Coke oven gas purification system

Abstract

The application provides a coke oven gas purification system, wherein tar in raw coke oven gas is removed through a coking removal device, the raw coke oven gas after coking removal is pressurized by a blower and then sent to a desulfurization device to remove hydrogen sulfide in the raw coke oven gas, the coke oven gas after desulfurization is first dehydrated by a gas-liquid separator and then sequentially subjected to oil removal by an oil removal device and naphthalene removal by a naphthalene removal device to produce purified coke oven gas. The system of the application removes tar, hydrogen sulfide, naphthalene and water in the raw coke oven gas through cooperation of the above devices, realizes purification of the raw coke oven gas, and effectively avoids problems such as equipment corrosion, catalyst poisoning, pipeline blockage, low combustion efficiency and environmental pollution caused by direct utilization of the raw coke oven gas.

Description

Technical Field

[0001] This application relates to the field of coke oven gas purification technology, and in particular to a coke oven gas purification system. Background Technology

[0002] Coke oven gas, also known as coke oven coal gas, is a high-calorific-value gas due to its high combustible content (coke oven gas is mainly composed of hydrogen and methane, accounting for 56% and 27% respectively, with small amounts of carbon monoxide, carbon dioxide, nitrogen, oxygen and other hydrocarbons). Coke oven gas refers to a combustible gas produced in a coke oven after high-temperature dry distillation of several types of bituminous coal to produce coke and tar products. It is a by-product of the coking industry.

[0003] Coke oven gas, a core byproduct of the coking industry, requires efficient purification and comprehensive utilization as a key link in promoting the industry's green transformation and achieving "dual carbon" goals. my country's annual coke oven gas production exceeds 150 billion cubic meters, but its composition is complex, containing impurities such as tar (2-12 g / m³), hydrogen sulfide (3-15 g / m³), naphthalene (0.5-3 g / m³), and moisture (saturated water content). This leads to problems such as equipment corrosion, catalyst poisoning, pipeline blockage, low combustion efficiency, and environmental pollution during subsequent utilization. Therefore, removing tar, H₂S, naphthalene, and moisture from coke oven gas has become the focus of the coke oven gas purification process. Utility Model Content

[0004] This application provides a coke oven gas purification system to remove tar, H2S, naphthalene and moisture from coke oven gas, so as to avoid the problems caused by the presence of the above substances in the subsequent utilization of coke oven gas, such as equipment corrosion, catalyst poisoning, pipeline blockage, low combustion efficiency and environmental pollution.

[0005] This application provides a coke oven gas purification system, including a raw gas pipeline, a coke removal device, a desulfurization device, a gas holder, a gas-liquid separator, an oil removal device, and a naphthalene removal device connected in series.

[0006] The coking unit and the desulfurization unit are connected by a gas blower;

[0007] The gas holder and the gas-liquid separator are connected by a compressor.

[0008] Optionally, the decoking device includes a separator, a primary cooler, and an electrostatic precipitator connected in series.

[0009] Both the separator and the primary cooler are connected to the mechanized tar-ammonia clarification tank;

[0010] The gas output end of the electrostatic precipitator is connected to a gas blower.

[0011] Optionally, the primary cooler is divided into an upper cooling zone and a lower cooling zone by a partition;

[0012] Cooling tubes are installed in the upper and lower cooling zones respectively;

[0013] The partition is penetrated by a vertically arranged connecting pipe, which connects the cooling zone and the lower cooling zone. The connecting pipe is equipped with a rainproof cap at the top of the upper cooling zone.

[0014] The primary cooler has an air inlet on one side of the upper part and an exhaust outlet on one side of the lower part.

[0015] The upper cooling zone is sequentially connected to the first water seal tank, the first cleaning fluid circulation tank, and the first circulation pump to form a loop;

[0016] The upper cooling zone is connected in sequence to the second water seal tank, the second cleaning fluid circulation tank, and the second circulation pump to form a loop;

[0017] The first and second cleaning fluid circulation tanks are connected by a pipe.

