Method for removing ammonia in pressurized coke oven gas

Abstract

The invention discloses a method for removing ammonia in pressurized coke oven gas, and belongs to the technical field of coke oven gas purification. Aiming at the problems of high equipment investment, large occupied area of a device, high absorption energy consumption and high material requirement of the existing coke oven gas purification process, the removal method disclosed by the invention comprises the following steps: taking coke oven gas as purified gas, and taking ammonia distillation wastewater as a washing solution when the ammonia content in the purified coke oven gas is required to be 30-50mg / Nm < 3 >; the device comprises a coal gas precooler, a gas-liquid separator, a pressurized ammonia washing tower, an ammonia distillation wastewater booster pump, an ammonia distillation wastewater cooler and a lower section washing pump, when the ammonia content in the purified coke-oven gas is required to be lower than 30mg / Nm < 3 >, ammonia distillation wastewater and soft water are used as washing liquid; the device further comprises an intermediate heat exchanger and an upper section washing pump. Compared with the traditional ammonia washing process under the same purification requirement, the method provided by the invention adopts a single ammonia washing tower, the total height of filler is lower, the tower diameter is smaller, and the spraying amount of absorption liquid is only 2 / 3 of that of single equipment in the traditional ammonia washing process, so that the method has lower energy consumption.

Description

Technical Field

[0001] The invention belongs to the technical field of coke oven gas purification, and in particular relates to a method for removing ammonia from pressurized coke oven gas. Background Art

[0002] Currently, coke oven gas purification processes are based on atmospheric pressure, of which ammonia removal is a component. Common purification processes include ammonium sulfate production, ammonium phosphate absorption, and ammonia washing-ammonia evaporation-ammonia decomposition. All three processes operate at near-ambient pressure, requiring bulky equipment, high investment, extensive floor space, and high production costs.

[0003] In the semi-direct ammonium sulfate production process of the spray saturator method and the acid washing method, sulfuric acid is used as the absorption liquid in the deammoniation process. Although the ammonia content in the gas can be lower than 30mg / Nm after purification by this process, 3 However, the process has high requirements on the corrosion resistance of equipment materials and the equipment investment is high.

[0004] The ammonia content in the coke oven gas after purification by ammonium phosphate absorption method or water washing ammonia process under normal pressure is higher than 100 mg / Nm 3 . Summary of the Invention

[0005] In view of the problems of high investment in equipment for current coke oven gas purification process, large device footprint, high absorption energy consumption and high material requirements, the present invention provides a method for removing ammonia from pressurized coke oven gas.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A method for removing ammonia from pressurized coke oven gas, using coke oven gas as the gas to be purified, when the ammonia content in the purified coke oven gas is required to be 30-50 mg / Nm 3 When using ammonia wastewater as washing liquid;

[0008] The equipment used includes a gas precooler, a gas-liquid separator, a pressurized ammonia washing tower, an ammonia distillation wastewater booster pump, an ammonia distillation wastewater cooler, and a lower section washing pump;

[0009] The top of the pressurized ammonia washing tower is provided with a purified coke oven gas outlet; the upper section of the pressurized ammonia washing tower is provided with an ammonia vapor wastewater inlet; the lower section of the pressurized ammonia washing tower is provided with a coke oven gas inlet; and the bottom of the pressurized ammonia washing tower is provided with a liquid outlet;

[0010] Ammonia vapor wastewater enters the pressurized ammonia washing tower from the ammonia vapor wastewater inlet through the ammonia vapor wastewater booster pump and the ammonia vapor wastewater cooler; before entering the tower, the coke oven gas passes through the gas precooler and the gas-liquid separator and enters the pressurized ammonia washing tower from the coke oven gas inlet; one section of the gas-liquid separator is connected to the condensate; the washing liquid flowing out of the liquid outlet is pressurized by the lower section washing pump and then sent to the ammonia distillation device; the purified coke oven gas is discharged from the purified coke oven gas outlet.

