Treatment device for preparing dilute ammonia water by recycling conversion condensate liquid ammonia

Abstract

The treatment device comprises a deacidification tower, a purified condensate heat exchanger, a desorption tower, a desorption tower return tank, an ammonia water tank and an ammonia recovery tower, the deacidification tower and the desorption tower are connected in series for operation, and the control is simple. By adopting the device, the technological process is reliable, the operation is simple, the operation flexibility is high, the ammonia-containing condensate is discharged after reaching the standard, the NH3 is recycled, the whole process is more simplified, and the device has good environmental and economic benefits.

Description

Technical Field

[0001] This utility model relates to the field of ammonia-containing shift condensate wastewater treatment technology, and in particular to a treatment device for preparing dilute ammonia water by stripping ammonia from carbon monoxide shift ammonia condensate, in order to solve the problem that ammonia-containing condensate wastewater from carbon monoxide shift cannot be treated or the quality of the treated dilute ammonia water cannot meet relevant standards. Background Technology

[0002] In crude syngas (mainly CO + H2) produced from natural gas, residual oil, and coal, the ratio of CO to H2 varies depending on the gasification process. However, the required CO content also differs depending on the intended use of the syngas. Therefore, a carbon monoxide shift process is needed to adjust the CO ratio in the feedstock gas before proceeding with Fischer-Tropsch synthesis, ammonia synthesis, and the production of chemical feedstocks such as methanol and clean oil products. The carbon monoxide shift process is a crucial technology in chemical production.

[0003] Because various ammonia-containing functional groups in the syngas feedstock undergo thermal cracking, trace amounts of nitrogen in oxygen undergo redox reactions in a high-temperature, high-hydrogen environment, partially converting into ammonia. In the CO shift reaction section, HCN is hydrolyzed or hydrogenated to convert into ammonia, and trace amounts of N2 and H2 in the shift reactor also generate trace amounts of ammonia under the action of the shift reaction catalyst. When the crude syngas undergoes energy recovery in the shift section, a large amount of condensate wastewater containing CO2, NH3, and a small amount of H2S is generated. If not removed, these acidic components will continuously accumulate in the coal gasification and shift units, causing corrosion or crystallization blockage of equipment and pipelines, seriously affecting the normal and stable operation of the unit, and must be treated.

[0004] Currently, the mainstream conversion condensate wastewater treatment processes mainly include single-tower stripping, single-tower pressurized side-stream ammonia stripping, and double-tower stripping.

[0005] The main process flow of single-tower stripping is as follows: Figure 1As shown, the main process is described as follows: Ammonia-containing condensate wastewater is preheated in stripper condenser 1 and then sent to the upper part of stripper 2. A certain amount of low-pressure steam is introduced into the bottom of stripper 2. The light component acidic gas in the ammonia-containing condensate wastewater is separated from the condensate wastewater under the action of low-pressure steam stripping and discharged from the top of stripper 2. After condensation in stripper condenser 1, the acidic gas is separated and discharged into a flare or sulfur recovery unit. The ammonia-containing purified condensate is returned to the upper part of stripper 2 or discharged as wastewater without recirculation. If the above single-tower steam stripping process is used to treat the shift condensate, if the ammonia-containing condensate in stripper condenser 1 is not recirculated, stripping wastewater will need to be discharged. If the condensate is returned to stripper 2 for washing, carbon dioxide, hydrogen sulfide, and ammonia will accumulate in the recirculation process, causing corrosion and blockage of equipment and pipelines. The single-tower stripping process fails to recover ammonia from the shift condensate, resulting not only in resource waste but also increased treatment costs.

