System for reducing amount of regenerated tail gas generated by wet-type ammonia oxidation process multi-stage desulfurization

Abstract

The utility model relates to a system for reducing the amount of regenerated tail gas of wet-type ammonia oxidation multi-stage desulfurization. The system comprises a multi-stage desulfurization system, in each stage of desulfurization system, the top of the regeneration tower is connected with the bottom of the regeneration tower through a regeneration circulating gas pipeline, and the regeneration circulating gas pipeline of each stage of desulfurization system is connected with the regeneration circulating gas pipeline of the next stage of desulfurization system through a corresponding middle tail gas pipeline; the regeneration recycle gas pipeline of the first-stage desulfurization system is additionally connected with a compressed air pipeline, and the regeneration recycle gas pipeline of the last-stage desulfurization system is additionally connected with a tail gas exhaust pipeline; or in each stage of desulfurization system, the regeneration gas pipeline at the top of the regeneration tower is respectively connected with a regeneration gas main pipeline, the regeneration gas main pipeline is respectively connected with the regeneration tower of each stage of desulfurization system through a regeneration circulating gas pipeline, and the regeneration gas main pipeline is additionally connected with a compressed air pipeline and an exhaust tail gas pipeline. According to the utility model, the emission of regenerated tail gas can be greatly reduced, and the follow-up treatment cost of the regenerated tail gas is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of coke chemical product recovery, in particular to a system for reducing the amount of regenerated tail gas from wet oxidation ammonia multi-stage desulfurization. Background Art

[0002] Removing hydrogen sulfide from coke oven gas is of great significance for reducing corrosion to waste gas recovery equipment and gas storage and transportation equipment, reducing the concentration of harmful gas emissions, alleviating air pollution, and producing high-quality steel. The desulfurization process of coke oven gas can be divided into two categories: dry desulfurization and wet desulfurization. The wet desulfurization is further divided into wet oxidation and wet absorption. Among them, wet oxidation desulfurization uses dilute alkali liquid to absorb H2S in the gas phase. In the liquid phase that absorbs H2S, due to the action of the oxidation catalyst, H2S is oxidized to elemental sulfur and separated and recovered.

[0003] The wet oxidation ammonia desulfurization process uses ammonia in coal gas as an alkali source. It has the advantages of not requiring an external alkali source and low hydrogen sulfide content in the purified coal gas, so it has been widely used. The desulfurization regeneration tail gas of the wet oxidation ammonia method has the characteristics of large gas volume, high oxygen content, and complex impurity components (including ammonia, hydrogen sulfide, hydrogen cyanide, etc.). At present, the main method used is to purify the regenerated tail gas by acid washing, alkali washing and water washing, but the purification effect is not good, so the treatment of the desulfurization tail gas of the wet oxidation ammonia method is still a problem.

[0004] The Chinese invention patent with application number 201910384835.4 discloses "a wet oxidation desulfurization oxygen jet regeneration process and device", which uses oxygen or oxygen-rich gas to circulate and jet to regenerate the desulfurization liquid, and continuously replenishes oxygen or oxygen-rich gas to supplement the oxygen in the regeneration and consumption circulating gas to achieve closed cycle regeneration without desulfurization regeneration tail gas emissions. However, this technical solution has the following problems:

[0005] 1) The desulfurization liquid contacts the coal gas in the desulfurization tower in countercurrent, and will carry the coal gas into the regeneration tower. The combustible components in the closed circulation gas in the regeneration tower will continue to accumulate, posing a safety hazard;

[0006] 2) In the wet oxidation ammonia desulfurization process, oxygen participates in the redox reaction of hydrogen sulfide into elemental sulfur, and also participates in the side reaction of producing secondary salts such as ammonium hydrosulfide and ammonium thiosulfate. High concentration or excess oxygen in contact with the desulfurization liquid will aggravate the side reaction. If the secondary salt content in the desulfurization liquid is too high, the desulfurization reaction rate will be reduced, affecting the desulfurization effect.

[0007] The Chinese patent application with application number 202311308900.8 discloses "a coke oven gas purification system for reducing the amount of air used for HPF desulfurization regeneration". In order to improve the regeneration effect and reduce the amount of regeneration air used, a jet absorber group is installed at the bottom of the regeneration tower, and multiple bubble combiners are installed in the middle of the regeneration tower. A small part of the exhaust gas discharged from the regeneration tower is sent to the subsequent exhaust gas treatment, and most of it enters the circulating gas compressor as desulfurization circulating gas, and is mixed with externally supplemented compressed air and re-enters the regeneration tower for circulation. However, this technical solution has the following problems:

[0008] 1) The index requirement for coke oven gas after wet oxidation ammonia desulfurization purification is hydrogen sulfide ≤ 20 mg / m 3 At present, the multi-stage series desulfurization process is basically adopted. When this technical solution is applied to multi-stage desulfurization, the amount of tail gas generated is still relatively large;