[0018] The second circulation pump is also connected to a mechanized tar-ammonia clarification tank.

[0019] Optionally, the desulfurization unit includes a precooling tower and a desulfurization tower connected in series;

[0020] The desulfurization tower is connected to the gas holder.

[0021] Optionally, the desulfurization tower is connected in sequence to the desulfurization liquid circulation tank, the desulfurization liquid circulation pump, and the regeneration tower to form a loop;

[0022] The regeneration tower is also connected in sequence to the sulfur foam tank, sulfur foam pump, sulfur melting kettle and desulfurization liquid circulation tank;

[0023] The regeneration tower is also connected to a compressed air pipeline;

[0024] The desulfurization liquid circulation tank is also connected to the catalyst metering pump and the ammonia supply device.

[0025] Optionally, the regeneration tower includes a tower body, with a desulfurization liquid inlet and an air inlet respectively opened on the lower side of the tower body;

[0026] The top of the tower is sealed by a buffer cap, and an overflow port is provided on the side of the top of the tower inside the buffer cap.

[0027] A circulation port is provided on the upper part of the tower body and on one side outside the buffer cap, and the circulation port is connected to the desulfurization tower.

[0028] The top of the buffer cap is equipped with a float valve, the bottom of the buffer cap is inclined, and the lower side of the bottom is connected to the sulfur foam tank through a pipe.

[0029] Optionally, the oil removal device includes multiple oil removal towers connected in series;

[0030] The naphthalene removal unit consists of multiple naphthalene removal towers connected in series.

[0031] The coke oven gas purification system provided in this application removes tar from raw coke oven gas through a coke removal device. The decoked raw coke oven gas is then pressurized by a blower and sent to a desulfurization device to remove hydrogen sulfide. The desulfurized gas then passes through a gas-liquid separator to remove water, followed by an oil removal device and a naphthalene removal device to remove naphthalene, ultimately producing purified gas. This system, through the coordinated use of the above devices, removes tar, hydrogen sulfide, naphthalene, and moisture from the raw coke oven gas, achieving purification and effectively avoiding problems such as equipment corrosion, catalyst poisoning, pipeline blockage, low combustion efficiency, and environmental pollution caused by the direct use of raw coke oven gas. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 A schematic diagram of a coke oven gas purification system is provided for one embodiment of this application;

[0034] Figure 2 This is a schematic diagram of a decoking device provided in one embodiment of this application;

[0035] Figure 3 This is a schematic diagram of the structure of a primary cooler provided in one embodiment of this application;

[0036] Figure 4 This is a schematic diagram of a desulfurization device provided in one embodiment of this application;

[0037] Figure 5 This is a schematic diagram of the structure of a regeneration tower provided in an embodiment of this application;

[0038] Figure 6 This is a schematic diagram of an oil removal device and a naphthalene removal device provided in an embodiment of this application.

[0039] Explanation of reference numerals in the attached figures:

[0040] 1. Raw coal gas pipeline; 2. Coke removal device; 3. Desulfurization device; 4. Gas holder; 5. Gas-liquid separator; 6. Oil removal device; 7. Naphthalene removal device; 10. Coal gas blower; 20. Compressor; 21. Separator; 22. Primary cooler; 23. Electrostatic precipitator for tar; 24. Mechanized tar-ammonia water clarification tank; 31. Precooling tower; 32. Desulfurization tower; 33. Desulfurization liquid circulation tank; 34. Desulfurization liquid circulation pump; 35. Regeneration tower; 36. Sulfur foam tank; 37. Sulfur melting kettle; 61. Oil removal tower; 71. Naphthalene removal tower; 211. First water seal tank; 212. First cleaning liquid circulation tank. 213. Tank; 214. First circulating pump; 215. Second water seal tank; 216. Second cleaning fluid circulating tank; 221. Second circulating pump; 221. Baffle plate; 300. Compressed air pipeline; 310. Sulfur foam pump; 320. Catalyst metering pump; 330. Ammonia water supply device; 351. Tower body; 352. Buffer cap; 2201. Air inlet; 2202. Exhaust port; 2211. Connecting pipe; 2212. Rainproof cap; 3500. Float valve; 3501. Desulfurization liquid inlet; 3502. Air inlet; 3503. Overflow port; 3504. Circulation port. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application are described clearly and completely below. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are also within the scope of protection of this application.

