Coke oven gas desulfurization treatment method and device

Abstract

The invention provides a coke oven gas desulfurization treatment method and device, and relates to the technical field of coal chemical industry, and the method comprises the following steps: high-temperature concentrated ammonia gas distilled from an ammonia distillation tower enters the bottom of a desulfurization precooling tower through a concentrated ammonia gas branch pipe, and is mixed with coal gas at the bottom of the desulfurization precooling tower; circulating liquid at the bottom of the desulfurization precooling tower is cooled by a precooling tower heat exchanger and then returns to the desulfurization precooling tower to cool the coal gas and the concentrated ammonia gas; adjusting a valve of the coal gas out of the precooling tower to enable the coal gas to enter the desulfurization tower through an output end at the top of the desulfurization precooling tower; the temperatures of the coal gas and the concentrated ammonia gas at the outlet of the desulfurization precooling tower are less than or equal to 30 DEG C, and the saturated water quantity of the coal gas is 25.8-30.4 g / m < 3 The temperature of the gas at the outlet of the desulfurizing tower is 37-40 DEG C, and the saturated water quantity of the gas is 44.8-51.2 g / m < 3 >. Transfer of ammonia and cooling of concentrated ammonia gas are achieved, the content of ammonia volatilized in coal gas is increased, and the amount of desulfurization waste liquid is effectively reduced.

Description

Technical Field

[0001] The invention relates to the technical field of coal chemical industry, and in particular to a method and device for desulfurizing coke oven gas. Background Art

[0002] At present, the ammonia required for the HPF desulfurization process of the coking plant is mainly achieved by cooling the ammonia gas in the ammonia still into ammonia water or purchasing concentrated ammonia water to supplement the desulfurization reaction tank or desulfurization tower. The residual ammonia water produced by the cold drum tar ammonia water separation tank is pumped into the ammonia still tower after oil removal. The ammonia water is preheated with the wastewater after ammonia evaporation, mixed with the added sodium hydroxide, and enters the ammonia still tower from the feed inlet of the distillation section of the ammonia still tower. Steam is introduced into the bottom of the ammonia still tower to distill the ammonia water. The ammonia gas produced is cooled by the ammonia fractionator at the top of the tower and then continues to be cooled by the ammonia cooler to generate ammonia water. The concentration of the ammonia water produced at this time is generally between 10% and 20%. After adding the desulfurization system, an additional 80%-90% of water is added to the desulfurization system to become a desulfurization liquid. In order to ensure the water balance of the desulfurization system, the excess desulfurization liquid needs to be discharged from the desulfurization system regularly. The desulfurization liquid contains desulfurization catalyst, ammonium thiosulfate, ammonium sulfate, ammonium thiocyanate, ammonia, etc., which need to be treated for environmental protection. At present, the main treatment methods are evaporation and crystallization of salt or incineration and acid production. However, due to the complex composition, difficulty in treatment, high cost, and serious corrosion of treatment equipment, desulfurization liquid has become an environmental risk control point for coking plants.

[0003] Therefore, there is an urgent need for a technical process to reduce the amount of desulfurization waste liquid generated to solve the above-mentioned problems faced by coking enterprises. Summary of the invention

[0004] The object of the present invention is to provide a method and device for desulfurizing coke oven gas. By setting a concentrated ammonia branch pipe, the concentrated ammonia is directly introduced into a desulfurization precooling tower. After the high-temperature concentrated ammonia enters the desulfurization precooling tower, the ammonia directly contacts with the coal gas, and gas phase mass transfer is achieved, thereby realizing the transfer of ammonia and cooling of the concentrated ammonia, and also increasing the content of volatile ammonia in the coal gas, and there is no need to change the structure of the original precooling tower equipment. The present invention also controls the water content entering the desulfurization precooling tower by controlling the coal gas temperature of the desulfurization precooling tower to be lower than the coal gas temperature at the outlet of the desulfurization tower, and utilizes the difference in saturated water content at different temperatures, thereby effectively reducing the water entering the desulfurization liquid and further reducing the amount of desulfurization waste liquid.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] The present invention provides a coke oven gas desulfurization treatment method, comprising:

[0007] The high-temperature concentrated ammonia gas evaporated from the ammonia evaporation tower (15) directly enters the bottom of the desulfurization precooling tower (17) and is mixed with the coal gas entering the bottom of the desulfurization precooling tower (17). The circulating liquid at the bottom of the desulfurization precooling tower (17) is cooled and then returns to the top of the desulfurization precooling tower (17), and then contacts with the coal gas and the concentrated ammonia gas in reverse direction to cool them. The cooled coal gas and the concentrated ammonia gas are discharged from the top outlet of the desulfurization precooling tower (17), and then enter the desulfurization tower (16) for desulfurization treatment.

[0008] The temperature of the coal gas and concentrated ammonia gas at the outlet of the desulfurization precooling tower (17) is ≤30°C;

[0009] Among them, the gas saturated water content is 25.8-30.4g / m 3 ;

[0010] The temperature of the coal gas at the outlet of the desulfurization tower (16) is 37-40°C;

[0011] The gas saturated water content is 44.8-51.2g / m 3 .

[0012] Further, on the basis of the above technical solution, the temperature of the high-temperature concentrated ammonia gas is 90-97°C;

[0013] and / or, the temperature of the circulating liquid returning to the top of the desulfurization precooling tower (17) after being cooled by the precooling tower heat exchanger (6) is 25-30°C;

[0014] and / or, the temperature of the desulfurization liquid in the desulfurization tower (16) is 35-40° C.;

[0015] The cooling water volume in the desulfurization tower (16) is 350-550m 3 / h.

[0016] Further, on the basis of the above technical solution, when the desulfurization tower (16) needs to be replenished, the high-temperature concentrated ammonia gas evaporated from the ammonia evaporation tower (15) is first cooled and separated to obtain ammonia gas and cooling ammonia water;

[0017] The separated ammonia gas enters the bottom of the desulfurization precooling tower (17) and is then mixed with the coal gas entering the bottom of the desulfurization precooling tower (17);

[0018] The separated cooling ammonia water enters the desulfurization tower for liquid replenishment.

[0019] Furthermore, based on the above technical solution, it also includes:

[0020] The cooled concentrated ammonia gas and the circulating liquid at the bottom of the desulfurization precooling tower (17) enter the tar-ammonia separation tank (18) for mixing and separation. The tar separated in the tar-ammonia separation tank (18) is treated in a coke oven (19) to produce coal gas.

[0021] The part of ammonia water separated by the tar-ammonia water separation tank (18) is used to cool the coal gas in the coke oven (19), and the remaining ammonia water separated is sent to the ammonia evaporation tower (15) for ammonia evaporation treatment, and the ammonia evaporation wastewater generated by the ammonia evaporation treatment is subjected to biochemical treatment;

[0022] The coal gas discharged from the coke oven (19) is treated by the cooling drum (20) and then enters the bottom of the desulfurization precooling tower (17) to mix with the concentrated ammonia gas.

