A coke oven gas desulfurization device

Abstract

This application relates to the field of desulfurization tower technology, and in particular to a coke oven gas desulfurization device. The coke oven gas desulfurization device includes: a tower body with an outlet at the top and an inlet at the bottom; a pre-desulfurization section located at the bottom of the tower body, above the inlet; a second desulfurization section located at the top of the tower body, below the outlet; and a first desulfurization section located within the tower body, between the pre-desulfurization section and the second desulfurization section; wherein a liquid cut-off plate is provided between the first and second desulfurization sections. This application, by incorporating a pre-desulfurization section, a first desulfurization section, and a second desulfurization section within the tower body, achieves a better desulfurization effect without requiring a secondary or tertiary desulfurization tower.

Description

Technical Field

[0001] This utility model relates to the field of desulfurization tower technology, and in particular to a desulfurization device for coke oven gas. Background Technology

[0002] The coke oven gas desulfurization tower is the core equipment of the coke oven gas purification system. It is mainly used to remove hydrogen sulfide (H2S), hydrogen cyanide (HCN) and other sulfides and some organic sulfur from coke oven gas to meet the quality requirements of subsequent processing (such as hydrogen production and city gas production) and reduce the pollution of the environment caused by sulfide emissions.

[0003] Based on the gas-liquid contact method, coke oven gas desulfurization towers are mainly divided into wet desulfurization towers and dry desulfurization towers. Wet desulfurization is a commonly used method. It involves contacting the gas with an absorbent containing an oxidant, causing the sulfur dioxide in the gas to be oxidized into sulfate ions, thus achieving desulfurization. However, coke oven gas contains a large amount of sulfur dioxide and other harmful gases, posing a significant threat to air quality and the environment. Therefore, desulfurization treatment is necessary when using or discharging coke oven gas to ensure gas quality and meet environmental protection requirements.

[0004] In existing technologies, a single desulfurization tower can only perform one stage of desulfurization, which has a relatively low removal efficiency. However, subsequent processes such as methanol or natural gas production from coke oven gas require desulfurization towers with high H2S removal efficiency. Therefore, a single desulfurization tower's one-stage desulfurization is insufficient to meet the H2S content requirements of these subsequent processes. Consequently, additional two- or three-stage desulfurization towers are necessary. However, for coking plants with existing desulfurization facilities, space constraints make it extremely difficult to add additional two- or three-stage desulfurization towers, which severely impacts the progress of subsequent processes such as methanol or natural gas production from coke oven gas. Utility Model Content

[0005] In view of the shortcomings or problems existing in the prior art, this disclosure provides a desulfurization device for coke oven gas, which has a high removal efficiency for hydrogen sulfide in coke oven gas.

[0006] The technical solution adopted by this disclosure to solve the above-mentioned technical problem is: a coke oven gas desulfurization device, comprising:

[0007] The tower body has an air outlet at the top and an air inlet at the bottom;

[0008] The pre-desulfurization section is located at the bottom of the tower body and above the air inlet;

[0009] The second desulfurization section is located in the upper part of the tower body and below the gas outlet;

[0010] The first desulfurization section is located in the tower body and between the pre-desulfurization section and the second desulfurization section;

[0011] A liquid cut-off plate is provided between the first desulfurization section and the second desulfurization section.

[0012] In a preferred embodiment, the first desulfurization section includes a first packing layer, a first liquid distributor, a second packing layer, and a second liquid distributor, which are arranged sequentially from bottom to top.

[0013] In a preferred embodiment, the first liquid distributor is a tray-type liquid distributor; the second liquid distributor is an annular groove-type liquid distributor.

[0014] In a preferred embodiment, the second desulfurization section includes a third packing layer, a third liquid distributor, a fourth packing layer, and a fourth liquid distributor, which are arranged sequentially from bottom to top.

[0015] In a preferred embodiment, a fifth packing layer is further provided between the third packing layer and the third liquid distributor.

[0016] In a preferred embodiment, the third liquid distributor is a tray-type liquid distributor; the fourth liquid distributor is an annular groove-type liquid distributor.

