipeline, the top of the condenser being connected to a vacuum pump via a pipeline, the evaporator being provided with a tail gas wastewater inlet pipeline and a steam inlet pipeline, the crystallizer being provided with a dilute ammonia water inlet pipeline, and the condenser and the crystallizer being provided with a circulating water inlet and outlet, respectively.

[0005] Preferably, a stirrer and a thermometer are provided inside the evaporation kettle.

[0006] Preferably, the bottom of the condenser is connected to the condensed water storage tank through a pipeline, and the bottom of the crystallization kettle is connected to the centrifuge and the filtrate storage tank in sequence through pipelines.

[0007] Preferably, a material transfer pump is provided between the evaporation kettle and the crystallization kettle.

[0008] Preferably, a second thermometer, a second agitator and a pH meter are provided in the crystallization kettle.

[0009] A method for recycling ammonium sulfate during the treatment of glyphosate mother liquor comprises the following steps:

[0010] 1) Add the high COD and high ammonia nitrogen tail gas absorption wastewater generated during the glyphosate mother liquor treatment process into the evaporator, stir and mix evenly, start the vacuum pump, open the evaporator jacket steam valve, evaporate and concentrate the material in the evaporator, and collect the condensed water for reuse in production;

[0011] 2) After evaporation is completed, the material in the evaporation kettle is transferred to the crystallization kettle through a transfer pump. The circulating water in the jacket of the crystallization kettle is turned on to cool the material in the kettle to 30-40°C. Then, dilute ammonia water is added to the crystallization kettle to adjust the pH to 5-6. The tail gas generated enters the tail gas absorption system for treatment and then meets the emission standards.

[0012] 3) When the temperature of the material in the crystallizer drops to 20-30℃, open the discharge valve of the crystallizer and transfer the material in the crystallizer into the centrifuge for solid-liquid separation to obtain a high-purity ammonium sulfate product. The filtrate from the centrifuge is temporarily stored in the filtrate storage tank and used to produce organic fertilizer.

[0013] Preferably, the high COD and high ammonia nitrogen tail gas absorption wastewater is tail gas absorption wastewater with high COD and ammonia nitrogen content obtained by absorbing the tail gas generated in the wet oxidation process of glyphosate mother liquor through dilute sulfuric acid, and its flow rate is 1.0~1.5m3 / h. The dilute ammonia water is dilute ammonia water with high COD and ammonium carbonate content generated in the evaporation process of the oxidation liquid obtained after the wet oxidation of glyphosate mother liquor, and the content is 8-10%, and its flow rate is 0.3~0.5m3 / h.

[0014] Preferably, in step 1) and step 2), the pH of the material in the kettle is controlled at 5-6.

[0015] Preferably, the material is cooled to 20-30° C. in the crystallization kettle.

[0016] The beneficial effects of the utility model are:

[0017] The utility model discloses a method and device for recycling ammonium sulfate in the process of treating glyphosate mother liquor. The method and device are provided with an evaporating kettle, an agitator and a thermometer, a jacket is passed through with steam, and the tail gas absorption wastewater can be fully evaporated and concentrated to reduce the water content therein. The crystallization kettle is provided with an agitator, a thermometer and a pH meter, and the jacket is passed through with circulating water, which can accurately control the crystallization pH value and crystallization temperature, thereby fully crystallizing the produced ammonium sulfate. The carbon dioxide in the tail gas enters the tail gas absorption system for treatment and achieves standard discharge. Then, the ammonium sulfate product and filtrate are obtained by centrifugation, which are sold to the outside world and used to produce organic fertilizer. The evaporated condensed water produced by the evaporating kettle can be reused in production. Thus, the nitrogen element in the wastewater is fully utilized to generate the ammonium sulfate product and filtrate, and the organic fertilizer is produced, thereby realizing its resource utilization. While treating concentrated ammonia nitrogen wastewater, waste utilization is achieved, which is more cost-effective and realizes the resource utilization of high-concentration nitrogen-containing wastewater. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 Schematic diagram of the method and apparatus for resource recovery of ammonium sulfate during glyphosate mother liquor treatment.