[0023] Further, based on the above technical solution, the temperature of the coal gas generated in the coke oven (19) is 450-500°C;

[0024] and / or, the temperature of the coal gas after cooling down the part of ammonia water separated by the tar ammonia water separation tank (18) is 75-85°C;

[0025] And / or, the temperature of the coal gas after being cooled by the cold drum (20) is 45-55°C.

[0026] The present invention also provides a device for the above-mentioned coke oven gas desulfurization treatment method, comprising an ammonia evaporation tower (15), a concentrated ammonia cooler (2), a desulfurization tower (16), a desulfurization precooling tower (17) and a precooling tower heat exchanger (6);

[0027] A first pipeline and a second pipeline are arranged between the ammonia evaporation tower (15) and the desulfurization precooling tower (17). The ammonia evaporation tower (15) is connected to the desulfurization precooling tower (17) through the first pipeline or the second pipeline. The first pipeline is used to directly pass the high-temperature concentrated ammonia gas evaporated from the ammonia evaporation tower (15) to the bottom of the desulfurization precooling tower (17). The second pipeline is provided with a concentrated ammonia cooler (2). The concentrated ammonia cooler (2) is used to first cool the high-temperature concentrated ammonia gas evaporated from the ammonia evaporation tower (15), pass the separated ammonia gas to the bottom of the desulfurization precooling tower (17) for cooling, and pass the separated ammonia water to the desulfurization tower (16) for liquid supplement;

[0028] The top outlet of the desulfurization precooling tower (17) is connected to the inlet of the desulfurization tower (16), and the cooled coal gas and concentrated ammonia gas enter the desulfurization tower (16) from the top of the desulfurization precooling tower (17) for desulfurization treatment.

[0029] Furthermore, based on the above technical solution, a concentrated ammonia gas inlet precooling tower valve (4) is provided on the first pipeline;

[0030] An ammonia evaporation tower ammonia gas inlet cooler valve (1) is provided between the ammonia evaporation tower (15) and the concentrated ammonia gas cooler (2);

[0031] A concentrated ammonia valve (3) after the cooler is provided between the concentrated ammonia cooler (2) and the desulfurization precooling tower (17).

[0032] Furthermore, based on the above technical solution, a precooling tower heat exchanger (6) is provided between the bottom and the top of the desulfurization precooling tower (17), and the precooling tower heat exchanger (6) is used to transport the circulating liquid cooled at the bottom of the desulfurization precooling tower (17) to the top of the desulfurization precooling tower (17) to cool the coal gas and concentrated ammonia.

[0033] Furthermore, based on the above technical solution, it also includes a tar-ammonia water separation tank (18), a coke oven (19) and a gas collecting pipe (9);

[0034] The bottom outlet of the desulfurization precooling tower (17) is connected to the first inlet of the tar-ammonia water separation tank (18), and the concentrated ammonia gas and the bottom circulating liquid of the desulfurization precooling tower (17) enter the tar-ammonia water separation tank (18) from the bottom outlet of the desulfurization precooling tower (17) to be separated;

[0035] The outlet of the tar-ammonia-water separation tank (18) is connected to the inlet of the coke oven (19), and the tar separated from the tar-ammonia-water separation tank (18) is transported to the coke oven (19) for treatment;

[0036] The tar-ammonia separation tank (18) is provided with a circulating ammonia tank (22) for storing ammonia separated from the tar-ammonia separation tank (18);

[0037] The first outlet of the circulating ammonia water tank (22) is connected to the gas collecting pipe (9), and the cooling ammonia water in the circulating ammonia water tank (22) cools the coal gas in the gas collecting pipe (9);

[0038] The second outlet of the circulating ammonia water tank (22) is connected to the inlet of the ammonia evaporation tower (15), and the remaining ammonia water in the circulating ammonia water tank (22) enters the ammonia evaporation tower (15) for ammonia evaporation treatment.

[0039] Furthermore, based on the above technical solution, it also includes a cold drum (20);

[0040] The outlet of the coke oven (19) is connected to the inlet of the cooling drum (20), and the coal gas generated from the coke oven (19) enters the cooling drum (20) for cooling;

[0041] The first outlet of the cold drum (20) is connected to the bottom inlet of the desulfurization precooling tower (17), and the coal gas cooled from the cold drum (20) enters the bottom of the desulfurization precooling tower (17) for cooling treatment;

[0042] The second outlet of the cold drum (20) is connected to the second inlet of the tar-ammonia-water separation tank (18), and the ammonia water and tar separated from the cold drum (20) enter the tar-ammonia-water separation tank (18) for separation.

[0043] The present invention provides a method and device for desulfurizing coke oven gas, and the beneficial effects are as follows:

[0044] 1. A first pipeline is directly set on the concentrated ammonia pipeline in front of the concentrated ammonia condenser cooler, and a concentrated ammonia inlet precooling tower valve is installed on the first pipeline. The high-temperature concentrated ammonia evaporated from the ammonia evaporation tower directly enters the bottom of the desulfurization precooling tower. After the high-temperature concentrated ammonia enters the desulfurization precooling tower, the ammonia directly contacts the coal gas, and the gas phase mass transfer is realized, thereby realizing the transfer of ammonia and the cooling of the concentrated ammonia, and also increasing the content of volatile ammonia in the coal gas, and there is no need to change the structure of the original precooling tower equipment.

[0045] 2. After the circulating liquid at the bottom of the desulfurization precooling tower is cooled by the precooling tower heat exchanger, the concentrated ammonia gas at the bottom of the desulfurization precooling tower is cooled to form cooled ammonia water. The circulating liquid containing cooled ammonia water and concentrated ammonia gas enter the tar ammonia water separation tank for separation. The separated ammonia water enters the circulating ammonia water tank, which stabilizes the amount of circulating ammonia water in the whole system. It is sprayed on the coke oven gas collecting pipe through the circulating ammonia water pump to improve the gas cooling efficiency. At the same time, the evaporated ammonia gas is transferred to the gas system to increase the content of volatile ammonia in the gas. The ammonia in the remaining ammonia water is gasified in the ammonia evaporation tower to achieve repeated utilization.

[0046] 3. The present invention limits the temperature of the coal gas at the outlet of the desulfurization precooling tower to ≤30°C, and the temperature of the coal gas at the outlet of the desulfurization tower is 37-40°C. The coal gas temperature of the desulfurization precooling tower is lower than the coal gas temperature at the outlet of the desulfurization tower. The moisture brought into the coal gas in the desulfurization tower is less than the moisture brought out. The difference in saturated moisture content at different temperatures is used to control the moisture entering the desulfurization tower, effectively reduce the moisture entering the desulfurization liquid, and further reduce the amount of desulfurization waste liquid.