[0009] 2) In the wet oxidation ammonia desulfurization process, the hydrogen sulfide content in the coal gas decreases step by step. When this technical solution is applied to multi-stage desulfurization regeneration, the hydrogen sulfide content in the subsequent desulfurization liquid is low. When compressed air is used to update the regenerated circulating gas, on the one hand, the operating cost is increased, and on the other hand, the high oxygen content will cause the side reactions to intensify, affecting the desulfurization effect. Summary of the invention

[0010] The utility model provides a system for reducing the amount of regenerated tail gas in a wet oxidation ammonia method multi-stage desulfurization, which recycles and partially renews the regeneration gas discharged when the desulfurization liquid in the multi-stage desulfurization system is regenerated, thereby realizing the step-by-step application of the regeneration gas and reducing the consumption of compressed air when the desulfurization liquid is regenerated. Compared with the existing conventional process, the system can greatly reduce the amount of regeneration tail gas discharged and reduce the subsequent treatment cost of the regeneration tail gas, and is particularly suitable for upgrading and transformation of existing process systems.

[0011] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0012] A system for reducing the amount of regenerated tail gas in a wet oxidation ammonia method multi-stage desulfurization, comprising a multi-stage desulfurization system; in each stage of the desulfurization system, a desulfurization tower and a corresponding regeneration tower are connected via a desulfurization liquid pipeline to form a desulfurization liquid circulation system; in each stage of the desulfurization system, the top of the regeneration tower is connected to the bottom of the regeneration tower via a regeneration circulation gas pipeline, and the regeneration circulation gas pipeline of each stage of the desulfurization system is connected to the regeneration circulation gas pipeline of the next stage of the desulfurization system via a corresponding intermediate tail gas pipeline; the regeneration circulation gas pipeline of the first stage of the desulfurization system is additionally connected to a compressed air pipeline, and the regeneration circulation gas pipeline of the last stage of the desulfurization system is additionally connected to an external tail gas pipeline; or, as an alternative, in each stage of the desulfurization system, the regeneration gas pipelines at the top of the regeneration tower are respectively connected to the regeneration gas main pipeline, the regeneration gas main pipeline is respectively connected to the regeneration towers of each stage of the desulfurization system via the regeneration circulation gas pipeline, and the regeneration gas main pipeline is additionally connected to the compressed air pipeline and the external tail gas pipeline.

[0013] A system for reducing the amount of regenerated tail gas from a wet oxidation ammonia process multi-stage desulfurization, comprising a primary desulfurization system, a secondary desulfurization system and a tertiary desulfurization system; in the primary desulfurization system, a 1# desulfurization tower and a 1# regeneration tower are connected via a desulfurization liquid pipeline to form a desulfurization liquid circulation system; in the secondary desulfurization system, a 2# desulfurization tower and a 2# regeneration tower are connected via a desulfurization liquid pipeline to form a desulfurization liquid circulation system; in the tertiary desulfurization system, a 3# desulfurization tower and a 3# regeneration tower are connected via a desulfurization liquid pipeline to form a desulfurization liquid circulation system; characterized in that the regeneration gas outlet at the top of the 1# regeneration tower is connected via a primary desulfurization regeneration gas pipeline to a primary desulfurization regeneration circulation gas pipeline and a primary intermediate tail gas pipeline, and the primary desulfurization regeneration circulation gas pipeline is separately The compressed air pipeline is externally connected to the desulfurization regeneration circulating gas inlet at the bottom of the 1# regeneration tower; the regeneration gas outlet at the top of the 2# regeneration tower is connected to the secondary desulfurization regeneration circulating gas pipeline and the secondary intermediate tail gas pipeline through the secondary desulfurization regeneration gas pipeline, and the secondary desulfurization regeneration circulating gas pipeline is additionally connected to the primary intermediate tail gas pipeline and the desulfurization regeneration circulating gas inlet at the bottom of the 2# regeneration tower; the regeneration gas outlet at the top of the 3# regeneration tower is connected to the tertiary desulfurization regeneration circulating gas pipeline and the external exhaust gas pipeline through the tertiary desulfurization regeneration gas pipeline, and the tertiary desulfurization regeneration circulating gas pipeline is additionally connected to the secondary intermediate tail gas pipeline and the desulfurization regeneration circulating gas inlet at the bottom of the 3# regeneration tower; the external exhaust gas pipeline is connected to the exhaust gas purification treatment device.