[0011] Furthermore, the ammonia content in coke oven gas is 6-10 g / Nm 3 , the inlet temperature of the tower is controlled at 30℃; the inlet temperature of the evaporated ammonia wastewater is controlled at 25~30℃; the inlet temperature of the refluxed evaporated ammonia wastewater is controlled at 25~30℃.

[0012] Furthermore, the pressurized ammonia scrubbing tower is a plate tower, a packed tower, or a composite tower. Different types of tower internals can be selected according to different operating conditions.

[0013] Furthermore, the theoretical number of plates of the pressurized ammonia washing tower is 4 to 10, the absolute operating pressure is 750 kPa, the top temperature is not higher than 30° C., and the bottom temperature is 31 to 35° C.

[0014] When the ammonia content in the purified coke oven gas is required to be less than 30 mg / Nm 3 When washing, ammonia wastewater and soft water are used as washing liquid; the device also includes an intermediate heat exchanger and an upper washing pump;

[0015] The top of the pressurized ammonia washing tower is provided with a purified coke oven gas outlet, the upper section of the pressurized ammonia washing tower is provided with a soft water inlet, an upper section washing liquid material stream extraction outlet and an upper section washing liquid reflux outlet; the middle section of the pressurized ammonia washing tower is provided with an ammonia distillation wastewater inlet; the lower section of the pressurized ammonia washing tower is provided with a coke oven gas inlet, a lower section washing liquid reflux outlet, and a liquid outlet at the bottom of the pressurized ammonia washing tower;

[0016] An upper section washing liquid material stream extraction outlet is provided below at least one tray (or packing of appropriate height) below the soft water inlet; the upper section washing liquid reflux outlet is provided between the soft water inlet and the upper section washing liquid material stream extraction outlet, or at the same height as the soft water inlet; below the upper section washing liquid material stream extraction outlet is an ammonia distillation wastewater inlet, and below at least one tray (or packing of appropriate height) below the ammonia distillation wastewater inlet is a lower section washing liquid reflux outlet; below at least one tray (or packing of appropriate height) below the lower section washing liquid reflux outlet is a coke oven gas inlet; an upper section washing pump is provided in the pipeline between the upper section washing liquid material stream extraction outlet and the upper section washing liquid reflux outlet; a lower section washing pump and an intermediate heat exchanger are provided in the pipeline between the liquid outlet and the lower section washing liquid reflux outlet; a portion of the liquid pressurized by the lower section washing pump is returned to the pressurized ammonia washing tower after heat exchange and cooling in the intermediate heat exchanger, and the remaining portion of the washing liquid is sent to the ammonia distillation unit;

[0017] Soft water enters the pressurized ammonia washing tower through the soft water inlet; ammonia vapor wastewater enters the pressurized ammonia washing tower from the ammonia vapor wastewater inlet through the ammonia vapor wastewater booster pump and the ammonia vapor wastewater cooler; coke oven gas enters the pressurized ammonia washing tower from the coke oven gas inlet through the gas precooler and the gas-liquid separator before entering the tower; a section of the gas-liquid separator is connected to condensate; purified coke oven gas is discharged from the purified coke oven gas outlet.

[0018] Furthermore, the temperature of the soft water entering the tower is controlled at 25-30°C.

[0019] Furthermore, ammonia distillation wastewater is preferably used as the washing liquid.

[0020] The pressurized coke oven gas deamination process disclosed in the present invention has the following advantages compared with the prior art:

[0021] 1) This process uses pressurized absorption technology to significantly reduce the equipment diameter of the ammonia scrubbing tower, and the device occupies a smaller area.

[0022] 2) Pressurized operation reduces the diameter of the ammonia washing tower equipment, reduces the circulation volume of the circulating absorption liquid, and reduces power consumption.

[0023] 3) Pressurized operation increases the solubility of ammonia in the absorption liquid, reduces the liquid-gas ratio of the absorption tower, reduces power consumption, and reduces the ammonia treatment capacity of the ammonia distillation unit, which can reduce the overall energy consumption.