[0047] 4. After the ammonia is cooled in the precooling tower, the separated water is transformed into cold dilute ammonia water, which has not come into contact with the desulfurization catalyst, etc., and does not contain catalysts and sulfur-containing secondary salts. In addition, the high-temperature concentrated ammonia is cooled in the desulfurization precooling tower to separate the water entrained in the concentrated ammonia from the coal gas, thus avoiding the desulfurization system from entering the water. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0049] Figure 1 A flow chart of the coke oven gas desulfurization treatment method provided by the present invention;

[0050] Icons: 1. Valve for ammonia gas inlet to cooler of ammonia evaporation tower; 2. Cooler for concentrated ammonia gas; 3. Valve for concentrated ammonia gas after cooler; 4. Valve for concentrated ammonia gas inlet to precooling tower; 5. Valve for spraying liquid of precooling tower; 6. Heat exchanger for precooling tower; 7. Valve for coolant of precooling tower to send tar-ammonia separation tank; 8. Valve for ammonia water to gas collecting pipe; 9. Gas collecting pipe; 10. Valve for coke oven gas inlet to precooling tower; 11. Centrifugal pump for spraying liquid of precooling tower; 12. Valve for gas outlet from precooling tower; 13. Circulating ammonia water pump; 14. Residual ammonia water pump; 15. Ammonia evaporation tower; 16. Desulfurization tower; 17. Desulfurization precooling tower; 18. Tar-ammonia separation tank; 19. Coke oven; 20. Cold drum; 21. Biochemical system; 22. Circulating ammonia water tank. DETAILED DESCRIPTION

[0051] In order to make the purpose, technical scheme and advantages of the present invention clearer, the technical scheme in the embodiment of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present invention. The process parameters of the following embodiments that do not specify specific conditions are usually based on conventional conditions.

[0052] The endpoints and any values ​​of the ranges disclosed in the present invention are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be regarded as specifically disclosed in the present invention.

[0053] According to a first aspect of the present invention, there is provided a method for desulfurizing coke oven gas, comprising:

[0054] The high-temperature concentrated ammonia gas evaporated from the ammonia evaporation tower 15 directly enters the bottom of the desulfurization precooling tower 17, and is mixed with the coal gas entering the bottom of the desulfurization precooling tower 17. The circulating liquid at the bottom of the desulfurization precooling tower 17 returns to the top of the desulfurization precooling tower 17 after cooling, and then contacts with the coal gas and concentrated ammonia gas in reverse to cool them; the cooled coal gas and concentrated ammonia gas are discharged from the top outlet of the desulfurization precooling tower 17, and then enter the desulfurization tower 16 for desulfurization treatment;

[0055] The temperature of the coal gas and concentrated ammonia at the outlet of the desulfurization precooling tower 17 is ≤30°C (e.g. 26°C, 27°C, 28°C, 29°C, etc.);

[0056] Among them, the gas saturated water content is 25.8-30.4g / m 3 (For example, 26g / m 3, 27g / m 3 , 28g / m 3 , 29g / m 3 , 30g / m 3 wait);

[0057] The temperature of the coal gas at the outlet of the desulfurization tower 16 is 37-40°C (e.g., 37.5°C, 38°C, 38.5°C, 39°C, 39.5°C, etc.);

[0058] The gas saturated water content is 44.8-51.2g / m 3 (For example 45g / m 3 , 46g / m 3 , 47g / m 3 , 48g / m 3 , 49g / m 3 , 50g / m 3 , 51g / m 3 wait).

[0059] Specifically, Figure 1 As shown, the present invention is provided with a concentrated ammonia branch pipe, i.e., the first pipeline, so that the high-temperature concentrated ammonia evaporated from the ammonia evaporation tower 15 directly enters the bottom of the desulfurization precooling tower 17, and is mixed with the coal gas in the bottom of the desulfurization precooling tower 17. The concentrated ammonia and the coal gas are used to flow in the same direction for mass transfer, thereby increasing the content of volatile ammonia in the coal gas. The higher the content of volatile ammonia in the coal gas, the more the desulfurization liquid will absorb the volatile ammonia in the coal gas after entering the desulfurization tower 16. The higher the concentration of volatile ammonia in the desulfurization liquid, the more conducive it is to the absorption efficiency of substances such as hydrogen sulfide and hydrogen cyanide during the desulfurization process. Moreover, after the high-temperature concentrated ammonia is cooled in the desulfurization precooling tower 17, the moisture therein is more easily condensed and separated, thereby reducing the moisture content entering the desulfurization tower 16, realizing the separation of moisture entrained by the concentrated ammonia from the coal gas, and avoiding moisture entering the desulfurization system in the desulfurization tower 16.

[0060] Furthermore, based on the principle that the higher the temperature, the higher the saturated moisture entrained by the gas, the temperature of the coal gas at the outlet of the desulfurization precooling tower 17 is limited to ≤30°C, and the temperature of the coal gas at the outlet of the desulfurization tower 16 is limited to 37-40°C. The coal gas temperature of the desulfurization precooling tower 17 is lower than the coal gas temperature at the outlet of the desulfurization tower 16. The moisture brought into the coal gas in the desulfurization tower 16 is less than the moisture brought out. The difference in saturated moisture content at different temperatures is used to control the moisture entering the desulfurization tower 16, effectively reducing the amount of moisture entering the desulfurization liquid, and further reducing the amount of desulfurization waste liquid.

[0061] Furthermore, the precooling tower heat exchanger 6 controls the temperature of the outlet gas of the desulfurization precooling tower 17 to be ≤30°C. If the temperature is higher than the limit, the desulfurization liquid increases, thereby affecting the balance of the desulfurization liquid.

[0062] Furthermore, under normal circumstances, in order to ensure the desulfurization effect, the temperature of the coal gas at the outlet of the desulfurization tower 16 is controlled at 30-35°C. However, in the present invention, the temperature of the coal gas at the outlet of the desulfurization tower 16 is controlled at 37-40°C. This is because if it is higher than the temperature specified in the present invention, the temperature of the desulfurization liquid will increase, affecting the subsequent treatment effect of the desulfurization liquid; if it is lower than the temperature specified in the present invention, the steam consumption for heating the coal gas in the subsequent process will increase, and it will also lead to an increase in the desulfurization liquid, thereby affecting the balance of the desulfurization liquid.