[0017] In a preferred embodiment, a solution circulation tank is provided at the bottom of the tower body, which is located below the air inlet. The solution circulation tank is used to store absorbent. The first desulfurization section is provided with a first liquid inlet pipe, one end of which is connected to the solution circulation tank, and the other end is connected to a first liquid distributor and a second liquid distributor respectively. The first liquid inlet pipe is connected to a first valve.

[0018] In a preferred embodiment, the second desulfurization section is provided with a second liquid inlet pipe, one end of which is connected to the solution circulation tank, and the other end is connected to the third liquid distributor and the fourth liquid distributor respectively. The second liquid inlet pipe is also connected to a second valve.

[0019] In a preferred embodiment, the pre-desulfurization section includes an air-spray section spray assembly and a third liquid inlet pipe. One end of the third liquid inlet pipe is connected to the solution circulation tank, and the other end is connected to the air-spray section spray assembly. The third liquid inlet pipe is connected to a third valve.

[0020] In a preferred embodiment, a gas inlet distributor is provided between the gas inlet and the pre-desulfurization section.

[0021] In a preferred embodiment, a mist-catching device is provided between the fourth liquid distributor and the air outlet. The mist-catching device includes a mist-catching section packing and a mist-catching section spray assembly located above the mist-catching section packing.

[0022] Compared with existing technologies, the beneficial effects of this application are as follows: a pre-desulfurization section, a first desulfurization section, and a second desulfurization section are sequentially arranged between the gas inlet and the gas outlet. The pre-desulfurization section pre-treats the coal gas entering the tower body and can be regarded as a rough desulfurization of the coal gas. The gas treated by the pre-desulfurization section continues to rise to the first desulfurization section, where it undergoes further desulfurization. The gas treated by the first desulfurization section continues to rise to the second desulfurization section, where it continues to desulfurize the gas. In other words, the coal gas undergoes three desulfurization processes before entering the tower body. This stepped desulfurization method significantly improves desulfurization efficiency. A liquid cut-off plate is installed between the first and second desulfurization sections, allowing the gas to continue rising to the second section while preventing liquid from entering the first section. This avoids interference between the second and second sections, ensuring high desulfurization efficiency. This application achieves good desulfurization results by setting a pre-desulfurization section, a first desulfurization section, and a second desulfurization section within the tower body, without requiring additional secondary or tertiary desulfurization towers. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the structure of a coke oven gas desulfurization device according to this application.

[0024] In the diagram: 1. Tower body; 2. Air inlet; 3. Air outlet; 4. Pre-desulfurization section; 5. First desulfurization section; 6. Second desulfurization section; 7. Liquid cut-off plate; 8. First packing layer; 9. First liquid distributor; 10. Second packing layer; 11. Second liquid distributor; 12. Third packing layer; 13. Third liquid distributor; 14. Fourth packing layer; 15. Fourth liquid distributor; 16. Fifth packing layer; 17. Air spray section spray assembly; 18. Mist catching section packing; 19. Mist catching section spray assembly; 20. Gas inlet distributor. Detailed Implementation

[0025] To enable those skilled in the art to better understand the technical solutions of this disclosure, the following detailed, clear, and complete description of this disclosure is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of this disclosure and are not intended to limit it.

[0026] Those skilled in the art should understand that in the disclosure of this utility model, the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the above terms should not be construed as a limitation of this utility model.