[0042] like Figure 1 As shown, this application provides a coke oven gas purification system, including a raw gas pipeline 1, a coke removal device 2, a desulfurization device 3, a gas holder 4, a gas-liquid separator 5, an oil removal device 6, and a naphthalene removal device 7 connected in series.

[0043] The coke removal unit 2 and the desulfurization unit 3 are connected by a gas blower 10;

[0044] The gas holder 4 and the gas-liquid separator 5 are connected by a compressor 20.

[0045] In operation, the system of this application, during the coking process, involves the raw coal gas produced by the coking process being cooled by ammonia water spraying, and then output through the raw coal gas pipeline 1 to the coking removal device 2 for coking removal (e.g., electrostatic precipitator coking removal). After tar removal, the raw coal gas is pressurized by the gas blower 10 and transported to the desulfurization device 3 for desulfurization. The desulfurized raw coal gas is then output from the desulfurization device 3 into the gas holder 4.

[0046] The desulfurized coal gas temporarily stored in the gas holder 4 is compressed and pressurized by the compressor 20 (compressor 20 is, for example, a screw compressor) and then input into the gas-liquid separator 5 to separate the moisture in the coal gas. After the water is separated, the coal gas passes through the oil removal device 6 and the naphthalene removal device 7 in sequence to remove oil and naphthalene, thereby obtaining purified finished coal gas, which can be used for external sale or internal use of the enterprise.

[0047] The coke oven gas purification system provided in this application removes tar from the raw coke oven gas by setting up a coke removal device 2. The coke-removed raw coke oven gas is then pressurized by a blower 10 and sent to a desulfurization device 3 to remove hydrogen sulfide. The desulfurized gas then passes through a gas-liquid separator 5 to remove water, followed by an oil removal device 6 for oil removal, and a naphthalene removal device 7 to remove naphthalene, resulting in purified gas. This system, through the combined use of the above devices, removes tar, hydrogen sulfide, naphthalene, and moisture from the raw coke oven gas, achieving purification and effectively avoiding problems such as equipment corrosion, catalyst poisoning, pipeline blockage, low combustion efficiency, and environmental pollution caused by the direct use of raw coke oven gas.

[0048] like Figure 2 As shown, optionally, the decoking device 2 includes a separation tank 21, a primary cooler 22 and an electrostatic precipitator 23 connected in series.

[0049] Both the separator 21 and the primary cooler 22 are connected to the mechanized tar-ammonia clarification tank 24;

[0050] The gas output end of the electrostatic precipitator 23 is connected to the gas blower 10.

[0051] In operation, the raw coal gas produced during the coking process of this application is cooled by ammonia spray and then output through raw coal gas pipeline 1 to the separation tank 21 of the decoking device 2. The raw coal gas mixed with ammonia droplets is separated in the separation tank 21. The separated ammonia water (which contains tar) is discharged to the mechanized tar ammonia water clarification tank 24 for further treatment. The separated raw coal gas then enters the primary cooler 22 for cooling. After cooling, the raw coal gas is input into the electrostatic precipitator 23 for electrostatic coking. After tar removal by electrostatic precipitator, the raw coal gas is pressurized by the gas blower 10 and sent to the desulfurization device 3 for desulfurization.