[0014] A tail gas pressurizing fan 1 is arranged on the first-stage desulfurization regeneration gas pipeline, a tail gas pressurizing fan 2 is arranged on the second-stage desulfurization regeneration gas pipeline, and a tail gas pressurizing fan 3 is arranged on the tertiary desulfurization regeneration gas pipeline; a pressure measuring device 1 with an overpressure alarm function is respectively arranged on the top of the 1# regeneration tower, the 2# regeneration tower and the 3# regeneration tower; the pressure measuring device 1 is interlocked with the pressure remote control valve arranged on the top of the corresponding regeneration tower and the tail gas pressurizing fan arranged on the corresponding desulfurization regeneration gas pipeline; or an overpressure safety relief device is respectively arranged on the circulating regeneration gas pipeline of each stage of the desulfurization system.

[0015] Flow measurement control devices are respectively arranged on the first-stage desulfurization regeneration circulating gas pipeline, the second-stage desulfurization regeneration circulating gas pipeline and the third-stage desulfurization regeneration circulating gas pipeline; flow regulating valves 1 are respectively arranged on the first-stage intermediate tail gas pipeline, the second-stage intermediate tail gas pipeline and the external exhaust tail gas pipeline; the flow measurement control device in each stage of the desulfurization system is interlocked with the corresponding flow regulating valve 1 for control.

[0016] The compressed air pipeline is provided with a flow measurement control operation device 1 and a flow regulating valve 2, and the primary desulfurization regeneration circulating gas pipeline upstream of the 1# regeneration tower is provided with an oxygen content analysis device, which is interlocked with the flow measurement control operation device 1 and the flow regulating valve 2.

[0017] Alternatively, a system for reducing the amount of regenerated tail gas from a wet oxidation ammonia process multi-stage desulfurization comprises a primary desulfurization system, a secondary desulfurization system and a tertiary desulfurization system; in the primary desulfurization system, a 1# desulfurization tower and a 1# regeneration tower are connected via a desulfurization liquid pipeline to form a desulfurization liquid circulation system; in the secondary desulfurization system, a 2# desulfurization tower and a 2# regeneration tower are connected via a desulfurization liquid pipeline to form a desulfurization liquid circulation system; in the tertiary desulfurization system, a 3# desulfurization tower and a 3# regeneration tower are connected via a desulfurization liquid pipeline to form a desulfurization liquid circulation system; characterized in that the regeneration gas outlet at the top of the 1# regeneration tower, the 2# regeneration tower, The regeneration gas outlet at the top of the tower and the regeneration gas outlet at the top of the 3# regeneration tower are respectively connected to the regeneration gas main pipeline; a tail gas compression fan is arranged on the regeneration gas main pipeline; the regeneration gas main pipeline downstream of the tail gas compression fan is respectively connected to the regeneration circulating gas main pipeline, the compressed air pipeline and the external exhaust gas pipeline; the regeneration circulating gas main pipeline is respectively connected to the 1# regeneration tower through the first-level desulfurization regeneration circulating gas pipeline, connected to the 2# regeneration tower through the second-level desulfurization regeneration circulating gas pipeline, and connected to the 3# regeneration tower through the tertiary desulfurization regeneration circulating gas pipeline; the external exhaust gas pipeline is connected to the exhaust gas purification treatment device.

[0018] The first-stage desulfurization regeneration circulating gas pipeline, the second-stage desulfurization regeneration circulating gas pipeline and the third-stage desulfurization regeneration circulating gas pipeline are interlockedly provided with a flow measurement control device and a flow regulating valve 1.

[0019] A flow measurement control device is arranged on the regeneration gas main pipeline, and is interlocked with a flow regulating valve arranged on the exhaust gas pipeline for control.

[0020] The compressed air pipeline is provided with a flow measurement control operation device 1 and a flow control valve 2; the regeneration circulation gas main pipeline is provided with an oxygen content analysis device, and the oxygen content analysis device is interlocked with the flow measurement control operation device 1 and the flow control valve 2 for control.

[0021] A pressure measuring device with an overpressure alarm function is respectively arranged on the top of the 1# regeneration tower, the 2# regeneration tower and the 3# regeneration tower; the pressure measuring device is interlocked with the pressure remote control valve arranged on the top of the corresponding regeneration tower and the tail gas pressurizing fan arranged on the regeneration gas main pipeline; or an overpressure safety relief device is respectively arranged on the circulating regeneration gas pipeline of each level of the desulfurization system.