[0063] As an optional embodiment of the present invention, the temperature of the high-temperature concentrated ammonia gas is 90-97° C. (such as 91° C., 92° C., 93° C., 94° C., 95° C., 96° C., etc.);

[0064] and / or, the temperature of the spray liquid at the top of the desulfurization precooling tower 17 after being cooled by the precooling tower heat exchanger 6 is 25-30° C. (e.g., 26° C., 27° C., 28° C., 29° C., etc.);

[0065] and / or, the temperature of the desulfurization liquid in the desulfurization tower 16 is 35-40° C. (e.g., 36° C., 37° C., 38° C., 39° C., etc.);

[0066] The cooling water volume in the desulfurization tower 16 is 350-550m 3 / h(e.g. 380m 3 / h、400m 3 / h、420m 3 / h、440m 3 / h、460m 3 / h、480m 3 / h、500m 3 / h、520m 3 / h、540m 3 / h, etc.).

[0067] Specifically, the outlet gas temperature of the desulfurization tower 16 is affected by the temperature of the desulfurization liquid and the amount of cooling water in the desulfurization tower 16. By properly regulating the temperature of the desulfurization liquid and the amount of cooling water, the outlet gas temperature of the desulfurization tower 16 can be maintained within the range of 37-40°C.

[0068] As an optional embodiment of the present invention, when the desulfurization tower 16 needs to be replenished, the high-temperature concentrated ammonia gas evaporated from the ammonia evaporation tower 15 is first cooled and separated to obtain ammonia gas and cooling ammonia water;

[0069] The separated ammonia enters the bottom of the desulfurization precooling tower 17, and then mixes with the coal gas entering the bottom of the desulfurization precooling tower 17;

[0070] The separated cooling ammonia water enters the desulfurization tower 16 for liquid replenishment.

[0071] Specifically, when the liquid level in the desulfurization system is insufficient and liquid needs to be supplemented, the valve 1 for the ammonia gas entering the cooler of the ammonia evaporation tower and the valve 3 for the concentrated ammonia gas after the cooler are opened, and the valve 4 for the concentrated ammonia gas entering the pre-cooling tower is closed. The amount of cooling water in the concentrated ammonia gas cooler 2 is controlled to cool part of the concentrated ammonia gas. A large amount of water mixed in the concentrated ammonia gas will condense when it is cooled and separate from the concentrated ammonia gas to form ammonia water. The cooled ammonia water enters the desulfurization tower 16 for liquid supplement; the separated ammonia gas enters the bottom of the desulfurization pre-cooling tower 17 through the valve 3 for the concentrated ammonia gas after the cooler.

[0072] As an optional embodiment of the present invention, the cooled concentrated ammonia gas and the bottom circulating liquid of the desulfurization precooling tower 17 enter the tar-ammonia separation tank 18 for mixing and separation, and the tar separated by the tar-ammonia separation tank 18 is treated in the coke oven 19 to produce coal gas;

[0073] The part of ammonia water separated by the tar-ammonia water separation tank 18 is used to cool the coal gas in the coke oven 19, and the remaining ammonia water separated enters the ammonia evaporation tower 15 for ammonia evaporation treatment, and the ammonia evaporation wastewater generated by the ammonia evaporation treatment is subjected to biochemical treatment;

[0074] The coal gas discharged from the coke oven 19 is treated by the cooling drum 20 and then enters the bottom of the desulfurization precooling tower 17 to mix with the concentrated ammonia gas.

[0075] Specifically, the circulating liquid at the bottom of the desulfurization precooling tower 17 mainly includes water, ammonia water, dissolved acidic gases (such as hydrogen sulfide, carbon dioxide, etc.), solid impurities (coal dust, tar particles, naphthalene, etc.) and salts (such as ammonium sulfate, sodium thiosulfate, etc.).

[0076] It is a continuous process that the circulating liquid at the bottom of the desulfurization precooling tower 17 is cooled and then sprayed on the top of the desulfurization precooling tower 17. When the circulating liquid level at the bottom of the desulfurization precooling tower 17 exceeds the liquid level limit (for example, 1 meter), the valve 7 for sending the cooling liquid of the precooling tower to the tar ammonia water separation tank is opened to transport the circulating liquid at the bottom of the desulfurization precooling tower 17 to the tar ammonia water separation tank 18.

[0077] like Figure 1 As shown, after the circulating liquid at the bottom of the desulfurization precooling tower 17 is cooled by the precooling tower heat exchanger 6, the precooling tower spraying liquid valve 5 is opened and the liquid returns to the desulfurization precooling tower 17 and is sprayed from the top of the desulfurization precooling tower 17 to cool down and transfer heat to the coal gas and concentrated ammonia in the desulfurization precooling tower 17;

[0078] A part of the concentrated ammonia gas after cooling is transferred to the coal gas, thereby increasing the volatile ammonia in the coal gas, and a part of it is transferred to the circulating liquid at the bottom of the desulfurization precooling tower 17 to form dilute ammonia water.

[0079] When the circulating liquid at the bottom of the desulfurization precooling tower 17 exceeds the liquid level limit (e.g. 1 meter), the valve 7 for sending the cooling liquid of the precooling tower to the tar-ammonia separation tank is opened, and the tar and other solid impurities sunk at the bottom of the circulating liquid will enter the tar-ammonia separation tank 18 together with the ammonia and other substances in the circulating liquid;

[0080] The separation of ammonia water and tar is achieved in the tar-ammonia water separation tank 18;

[0081] A circulating ammonia water tank 22 is provided in the tar-ammonia water separation tank 18. The ammonia water separated by the tar-ammonia water separation tank 18 enters the circulating ammonia water tank 22, and enters the ammonia evaporation tower 15 again through the residual ammonia water pump 14 to evaporate the ammonia gas in the ammonia water. The discharged ammonia evaporation wastewater enters the wastewater debiochemical system 21 for biochemical treatment.

[0082] The valve 8 for sending ammonia water to the gas collecting pipe is opened, and the tar separated by the tar-ammonia water separation tank 18 enters the bridge pipe in the coke oven 19, and is processed to participate in the generation of coal gas, and the coal gas enters the gas collecting pipe 9. The ammonia water in the circulating ammonia water tank 22 is lifted to the gas collecting pipe 9 by the circulating ammonia water pump 13, and the coal gas in the gas collecting pipe 9 is sprayed and cooled;

[0083] Ammonia water, coal gas and impurities such as tar enter the cold drum 20, and the cold drum 20 uses ammonia water in the circulating ammonia water tank 22 to further cool the coal gas. The valve 10 for the coke oven gas to enter the precooling tower is opened, and the coal gas enters the bottom of the desulfurization precooling tower 17 and is mixed with the concentrated ammonia gas again to cool down.

[0084] The ammonia water and tar and other impurities in the cold drum 20 enter the tar ammonia water separation tank 18 again for separation, and the above operation is repeated.