[0052] like Figure 3 As shown, optionally, the primary cooler 22 is divided into an upper cooling zone and a lower cooling zone by a partition 221;

[0053] Cooling tubes 222 are provided in the upper cooling zone and the lower cooling zone respectively;

[0054] The partition 221 is penetrated by a vertically arranged connecting pipe 2211, which connects the cooling zone and the lower cooling zone. The connecting pipe 2211 is located at the top of the upper cooling zone and is equipped with a rainproof cap 2212.

[0055] The primary cooler 22 has an air inlet 2201 on one side of the upper part and an exhaust port 2202 on one side of the lower part.

[0056] The upper cooling zone is connected in sequence to the first water seal tank 211, the first cleaning fluid circulation tank 212, and the first circulation pump 213 to form a loop;

[0057] The upper cooling zone is connected in sequence to the second water seal tank 214, the second cleaning fluid circulation tank 215, and the second circulation pump 216 to form a loop;

[0058] The first cleaning fluid circulation tank 212 and the second cleaning fluid circulation tank 215 are connected by a pipe.

[0059] The second circulation pump 216 is also connected to the mechanized tar ammonia clarification tank 24.

[0060] In the primary cooler 22 of this application, the portion of the connecting pipe 2211 located in the upper cooling zone extends above the baffle 221 to prevent the washing liquid in the upper cooling zone from flowing into the cooling tubes 222 in the lower cooling zone during washing, thus preventing secondary contamination of the lower cooling tubes 222. Simultaneously, a rainproof cap 2212 is provided at the top of the connecting pipe 2211 to prevent the washing liquid from directly falling into the connecting pipe 2211. A gap is left between the connecting pipe 2211 and the rainproof cap 2212 to facilitate gas flow. The connecting pipe 2211 and the rainproof cap 2212 can be connected, for example, by multiple connecting ribs arranged circumferentially along the top of the connecting pipe 2211.

[0061] Because the upper cooling zone comes into contact with the tar-containing raw coal gas first, the outer wall of the cooling tubes 222 in the upper cooling zone is more heavily soiled, and the upper cooling zone requires more frequent washing. This arrangement allows the washing processes of the upper and lower cooling zones to be independent of each other. A corresponding washing device, such as a spray nozzle, is installed at the top of the upper cooling zone, and a corresponding spray washing device is also installed in the lower cooling zone. (To avoid the tar in the raw coal gas contaminating the washing device, the outlet of the raw coal gas entering the upper cooling zone should be lower than the position of the washing device; similarly, the outlet of the raw coal gas entering the lower cooling zone should also be lower than the position of the washing device in that zone. For example, the lower outlet of the connecting pipe 2211 can be set lower than the position of the washing device in that zone.)

[0062] During cooling in the primary cooler 22, the raw coal gas is input from the inlet 2201 of the upper cooling zone, passes downward through the cooling tubes 222 in the upper cooling zone, and exchanges heat with the heat exchange medium in the cooling tubes 222 to cool down. After cooling down in the upper cooling zone, the raw coal gas goes down through the connecting pipe 2211 into the lower cooling zone, exchanges heat with the cooling tubes 222 in the lower cooling zone to cool down, and is discharged from the exhaust port 2202 of the lower cooling zone after cooling down.

[0063] Because the raw coal gas in the primary cooler 22 contains tar droplets and other substances during use, these tar droplets will adhere to the outer wall of the cooling tubes during primary cooling, thus requiring regular cleaning. During cleaning, the upper and lower cooling zones can be cleaned independently. When cleaning the upper cooling zone, the first circulation pump 213 draws cleaning fluid (mainly ammonia) from the first cleaning fluid circulation tank 212 and pumps it into the spray device of the upper cooling zone to clean the cooling tubes. The cleaning fluid falls onto the partition 221. Since the upper and lower cooling zones are connected by a connecting pipe 2211, which extends above the partition 221 and is equipped with a rainproof cap 2212, the cleaning fluid from the upper cooling tubes is prevented from falling into the lower cooling zone. The cleaning fluid then flows from the upper cooling zone through the first water seal tank 211 (the water seal tank prevents gas leakage from the primary cooler 22 and prevents outside air from entering the primary cooler 22) before entering the first cleaning fluid circulation tank 212 for settling. The supernatant is used for washing. The corresponding cleaning process for the lower cooling zone is similar to that for the upper cooling zone and will not be described in detail here. Furthermore, since the first cleaning fluid circulation tank 212 and the second cleaning fluid circulation tank 215 are connected by a pipe, they form a communicating vessel, allowing for mutual fluid replenishment during operation. When the tar in the cleaning fluid accumulates to a certain level, the cleaning fluid is transferred to the mechanized tar-ammonia water clarification tank 24 for further treatment via the second circulation pump 216.