[0006] The main process flow of double-tower stripping is as follows: Figure 2 As shown, the main process is described as follows: The dual-tower stripping process uses two overlapping stripping towers to strip the shift condensate. The upper tower is a CO2 stripping tower 2a, and the lower tower is an NH3 stripping tower 2b. After being preheated by the stripping tower condenser 1 at the top of the CO2 stripping tower 2a, the shift condensate enters the upper part of the upper tower. Secondary steam generated in the upper part of the NH3 stripping tower 2b is introduced into the bottom for stripping, stripping most of the acidic gas from the top of the upper tower. After condensation and separation, the non-condensable gas at the top is discharged into the flare or sulfur recovery unit, while the liquid phase containing a small amount of CO2 and most of NH3 enters the upper part of the NH3 stripping tower 2b. Low-pressure steam is introduced into the bottom of the tower for stripping, and high-temperature purified shift condensate is discharged from the bottom of the tower. This condensate can be sent back to the unit for reuse or sent out of the boundary. The NH3 steam is discharged from the top of the tower and, after secondary condensation, yields ammonia-rich gas and condensate wastewater. The primary condensate is returned to the NH3 steam tower 2b, the secondary condensate is discharged as wastewater, and the ammonia-rich gas is discharged into the flare or sulfur recovery unit. This process overcomes some of the shortcomings of single-tower steam stripping, but it still treats ammonia as a harmful substance and does not recover it, and wastewater from the process needs to be discharged.

[0007] The main process flow of single-tower pressurized side-stream ammonia stripping is as follows: Figure 3As shown, the main process is described as follows: The ammonia-containing condensate wastewater from the shift reaction is divided into cold and hot streams, which enter the upper and upper-middle sections of stripping tower 2c, respectively. Stripping is performed at the bottom of the tower via reboiler 3. The stripped CO2, H2S, and other acidic gases are discharged from the top of stripping tower 2c and sent to a sulfur recovery unit or flare for treatment. The stripped NH3 is collected at the middle enrichment section. The collected crude ammonia gas undergoes three-stage condensation and liquid separation to obtain high-concentration ammonia gas, which is then sent to the ammonia refining section for further processing. The three-stage condensate is mixed and returned to the raw material tank. If the above-mentioned single-tower pressurized side-stream ammonia stripping process is used to treat the shift reaction condensate, the purity of the ammonia gas after three-stage condensation can reach 99%, with a CO2 content of approximately 20 ppm and an H2S content of approximately 1000 ppm. However, it is still not possible to directly prepare a qualified product, dilute ammonia water, with an H2S content of less than 20 ppm and a concentration of 20%. Utility Model Content

[0008] The purpose of this invention is to address the problems of substandard conventional conversion condensate treatment, lack of NH3 recovery in the condensate, and unqualified dilute ammonia water prepared by NH3 recovery. This invention provides a treatment device for preparing dilute ammonia water by recovering ammonia from conversion condensate. Based on double-tower stripping, it uses two-stage condensation and ammonia purification to produce qualified dilute ammonia water.

[0009] The objective of this utility model can be achieved through the following technical solutions:

[0010] A treatment apparatus for recovering ammonia from condensate to prepare dilute ammonia water, comprising:

[0011] A deacidification tower is provided with a first acidic gas outlet at the top, a first conversion ammonia-containing condensate inlet and a first purified condensate inlet at the upper part, a second conversion ammonia-containing condensate inlet and a separate condensate ammonia water inlet at the middle part, and a deacidification wastewater outlet at the bottom. A deacidification tower reboiler is provided at the lower part of the deacidification tower. A stream of conversion ammonia-containing condensate is directly input at the first conversion ammonia-containing condensate inlet.

[0012] A purified condensate heat exchanger has a third ammonia-containing condensate inlet, a first ammonia-containing condensate outlet, a first purified condensate inlet, and a first purified condensate outlet. Another stream of ammonia-containing condensate enters the purified condensate heat exchanger through the third ammonia-containing condensate inlet, exchanges heat with the purified condensate entering the heat exchanger, and is then sent out through the first ammonia-containing condensate outlet to the second ammonia-containing condensate inlet and fed into the middle of the deacidification tower. The first purified condensate outlet is connected to the inlet of a purified cooler. The purified condensate from the outlet of the purified cooler is divided into two streams: one stream is sent out of the boundary area through the first purified condensate outlet pipeline, and the other stream is sent into the upper part of the deacidification tower through the second purified condensate outlet pipeline and the first purified condensate inlet.