[0027] Please refer to Figure 1 As shown, this application discloses a coke oven gas desulfurization device, including a tower body 1. The top of the tower body 1 is provided with an outlet 3, and the bottom is provided with an inlet 2. Coal gas enters the tower body from the inlet 2. The bottom of the tower body 1 is provided with a pre-desulfurization section 4, which is located above the inlet 2. The top of the tower body 1 is provided with a second desulfurization section 6, which is located below the outlet 3. A first desulfurization section 5 is provided between the pre-desulfurization section 4 and the second desulfurization section 6. A liquid cut-off plate 7 is provided between the first desulfurization section 5 and the second desulfurization section 6. The pre-desulfurization section 4 is located above the air inlet 2 and can perform preliminary desulfurization on the coke oven gas entering the tower body 1. The gas treated by the pre-desulfurization section 4 continues to rise to the first desulfurization section 5, where it undergoes further desulfurization. The gas then continues to rise to the second desulfurization section 6, where it continues to desulfurize. In other words, the gas undergoes three desulfurization processes before entering the tower body 1. This stepped desulfurization significantly improves the desulfurization efficiency. The liquid cut-off plate 7, also known as the liquid collection plate, is used to cut off the longitudinal flow of liquid in the tower body 1. When the tower body 1 is equipped with multiple layers of packing (or simultaneously includes different functional areas such as absorption section and demister section), the liquid cut-off plate 7 can physically separate the upper and lower areas, preventing the liquid in the lower packing layer from flowing directly into the upper layer, or preventing mist and impurities in the upper layer from entering the lower layer, ensuring that each area functions independently. A liquid cut-off plate 7 is installed between the first desulfurization section 5 and the second desulfurization section 6, allowing the gas to continue rising to the second desulfurization section 6 while preventing liquid from the first desulfurization section 5 from entering the second desulfurization section 6, and vice versa. This avoids interference between the liquid in the second desulfurization section 6 and the liquid in the first desulfurization section 5, thus ensuring high desulfurization efficiency of the desulfurization unit. Specifically, the liquid cut-off plate 7 in this application is a fully enclosed structure, which is prior art and will not be described in detail here. This application achieves good desulfurization effect of the desulfurization unit by setting a pre-desulfurization section, a first desulfurization section, and a second desulfurization section in the tower body, without adding a secondary or tertiary desulfurization tower.

[0028] Specifically, the pre-desulfurization section 4 includes an air-spray section spray assembly 17, which is located near the air inlet 2. Its function is to atomize the absorbent liquid (such as limestone slurry, ammonia water, etc.) into fine droplets. When the droplets come into contact with the flue gas in a counter-current or cross-current manner, they are fully mixed and contacted with the sulfur-containing flue gas (H2S and SO2, etc.) through collision, diffusion, etc., and the pollutants in the flue gas are absorbed through chemical reaction. The pre-desulfurization section 4 of this application has a removal efficiency of H2S in coal gas of greater than or equal to 20%. The specific structure of the air-spray section spray assembly 17 is prior art and will not be described in detail here.

[0029] Furthermore, the first desulfurization section 5 includes a first packing layer 8, a first liquid distributor 9, a second packing layer 10, and a second liquid distributor 11, arranged sequentially from bottom to top. The first packing layer 8 and the first liquid distributor 9 constitute one desulfurization unit, and the second packing layer 10 and the second liquid distributor 11 constitute another desulfurization unit, further removing sulfides from the flue gas. The flue gas desulfurized in the pre-desulfurization section 4 continues to rise to the first desulfurization section 5, where it undergoes desulfurization treatment by two desulfurization units before continuing to rise to the second desulfurization section 6.

[0030] Specifically, the first liquid distributor 9 is a tray-type liquid distributor; the second liquid distributor 11 is an annular tray-type liquid distributor. The tray-type liquid distributor has multiple distribution slots, allowing the absorbent liquid to be evenly distributed within these slots. When the absorbent liquid flows into the tray-type distributor, it is evenly distributed into each slot and then flows out from the edge of the slot or a specific opening, ensuring the liquid evenly covers the first packing layer 8. For the first desulfurization section 5, its main function is to further desulfurize the gas after passing through the pre-desulfurization section 4. The uniform liquid distribution ensures that each part of the first packing layer 8 has a sufficient amount of absorbent liquid to react with the sulfides in the gas. The annular tray-type liquid distributor distributes the liquid along the circumference of the annular slot, allowing the absorbent liquid to form a relatively uniform annular liquid layer above the second packing layer 10. Through its annular distribution, the annular tray-type distributor allows the liquid to flow evenly in all directions, covering the entire surface of the second packing layer 10, thereby improving the desulfurization effect and ensuring that the sulfide content of the gas reaches a lower level after treatment in the first desulfurization section 5. The first desulfurization stage 5 first achieves large-scale and uniform liquid distribution through a tray-type distributor, providing good conditions for preliminary desulfurization; then, a ring-type distributor achieves fine liquid distribution, further desulfurizing the remaining sulfides.