[0085] Furthermore, the water separated from the concentrated ammonia after cooling in the desulfurization pre-cooling tower 17 is converted into cold dilute ammonia water, which has not come into contact with the desulfurization catalyst and does not contain the desulfurization catalyst. At the same time, since the dilute ammonia water does not participate in the desulfurization reaction, it does not contain sulfur-containing secondary salts that may be produced during the desulfurization process. The dilute ammonia water enters the circulating ammonia water tank 22. Since the dilute ammonia water has the characteristics of being clean, free of catalysts and sulfur-containing secondary salts, it meets the conditions for entering the coke oven 19 for cooling. After the cooled dilute ammonia water enters the ammonia water system of the cold drum 20, the ammonia content of the circulating ammonia water is stabilized. In addition, the ammonia water has a large latent heat of vaporization, which improves the cooling effect when the gas collecting pipe 9 is cooled.

[0086] As an optional embodiment of the present invention, the temperature of the coal gas generated in the coke oven 19 is 450-500° C. (such as 460° C., 470° C., 480° C., 490° C., etc.);

[0087] and / or, the temperature of the coal gas after being cooled by the gas collecting pipe 9 is 75-85° C. (e.g., 76° C., 77° C., 78° C., 79° C., 80° C., 81° C., 82° C., 83° C., 84° C., etc.);

[0088] And / or, the temperature of the coal gas after cooling by the cold drum 20 is 45-55°C (e.g., 46°C, 47°C, 48°C, 49°C, 50°C, 51°C, 52°C, 53°C, 54°C, etc.).

[0089] According to a second aspect of the present invention, there is provided a device for the above-mentioned coke oven gas desulfurization treatment method, comprising an ammonia evaporation tower 15, a concentrated ammonia cooler 2, a desulfurization tower 16, a desulfurization precooling tower 17 and a precooling tower heat exchanger 6;

[0090] A first pipeline and a second pipeline are arranged between the ammonia evaporation tower 15 and the desulfurization precooling tower 17. The ammonia evaporation tower 15 is connected to the desulfurization precooling tower 17 through the first pipeline or the second pipeline. The first pipeline is used to directly pass the high-temperature concentrated ammonia gas evaporated from the ammonia evaporation tower 15 to the bottom of the desulfurization precooling tower 17. The second pipeline is provided with a concentrated ammonia cooler 2, which is used to first cool the high-temperature concentrated ammonia gas evaporated from the ammonia evaporation tower 15, pass the separated ammonia gas into the bottom of the desulfurization precooling tower 17 for cooling, and pass the separated ammonia water into the desulfurization tower 16 for liquid supplement;

[0091] The top outlet of the desulfurization precooling tower 17 is connected to the inlet of the desulfurization tower 16, and the cooled coal gas and concentrated ammonia gas enter the desulfurization tower 16 from the top of the desulfurization precooling tower 17 for desulfurization treatment.

[0092] As an optional embodiment of the present invention, a concentrated ammonia gas inlet precooling tower valve 4 is provided on the first pipeline;

[0093] An ammonia still tower ammonia gas inlet cooler valve 1 is provided between the ammonia still tower 15 and the concentrated ammonia gas cooler 2;

[0094] A post-cooler concentrated ammonia valve 3 is provided between the concentrated ammonia cooler 2 and the desulfurization precooling tower 17 .

[0095] As an optional embodiment of the present invention, a precooling tower heat exchanger 6 is provided between the bottom and the top of the desulfurization precooling tower 17, and the precooling tower heat exchanger 6 is used to transport the circulating liquid cooled at the bottom of the desulfurization precooling tower 17 to the top of the desulfurization precooling tower 17 to cool the coal gas and concentrated ammonia.

[0096] As an optional embodiment of the present invention, it also includes a tar-ammonia water separation tank 18, a coke oven 19 and a gas collecting pipe 9;

[0097] The bottom outlet of the desulfurization precooling tower 17 is connected to the first inlet of the tar-ammonia separation tank 18, and the concentrated ammonia gas and the bottom circulating liquid of the desulfurization precooling tower 17 enter the tar-ammonia separation tank 18 from the bottom outlet of the desulfurization precooling tower 17 to be separated;

[0098] The outlet of the tar-ammonia separation tank 18 is connected to the inlet of the coke oven 19, and the tar separated from the tar-ammonia separation tank 18 is transported to the coke oven 19 for processing;

[0099] The tar-ammonia separation tank 18 is provided with a circulating ammonia tank 22 for storing the ammonia separated from the tar-ammonia separation tank 18;

[0100] The first outlet of the circulating ammonia water tank 22 is connected to the gas collecting pipe 9, and the cooling ammonia water in the circulating ammonia water tank 22 cools the coal gas in the gas collecting pipe 9;

[0101] The second outlet of the circulating ammonia water tank 22 is connected to the inlet of the ammonia evaporation tower 15, and the remaining ammonia water in the circulating ammonia water tank 22 enters the ammonia evaporation tower 15 for ammonia evaporation treatment.

[0102] As an optional embodiment of the present invention, the outlet of the coke oven 19 is connected to the inlet of the cold drum 20, and the coal gas generated from the coke oven 19 enters the cold drum 20 for cooling;

[0103] The first outlet of the cold drum 20 is connected to the bottom inlet of the desulfurization precooling tower 17, and the coal gas cooled from the cold drum 20 enters the bottom of the desulfurization precooling tower 17 for cooling treatment;

[0104] The second outlet of the cold drum 20 is communicated with the second inlet of the tar-ammonia-water separation tank 18 , and the ammonia water and tar separated from the cold drum 20 enter the tar-ammonia-water separation tank 18 for separation.

[0105] The present invention will be further described in detail below with reference to specific embodiments and comparative examples.

[0106] Example 1

[0107] The high-temperature concentrated ammonia gas (95°C) evaporated from the ammonia evaporation tower 15 enters the bottom of the desulfurization precooling tower 17 through the concentrated ammonia gas branch pipe (first pipeline) and mixes with the coal gas (55°C) at the bottom of the desulfurization precooling tower 17. The temperature of the circulating liquid at the bottom of the desulfurization precooling tower 17 after being cooled by the precooling tower heat exchanger 6 is 26°C. The precooling tower spraying liquid valve 5 is opened and returned to the desulfurization precooling tower 17. The liquid is sprayed from the top of the desulfurization precooling tower 17 to cool down and transfer heat to the coal gas and concentrated ammonia gas in the desulfurization precooling tower 17. The temperature of the coal gas and concentrated ammonia gas at the outlet of the desulfurization precooling tower 17 is 28°C, and the saturated water content of the coal gas is 27.3g / m 3 , adjust the gas outlet valve 12 of the precooling tower to allow the gas to enter the desulfurization tower 16 through the output end at the top of the desulfurization precooling tower 17. The outlet gas temperature of the desulfurization tower 16 is 38°C, and the saturated water content of the gas is 49.3g / m 3 .