[0013] A deacidification tower is provided; the deacidification tower has a deacidification wastewater inlet in the middle, an ammonia vapor and water vapor mixture outlet at the top, a liquid phase reflux port at the top, and a second purified condensate outlet at the bottom; the deacidification wastewater outlet is connected to the deacidification wastewater inlet through the deacidification tower bottom pump inlet pipeline, the deacidification tower bottom pump, and the deacidification tower bottom pump outlet pipeline; the second purified condensate outlet is connected to the first purified condensate inlet through the deacidification tower bottom pump inlet pipeline, the deacidification tower bottom pump, and the deacidification tower bottom pump outlet pipeline; a deacidification tower reboiler is provided at the bottom of the deacidification tower;

[0014] An alkali input pipeline is provided, the inlet of which is connected to an external alkali source, and the outlet of which is connected to the outlet pipeline of the bottom pump of the deacidification tower.

[0015] A stripping tower reflux tank is provided, with an inlet for an ammonia vapor and water vapor mixture at the top, a gas phase outlet at the top, and a liquid phase outlet at the bottom; the ammonia vapor and water vapor mixture outlet is connected to the ammonia vapor and water vapor mixture inlet through a stripping tower water cooler and an ammonia vapor and water vapor mixture conveying pipeline, and the liquid phase outlet is connected to the liquid phase reflux port through a stripping tower reflux pump and a liquid phase reflux pipeline;

[0016] An ammonia tank is provided with a gas phase inlet at the top, an ammonia gas outlet at the top, and a condensate ammonia outlet at the bottom. The gas phase inlet is connected to the gas phase outlet through an ammonia cooler and a gas phase delivery pipeline. The condensate ammonia outlet is connected to the condensate ammonia inlet through a secondary condensate return pump and a condensate ammonia delivery pipeline.

[0017] An ammonia recovery tower is provided, with a second acid gas outlet at the top, a demineralized water inlet at the top, an ammonia gas inlet and a dilute ammonia water reflux inlet in the middle, and a dilute ammonia water reflux outlet at the bottom. The ammonia gas inlet is connected to the ammonia gas outlet via an ammonia gas delivery pipeline. The first acid gas outlet and the first acid gas outlet are sent to the downstream sulfur recovery unit via an acid gas output pipeline. External demineralized water is sent into the ammonia recovery tower through the demineralized water inlet. The dilute ammonia water reflux outlet is connected to the dilute ammonia water reflux inlet on one hand, through a dilute ammonia water cooler, a dilute ammonia water pump, and a dilute ammonia water delivery pipeline, and on the other hand, it is sent out of the boundary area.

[0018] In a preferred embodiment of this invention, steam is used as the heating agent in the deacidification tower reboiler.

[0019] In a preferred embodiment of this invention, steam is used as the heating agent in the reboiler of the desorption tower.

[0020] Due to the adoption of the above technical solution, the working principle of this utility model is as follows:

[0021] The ammonia-containing condensate is divided into two streams. One stream enters the upper part of the deacidification tower directly, while the other stream is heated by a purified condensate heat exchanger and then sent to the middle part of the deacidification tower. Steam is used as the heating agent in the reboiler of the deacidification tower. In the deacidification tower, CO2 and H2S are removed from the water through high temperature and reduced pressure. The distilled acidic gas is sent to the downstream sulfur recovery unit.