[0031] Furthermore, the second desulfurization stage 6 includes a third packing layer 12, a third liquid distributor 13, a fourth packing layer 14, and a fourth liquid distributor 15, arranged sequentially from bottom to top. A fifth packing layer 16 is also provided between the third packing layer 12 and the third liquid distributor 13. The multi-layered packing layers and liquid distributors arranged from bottom to top enable stratified desulfurization. The third packing layer 12 and the third liquid distributor 13 remove the main residual sulfides in the gas after treatment in the first desulfurization stage 5, while the fourth packing layer 14 and the fourth liquid distributor 15 can further treat more difficult-to-remove sulfides. The fifth packing layer 16 serves as an auxiliary desulfurization layer, acting as a transition between the third packing layer 12 and the third liquid distributor 13, making the desulfurization process more stable. When the desulfurizing agent in the third packing layer 12 gradually becomes ineffective, the fifth packing layer 16 can provide a certain desulfurization capacity, preventing a rapid increase in sulfide concentration in a short period of time and ensuring the continuity and stability of the entire desulfurization process. Preferably, the third liquid distributor 13 is a tray-type liquid distributor; the fourth liquid distributor 15 is an annular tank-type liquid distributor. The removal efficiency of H2S in the coal gas in the second desulfurization section 6 is greater than or equal to 79%.

[0032] It should be noted that the first packing layer 8, the second packing layer 10, the third packing layer 12, the fourth packing layer 14, and the fifth packing layer 16 can be Raschig ring packing, Pall ring packing, corrugated packing, honeycomb packing, light ceramic packing, or activated carbon packing. The type and thickness of the packing in the first packing layer 8, the second packing layer 10, the third packing layer 12, the fourth packing layer 14, and the fifth packing layer 16 can be the same or different, and this application does not impose specific restrictions.

[0033] In one embodiment of this disclosure, a solution circulation tank is provided at the bottom of the tower body 1, located below the air inlet 2. The solution circulation tank is used to store the absorbent. The first desulfurization section 5 is provided with a first inlet pipe, one end of which is connected to the solution circulation tank, and the other end is connected to a first liquid distributor 9 and a second liquid distributor 11, respectively. A first valve is connected to the first inlet pipe. It is understood that the solution circulation tank is connected to a circulation pump. After the absorbent in the solution circulation tank is pressurized by the circulation pump, it is transported to the first liquid distributor 9 and the second liquid distributor 11 through the first inlet pipe. After the absorbent completes the absorption of pollutants in the tower body 1, it carries the reaction products (such as gypsum, ammonium sulfite, etc.) back to the solution circulation tank for temporary storage. This recycling method allows the absorbent to be reused repeatedly during the desulfurization process, which reduces the amount of fresh absorbent used and lowers the desulfurization cost. The first valve connected to the first inlet pipe allows for flexible control of the flow rate of the absorbent from the solution circulation tank to the first desulfurization section 5.

[0034] Furthermore, the second desulfurization section 6 is equipped with a second inlet pipe. One end of the second inlet pipe is connected to the solution circulation tank, and the other end is connected to the third liquid distributor 13 and the fourth liquid distributor 15 respectively. The second inlet pipe is connected to a second valve, through which the flow rate of the absorbent liquid from the solution circulation tank to the second desulfurization section 6 can be flexibly controlled.

[0035] The pre-desulfurization section 4 also includes a third inlet pipe. One end of the third inlet pipe is connected to the solution circulation tank, and the other end is connected to the air spray section spray assembly 17. The third inlet pipe is connected to a third valve, which can flexibly control the flow rate of the absorbent liquid from the solution circulation tank to the pre-desulfurization section 4.

[0036] Preferably, a gas inlet distributor 20 is provided between the gas inlet 2 and the pre-desulfurization section 4. The gas inlet distributor 20 can evenly distribute the gas entering from the gas inlet 2 across the entire cross-section of the pre-desulfurization section 4. Without a distributor, the gas may concentrate in a localized area of ​​the tower body 1 when entering the pre-desulfurization section 4, resulting in uneven gas flow distribution.