[0024] In summary, the process for removing ammonia from pressurized coke oven gas disclosed in the present invention uses soft water and ammonia evaporation wastewater as washing liquids. After the gas is washed with lower circulating liquid, washed with ammonia evaporation wastewater, and washed with upper circulating liquid in the ammonia washing tower, the ammonia content in the outlet coke oven gas can reach 30-50 mg / Nm 3 , which realizes the purification of coke oven gas and greatly simplifies the process. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 The ammonia content in the purified coke oven gas is required to be 30-50 mg / Nm 3 Schematic diagram of the device for removing ammonia from pressurized coke oven gas according to the present invention;

[0026] Figure 2 Schematic diagram of the apparatus for removing ammonia from pressurized coke oven gas according to the present invention during normal operation;

[0027] In the figure, 1. Gas precooler; 2. Gas-liquid separator; 3. Pressurized ammonia washing tower; 4. Ammonia evaporation wastewater booster pump; 5. Ammonia evaporation wastewater cooler; 6. Lower section washing pump; 7. Intermediate heat exchanger; 8. Upper section washing pump; 9. Purified coke oven gas outlet; 10. Soft water inlet; 11. Upper section washing liquid material stream extraction outlet; 12. Upper section washing liquid reflux port; 13. Ammonia evaporation wastewater inlet; 14. Coke oven gas inlet; 15. Lower section washing liquid reflux port; 16. Liquid outlet. DETAILED DESCRIPTION

[0028] To gain a deeper understanding of the present invention, we will provide a comprehensive and detailed description thereof. However, the present invention has various implementations and is not limited to the specific examples listed herein. These examples are presented to enhance a comprehensive understanding of the present disclosure.

[0029] A method for removing ammonia from pressurized coke oven gas, using coke oven gas as the gas to be purified, when the ammonia content in the purified coke oven gas is required to be 30-50 mg / Nm 3 When using ammonia wastewater as washing liquid;

[0030] The using device includes a gas precooler 1, a gas-liquid separator 2, a pressurized ammonia washing tower 3, an ammonia vapor wastewater booster pump 4, an ammonia vapor wastewater cooler 5, and a lower section washing pump 6; the top of the pressurized ammonia washing tower 3 is provided with a purified coke oven gas outlet 9; the upper section of the pressurized ammonia washing tower 3 is provided with an ammonia vapor wastewater inlet 13; the lower section of the pressurized ammonia washing tower 3 is provided with a coke oven gas inlet 14; the bottom of the pressurized ammonia washing tower 3 is provided with a liquid outlet 16; the ammonia vapor wastewater enters the pressurized ammonia washing tower 3 from the ammonia vapor wastewater inlet 13 through the ammonia vapor wastewater booster pump 4 and the ammonia vapor wastewater cooler 5; before entering the tower, the coke oven gas enters the pressurized ammonia washing tower 3 from the coke oven gas inlet 14 through the gas precooler 1 and the gas-liquid separator 2; a section of the gas-liquid separator 2 is connected to a condensate; the washing liquid flowing out of the liquid outlet 16 is pressurized by the lower section washing pump 6 and sent to the ammonia distillation device; the purified coke oven gas is discharged from the purified coke oven gas outlet 9.

[0031] The ammonia content in coke oven gas is 6-10g / Nm 3 , the inlet temperature of the tower is controlled at 30℃; the inlet temperature of the evaporated ammonia wastewater is controlled at 25~30℃; the inlet temperature of the refluxed evaporated ammonia wastewater is controlled at 25~30℃.

[0032] The pressurized ammonia washing tower 3 is a plate tower, a packed tower or a composite tower. The theoretical number of plates of the pressurized ammonia washing tower 3 is 4 to 10, the absolute operating pressure is 750 kPa, the tower top temperature is not higher than 30°C, and the tower bottom temperature is 31 to 35°C.