[0022] The deacidification wastewater at the bottom of the tower is mixed with alkaline solution from outside the tower via a bottom pump. After adjusting the pH value of the deacidification wastewater, it is sent to the desorption tower. In the reboiler of the desorption tower, steam is used as the heating agent. The ammonia-containing condensate flows from top to bottom and comes into direct contact with the countercurrent steam from the bottom of the deacidification tower, carrying out mass and heat transfer. This allows ammonia to be gradually released from the condensate. Free ammonia is continuously separated in the tower plates and concentrated at the top of the tower. A mixture of ammonia vapor and steam is obtained at the top of the tower, while a relatively pure purified condensate is obtained at the bottom of the tower.

[0023] Ammonia gas from the top of the stripping tower is cooled by the stripping tower water cooler and then sent to the stripping tower reflux tank for gas-liquid separation. The liquid phase is refluxed to the top of the stripping tower, while the gas phase is cooled by the ammonia cooler and sent to the ammonia water tank for condensation. The ammonia gas then enters the ammonia recovery tower to prepare qualified dilute ammonia water through demineralization. The condensed ammonia water is refluxed to the deacidification tower to remove hydrogen sulfide and other acidic gases. The purified condensate from the bottom of the stripping tower is pumped back to the purified condensate heat exchanger for heat exchange, and then cooled by the purified cooler. Most of it is then sent out of the boundary area, and a small amount is sent back to the top of the deacidification tower to wash the acidic gas.

[0024] This utility model has the following technical features:

[0025] 1. The process is reliable, simple to operate, and highly flexible, meeting the requirements of production tasks.

[0026] 2. After most of the acidic gas is removed by the deacidification tower, the ammonia gas at the top of the stripping tower adopts a two-stage fractional condensation process of "high temperature water separation and low temperature sulfur fixation" to avoid the crystallization and corrosion of ammonium salts at the top of the tower.

[0027] 3. After secondary condensation, the gas phase ammonia recovery tower produces dilute ammonia water. The condensate is returned to the deacidification tower for recycling and stripping H2S, which reduces the sulfur content in the product dilute ammonia water and avoids the generation of stripping wastewater.

[0028] 4. The ammonia recovery tower uses condensed ammonia water for reflux washing and concentration to prepare 20wt% dilute ammonia water. The ammonia water concentration is adjustable, saving the amount of demineralized water used.

[0029] 5. The purified condensate is basically free of H2S, NH3 and other substances, and can be directly sent to gasification or biological treatment, reducing the burden of wastewater discharge.

[0030] 6. The acid gas after removal by the deacidification tower has a low NH3 content, which improves the stability and recovery rate of the sulfur recovery unit.

[0031] 7. The hot and cold condensate of the deacidification tower is fed in a ratio. By setting up a heat exchanger for purified condensate to preheat the ammonia-containing shift condensate, the heat of the purified condensate is recovered, and the consumption of steam in the reboiler of the deacidification tower and circulating cooling water in the purified condensate cooler is reduced.

[0032] 8. The deacidification tower is equipped with a reboiler, which allows the deacidification tower to operate independently and improves the stability of the unit's operation.

[0033] The technical innovations of this utility model that should be protected are:

[0034] 9. The ammonia gas at the top of the analytical tower adopts a two-stage condensation process of "high temperature water separation and low temperature sulfur fixation" to avoid the crystallization and corrosion of ammonium salts at the top of the tower.

[0035] 9. After secondary condensation, the gas phase is sent to the ammonia recovery tower, and the condensate is returned to the deacidification tower for stripping. This not only effectively reduces the H2S content in the product dilute ammonia water, but also avoids the generation of wastewater.

[0036] 10. The ammonia recovery tower uses condensed ammonia water for reflux washing and concentration to prepare 20wt% dilute ammonia water. The ammonia water concentration is adjustable, saving the amount of demineralized water used.

[0037] 11. The purified condensate can be directly sent to gasification or biochemical treatment, reducing the burden of wastewater discharge.

[0038] 12. The acid gas after removal by the deacidification tower has a low NH3 content, which improves the stability and recovery rate of the sulfur recovery unit.