[0019] In the figure: 1-evaporation kettle, 2-transfer pump, 3-vacuum pump, 4-condenser, 5-condensed water storage tank, 6-crystallization kettle, 7-centrifuge, 8-filtrate storage tank, a-first thermometer, b-first agitator, c-second thermometer, d-second agitator, e-pH meter. DETAILED DESCRIPTION

[0020] The following will be combined with the specific embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. The embodiments described 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 making creative efforts are within the scope of protection of the present invention.

[0021] A device for recycling ammonium sulfate in a glyphosate mother liquor treatment process comprises an evaporator 1, the evaporator 1 being connected to a crystallizer 6 via a pipeline, the top of the evaporator 1 being connected to a condenser 4 via a pipeline, the top of the condenser 4 being connected to a vacuum pump 3 via a pipeline, the evaporator 1 being provided with a tail gas wastewater inlet pipeline and a steam inlet pipeline, the crystallizer 6 being provided with a dilute ammonia water inlet pipeline, and the condenser 4 and the crystallizer 6 being provided with a circulating water inlet and outlet, respectively.

[0022] Preferably, a stirrer b and a thermometer a are provided inside the evaporation kettle 1 .

[0023] Preferably, the bottom of the condenser 4 is connected to the condensed water storage tank 5 through a pipeline, and the bottom of the crystallization kettle 6 is connected to the centrifuge 7 and the filtrate storage tank 8 in sequence through a pipeline.

[0024] Preferably, a material transfer pump 2 is provided between the evaporation kettle 1 and the crystallization kettle 6 .

[0025] Preferably, a second thermometer c, a second agitator d and a pH meter e are provided in the crystallization kettle 6.

[0026] A method and apparatus for recycling ammonium sulfate during the treatment of glyphosate mother liquor, comprising the following steps:

[0027] 1) Add the high-COD and high-ammonia nitrogen tail gas absorption wastewater generated during the treatment of glyphosate mother liquor into evaporator 1, stir and mix evenly, start the vacuum pump 3, open the steam valve of the jacket of evaporator 1, evaporate and concentrate the material in evaporator 1, and collect the condensed water for reuse in production;

[0028] 2) After evaporation is completed, the material in the evaporation kettle is transferred to the crystallization kettle 6 via a transfer pump. The circulating water in the jacket of the crystallization kettle 6 is turned on to cool the material in the kettle to 30-40°C. Then, dilute ammonia water is added to the crystallization kettle 6 to adjust the pH to 5-6. The generated tail gas enters the tail gas absorption system for treatment and meets the discharge standards;

[0029] 3) When the temperature of the material in the crystallizer 6 drops to 20-30°C, the discharge valve of the crystallizer 6 is opened, and the material in the crystallizer 6 is transferred to the centrifuge 7 for solid-liquid separation to obtain a high-purity ammonium sulfate product. The filtrate of the centrifuge 7 is temporarily stored in the filtrate storage tank and used to produce organic fertilizer;

[0030] Furthermore, the high COD and high ammonia nitrogen tail gas absorption wastewater is the tail gas absorption wastewater with high COD and ammonia nitrogen content obtained by absorbing the tail gas generated in the wet oxidation process of glyphosate mother liquor through dilute sulfuric acid, and its flow rate is 1.0~1.5m3 / h. The dilute ammonia water is the dilute ammonia water with high COD and ammonium carbonate content generated in the evaporation process of the oxidation liquid obtained after the wet oxidation of glyphosate mother liquor, and the content is 8-10%. Its flow rate is 0.3~0.5m3 / h.

[0031] Furthermore, in step 1) and step 2), the temperature of the material in the kettle is lowered to 30-40° C., and the pH is controlled at 5-6.

[0032] Furthermore, in step 3), the material is cooled to 20-30° C. in the crystallization kettle.

[0033] Furthermore, the resource recovery device includes an evaporator, a material transfer pump, a vacuum pump, a condenser, a condensed water storage tank, a crystallization kettle, a centrifuge and a filtrate storage tank.