[0033] Provide another method for removing ammonia from pressurized coke oven gas

[0034] When the ammonia content in the purified coke oven gas is required to be less than 30 mg / Nm 3 When washing, ammonia wastewater and soft water are used as washing liquid; the device also includes an intermediate heat exchanger 7 and an upper washing pump 8;

[0035] The top of the pressurized ammonia washing tower 3 is provided with a purified coke oven gas outlet 9, the upper section of the pressurized ammonia washing tower 3 is provided with a soft water inlet 10, an upper section washing liquid material stream extraction outlet 11 and an upper section washing liquid reflux outlet 12; the middle section of the pressurized ammonia washing tower 3 is provided with an ammonia distillation wastewater inlet 13; the lower section of the pressurized ammonia washing tower 3 is provided with a coke oven gas inlet 14, a lower section washing liquid reflux outlet 15; and the bottom of the pressurized ammonia washing tower 3 is provided with a liquid outlet 16.

[0036] An upper washing liquid material stream extraction port 11 is provided below at least one tray (or packing of appropriate height) below the soft water inlet 10; an upper washing liquid reflux port 12 is provided between the soft water inlet 10 and the upper washing liquid material stream extraction port 11, or at the same height as the soft water inlet 10; an ammonia distillation wastewater inlet 13 is provided below the upper washing liquid material stream extraction port 11, and a lower washing liquid reflux port 15 is provided below at least one tray (or packing of appropriate height) below the ammonia distillation wastewater inlet 13; Below at least one tray (or packing of appropriate height) below the lower scrubbing liquid reflux port 15 is a coke oven gas inlet 14. An upper scrubbing pump 8 is provided in the pipeline between the upper scrubbing liquid material stream extraction port 11 and the upper scrubbing liquid reflux port 12. A lower scrubbing pump 6 and an intermediate heat exchanger 7 are provided in the pipeline between the liquid outlet 16 and the lower scrubbing liquid reflux port 15. A portion of the pressurized liquid from the lower scrubbing pump 6 is cooled by heat exchange in the intermediate heat exchanger 7 before being returned to the pressurized ammonia scrubbing tower 3. The remaining portion of the scrubbing liquid is delivered to the ammonia distillation unit.

[0037] Soft water enters the pressurized ammonia washing tower 3 through the soft water inlet 10; the ammonia vapor wastewater enters the pressurized ammonia washing tower 3 from the ammonia vapor wastewater inlet 13 through the ammonia vapor wastewater booster pump 4 and the ammonia vapor wastewater cooler 5; before entering the tower, the coke oven gas passes through the gas precooler 1 and the gas-liquid separator 2 and enters the pressurized ammonia washing tower 3 from the coke oven gas inlet 14; a section of the gas-liquid separator 2 is connected to the condensate; and the purified coke oven gas is discharged from the purified coke oven gas outlet 16.

[0038] The temperature of soft water entering the tower is controlled at 25-30°C. Ammonia distillation wastewater is preferably used as the washing liquid.

[0039] Example 1

[0040] like Figure 1 As shown, a method for removing ammonia from pressurized coke oven gas.

[0041] Coke oven gas volume 20000Nm 3 / h, operating pressure 650kPa(A), temperature 40℃, ammonia content in gas is 7.01g / Nm 3 .

[0042] a. The coke oven gas is cooled to 30°C in the gas precooler 1, separated in the gas-liquid separator 2, and then enters the pressurized ammonia washing tower 3.

[0043] b. The operating pressure of the pressurized ammonia washing tower 3 is 650kPa(A), the operating temperature is 30℃, and it is equipped with two sections of packing with a total height of 8m.

[0044] c. Add ammonia evaporation wastewater to the top of the pressurized ammonia washing tower 3 at a water rate of 20,000 kg / h. The ammonia content in the ammonia evaporation wastewater is 100 mg / m 3 .

[0045] d. The temperature of the washing liquid in the lower part of the pressurized ammonia washing tower 3 is 38℃, and the ammonia content is 6.64kg / m 3 , sent to the ammonia distillation unit.