[0039] 13. The hot and cold condensate of the deacidification tower is fed in a ratio. By setting up a heat exchanger for purified condensate to preheat the ammonia-containing shift condensate, the heat of the purified condensate is recovered, and the consumption of steam in the reboiler of the deacidification tower and circulating cooling water in the purified condensate cooler is reduced.

[0040] 14. The deacidification tower is equipped with a reboiler, which allows the deacidification tower to operate independently and improves the stability of the unit's operation.

[0041] The process using this utility model is reliable, simple to operate, and highly flexible. Ammonia-containing condensate is discharged in compliance with standards, and NH3 is recovered and utilized. The entire process is further simplified, resulting in excellent environmental and economic benefits.

[0042] The specific effects that can be achieved are as follows:

[0043] 1. In this utility model, the purified condensate is discharged in compliance with standards or sent to other devices.

[0044] 2. By adopting the process flow of this utility model, the NH3 in the condensate can be reduced to below 100 ppm.

[0045] 3. By using this invention, the NH3 in acidic gas can be reduced to below 100 ppm.

[0046] 4. By using this invention, the H2S in acidic gas can be reduced to below 20 ppm.

[0047] 5. By using this invention, the H2S content in dilute ammonia water can be reduced to below 20 ppm. Attached Figure Description

[0048] Figure 1 This is a process flow diagram for single-tower stripping.

[0049] Figure 2 This is a process flow diagram for double-tower stripping.

[0050] Figure 3 A process flow diagram for ammonia stripping via pressurized side-stream extraction in a single tower.

[0051] Figure 4 The process flow diagram of the treatment device for preparing dilute ammonia water by recovering ammonia from shift condensate according to this utility model is shown. Detailed Implementation

[0052] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0053] See Figure 4 The device shown in the figure is a treatment device for preparing dilute ammonia water by recovering ammonia from condensate, including: a deacidification tower 10, a purified condensate heat exchanger 20, a stripping tower 30, a stripping tower reflux tank 40, an ammonia water tank 50, and an ammonia recovery tower 60.

[0054] The deacidification tower 10 has external dimensions (ID×TT) mm: 1400x14650, and is made of SS304. It has an acid gas outlet 11 (the aforementioned first acid gas outlet) at the top, a conversion ammonia-containing condensate inlet 12 (the aforementioned first conversion ammonia-containing condensate inlet) and a purified condensate inlet 13 (the aforementioned first purified condensate inlet) at the upper part, a conversion ammonia-containing condensate inlet 14 (the aforementioned second conversion ammonia-containing condensate inlet) and a condensate ammonia water inlet 15 at the middle part, and a deacidification wastewater outlet 16 at the bottom. A deacidification tower reboiler 17 is located at the lower part of the deacidification tower 10.

[0055] The purified condensate heat exchanger 20 has an ammonia-containing condensate inlet 21 (the aforementioned third ammonia-containing condensate inlet), an ammonia-containing condensate outlet 22 (the aforementioned first ammonia-containing condensate outlet), a first purified condensate inlet 23 (the aforementioned first purified condensate inlet), and a first purified condensate outlet 24 (the aforementioned first purified condensate outlet).

[0056] The analytical column 30 has external dimensions (ID×TT) mm: 2200x19850, and is made of CS+SS304 stainless steel. It has a deacidification wastewater inlet 31 in the middle, an ammonia vapor and water vapor mixture outlet 32 ​​at the top, a liquid phase reflux inlet 33 at the top, and a purified condensate outlet 34 (the aforementioned second purified condensate outlet) at the bottom. A reboiler 35 is located at the bottom of the analytical column 30.

[0057] The upper part of the analytical tower reflux tank 40 is provided with an inlet 41 for a mixture of ammonia vapor and water vapor, the top is provided with a gas phase outlet 42, and the bottom is provided with a liquid phase outlet 43.

[0058] The ammonia tank 50 is provided with a gas inlet 51 at the top, an ammonia outlet 52 at the top, and a condensate ammonia outlet 53 at the bottom.