[0064] like Figure 4 As shown, optionally, the desulfurization unit 3 includes a precooling tower 31 and a desulfurization tower 32 connected in series.

[0065] The desulfurization tower 32 is connected to the gas holder 4.

[0066] In this application, during desulfurization in desulfurization unit 3, since the proposed method is PDS wet desulfurization, heat is released during the desulfurization process, causing the temperature of the reaction system to rise. This method of desulfurization has strict temperature requirements and should be controlled to not exceed 60℃, otherwise it will accelerate the occurrence of side reactions. Therefore, the raw coal gas is first pre-cooled in pre-cooling tower 31 (to a temperature of 10~15℃). The cooled raw coal gas enters desulfurization tower 32 and travels from bottom to top, making countercurrent contact with the desulfurization liquid sprayed from the top of the tower. The desulfurization liquid absorbs the sulfur-containing compounds (mainly hydrogen sulfide) in the raw coal gas. The desulfurized raw coal gas is then output from the top of desulfurization tower 32 into gas holder 4.

[0067] like Figure 4 As shown, optionally, the desulfurization tower 32 is connected in sequence to the desulfurization liquid circulation tank 33, the desulfurization liquid circulation pump 34 and the regeneration tower 35 to form a loop;

[0068] The regeneration tower 35 is also connected in sequence to the sulfur foam tank 36, the sulfur foam pump 310, the sulfur melting kettle 37 and the desulfurization liquid circulation tank 33;

[0069] The regeneration tower 35 is also connected to the compressed air line 300;

[0070] The desulfurization liquid circulation tank 33 is also connected to the catalyst metering pump 320 and the ammonia water supply device 330.

[0071] The desulfurization liquid that absorbs sulfides in the desulfurization tower 32 has PDS catalyst in it oxidizing the absorbed sulfides into elemental sulfur. The desulfurization liquid mixed with elemental sulfur is then fed into the desulfurization liquid circulation tank 33. After being pumped into the regeneration tower 35 by the desulfurization liquid circulation pump 34 for regeneration, it is then circulated back to the desulfurization tower 32 for reuse. When the regeneration tower 35 is in operation, compressed air supplied by the compressed air pipeline 300 is introduced into the regeneration tower 35 and comes into contact with the desulfurization liquid in the form of aeration. The active ions of the catalyst in the desulfurization liquid re-adsorb oxygen to complete the regeneration. During this process, since the desulfurization liquid also contains sulfur elemental particles produced by oxidation in the desulfurization tower, sulfur-containing foam is formed floating on the surface of the desulfurization liquid during the compressed air aeration process. These sulfur-containing foams are output to the sulfur foam tank 36 and then pumped into the sulfur melting kettle 37 by the sulfur foam pump 310 for heating and melting. Since the sulfur foam input into the sulfur melting kettle 37 is mixed with some desulfurization liquid, the desulfurization liquid and liquid sulfur are separated after the sulfur is melted. The separated desulfurization liquid is returned to the desulfurization liquid circulation tank 33 for recovery, while the liquid sulfur is sent to the subsequent refining section for further processing and purification.