[0046] After the coke oven gas has gone through the above process, the outlet gas temperature is 32°C and the outlet ammonia content is 40.18 mg / Nm 3 .

[0047] Example 2

[0048] like Figure 2 As shown, a method for removing ammonia from pressurized coke oven gas.

[0049] Coke oven gas volume 20000Nm 3 / h, operating pressure 750kPa(A), temperature 40℃, ammonia content in gas is 6.16g / Nm 3 .

[0050] a. The coke oven gas is cooled to 30°C in the gas precooler 1, separated in the gas-liquid separator 2, and then enters the pressurized ammonia washing tower 3.

[0051] b. The operating pressure of the pressurized ammonia washing tower 3 is 750kPa(A), the operating temperature is 30℃, it is equipped with three sections of packing, the total height of the packing is 10m, and the diameter of the ammonia washing tower is Ф1400mm.

[0052] c. Add soft water to the top of the pressurized ammonia washing tower 3 at a rate of 3000 kg / h.

[0053] d. The washing liquid on the pressurized ammonia washing tower 3 is pressurized by the upper washing pump 6 and then returned to the ammonia washing tower with a reflux rate of 15,000 kg / h and a reflux liquid temperature of 30°C.

[0054] Add ammonia wastewater to the middle of the pressurized ammonia washing tower 3 at a rate of 30,000 kg / h. The ammonia content in the ammonia wastewater is 150 mg / m 3 .

[0055] A portion of the washing liquid at the bottom of the pressurized ammonia washing tower 3 is pressurized by the lower washing pump 6 and then returned to the pressurized ammonia washing tower 3 at a reflux rate of 30,000 kg / h. The reflux liquid is cooled by the intermediate heat exchanger 7 to a temperature of 26°C. The other portion of the washing liquid is sent to the ammonia distillation device at a temperature of 31°C. The ammonia content of the washing liquid in the tower bottom is 3.58 kg / m 3 .

[0056] After the coke oven gas has gone through the above process, the outlet gas temperature is 30℃ and the ammonia content is 11mg / Nm 3 .

[0057] Comparison of traditional water washing ammonia process:

[0058] Coke oven gas volume 20000Nm 3 / h, operating pressure 118kPa(A), temperature 30℃, ammonia content in gas is 6.16g / Nm 3 . Export ammonia content ~ 100mg / Nm 3 .

[0059] The operating pressure of the ammonia washing tower is 118kPa(A), the operating temperature is 30℃, there are two towers, each tower is equipped with 4 sections of packing, the total height of each tower packing is 16m, the diameter of the ammonia washing tower is 2600mm, and the soft water consumption is 20m 3 / h.

[0060] Example 3

[0061] like Figure 2 As shown, a method for removing ammonia from pressurized coke oven gas.

[0062] Coke oven gas volume 20000Nm 3 / h, operating pressure 650kPa(A), temperature 40℃, ammonia content in gas is 7.01g / Nm 3 .

[0063] a. The coke oven gas is cooled to 30°C in the gas precooler 1, separated in the gas-liquid separator 2, and then enters the pressurized ammonia washing tower 3.

[0064] b. The operating pressure of the pressurized ammonia washing tower 3 is 650kPa(A), the operating temperature is 30℃, and it is equipped with three sections of packing with a total height of 8m.

[0065] c. Add soft water to the top of the pressurized ammonia washing tower 3 at a rate of 1500 kg / h.

[0066] d. The washing liquid on the pressurized ammonia washing tower 3 is pressurized by the upper washing pump 8 and then returned to the ammonia washing tower with a reflux rate of 15,000 kg / h and a reflux liquid temperature of 30°C.

[0067] Add ammonia wastewater to the middle of the pressurized ammonia washing tower 3 at a rate of 20,000 kg / h. The ammonia content in the ammonia wastewater is 140 mg / m 3 .