[0022] Compared with the prior art, the beneficial effects of the utility model are:

[0023] 1) The process described in the utility model can significantly reduce the amount of regeneration tail gas discharged from the wet oxidation ammonia method multi-stage desulfurization process, and reduce the subsequent treatment cost of the regeneration tail gas; taking the three-stage wet oxidation ammonia method desulfurization process as an example, compared with the conventional non-circulation regeneration tail gas process (such as Figure 1Compared with the patent application number 202311308900.8, “A coke oven gas purification system for reducing the amount of air used for HPF desulfurization regeneration”, the process described in the utility model can reduce the amount of regeneration tail gas by about 20%;

[0024] 2) The utility model is applicable to a wet oxidation ammonia multi-stage desulfurization process, in which the first stage of desulfurization can remove about 90% of the hydrogen sulfide in the coal gas, and the hydrogen sulfide content in the coal gas decreases step by step after each subsequent stage of desulfurization; when the first method is adopted, that is, the regeneration gas of each stage of desulfurization is recycled within the stage, the circulating regeneration gas during the first stage of desulfurization is updated with compressed air, and a part of the regeneration gas discharged from each stage of desulfurization except the last stage is used as intermediate tail gas for updating the regeneration tail gas of the next stage of desulfurization; the second method is adopted, that is, the regeneration gas of each stage of desulfurization is combined and uniformly recycled within the system, and compressed air is used to update the total regeneration gas pipeline; the above two methods of utilizing the regeneration gas will not only not affect the desulfurization effect, but also avoid the problem of serious side reactions caused by low hydrogen sulfide content and high oxygen content in the subsequent desulfurization process.

[0025] 3) Compared with the conventional non-recycling regeneration tail gas process (such as Figure 1 Compared with the conventional method, the process described in the utility model does not require large-scale increase in equipment investment, is applicable to multi-stage desulfurization, and is not limited by the number of desulfurization stages; the modification cost of the already operating multi-stage wet oxidation ammonia desulfurization system is low and simple. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a structural schematic diagram of a conventional wet oxidation multi-stage desulfurization system (regenerated tail gas is not recycled) described in a comparative example of the utility model (taking three-stage desulfurization as an example).

[0027] Figure 2 It is a structural schematic diagram of a system for reducing the amount of regenerated tail gas in multi-stage desulfurization by wet oxidation method as described in Example 1 of the utility model (taking three-stage desulfurization as an example).

[0028] Figure 3 It is a structural schematic diagram of a system for reducing the amount of regenerated tail gas in multi-stage desulfurization by wet oxidation method as described in Example 2 of the utility model (taking three-stage desulfurization as an example).

[0029] In the figure: 1.1# desulfurization tower 2.1# regeneration tower 3.2# desulfurization tower 4.2# regeneration tower 5.3# desulfurization tower 6.3# regeneration tower 11. Tail gas pressurization fan 1 12. Flow measurement and control device 13. Flow control valve 1 14. Pressure measurement device 1 15. Pressure remote control valve 16. Flow measurement and control computing device 1 17. Flow control valve 2 18. Oxygen content analysis device 19. Flow measurement and control computing device 2 20. Flow control valve 3 21. Pressure measurement device 2 22. Tail gas pressurization fan 2 23. Tail gas pressurization fan 3 24. Tail gas pressurization fan DETAILED DESCRIPTION

[0030] The specific implementation of the utility model is further described below in conjunction with the accompanying drawings:

[0031] The utility model discloses a system for reducing the amount of regenerated tail gas in a multi-stage desulfurization by a wet oxidation ammonia method, comprising a multi-stage desulfurization system; a desulfurization tower in each stage of the desulfurization system is connected with a corresponding regeneration tower through a desulfurization liquid pipeline to form a desulfurization liquid circulation system; as an implementation scheme, in each stage of the desulfurization system, the top of the regeneration tower is connected to the bottom of the regeneration tower through a regeneration circulation gas pipeline, and the regeneration circulation gas pipeline of each stage of the desulfurization system is connected to the regeneration circulation gas pipeline of the next stage of the desulfurization system through a corresponding intermediate tail gas pipeline; the regeneration circulation gas pipeline of the first stage of the desulfurization system is additionally connected to a compressed air pipeline, and the regeneration circulation gas pipeline of the last stage of the desulfurization system is additionally connected to an external tail gas pipeline; or, as an alternative, in each stage of the desulfurization system, the regeneration gas pipelines at the top of the regeneration tower are respectively connected to the regeneration gas main pipeline, the regeneration gas main pipelines are respectively connected to the regeneration towers of the desulfurization systems of each stage through the regeneration circulation gas pipeline, and the regeneration gas main pipeline is additionally connected to the compressed air pipeline and the external tail gas pipeline.