[0072] In this application, the desulfurization liquid should be kept alkaline to ensure that it can fully absorb sulfides. In this application, ammonia water (which comes from the ammonia water purified by the ammonia stripping tower) is supplied to the desulfurization liquid circulation tank 33 through the ammonia water supply device 330. At the same time, the catalyst metering pump 320 is also required to replenish the desulfurization catalyst (PDS catalyst) to the desulfurization liquid circulation tank 33 in a timely manner.

[0073] like Figure 5 As shown, optionally, the regeneration tower 35 includes a tower body 351, and the lower side of the tower body 351 is provided with a desulfurization liquid inlet 3501 and an air inlet 3502 respectively.

[0074] The top of the tower body 351 is closed by a buffer cap 352, and an overflow port 3503 is provided on the side of the top of the tower body 351 inside the buffer cap 352.

[0075] A circulation port 3504 is provided on the upper part of the tower body 351 and on one side outside the buffer cap 352. The circulation port 3504 is connected to the desulfurization tower 32.

[0076] The top of the buffer cap 352 is equipped with a float valve 3500, the bottom of the buffer cap 352 is inclined, and the lower side of the bottom is connected to the sulfur foam tank 36 through a pipe.

[0077] When the desulfurization liquid is regenerated in the regeneration tower 35, compressed air supplied by the compressed air pipeline 300 is introduced into the regeneration tower 35 through the air inlet 3502 and comes into contact with the desulfurization liquid in the form of aeration. The active ions of the catalyst in the desulfurization liquid re-adsorb oxygen to complete the regeneration. During this process, since the desulfurization liquid also contains sulfur elemental particles generated by oxidation in the desulfurization tower, sulfur-containing foam is formed floating on the surface of the desulfurization liquid during the compressed air aeration process. These sulfur-containing foams are discharged into the buffer cap 352 through the overflow port 3503 opened at the top of the tower body 351, and then output to the sulfur foam tank 36 and then pumped into the sulfur melting kettle 37 by the sulfur foam pump 310 for heating and melting. Since the sulfur foam input into the sulfur melting kettle 37 is mixed with some desulfurization liquid, the desulfurization liquid and liquid sulfur are separated after the sulfur is melted. The separated desulfurization liquid is returned to the desulfurization liquid circulation tank 33 for recovery, while the liquid sulfur is sent to the subsequent refining section for further processing and purification.

[0078] The desulfurization liquid regenerated in regeneration tower 35 is output from the circulation port 3504 at the top of tower body 351. To prevent elemental sulfur from flowing back into desulfurization tower 32 and clogging the spray nozzles, a filter screen should be installed at the circulation port 3504 inside the tower, or a filter should be installed on the pipeline returning to desulfurization tower 32. Since a float valve 3500 is installed at the top of regeneration tower 35 to facilitate timely discharge of air from the tower, to prevent outside air from being polluted, a tail gas treatment device can be connected after the float valve 3500, or it can be connected to a centralized tail gas pipeline for centralized treatment.

[0079] like Figure 6 As shown, optionally, the oil removal device 6 includes a plurality of oil removal towers 61 connected in series;

[0080] The naphthalene removal unit 7 includes multiple naphthalene removal towers 71 connected in series.

[0081] A coke oven gas purification system, the working process of which is as follows:

[0082] During operation, the raw coal gas produced during the coking process is cooled by ammonia spray and then output to the separation tank 21 of the coke removal device 2 through the raw coal gas pipeline 1. The raw coal gas mixed with ammonia droplets is separated in the separation tank 21. The separated ammonia water (which contains tar) is discharged to the mechanized tar ammonia water clarification tank 24 for treatment. The separated raw coal gas then enters the primary cooler 22 for cooling. During cooling in the primary cooler 22, the raw coal gas is input from the inlet 2201 of the upper cooling zone, passes downward through the cooling tubes 222 in the upper cooling zone, and exchanges heat with the heat exchange medium in the cooling tubes 222 to cool down. After cooling down in the upper cooling zone, the raw coal gas goes down through the connecting pipe 2211 into the lower cooling zone, where it exchanges heat with the cooling tubes 222 to cool down. After cooling down, the raw coal gas is discharged from the exhaust port 2202 of the lower cooling zone and enters the electrostatic precipitator 23 for electrostatic coking. After tar removal by electrostatic coking, the raw coal gas is pressurized by the gas blower 10 and transported to the desulfurization unit 3 for desulfurization.