[0068] The washing liquid at the bottom of the pressurized ammonia washing tower 3 is pressurized by the lower washing pump 6 and then returned to the ammonia washing tower at a reflux rate of 28,000 kg / h. The reflux liquid is cooled by the intermediate heat exchanger 7 to a temperature of 25°C. The other part of the washing liquid is sent to the ammonia distillation device at a temperature of 31°C. The ammonia content of the washing liquid in the tower bottom is 6.208 kg / m 3 .

[0069] After the coke oven gas has gone through the above process, the outlet gas temperature is 30°C and the outlet ammonia content is 27.8 mg / Nm 3 .

[0070] Comparison of traditional water washing ammonia process:

[0071] Coke oven gas volume 20000Nm 3 / h, operating pressure 118kPa(A), temperature 30℃, ammonia content in gas is 7.01g / Nm 3 . Export ammonia content ~ 100mg / Nm 3 .

[0072] The operating pressure of the ammonia washing tower is 118kPa(A), the operating temperature of the tower top is 30℃, and the operating temperature of the tower bottom is 31℃. There are two towers, and each ammonia washing tower is equipped with 4 sections of packing. The total height of each tower packing is 16m. The diameter of the ammonia washing tower is 2600mm. The soft water consumption is 24m3. 3 / h.

[0073] The present invention is a part of the pressurized coke oven gas purification, the purpose of which is to remove ammonia through the present invention, and the ammonia in the coke oven gas can be removed to 10-50 mg / Nm 3 The equipment used is smaller and occupies less space than the existing process. Compared with the traditional ammonium sulfate production process, it can avoid the use of high-grade equipment materials under the same purification requirements. Compared with the traditional ammonium phosphate absorption method, the absorption energy consumption is lower and the gas purification degree is higher. Compared with the traditional water-washing ammonia process, the traditional atmospheric pressure ammonia washing tower requires two, each with four sections and about 4m high filler, and the ammonia content after the tower is usually higher than 100mg / Nm 3 The present invention uses a single ammonia washing tower with two to three sections of packing with a total height of about 8 to 12 meters, and the tower diameter is smaller. The absorption liquid spraying amount is only 2 / 3 of that of a single device in the traditional water-washing ammonia process, so it has lower energy consumption.

[0074] Any matters not described in detail in this specification are prior art known to those skilled in the art. Although the above description of the present invention is based on specific embodiments to facilitate understanding of the present invention by those skilled in the art, it should be understood that the present invention is not limited to the scope of the specific embodiments. As long as various modifications are within the spirit and scope of the present invention as defined and determined by the appended claims, such modifications will be obvious to those skilled in the art, and all inventions and creations utilizing the concepts of the present invention are protected.

Claims

1. A method for removing ammonia from pressurized coke oven gas, characterized in that: Taking coke oven gas as the purified gas, the ammonia content in the purified coke oven gas is required to be 30-50 mg / Nm 3 When using ammonia wastewater as washing liquid; The device comprises a coal gas precooler (1), a gas-liquid separator (2), a pressurized ammonia washing tower (3), an ammonia evaporation wastewater booster pump (4), an ammonia evaporation wastewater cooler (5), and a lower washing pump (6); The top of the pressurized ammonia washing tower (3) is provided with a purified coke oven gas outlet (9); the upper section of the pressurized ammonia washing tower (3) is provided with an ammonia evaporation wastewater inlet (13); the lower section of the pressurized ammonia washing tower (3) is provided with a coke oven gas inlet (14); the bottom of the pressurized ammonia washing tower (3) is provided with a liquid outlet (16); Ammonia wastewater enters the pressurized ammonia washing tower (3) from the ammonia wastewater inlet (13) through the ammonia wastewater booster pump (4) and the ammonia wastewater cooler (5); coke oven gas enters the pressurized ammonia washing tower (3) from the coke oven gas inlet (14) through the gas precooler (1) and the gas-liquid separator (2) before entering the tower; a section of the gas-liquid separator (2) is connected to condensate; the washing liquid flowing out of the liquid outlet (16) is pressurized by the lower section washing pump (6) and then sent to the ammonia distillation device; the purified coke oven gas is discharged from the purified coke oven gas outlet (9).