[0059] The ammonia recovery tower 60 has external dimensions (ID×TT) mm: 600x11500, is made of CS material, and has an acid gas outlet 61 (the aforementioned second acid gas outlet) at the top, a demineralized water inlet 62 at the top, an ammonia gas inlet 63 and a dilute ammonia water reflux inlet 64 in the middle, and a dilute ammonia water reflux outlet 65 at the bottom.

[0060] This invention features a dual-tower series operation of deacidification tower 10 and stripping tower 30, which is simple to control. The process is briefly described below:

[0061] The ammonia-containing condensate is divided into two streams. One stream of ammonia-containing condensate is cooled to 40°C and then enters the upper part of the deacidification tower 10 directly through the ammonia-containing condensate inlet 12. The other stream of ammonia-containing condensate enters the purified condensate heat exchanger 20 through the ammonia-containing condensate inlet 21. After exchanging heat with the purified condensate entering the purified condensate heat exchanger 20 and being heated to 110°C, it is sent out through the ammonia-containing condensate outlet 22 to the ammonia-containing condensate inlet 14 and then sent into the middle part of the deacidification tower 10.

[0062] In the reboiler 17 of the deacidification tower, 1.0 MPag steam is used as the heating agent. In the deacidification tower 10, CO2 and H2S are removed from the water through high temperature and reduced pressure. The distilled acidic gas is sent to the downstream sulfur recovery unit through the acidic gas outlet 11. To maintain ammonia balance, the ammonia content in the acidic gas at the top of the deacidification tower 10 needs to be controlled within a certain range. A small portion of the purified condensate is sent to the upper part of the deacidification tower 10 through the condensate ammonia inlet 15. Utilizing the principle that ammonia has high solubility while carbon dioxide has low solubility, the ammonia content in the acidic gas at the top of the deacidification tower 10 is controlled.

[0063] The deacidified wastewater from the deacidified wastewater outlet 16 at the bottom of the deacidification tower 10 is sent into the deacidification tower 30 through the deacidification tower bottom pump inlet pipeline 71, the deacidification tower bottom pump 72 and the deacidification tower bottom pump outlet pipeline 73, and the deacidified wastewater inlet 31 of the desorption tower 30.

[0064] Before being fed into the deacidification tower 30, the deacidified wastewater is mixed with the alkaline solution delivered through the alkaline solution input pipeline 74 in the deacidification tower bottom pump outlet pipeline 73 (the inlet of the alkaline solution input pipeline 74 is connected to an external alkaline source, and the outlet is connected to the deacidification tower bottom pump outlet pipeline 73). After adjusting the pH value of the deacidified wastewater, it is sent into the deacidification tower 30.

[0065] In the reboiler 35 of the stripping column, 1.0 MPag of steam is used as the heating agent. The ammonia-containing condensate flows from top to bottom in the stripping column 30 and comes into direct contact with the countercurrent steam from the bottom of the stripping column 30 for mass and heat transfer. As a result, ammonia is gradually released from the condensate. The free ammonia is continuously separated in the trays of the stripping column 30 and concentrated at the top of the stripping column 30. A mixture of ammonia vapor and steam is obtained at the top of the stripping column 30 and is sent out from the outlet 32 ​​of the ammonia vapor and steam mixture at the top of the stripping column 30. A relatively pure purified condensate is obtained at the bottom of the stripping column 30 and is sent out from the purified condensate outlet 34.

[0066] The ammonia vapor and water vapor mixture delivered from the outlet 32 ​​of the ammonia vapor and water vapor mixture at the top of the stripping tower 30 is cooled to 105°C by the stripping tower water cooler 80, and then sent to the stripping tower reflux tank 40 for gas-liquid separation through the ammonia vapor and water vapor mixture conveying pipeline 81 and the ammonia vapor and water vapor mixture inlet 41 at the top of the stripping tower reflux tank 40. The liquid phase separated by the stripping tower reflux tank 40 is sent out from the liquid phase outlet 43 at the bottom of the stripping tower reflux tank 40, and then sent to the top of the stripping tower 30 through the stripping tower reflux pump 82, the liquid phase reflux pipeline 83 and the liquid phase reflux port 33 at the top of the stripping tower 30.