[0032] Preferably, the utility model discloses a system for reducing the amount of regenerated tail gas from a wet oxidation ammonia process multi-stage desulfurization, comprising a primary desulfurization system, a secondary desulfurization system and a tertiary desulfurization system; in the primary desulfurization system, the 1# desulfurization tower 1 and the 1# regeneration tower 2 are connected through a desulfurization liquid pipeline to form a desulfurization liquid circulation system; in the secondary desulfurization system, the 2# desulfurization tower 3 and the 2# regeneration tower 4 are connected through a desulfurization liquid pipeline to form a desulfurization liquid circulation system, and in the tertiary desulfurization system, the 3# desulfurization tower 5 and the 3# regeneration tower 6 are connected through a desulfurization liquid pipeline to form a desulfurization liquid circulation system; the regeneration gas outlet at the top of the 1# regeneration tower 2 is connected to the primary desulfurization regeneration circulation gas pipeline and the primary intermediate tail gas pipeline through the primary desulfurization regeneration gas pipeline, and the primary desulfurization regeneration circulation gas pipeline is connected to the primary desulfurization regeneration circulation gas pipeline and the primary intermediate tail gas pipeline. The pipeline is also connected to the compressed air pipeline and the desulfurization regeneration circulating gas inlet at the bottom of the 1# regeneration tower 2; the regeneration gas outlet at the top of the 2# regeneration tower 4 is connected to the secondary desulfurization regeneration circulating gas pipeline and the secondary intermediate tail gas pipeline through the secondary desulfurization regeneration gas pipeline, and the secondary desulfurization regeneration circulating gas pipeline is also connected to the primary intermediate tail gas pipeline and the desulfurization regeneration circulating gas inlet at the bottom of the 2# regeneration tower 4; the regeneration gas outlet at the top of the 3# regeneration tower 6 is connected to the tertiary desulfurization regeneration circulating gas pipeline and the external tail gas pipeline through the tertiary desulfurization regeneration gas pipeline, and the tertiary desulfurization regeneration circulating gas pipeline is also connected to the secondary intermediate tail gas pipeline and the desulfurization regeneration circulating gas inlet at the bottom of the 3# regeneration tower 6; the external tail gas pipeline is connected to the tail gas purification treatment device.

[0033] A tail gas pressurizing fan 11 is arranged on the first-stage desulfurization regeneration gas pipeline, a tail gas pressurizing fan 2 22 is arranged on the second-stage desulfurization regeneration gas pipeline, and a tail gas pressurizing fan 3 23 is arranged on the tertiary desulfurization regeneration gas pipeline; a pressure measuring device 14 with an overpressure alarm function is respectively arranged on the top of the 1# regeneration tower 2, the 2# regeneration tower 4 and the 3# regeneration tower 6; the pressure measuring device 14 is interlocked with a pressure remote control valve 15 arranged on the top of the corresponding regeneration tower and the tail gas pressurizing fan (including tail gas pressurizing fan 11, tail gas pressurizing fan 2 22, tail gas pressurizing fan 3 23) arranged on the corresponding desulfurization regeneration gas pipeline, or an overpressure safety relief device is respectively arranged on the circulating regeneration gas pipeline of each level of the desulfurization system.

[0034] A flow measurement control device 12 is respectively arranged on the first-stage desulfurization regeneration circulating gas pipeline, the second-stage desulfurization regeneration circulating gas pipeline and the third-stage desulfurization regeneration circulating gas pipeline; a flow regulating valve 13 is respectively arranged on the first-stage intermediate tail gas pipeline, the second-stage intermediate tail gas pipeline and the external exhaust tail gas pipeline; the flow measurement control device 12 in each stage of the desulfurization system is interlocked with the corresponding flow regulating valve 13.

[0035] A flow measurement control operation device 16 and a flow regulating valve 2 17 are provided on the compressed air pipeline, and an oxygen content analysis device 18 is provided on the primary desulfurization regeneration circulating gas pipeline upstream of the 1# regeneration tower 2. The oxygen content analysis device 18 is interlocked with the flow measurement control operation device 16 and the flow regulating valve 2 17 for control.

[0036] Preferably, the utility model discloses a system for reducing the amount of regenerated tail gas from wet oxidation ammonia multi-stage desulfurization, comprising a primary desulfurization system, a secondary desulfurization system and a tertiary desulfurization system; in the primary desulfurization system, the 1# desulfurization tower 1 and the 1# regeneration tower 2 are connected through a desulfurization liquid pipeline to form a desulfurization liquid circulation system; in the secondary desulfurization system, the 2# desulfurization tower 3 and the 2# regeneration tower 4 are connected through a desulfurization liquid pipeline to form a desulfurization liquid circulation system; in the tertiary desulfurization system, the 3# desulfurization tower 5 and the 3# regeneration tower 6 are connected through a desulfurization liquid pipeline to form a desulfurization liquid circulation system; the regeneration gas outlet at the top of the 1# regeneration tower 1, the 2# regeneration tower 4 are connected through a desulfurization liquid pipeline to form a desulfurization liquid circulation system; The regeneration gas outlet at the top of tower 4 and the regeneration gas outlet at the top of 3# regeneration tower 6 are respectively connected to the regeneration gas main pipeline; the tail gas pressurizing fan 23 is arranged on the regeneration gas main pipeline; the regeneration gas main pipeline downstream of the tail gas pressurizing fan 23 is respectively connected to the regeneration circulating gas main pipeline, the compressed air pipeline and the external exhaust gas pipeline; the regeneration circulating gas main pipeline is respectively connected to the 1# regeneration tower 2 through the primary desulfurization regeneration circulating gas pipeline, connected to the 2# regeneration tower 4 through the secondary desulfurization regeneration circulating gas pipeline, and connected to the 3# regeneration tower 6 through the tertiary desulfurization regeneration circulating gas pipeline; the external exhaust gas pipeline is connected to the exhaust gas purification treatment device;