2. The method for removing ammonia from pressurized coke oven gas according to claim 1, characterized in that: The ammonia content in coke oven gas is 6-10g / Nm 3 , the inlet temperature of the tower is controlled at 30℃~30℃; the inlet temperature of the evaporated ammonia wastewater is controlled at 25~30℃; the inlet temperature of the refluxed evaporated ammonia wastewater is controlled at 25~30℃.

3. The method for removing ammonia from pressurized coke oven gas according to claim 1, characterized in that: The pressurized ammonia washing tower (3) is a plate tower, a packed tower or a composite tower.

4. The method for removing ammonia from pressurized coke oven gas according to claim 1, characterized in that: The theoretical number of plates of the pressurized ammonia washing tower (3) is 4 to 10, the absolute operating pressure is 750 kPa, the tower top temperature is not higher than 30°C, and the tower bottom temperature is 31 to 35°C.

5. The method for removing ammonia from pressurized coke oven gas according to claim 1, characterized in that: When the ammonia content in the purified coke oven gas is required to be less than 30 mg / Nm 3 When washing, ammonia wastewater and soft water are used as washing liquid; the using device also includes an intermediate heat exchanger (7) and an upper washing pump (8); The top of the pressurized ammonia washing tower (3) is provided with a purified coke oven gas outlet (9); the upper section of the pressurized ammonia washing tower (3) is provided with a soft water inlet (10), an upper section washing liquid material stream extraction outlet (11) and an upper section washing liquid reflux outlet (12); the middle section of the pressurized ammonia washing tower (3) is provided with an ammonia evaporation wastewater inlet (13); the lower section of the pressurized ammonia washing tower (3) is provided with a coke oven gas inlet (14) and a lower section washing liquid reflux outlet (15); the bottom of the pressurized ammonia washing tower (3) is provided with a liquid outlet (16); An upper washing liquid material stream extraction port (11) is arranged below at least one tower plate below the soft water inlet (10); the upper washing liquid reflux port (12) is arranged between the soft water inlet (10) and the upper washing liquid material stream extraction port (11), or is arranged at a position at the same height as the soft water inlet (10); an ammonia evaporation wastewater inlet (13) is arranged below the upper washing liquid material stream extraction port (11); and a lower washing liquid reflux port (15) is arranged below at least one tower plate below the ammonia evaporation wastewater inlet (13); and a lower washing liquid reflux port (15) is arranged below the lower washing liquid reflux port (12). The lower part of at least one tower plate below the opening (15) is a coke oven gas inlet (14); an upper washing pump (8) is provided on the pipeline between the upper washing liquid material stream extraction outlet (11) and the upper washing liquid reflux outlet (12); a lower washing pump (6) and an intermediate heat exchanger (7) are provided on the pipeline between the liquid outlet (16) and the lower washing liquid reflux outlet (15); a part of the liquid pressurized by the lower washing pump (6) is returned to the pressurized ammonia washing tower (3) after heat exchange and temperature reduction in the intermediate heat exchanger (7), and the other part of the washing liquid is sent to the ammonia distillation device; Soft water enters the pressurized ammonia washing tower (3) through the soft water inlet (10); ammonia waste water enters the pressurized ammonia washing tower (3) from the ammonia waste water inlet (13) through the ammonia waste water booster pump (4) and the ammonia waste water cooler (5); coke oven gas enters the pressurized ammonia washing tower (3) from the coke oven gas inlet (14) through the gas precooler (1) and the gas-liquid separator (2) before entering the tower; a section of the gas-liquid separator (2) is connected to condensate; and purified coke oven gas is discharged from the purified coke oven gas outlet (16).

6. The method for removing ammonia from pressurized coke oven gas according to claim 1, characterized in that: The temperature of soft water entering the tower is controlled at 25-30℃.

7. The method for removing ammonia from pressurized coke oven gas according to claim 1, characterized in that: Ammonia distillation wastewater is preferably used as the washing liquid.

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