[0108] A part of the concentrated ammonia gas after cooling is transferred to the coal gas, thereby increasing the volatile ammonia in the coal gas, and a part of it is transferred to the circulating liquid at the bottom of the desulfurization precooling tower 17 to form dilute ammonia water.

[0109] When the circulating liquid at the bottom of the desulfurization precooling tower 17 exceeds the liquid level limit of 1 meter, the valve 7 for sending the cooling liquid of the precooling tower to the tar-ammonia separation tank is opened, and the tar and other solid impurities sunk at the bottom of the circulating liquid will enter the tar-ammonia separation tank 18 together with the ammonia and other substances in the circulating liquid;

[0110] The separation of ammonia water and tar is achieved in the tar-ammonia water separation tank 18;

[0111] A circulating ammonia water tank 22 is provided in the tar-ammonia water separation tank 18. The ammonia water separated by the tar-ammonia water separation tank 18 enters the circulating ammonia water tank 22, and enters the ammonia evaporation tower 15 again through the residual ammonia water pump 14 to evaporate the ammonia gas in the ammonia water. The discharged residual wastewater enters the wastewater debiochemical system 21 for biochemical treatment.

[0112] Open the valve 8 for sending ammonia water to the gas collecting pipe, and the tar separated by the tar-ammonia water separation tank 18 enters the bridge pipe in the coke oven 19, and participates in the generation of coal gas after being processed. The coal gas enters the gas collecting pipe 9, and the ammonia water in the circulating ammonia water tank 22 is lifted to the gas collecting pipe 9 by the circulating ammonia water pump 13, and the coal gas in the gas collecting pipe 9 (the temperature is 470°C) is sprayed and cooled (the temperature of the cooled coal gas is 80°C);

[0113] Ammonia water, coal gas and impurities such as tar enter the cold drum 20, and the cold drum 20 uses ammonia water in the circulating ammonia water tank 22 to further cool the coal gas. The valve 10 for the coke oven gas to enter the precooling tower is opened, and the coal gas enters the bottom of the desulfurization precooling tower 17 and is mixed with the concentrated ammonia gas again to cool down.

[0114] The ammonia water and tar and other impurities in the cold drum 20 enter the tar ammonia water separation tank 18 again for separation, and the above operation is repeated.

[0115] Example 2

[0116] When the desulfurization tower 16 needs to be replenished, the valve 1 of the ammonia evaporation tower ammonia gas inlet cooler and the valve 3 of the concentrated ammonia gas after the cooler are opened, and the valve 4 of the concentrated ammonia gas inlet precooling tower is closed, and the high-temperature concentrated ammonia gas evaporated from the ammonia evaporation tower 15 enters the concentrated ammonia gas cooler 2, and the high-temperature concentrated ammonia gas is cooled and separated by the cooling water in the concentrated ammonia gas cooler 2 to obtain ammonia gas and cooling ammonia water;

[0117] The separated ammonia gas passes through the cooler and then enters the bottom of the desulfurization precooling tower 17 through the concentrated ammonia valve 3, and mixes with the coal gas at the bottom of the desulfurization precooling tower 17;

[0118] The separated cooled ammonia water enters the desulfurization tower 16 for liquid replenishment. After the liquid in the desulfurization tower 16 is replenished, the valve 1 for the ammonia gas entering the cooler of the ammonia evaporation tower and the valve 3 for the concentrated ammonia gas after the cooler are closed, and the valve 4 for the concentrated ammonia gas entering the precooling tower is opened, and the process in Example 1 is continued to operate.

[0119] Example 3

[0120] The high-temperature concentrated ammonia gas (97°C) evaporated from the ammonia evaporation tower 15 enters the bottom of the desulfurization precooling tower 17 through the concentrated ammonia gas branch pipe, and is mixed with the coal gas (50°C) at the bottom of the desulfurization precooling tower 17. The temperature of the circulating liquid at the bottom of the desulfurization precooling tower 17 is 30°C after being cooled by the precooling tower heat exchanger 6. The precooling tower spraying liquid valve 5 is opened and returned to the desulfurization precooling tower 17. The liquid is sprayed from the top of the desulfurization precooling tower 17 to cool down and transfer heat to the coal gas and concentrated ammonia gas in the desulfurization precooling tower 17. The temperature of the coal gas at the outlet of the desulfurization precooling tower 17 is 30°C, and the saturated water content of the coal gas is 30.4g / m 3 , adjust the gas outlet valve 12 of the precooling tower to allow the gas to enter the desulfurization tower 16 through the output end at the top of the desulfurization precooling tower 17. The outlet gas temperature of the desulfurization tower 16 is 40°C, and the saturated water content of the gas is 51.2 g / m 3 .

[0121] A part of the concentrated ammonia gas after cooling is transferred to the coal gas, thereby increasing the volatile ammonia in the coal gas, and a part of it is transferred to the circulating liquid at the bottom of the desulfurization precooling tower 17 to form dilute ammonia water.

[0122] When the circulating liquid at the bottom of the desulfurization precooling tower 17 exceeds the liquid level limit of 1 meter, the valve 7 for sending the cooling liquid of the precooling tower to the tar-ammonia separation tank is opened, and the tar and other solid impurities sunk at the bottom of the circulating liquid will enter the tar-ammonia separation tank 18 together with the ammonia and other substances in the circulating liquid;

[0123] The separation of ammonia water and tar is achieved in the tar-ammonia water separation tank 18;

[0124] The ammonia separated by the tar ammonia separation tank 18 enters the circulating ammonia tank 22, and enters the ammonia still 15 again through the residual ammonia pump 14 to evaporate the ammonia gas in the ammonia, and the remaining wastewater is discharged into the wastewater debiochemical system 21 for biochemical treatment;

[0125] Open the valve 8 for sending ammonia water to the gas collecting pipe, and the tar separated by the tar-ammonia water separation tank 18 enters the bridge pipe in the coke oven 19, and participates in the generation of coal gas after treatment. The coal gas enters the gas collecting pipe 9, and the ammonia water in the circulating ammonia water tank 22 is lifted to the gas collecting pipe 9 by the circulating ammonia water pump 13, and the coal gas in the gas collecting pipe 9 (temperature is 500°C) is sprayed and cooled (the temperature of the cooled coal gas is 85°C);

[0126] Ammonia water, coal gas and impurities such as tar enter the cold drum 20, and the cold drum 20 uses ammonia water in the circulating ammonia water tank 22 to further cool the coal gas. The valve 10 for the coke oven gas to enter the precooling tower is opened, and the coal gas enters the bottom of the desulfurization precooling tower 17 and is mixed with the concentrated ammonia gas again to cool down.