[0037] A flow measurement control device 12 and a flow regulating valve 13 are interlockedly arranged on the first-stage desulfurization regeneration circulating gas pipeline, the second-stage desulfurization regeneration circulating gas pipeline and the third-stage desulfurization regeneration circulating gas pipeline respectively; the flow measurement control device 12 arranged on the regeneration gas main pipeline is interlocked with the flow regulating valve 13 arranged on the exhaust tail gas pipeline; a flow measurement control operation device 16 and a flow regulating valve 17 are arranged on the compressed air pipeline; an oxygen content analysis device 18 is arranged on the regeneration circulating gas main pipeline, and the oxygen content analysis device 18 is interlocked with the flow measurement control operation device 16 and the flow regulating valve 17; a pressure measuring device 14 with an overpressure alarm function is arranged on the top of the 1# regeneration tower 2, the 2# regeneration tower 4 and the 3# regeneration tower 6 respectively; the pressure measuring device 14 is interlocked with the pressure remote control valve 15 arranged on the top of the corresponding regeneration tower and the tail gas pressurizing fan 24 arranged on the regeneration gas main pipeline, or an overpressure safety relief device is arranged on the circulating regeneration gas pipeline of each level of the desulfurization system.

[0038] The utility model discloses a system for reducing the amount of regenerated tail gas in a wet oxidation ammonia method multi-stage desulfurization, which recycles and partially renews the regeneration gas discharged during the regeneration of the desulfurization liquid in the multi-stage desulfurization system, thereby reducing the amount of waste gas generated during the desulfurization regeneration process; specifically, it includes two implementation methods:

[0039] Method 1: Most of the regeneration gas in each stage of the desulfurization system is used as the regeneration circulating gas for self-circulation within the stage. Except for the last stage of the desulfurization system, a small part of the regeneration gas in the remaining stages of the desulfurization system is used as the supplementary renewal gas for the regeneration circulating gas of the next stage of the desulfurization system; the first stage of the desulfurization system uses compressed air as the supplementary renewal gas for the regeneration circulating gas; a small part of the regeneration gas in the last stage of the desulfurization system is sent as tail gas to the tail gas purification treatment device for purification treatment;

[0040] Method 2: After the regeneration gas of the multi-stage desulfurization system is merged and pressurized, most of it is sent to the desulfurization systems at each level as regeneration circulating gas to realize system internal circulation; compressed air is used as the supplementary renewal gas of the regeneration circulating gas, and a small part is sent to the exhaust gas purification treatment device as exhaust gas for purification treatment.

[0041] When the first method is adopted, the sulfur-containing coal gas enters the 1# desulfurization tower 1, the 2# desulfurization tower 3 and the 3# desulfurization tower 5 in turn, and contacts with the regenerated desulfurization liquid in a countercurrent manner step by step to remove hydrogen sulfide in the coal gas; the desulfurization liquid at the bottom of the 1# desulfurization tower 1 enters the 1# regeneration tower 2 for regeneration through the 1# desulfurization liquid circulation pump, and the primary desulfurization regeneration gas discharged from the top of the 1# regeneration tower 2 is divided into two parts, most of which is used as the primary desulfurization regeneration circulating gas, and the rest enters the 2# regeneration tower 4 as the intermediate tail gas, as the renewal gas of the secondary desulfurization regeneration circulating gas; compressed air is introduced into the primary desulfurization regeneration circulating gas to supplement the air lost in the regeneration process and the external discharge of the intermediate tail gas; the desulfurization liquid at the bottom of the 2# desulfurization tower 3 enters the 2# regeneration tower 4 for regeneration through the 2# desulfurization liquid circulation pump, and the top of the 2# regeneration tower 4 is discharged The secondary desulfurization regeneration gas discharged is also divided into two parts, most of which are used as secondary desulfurization regeneration circulating gas, and the intermediate tail gas discharged from the primary desulfurization is supplemented into the secondary desulfurization regeneration circulating gas for regeneration of the desulfurization liquid in the 2# desulfurization tower 3; the rest of the secondary desulfurization regeneration gas enters the 3# regeneration tower 6 as the intermediate tail gas, and is used as the renewal gas for the tertiary desulfurization regeneration circulating gas; similarly, the tertiary desulfurization regeneration gas discharged from the top of the 3# regeneration tower 6 is also divided into two parts, most of which are used as tertiary desulfurization regeneration circulating gas, and the intermediate tail gas discharged from the secondary desulfurization is supplemented into the tertiary desulfurization regeneration circulating gas for regeneration of the desulfurization liquid in the 3# desulfurization tower 5; the tail gas generated by the 3# regeneration tower 6 is the external exhaust gas of the entire desulfurization system, which is sent to the tail gas purification treatment device for purification treatment.