[0034] Furthermore, a thermometer and a stirrer are provided on the top of the evaporation kettle, and steam is passed into the jacket; a thermometer and a stirrer are provided on the top of the crystallization kettle, a pH meter is provided on the kettle, and circulating water is passed into the jacket.

[0035] Example 1

[0036] The above device is used to pass the tail gas absorption wastewater with high COD and high ammonia nitrogen into the evaporator at a flow rate of 1m 3 / h,

[0037] Turn on the stirring of the evaporator, start the vacuum pump, open the steam valve of the evaporator jacket, let in steam, control the temperature of the evaporator to evaporate under reduced pressure at 90-110℃, and condense the gas phase coming out of the evaporator through the condenser to obtain evaporated condensate, which enters the condensate storage tank for temporary storage.

[0038] After evaporation is completed, turn on the transfer pump to transfer the evaporation kettle material into the crystallization kettle, open the crystallization kettle jacket circulating water valve, cool the crystallization kettle material to 30-40 ° C, add dilute ammonia water with high COD and ammonium carbonate content (ammonia water content 8-10%), and the flow rate is 0.3m 3 / h, adjust the pH to around 4, and continue cooling and crystallization. When the crystallizer temperature drops to 20-30°C, start the centrifuge, open the crystallizer discharge valve, and place the crystallizer material into the centrifuge for solid-liquid separation to obtain ammonium sulfate product and filtrate. The filtrate is temporarily stored in a filtrate storage tank for use in organic fertilizer production. Analysis and testing show that the obtained ammonium sulfate content is greater than 95% and can be sold directly. The filtrate has an organic matter content of ≥30%, a nitrogen content of ≥9%, and a moisture content of ≤30%, and can be used for organic fertilizer production.

[0039] Example 2

[0040] Using the above device, the tail gas absorption wastewater with high COD and high ammonia nitrogen is passed into the evaporator at a flow rate of 1.2m 3 / h, start the evaporator to stir, start the vacuum pump, open the steam valve of the evaporator jacket, let in steam, control the temperature of the evaporator to evaporate under reduced pressure at 90-110℃, and the gas phase coming out of the evaporator is condensed in the condenser to obtain evaporated condensate, which is temporarily stored in the condensate storage tank.

[0041] After evaporation is completed, turn on the transfer pump to transfer the evaporation kettle material into the crystallization kettle, open the crystallization kettle jacket circulating water valve, cool the crystallization kettle material to 30-40 ° C, add dilute ammonia water with high COD and ammonium carbonate content (ammonia water content 8-10%), and the flow rate is 0.4m 3 / h, adjust the pH to around 5, and continue cooling and crystallization. When the crystallizer temperature drops to 20-30°C, start the centrifuge, open the crystallizer discharge valve, and place the crystallizer material into the centrifuge for solid-liquid separation to obtain ammonium sulfate product and filtrate. The filtrate is temporarily stored in a filtrate storage tank for use in organic fertilizer production. Analysis and testing show that the obtained ammonium sulfate content is greater than 95% and can be sold directly. The filtrate has an organic matter content of ≥30%, a nitrogen content of ≥9%, and a moisture content of ≤30%, and can be used for organic fertilizer production.

[0042] Example 3

[0043] The above device is used to pass the tail gas absorption wastewater with high COD and high ammonia nitrogen into the evaporator at a flow rate of 1.5m 3 / h, start the evaporator to stir, start the vacuum pump, open the steam valve of the evaporator jacket, let in steam, control the temperature of the evaporator to evaporate under reduced pressure at 90-110℃, and the gas phase coming out of the evaporator is condensed in the condenser to obtain evaporated condensate, which is temporarily stored in the condensate storage tank.

[0044] After evaporation is completed, turn on the transfer pump to transfer the evaporation kettle material into the crystallization kettle, open the crystallization kettle jacket circulating water valve, cool the crystallization kettle material to 30-40 ° C, add dilute ammonia water with high COD and ammonium carbonate content (ammonia water content 8-10%), and the flow rate is 0.5m 3 / h, adjust the pH to around 6, and continue cooling and crystallization. When the crystallizer temperature drops to 20-30°C, start the centrifuge, open the crystallizer discharge valve, and place the crystallizer material into the centrifuge for solid-liquid separation to obtain ammonium sulfate product and filtrate. The filtrate is temporarily stored in a filtrate storage tank for use in organic fertilizer production. Analysis and testing show that the obtained ammonium sulfate content is greater than 95% and can be sold directly. The filtrate has an organic matter content of ≥30%, a nitrogen content of ≥9%, and a moisture content of ≤30%, and can be used for organic fertilizer production.