[0127] The ammonia water and tar and other impurities in the cold drum 20 enter the tar ammonia water separation tank 18 again for separation, and the above operation is repeated.

[0128] Example 4

[0129] The high-temperature concentrated ammonia gas (90°C) evaporated from the ammonia evaporation tower 15 enters the bottom of the desulfurization precooling tower 17 through the concentrated ammonia gas branch pipe, and is mixed with the coal gas (45°C) at the bottom of the desulfurization precooling tower 17. The temperature of the circulating liquid at the bottom of the desulfurization precooling tower 17 is 25°C after being cooled by the precooling tower heat exchanger 6. The precooling tower spraying liquid valve 5 is opened and returned to the desulfurization precooling tower 17. The liquid is sprayed from the top of the desulfurization precooling tower 17 to cool down and transfer heat to the coal gas and concentrated ammonia gas in the desulfurization precooling tower 17. The temperature of the coal gas at the outlet of the desulfurization precooling tower 17 is 26°C, and the saturated water content of the coal gas is 25.8g / m 3 , adjust the gas outlet valve 12 of the precooling tower to allow the gas to enter the desulfurization tower 16 through the output end at the top of the desulfurization precooling tower 17. The outlet gas temperature of the desulfurization tower 16 is 37°C, and the saturated water content of the gas is 44.8g / m 3 .

[0130] A part of the concentrated ammonia gas after cooling is transferred to the coal gas, thereby increasing the volatile ammonia in the coal gas, and a part of it is transferred to the circulating liquid at the bottom of the desulfurization precooling tower 17 to form dilute ammonia water.

[0131] When the circulating liquid at the bottom of the desulfurization precooling tower 17 exceeds the liquid level limit of 1 meter, the valve 7 for sending the cooling liquid of the precooling tower to the tar-ammonia separation tank is opened, and the tar and other solid impurities sunk at the bottom of the circulating liquid will enter the tar-ammonia separation tank 18 together with the ammonia and other substances in the circulating liquid;

[0132] The separation of ammonia water and tar is achieved in the tar-ammonia water separation tank 18;

[0133] A circulating ammonia water tank 22 is provided in the tar-ammonia water separation tank 18. The ammonia water separated by the tar-ammonia water separation tank 18 enters the circulating ammonia water tank 22, and enters the ammonia evaporation tower 15 again through the residual ammonia water pump 14 to evaporate the ammonia gas in the ammonia water. The discharged residual wastewater enters the wastewater debiochemical system 21 for biochemical treatment.

[0134] Open the valve 8 for sending ammonia water to the gas collecting pipe, and the tar separated by the tar-ammonia water separation tank 18 enters the bridge pipe in the coke oven 19, and participates in the generation of coal gas after treatment. The coal gas enters the gas collecting pipe 9, and the ammonia water in the circulating ammonia water tank 22 is lifted to the gas collecting pipe 9 by the circulating ammonia water pump 13, and the coal gas in the gas collecting pipe 9 (temperature is 450°C) is sprayed and cooled (the temperature of the cooled coal gas is 75°C);

[0135] Ammonia water, coal gas and impurities such as tar enter the cold drum 20, and the cold drum 20 uses ammonia water in the circulating ammonia water tank 22 to further cool the coal gas. The valve 10 for the coke oven gas to enter the precooling tower is opened, and the coal gas enters the bottom of the desulfurization precooling tower 17 and is mixed with the concentrated ammonia gas again to cool down.

[0136] The ammonia water and tar and other impurities in the cold drum 20 enter the tar ammonia water separation tank 18 again for separation, and the above operation is repeated.

[0137] Comparative Example 1

[0138] This comparative example is a traditional HPF desulfurization process, the main difference is that no concentrated ammonia branch pipe is set, the high-temperature concentrated ammonia produced in the ammonia evaporation tower first passes through the concentrated ammonia cooler, and the cooled ammonia and ammonia water enter the desulfurization precooling tower 17 together;

[0139] The content of the desulfurized liquid produced in this comparative example is shown in Table 1.

[0140] Comparative Example 2

[0141] The difference between this comparative example and Example 1 is that the temperature of the coal gas at the outlet of the desulfurization precooling tower 17 is 35°C, and the saturated water content of the coal gas is 40.2 g / m 3 , but the temperature of the coal gas at the outlet of the desulfurization tower 16 is controlled to be 38° C. (same as in Example 1), and the other technical parameters are controlled within the range defined in the present invention, and the operation steps are the same as in Example 1;

[0142] The content of the desulfurized liquid produced in this comparative example is shown in Table 1.

[0143] Comparative Example 3

[0144] The difference between this comparative example and Example 1 is that the temperature of the coal gas at the outlet of the desulfurization tower 16 is 35°C, and the saturated water content of the coal gas is 40.5 g / m 3 , but the temperature of the outlet gas of the desulfurization precooling tower 17 is 28° C. (same as in Example 1), and the other technical parameters are controlled within the range defined in the present invention, and the operation steps are the same as in Example 1;

[0145] The content of the desulfurized liquid produced in this comparative example is shown in Table 1.

[0146] The desulfurization liquid content (rounded) produced every day in Examples 1-4 and Comparative Examples 1-3 is shown in Table 1:

[0147] Table 1

[0148]

[0149] According to Table 1, compared with Example 1, since no concentrated ammonia branch pipe (i.e., the first pipeline) is added in Comparative Example 1, most of the ammonia water produced after passing through the concentrated ammonia cooler enters the desulfurization tower, resulting in the production of a large amount of desulfurization liquid.

[0150] According to Table 1, compared with Example 1, since the temperature of the coal gas and concentrated ammonia at the outlet of the desulfurization precooling tower is 35°C, the temperature of the coal gas at the outlet of the desulfurization precooling tower is too high, resulting in a smaller difference in the temperature of the coal gas at the outlet of the desulfurization precooling tower and the temperature of the coal gas at the outlet of the desulfurization precooling tower, resulting in an increase in the desulfurization liquid content.

[0151] According to Table 1, compared with Example 1, since the temperature of the desulfurization tower outlet gas and concentrated ammonia is 35°C, the temperature of the desulfurization tower outlet gas is too low, resulting in a smaller temperature difference between the desulfurization tower outlet gas and the desulfurization precooling tower outlet gas, resulting in an increase in the desulfurization liquid content.