[0042] A flow measurement control device 12 is respectively provided on the primary desulfurization regeneration circulating gas pipeline upstream of the 1# regeneration tower 2, the secondary desulfurization regeneration circulating gas pipeline upstream of the 2# regeneration tower 4, and the tertiary desulfurization regeneration circulating gas pipeline upstream of the 3# regeneration tower 6; a flow regulating valve 13 is respectively provided on the primary intermediate tail gas pipeline downstream of the 1# regeneration tower 2, the secondary intermediate tail gas pipeline downstream of the 2# regeneration tower 4, and the external exhaust gas pipeline downstream of the 3# regeneration tower 6. The flow measurement control device 12 in each stage of the desulfurization system is interlocked with the corresponding flow regulating valve 13 to control the stability of the desulfurization regeneration circulating gas volume at each stage.

[0043] A flow measurement control operation device 16 and a flow regulating valve 17 are provided on the compressed air pipeline upstream of the 1# regeneration tower 2, and an oxygen content analysis device 18 is provided on the primary desulfurization regeneration circulating gas pipeline upstream of the 1# regeneration tower 2. The oxygen content analysis device 18 is interlocked with the flow measurement control operation device 16 and the flow regulating valve 17 to control the oxygen content in the primary desulfurization regeneration circulating gas entering the 1# regeneration tower 2 within the range of 5% to 18%, and oxygen is added to the primary desulfurization circulating regeneration gas as needed; the proportion of the primary desulfurization regeneration gas used as the primary desulfurization regeneration circulating gas is 70% to 90%.

[0044] A pressure measuring device 14 with an overpressure alarm function is respectively installed on the top of the 1# regeneration tower 2, the 2# regeneration tower 4 and the 3# regeneration tower 6; the pressure measuring device 14 is interlocked with the pressure remote control valve 15 installed on the top of the corresponding regeneration tower and the tail gas pressurizing fan installed on the corresponding desulfurization regeneration gas pipeline, or an overpressure safety relief device is respectively installed on the circulating regeneration gas pipeline of each level of the desulfurization system to ensure the safe operation of the system.

[0045] When the second method is adopted, the sulfur-containing coal gas enters the 1# desulfurization tower 1, the 2# desulfurization tower 3 and the 3# desulfurization tower 5 in turn, and contacts with the regenerated desulfurization liquid in a countercurrent manner step by step to remove hydrogen sulfide in the coal gas; the desulfurization liquid at the bottom of the 1# desulfurization tower enters the 1# regeneration tower 2 for regeneration through the 1# desulfurization liquid circulation pump, the desulfurization liquid at the bottom of the 2# desulfurization tower enters the 2# regeneration tower 4 for regeneration through the 2# desulfurization liquid circulation pump, and the desulfurization liquid at the bottom of the 3# desulfurization tower enters the 3# regeneration tower 6 for regeneration through the 3# desulfurization liquid circulation pump; the primary desulfurization regeneration gas discharged from the top of the 1# regeneration tower 2, the secondary desulfurization regeneration gas discharged from the top of the 2# regeneration tower 4, and the 3# regeneration tower 6 are regenerated. The tertiary desulfurization regeneration gas discharged from the top of tower 6 is merged into the regeneration gas main pipeline. Most of the mixed regeneration gas pressurized by the tail gas compression fan 24 is used as regeneration circulating gas, and is sent to the 1# regeneration tower 2 through the first-level desulfurization regeneration circulating gas pipeline, to the 2# regeneration tower 4 through the second-level desulfurization regeneration circulating gas pipeline, and to the 3# regeneration tower 6 through the tertiary desulfurization regeneration circulating gas pipeline; compressed air is introduced into the desulfurization regeneration circulating gas to supplement the air lost in the regeneration process; a small part of the mixed regeneration gas is sent to the tail gas purification treatment device for purification as the external tail gas of the entire desulfurization system.

[0046] A flow measurement control device 12 and a flow regulating valve 13 are interlockedly arranged on the primary desulfurization regeneration circulating gas pipeline upstream of the 1# regeneration tower 2, the secondary desulfurization regeneration circulating gas pipeline upstream of the 2# regeneration tower 4, and the tertiary desulfurization regeneration circulating gas pipeline upstream of the 3# regeneration tower 6, respectively, to control the stability of the regeneration circulating gas volume entering the corresponding regeneration tower.