[0067] The gas phase is sent out from the gas phase outlet 42 at the top of the stripping tower reflux tank 40. After being cooled to 40°C by the ammonia cooler 90, it is sent into the ammonia water tank 50 for fractional condensation through the gas phase conveying pipeline 91 and the gas phase inlet 51 at the top of the ammonia water tank 50. The fractionated ammonia gas is sent out from the ammonia gas outlet 52 at the top of the ammonia water tank 50, and the fractionated dilute ammonia water is sent out from the condensate ammonia water outlet 53 at the bottom of the ammonia water tank 50.

[0068] The condensed ammonia gas sent from the ammonia outlet 52 at the top of the ammonia tank 50 enters the ammonia recovery tower 60 through the ammonia transmission pipeline 53 and the ammonia inlet 63 of the ammonia recovery tower 60, and is mixed with the demineralized water sent into the ammonia recovery tower 60 through the demineralized water inlet 62 of the ammonia recovery tower 60 to prepare qualified dilute ammonia water.

[0069] The dilute ammonia water after partial condensation, delivered from the ammonia water outlet 53 at the bottom of the ammonia water tank 50, is sent into the deacidification tower 10 through the secondary partial condensate return pump 54, the condensate ammonia water delivery pipeline 55, and the partial condensate ammonia water inlet 15 in the middle of the deacidification tower 10 to remove acidic gases such as hydrogen sulfide.

[0070] The purified condensate from the purified condensate outlet 34 of the stripping tower 30 is fed into the purified condensate heat exchanger 20 through the stripping tower bottom pump inlet pipeline 36, the stripping tower bottom pump 37, the stripping tower bottom pump outlet pipeline 38, and the purified condensate inlet 23 of the purified condensate heat exchanger 20. It exchanges heat with the ammonia-containing condensate fed into the purified condensate heat exchanger 20. The purified condensate after heat exchange is sent out through the purified condensate outlet 24 of the purified condensate heat exchanger 20.

[0071] The purified condensate, after heat exchange, is sent out from the purified condensate outlet 24 of the purified condensate heat exchanger 20 and cooled to 40°C by the purified cooler 100. It is then divided into two streams. One stream is sent out of the boundary area through the purified condensate outlet pipeline 110, and the other stream is sent into the upper part of the deacidification tower 10 to wash the acidic gas that is evaporated through the purified condensate outlet pipeline 120 and the purified condensate inlet 13 of the deacidification tower 10.

[0072] The non-condensable gas from the top of the ammonia recovery tower 60, delivered from the acid gas outlet 61, and the acid gas from the top of the deacidification tower 10, delivered together, go to the bottom of the downstream unit.

[0073] The dilute ammonia water sent from the dilute ammonia water return outlet 65 at the bottom of the ammonia recovery tower 60 is cooled to 40°C by the dilute ammonia water cooler 66, and then pressurized by the dilute ammonia water pump 67. Part of it is sent out of the boundary area through the dilute ammonia water delivery pipeline 68, and the other part is returned to the middle of the ammonia recovery tower 60 through the dilute ammonia water delivery pipeline 68 and the dilute ammonia water return inlet 69 of the ammonia recovery tower 60 to circulate and wash the ammonia-rich gas, thereby concentrating the dilute ammonia water.