[0152] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for desulfurizing coke oven gas, characterized in that: include: The high-temperature concentrated ammonia gas evaporated from the ammonia evaporation tower (15) directly enters the bottom of the desulfurization precooling tower (17) and is mixed with the coal gas entering the bottom of the desulfurization precooling tower (17). The circulating liquid at the bottom of the desulfurization precooling tower (17) is cooled and then returns to the top of the desulfurization precooling tower (17), and then contacts with the coal gas and the concentrated ammonia gas in reverse direction to cool them. The cooled coal gas and the concentrated ammonia gas are discharged from the top outlet of the desulfurization precooling tower (17), and then enter the desulfurization tower (16) for desulfurization treatment. The temperature of the coal gas and concentrated ammonia gas at the outlet of the desulfurization precooling tower (17) is ≤30°C; Among them, the gas saturated water content is 25.8-30.4g / m 3 ; The temperature of the coal gas at the outlet of the desulfurization tower (16) is 37-40°C; The gas saturated water content is 44.8-51.2g / m 3 .

2. The method for desulfurizing coke oven gas according to claim 1, characterized in that: The temperature of the high-temperature concentrated ammonia gas is 90-97°C; and / or, the temperature of the circulating liquid returning to the top of the desulfurization precooling tower (17) after being cooled by the precooling tower heat exchanger (6) is 25-30°C; and / or, the temperature of the desulfurization liquid in the desulfurization tower (16) is 35-40° C.; The cooling water volume in the desulfurization tower (16) is 350-550m 3 / h.

3. The method for desulfurizing coke oven gas according to claim 1, characterized in that: When the desulfurization tower (16) needs to be replenished, the high-temperature concentrated ammonia gas evaporated from the ammonia evaporation tower (15) is first cooled and separated to obtain ammonia gas and cooling ammonia water; The separated ammonia gas enters the bottom of the desulfurization precooling tower (17) and is then mixed with the coal gas entering the bottom of the desulfurization precooling tower (17); The separated cooling ammonia water enters the desulfurization tower for liquid replenishment.

4. The method for desulfurizing coke oven gas according to claim 1, characterized in that: Also includes: The cooled concentrated ammonia gas and the circulating liquid at the bottom of the desulfurization precooling tower (17) enter the tar-ammonia separation tank (18) for mixing and separation. The tar separated in the tar-ammonia separation tank (18) is treated in a coke oven (19) to produce coal gas. The part of ammonia water separated by the tar-ammonia water separation tank (18) is used to cool the coal gas in the coke oven (19), and the remaining ammonia water separated is sent to the ammonia evaporation tower (15) for ammonia evaporation treatment, and the ammonia evaporation wastewater generated by the ammonia evaporation treatment is subjected to biochemical treatment; The coal gas discharged from the coke oven (19) is treated by the cooling drum (20) and then enters the bottom of the desulfurization precooling tower (17) to mix with the concentrated ammonia gas.

5. The method for desulfurizing coke oven gas according to claim 4, characterized in that: The temperature of the coal gas generated in the coke oven (19) is 450-500°C; and / or, the temperature of the coal gas after cooling down the part of ammonia water separated by the tar ammonia water separation tank (18) is 75-85°C; And / or, the temperature of the coal gas after being cooled by the cold drum (20) is 45-55°C.

6. A device for the coke oven gas desulfurization method according to any one of claims 1 to 5, characterized in that: It comprises an ammonia evaporation tower (15), a concentrated ammonia cooler (2), a desulfurization tower (16), a desulfurization precooling tower (17) and a precooling tower heat exchanger (6); A first pipeline and a second pipeline are arranged between the ammonia evaporation tower (15) and the desulfurization precooling tower (17). The ammonia evaporation tower (15) is connected to the desulfurization precooling tower (17) through the first pipeline or the second pipeline. The first pipeline is used to directly pass the high-temperature concentrated ammonia gas evaporated from the ammonia evaporation tower (15) to the bottom of the desulfurization precooling tower (17). The second pipeline is provided with a concentrated ammonia cooler (2). The concentrated ammonia cooler (2) is used to first cool the high-temperature concentrated ammonia gas evaporated from the ammonia evaporation tower (15), pass the separated ammonia gas to the bottom of the desulfurization precooling tower (17) for cooling, and pass the separated ammonia water to the desulfurization tower (16) for liquid supplement; The top outlet of the desulfurization precooling tower (17) is connected to the inlet of the desulfurization tower (16), and the cooled coal gas and concentrated ammonia gas enter the desulfurization tower (16) from the top of the desulfurization precooling tower (17) for desulfurization treatment.

7. The device according to claim 6, characterized in that The first pipeline is provided with a concentrated ammonia gas inlet precooling tower valve (4); An ammonia evaporation tower ammonia gas inlet cooler valve (1) is provided between the ammonia evaporation tower (15) and the concentrated ammonia gas cooler (2); A concentrated ammonia valve (3) after the cooler is provided between the concentrated ammonia cooler (2) and the desulfurization precooling tower (17).

8. The device according to claim 6, characterized in that A precooling tower heat exchanger (6) is provided between the bottom and the top of the desulfurization precooling tower (17). The precooling tower heat exchanger (6) is used to transport the circulating liquid cooled at the bottom of the desulfurization precooling tower (17) to the top of the desulfurization precooling tower (17) to cool the coal gas and concentrated ammonia.

9. The device according to claim 6, characterized in that It also includes a tar-ammonia separation tank (18), a coke oven (19) and a gas collecting pipe (9); The bottom outlet of the desulfurization precooling tower (17) is connected to the first inlet of the tar-ammonia water separation tank (18), and the concentrated ammonia gas and the bottom circulating liquid of the desulfurization precooling tower (17) enter the tar-ammonia water separation tank (18) from the bottom outlet of the desulfurization precooling tower (17) to be separated; The outlet of the tar-ammonia-water separation tank (18) is connected to the inlet of the coke oven (19), and the tar separated from the tar-ammonia-water separation tank (18) is transported to the coke oven (19) for treatment; The tar-ammonia separation tank (18) is provided with a circulating ammonia tank (22) for storing ammonia separated from the tar-ammonia separation tank (18); The first outlet of the circulating ammonia water tank (22) is connected to the gas collecting pipe (9), and the cooling ammonia water in the circulating ammonia water tank (22) cools the coal gas in the gas collecting pipe (9); The second outlet of the circulating ammonia water tank (22) is connected to the inlet of the ammonia evaporation tower (15), and the remaining ammonia water in the circulating ammonia water tank (22) enters the ammonia evaporation tower (15) for ammonia evaporation treatment.

10. The device according to claim 8, characterized in that Also included is a cooling drum (20); The outlet of the coke oven (19) is connected to the inlet of the cooling drum (20), and the coal gas generated from the coke oven (19) enters the cooling drum (20) for cooling; The first outlet of the cold drum (20) is connected to the bottom inlet of the desulfurization precooling tower (17), and the coal gas cooled from the cold drum (20) enters the bottom of the desulfurization precooling tower (17) for cooling treatment; The second outlet of the cold drum (20) is connected to the second inlet of the tar-ammonia-water separation tank (18), and the ammonia water and tar separated from the cold drum (20) enter the tar-ammonia-water separation tank (18) for separation.

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