[0037] In a preferred embodiment, a mist-catching device is provided between the fourth liquid distributor 15 and the air outlet 3. The mist-catching device includes a mist-catching section packing 18 and a mist-catching section spray assembly 19 disposed above the mist-catching section packing 18. The mist-catching section spray assembly 19 is used to clean the mist-catching section packing 18 to prevent packing failure and maintain its performance. The mist-catching section packing 18 is used to physically intercept liquid droplets. Specifically, the mist-catching section packing 18 in this application is corrugated plate packing, grid packing, or wire mesh packing. Both the mist-catching section packing 18 and the mist-catching section spray assembly 19 are prior art and will not be described in detail here.

[0038] The present application has been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of the present application. The descriptions of the embodiments above are only for the purpose of helping to understand the present application and its core ideas. It should be noted that those skilled in the art can make several improvements and modifications to the present application without departing from the principles of the present application, and these improvements and modifications also fall within the protection scope of the claims of the present application.

Claims

1. A desulfurization device for coke oven gas, characterized in that, include: The tower body (1) has an air outlet (3) at the top and an air inlet (2) at the bottom. The pre-desulfurization section (4) is located at the lower part of the tower body (1) and above the air inlet (2); The second desulfurization section (6) is located at the top of the tower body (1) and below the gas outlet (3); The first desulfurization section (5) is located in the tower body (1) and between the pre-desulfurization section (4) and the second desulfurization section (6); A liquid cut-off plate (7) is provided between the first desulfurization section (5) and the second desulfurization section (6).

2. The coke oven gas desulfurization device according to claim 1, characterized in that, The first desulfurization section (5) includes a first packing layer (8), a first liquid distributor (9), a second packing layer (10), and a second liquid distributor (11), which are arranged sequentially from bottom to top.

3. The coke oven gas desulfurization device according to claim 2, characterized in that, The first liquid distributor (9) is a tray-type liquid distributor; the second liquid distributor (11) is an annular tank-type liquid distributor.

4. The coke oven gas desulfurization device according to claim 1, characterized in that, The second desulfurization section (6) includes a third packing layer (12), a third liquid distributor (13), a fourth packing layer (14), and a fourth liquid distributor (15), which are arranged sequentially from bottom to top.

5. The coke oven gas desulfurization device according to claim 4, characterized in that, A fifth packing layer (16) is also provided between the third packing layer (12) and the third liquid distributor (13).

6. The coke oven gas desulfurization device according to claim 4, characterized in that, The third liquid distributor (13) is a tray-type liquid distributor; the fourth liquid distributor (15) is an annular groove-type liquid distributor.

7. The coke oven gas desulfurization device according to claim 2, characterized in that, A solution circulation tank is provided at the bottom of the tower body (1). The solution circulation tank is located below the air inlet (2). The solution circulation tank is used to store the absorbent. The first desulfurization section (5) is provided with a first liquid inlet pipe. One end of the first liquid inlet pipe is connected to the solution circulation tank, and the other end is connected to the first liquid distributor (9) and the second liquid distributor (11) respectively. The first liquid inlet pipe is connected to a first valve.

8. The coke oven gas desulfurization device according to claim 7, characterized in that, The second desulfurization section (6) is equipped with a second liquid inlet pipe. One end of the second liquid inlet pipe is connected to the solution circulation tank, and the other end is connected to the third liquid distributor (13) and the fourth liquid distributor (15) respectively. The second liquid inlet pipe is connected to a second valve.

9. The coke oven gas desulfurization device according to claim 7, characterized in that, The pre-desulfurization section (4) includes an air spray section spray assembly (17) and a third liquid inlet pipe. One end of the third liquid inlet pipe is connected to the solution circulation tank, and the other end is connected to the air spray section spray assembly (17). The third liquid inlet pipe is connected to a third valve.

10. The coke oven gas desulfurization device according to claim 1, characterized in that, A gas inlet distributor (20) is installed between the gas inlet (2) and the pre-desulfurization section (4).

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