[0083] During desulfurization in desulfurization unit 3, since the proposed method is PDS wet desulfurization, heat is released during the process, causing the temperature of the reaction system to rise. This method of desulfurization has strict temperature requirements and should be controlled to not exceed 60℃, otherwise it will accelerate the occurrence of side reactions. Therefore, the raw coal gas is first pre-cooled in pre-cooling tower 31 (to a temperature of 10~15℃). The cooled raw coal gas enters desulfurization tower 32 and flows from bottom to top, making countercurrent contact with the desulfurization liquid sprayed from the top of the tower. The desulfurization liquid absorbs the sulfur-containing compounds (mainly hydrogen sulfide) in the raw coal gas. The desulfurized raw coal gas is then output from the top of desulfurization tower 32 into gas holder 4. The desulfurization liquid that has absorbed sulfides has its PDS catalyst oxidizing the absorbed sulfides into elemental sulfur. The desulfurization liquid mixed with elemental sulfur is then fed into the desulfurization liquid circulation tank 33, pumped into the regeneration tower 35 by the desulfurization liquid circulation pump 34 for regeneration, and then circulated back to the desulfurization tower 32 for reuse. When the desulfurization liquid is regenerated in the regeneration tower 35, compressed air supplied by the compressed air pipeline 300 is introduced into the regeneration tower 35 through the air inlet 3502 and comes into contact with the desulfurization liquid in the form of aeration. The active ions of the catalyst in the desulfurization liquid adsorb oxygen again to complete the regeneration. During this process, since the desulfurization liquid also contains sulfur elemental particles generated by oxidation in the desulfurization tower, sulfur-containing foam is formed floating on the surface of the desulfurization liquid during the compressed air aeration process. These sulfur-containing foams are discharged into the buffer cap 352 through the overflow port 3503 opened at the top of the tower body 351, and then output to the sulfur foam tank 36 and then pumped into the sulfur melting kettle 37 by the sulfur foam pump 310 for heating and melting. Since the sulfur foam input into the sulfur melting kettle 37 is mixed with some desulfurization liquid, the desulfurization liquid and liquid sulfur are separated after melting. The separated desulfurization liquid is returned to the desulfurization liquid circulation tank 33 for recovery, while the liquid sulfur is sent to the subsequent refining section for further processing and purification.

[0084] The desulfurization liquid regenerated in regeneration tower 35 is output from circulation port 3504 at the top of tower body 351. To prevent elemental sulfur from flowing back into desulfurization tower 32 and clogging the spray nozzles, a filter screen should be installed at circulation port 3504 inside the tower, or a filter should be installed on the pipeline returning to desulfurization tower 32. A float valve 3500 is installed at the top of regeneration tower 35.

[0085] The desulfurization liquid should be kept alkaline to ensure that it can fully absorb sulfides. In this application, ammonia water (which comes from the ammonia water purified by the ammonia stripping tower) is supplied to the desulfurization liquid circulation tank 33 through the ammonia water supply device 330. At the same time, the catalyst metering pump 320 is also required to replenish the desulfurization catalyst (PDS catalyst) to the desulfurization liquid circulation tank 33 in a timely manner.

[0086] The desulfurized coal gas temporarily stored in the gas holder 4 is compressed and pressurized by the compressor 20 (compressor 20 is, for example, a screw compressor), and then fed into the gas-liquid separator 5 to separate the moisture in the coal gas. The coal gas after water separation is fed into the oil removal device 6, and after oil removal by the multi-stage oil removal tower 61 connected in series, it is then fed into the multi-stage naphthalene removal tower 71 in the naphthalene removal device 7 to remove naphthalene, thereby obtaining the purified finished coal gas, which can be sold externally or used internally by the enterprise.