Claims

1. A treatment apparatus for recovering ammonia from condensate to prepare dilute ammonia water, characterized in that, include: A deacidification tower is provided with a first acidic gas outlet at the top, a first conversion ammonia-containing condensate inlet and a first purified condensate inlet at the upper part, a second conversion ammonia-containing condensate inlet and a separate condensate ammonia water inlet at the middle part, and a deacidification wastewater outlet at the bottom. A deacidification tower reboiler is provided at the lower part of the deacidification tower. A stream of conversion ammonia-containing condensate is directly input at the first conversion ammonia-containing condensate inlet. A purified condensate heat exchanger has a third ammonia-containing condensate inlet, a first ammonia-containing condensate outlet, a first purified condensate inlet, and a first purified condensate outlet. Another stream of ammonia-containing condensate enters the purified condensate heat exchanger through the third ammonia-containing condensate inlet, exchanges heat with the purified condensate entering the heat exchanger, and is then sent out through the first ammonia-containing condensate outlet to the second ammonia-containing condensate inlet and fed into the middle of the deacidification tower. The first purified condensate outlet is connected to the inlet of a purified cooler. The purified condensate from the outlet of the purified cooler is divided into two streams: one stream is sent out of the boundary area through the first purified condensate outlet pipeline, and the other stream is sent into the upper part of the deacidification tower through the second purified condensate outlet pipeline and the first purified condensate inlet. A deacidification tower is provided; the deacidification tower has a deacidification wastewater inlet in the middle, an ammonia vapor and water vapor mixture outlet at the top, a liquid phase reflux port at the top, and a second purified condensate outlet at the bottom; the deacidification wastewater outlet is connected to the deacidification wastewater inlet through the deacidification tower bottom pump inlet pipeline, the deacidification tower bottom pump, and the deacidification tower bottom pump outlet pipeline; the second purified condensate outlet is connected to the first purified condensate inlet through the deacidification tower bottom pump inlet pipeline, the deacidification tower bottom pump, and the deacidification tower bottom pump outlet pipeline; a deacidification tower reboiler is provided at the bottom of the deacidification tower; An alkali input pipeline is provided, the inlet of which is connected to an external alkali source, and the outlet of which is connected to the outlet pipeline of the bottom pump of the deacidification tower. A stripping tower reflux tank is provided, with an inlet for an ammonia vapor and water vapor mixture at the top, a gas phase outlet at the top, and a liquid phase outlet at the bottom; the ammonia vapor and water vapor mixture outlet is connected to the ammonia vapor and water vapor mixture inlet through a stripping tower water cooler and an ammonia vapor and water vapor mixture conveying pipeline, and the liquid phase outlet is connected to the liquid phase reflux port through a stripping tower reflux pump and a liquid phase reflux pipeline; An ammonia tank is provided with a gas phase inlet at the top, an ammonia gas outlet at the top, and a condensate ammonia outlet at the bottom. The gas phase inlet is connected to the gas phase outlet through an ammonia cooler and a gas phase delivery pipeline. The condensate ammonia outlet is connected to the condensate ammonia inlet through a secondary condensate return pump and a condensate ammonia delivery pipeline. An ammonia recovery tower is provided, with a second acid gas outlet at the top, a demineralized water inlet at the top, an ammonia gas inlet and a dilute ammonia water reflux inlet in the middle, and a dilute ammonia water reflux outlet at the bottom. The ammonia gas inlet is connected to the ammonia gas outlet via an ammonia gas delivery pipeline. The first acid gas outlet and the first acid gas outlet are sent to the downstream sulfur recovery unit via an acid gas output pipeline. External demineralized water is sent into the ammonia recovery tower through the demineralized water inlet. The dilute ammonia water reflux outlet is connected to the dilute ammonia water reflux inlet on one hand, through a dilute ammonia water cooler, a dilute ammonia water pump, and a dilute ammonia water delivery pipeline, and on the other hand, it is sent out of the boundary area.

2. The treatment apparatus for recovering ammonia from condensate to prepare dilute ammonia water according to claim 1, characterized in that, The deacidification tower reboiler uses steam as a heating agent.

3. The treatment apparatus for recovering ammonia from condensate to prepare dilute ammonia water according to claim 1, characterized in that, The reboiler of the analytical column uses steam as a heating agent.

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