[0045] The ammonium sulfate products obtained in Examples 1 to 3 were tested for purity, and the results are shown in Table 1 below:

[0046] Table 1 Purity of the industrial grade salt obtained in Examples 1 to 3

[0047]

[0048] Comparative Example 3

[0049] The above device is used to pass the tail gas absorption wastewater with high COD and high ammonia nitrogen into the evaporator at a flow rate of 1.5m 3 / h, start the evaporator to stir, start the vacuum pump, open the steam valve of the evaporator jacket, let in steam, control the temperature of the evaporator to evaporate under reduced pressure at 90-110℃, and the gas phase coming out of the evaporator is condensed in the condenser to obtain evaporated condensate, which is temporarily stored in the condensate storage tank.

[0050] After evaporation is completed, turn on the transfer pump to transfer the evaporation kettle material into the crystallization kettle, open the crystallization kettle jacket circulating water valve, cool the crystallization kettle material to 30-40 ° C, add dilute ammonia water with high COD and ammonium carbonate content (ammonia water content 8-10%), and the flow rate is 0.5m 3 / h, adjust the pH to around 6, and continue cooling and crystallization. When the crystallizer temperature drops to 20-30°C, start the centrifuge, open the crystallizer discharge valve, and place the crystallizer material into the centrifuge for solid-liquid separation to obtain ammonium sulfate product and filtrate. The filtrate is temporarily stored in a filtrate storage tank for use in organic fertilizer production. Analysis and testing show that the obtained ammonium sulfate content is greater than 95% and can be sold directly. The filtrate has an organic matter content of ≥30%, a nitrogen content of ≥9%, and a moisture content of ≤30%, and can be used for organic fertilizer production.

[0051] The above embodiments are used to explain the technical solutions of the present invention. However, the present invention is not limited to the above embodiments, which does not mean that the present invention must rely on the above specific embodiments to be implemented. Any improvements made by those skilled in the art based on the present invention, or equivalent replacement of materials used in the present invention, etc., shall fall within the scope of protection of the patent.

Claims

1. A device for recycling ammonium sulfate in the process of treating glyphosate mother liquor, characterized in that: The device comprises an evaporator (1), the evaporator (1) is connected to a crystallizer (6) via a pipeline, the top of the evaporator (1) is connected to a condenser (4) via a pipeline, the top of the condenser (4) is connected to a vacuum pump (3) via a pipeline, the evaporator (1) is provided with a tail gas wastewater inlet pipeline and a steam inlet pipeline, the crystallizer (6) is provided with a dilute ammonia water inlet pipeline, and the condenser (4) and the crystallizer (6) are respectively provided with a circulating water inlet and outlet.

2. The device for recycling ammonium sulfate in the process of treating glyphosate mother liquor according to claim 1, characterized in that: The evaporation kettle (1) is provided with an agitator (b) and a thermometer (a).

3. The device for recycling ammonium sulfate in the process of treating glyphosate mother liquor according to claim 1, characterized in that: The bottom of the condenser (4) is connected to the condensed water storage tank (5) through a pipeline, and the bottom of the crystallization kettle (6) is connected to the centrifuge (7) and the filtrate storage tank (8) in sequence through a pipeline.

4. The device for recycling ammonium sulfate in the process of treating glyphosate mother liquor according to claim 1, characterized in that: A material transfer pump (2) is provided between the evaporation kettle (1) and the crystallization kettle (6).

5. The device for recycling ammonium sulfate in the process of treating glyphosate mother liquor according to claim 1, characterized in that: A second thermometer (c), a second stirrer (d) and a pH meter (e) are provided in the crystallization kettle (6).

Images