[0087] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A coke oven gas cleaning system, characterized in that, It includes a raw coal gas pipeline (1), a coke removal device (2), a desulfurization device (3), a gas holder (4), a gas-liquid separator (5), an oil removal device (6), and a naphthalene removal device (7) connected in series. The decoking device (2) and the desulfurization device (3) are connected by a gas blower (10); The gas holder (4) and the gas-liquid separator (5) are connected by a compressor (20).

2. The coke oven gas cleaning system according to claim 1, characterized in that, The decoking device (2) includes a separator (21), a primary cooler (22) and an electrostatic precipitator (23) connected in series. The separation tank (21) and the primary cooler (22) are both connected to the mechanized tar ammonia water clarification tank (24); The gas output end of the electrostatic precipitator (23) is connected to the gas blower (10).

3. The coke oven gas cleaning system according to claim 2, characterized in that, The primary cooler (22) is divided into an upper cooling zone and a lower cooling zone by a partition (221); The upper cooling zone and the lower cooling zone are respectively equipped with cooling tubes (222). The partition (221) is penetrated by a vertically arranged connecting pipe (2211) and connects the cooling zone and the lower cooling zone. The connecting pipe (2211) is provided with a rainproof cap (2212) at the top of the upper cooling zone. The primary cooler (22) has an air inlet (2201) on one side of its upper part and an exhaust outlet (2202) on one side of its lower part. The upper cooling zone is sequentially connected to the first water seal tank (211), the first cleaning fluid circulation tank (212), and the first circulation pump (213) to form a loop; The upper cooling zone is sequentially connected to the second water seal tank (214), the second cleaning fluid circulation tank (215), and the second circulation pump (216) to form a loop; The first cleaning fluid circulation tank (212) and the second cleaning fluid circulation tank (215) are connected by a pipe; The second circulation pump (216) is also connected to the mechanized tar ammonia clarification tank (24).

4. The coke oven gas cleaning system according to claim 1, characterized in that, The desulfurization device (3) includes a precooling tower (31) and a desulfurization tower (32) connected in series. The desulfurization tower (32) is connected to the gas holder (4).

5. The coke oven gas cleaning system according to claim 4, characterized in that The desulfurization tower (32) is connected in sequence to the desulfurization liquid circulation tank (33), the desulfurization liquid circulation pump (34) and the regeneration tower (35) to form a loop; The regeneration tower (35) is also connected in sequence to the sulfur foam tank (36), the sulfur foam pump (310), the sulfur melting kettle (37), and the desulfurization liquid circulation tank (33); The regeneration tower (35) is also connected to a compressed air pipeline (300); The desulfurization liquid circulation tank (33) is also connected to the catalyst metering pump (320) and the ammonia water supply device (330).

6. The coke oven gas cleaning system according to claim 5, characterized in that The regeneration tower (35) includes a tower body (351), and the lower side of the tower body (351) is provided with a desulfurization liquid inlet (3501) and an air inlet (3502). The top of the tower body (351) is closed by a buffer cap (352), and an overflow port (3503) is provided on the side of the top of the tower body (351) inside the buffer cap (352). A circulation port (3504) is provided on the upper part of the tower body (351) and on one side outside the buffer cap (352), and the circulation port (3504) is connected to the desulfurization tower (32); The top of the buffer cap (352) is provided with a float ball valve (3500), the bottom of the buffer cap (352) is obliquely arranged, and the low side of the bottom is connected with the sulfur foam tank (36) through a pipeline.

7. The coke oven gas cleaning system according to claim 1, characterized in that, The oil removal device (6) comprises a plurality of oil removal towers (61) connected in series. The naphthalene removal device (7) comprises a plurality of naphthalene removal towers (71) connected in series.

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