[0047] A flow measurement control operation device 16 and a flow regulating valve 2 17 are arranged on the compressed air pipeline; an oxygen content analysis device 18 is arranged on the regeneration circulating gas main pipeline downstream of the compressed air pipeline, and the oxygen content analysis device 18 is interlocked with the flow measurement control operation device 16 and the flow regulating valve 2 17 to control the oxygen content in the regeneration circulating gas entering each level of the regeneration tower to be within the range of 5% to 18%; the proportion of the mixed regeneration gas used as the regeneration circulating gas is 70% to 90%; a pressure measuring device 14 with an overpressure alarm function is respectively arranged on the top of the 1# regeneration tower 2, the 2# regeneration tower 4 and the 3# regeneration tower 6; the pressure measuring device 14 is interlocked with the pressure remote control valve 15 arranged on the top of the corresponding regeneration tower and the tail gas pressurizing fan 24 arranged on the regeneration gas main pipeline, or an overpressure safety relief device is respectively arranged on the circulating regeneration gas pipeline of each level of the desulfurization system to ensure the safe operation of the system.

[0048] The following embodiments are implemented on the premise of the technical solution of the utility model, and provide detailed implementation methods and specific operation processes, but the protection scope of the utility model is not limited to the following embodiments.

[0049] [Comparative Example]

[0050] like Figure 1 As shown, it is a conventional wet oxidation multi-stage desulfurization process roadmap. Taking the wet oxidation ammonia method three-stage desulfurization system as an example, it includes a primary desulfurization system, a secondary desulfurization system and a tertiary desulfurization system; in the primary desulfurization system, the 1# desulfurization tower and the 1# regeneration tower are connected through a desulfurization liquid pipeline to form a desulfurization liquid circulation system; in the secondary desulfurization system, the 2# desulfurization tower and the 2# regeneration tower are connected through a desulfurization liquid pipeline to form a desulfurization liquid circulation system; in the tertiary desulfurization system, the 3# desulfurization tower and the 3# regeneration tower are connected through a desulfurization liquid pipeline to form a desulfurization liquid circulation system.

[0051] In this comparative example, the sulfur-containing coal gas enters the 1# desulfurization tower, 2# desulfurization tower and 3# desulfurization tower in turn for three-stage desulfurization, and the desulfurization liquid enters the corresponding 1# regeneration tower, 2# regeneration tower and 3# regeneration tower for regeneration. The desulfurization regeneration gas at the top of the 1# regeneration tower, 2# regeneration tower and 3# regeneration tower is combined into the same pipeline and discharged as tail gas.

[0052] The bottoms of the 1# regeneration tower, the 2# regeneration tower and the 3# regeneration tower are respectively provided with compressed air inlets connected to corresponding compressed air pipelines, and each compressed air pipeline is respectively provided with a flow measurement control operation device 2 19, a flow regulating valve 3 20 and a pressure measurement device 21.

[0053] [Example 1]

[0054] like Figure 2 As shown, in this embodiment, a system for reducing the amount of regenerated tail gas from a wet oxidation ammonia process multi-stage desulfurization comprises a primary desulfurization system, a secondary desulfurization system and a tertiary desulfurization system; in the primary desulfurization system, the 1# desulfurization tower 1 and the 1# regeneration tower 2 are connected through a desulfurization liquid pipeline to form a desulfurization liquid circulation system; in the secondary desulfurization system, the 2# desulfurization tower 3 and the 2# regeneration tower 4 are connected through a desulfurization liquid pipeline to form a desulfurization liquid circulation system, and in the tertiary desulfurization system, the 3# desulfurization tower 5 and the 3# regeneration tower 6 are connected through a desulfurization liquid pipeline to form a desulfurization liquid circulation system; the regeneration gas outlet at the top of the 1# regeneration tower 2 is connected to the primary desulfurization regeneration circulation gas pipeline and the primary intermediate tail gas pipeline through the primary desulfurization regeneration gas pipeline, The first-stage desulfurization regeneration circulating gas pipeline is additionally connected to the compressed air pipeline and the desulfurization regeneration circulating gas inlet at the bottom of the 1# regeneration tower 2; the regeneration gas outlet at the top of the 2# regeneration tower 4 is connected to the second-stage desulfurization regeneration circulating gas pipeline and the second-stage intermediate tail gas pipeline through the second-stage desulfurization regeneration gas pipeline, and the second-stage desulfurization regeneration circulating gas pipeline is additionally connected to the first-stage intermediate tail gas pipeline and the desulfurization regeneration circulating gas inlet at the bottom of the 2# regeneration tower 4; the regeneration gas outlet at the top of the 3# regeneration tower 6 is connected to the third-stage desulfurization regeneration circulating gas pipeline and the external exhaust gas pipeline through the third-stage desulfurization regeneration gas pipeline, and the third-stage desulfurization regeneration circulating gas pipeline is additionally connected to the second-stage intermediate tail gas pipeline and the desulfurization regeneration circulating gas inlet at the bottom of the 3# regeneration tower 6. The external exhaust gas pipeline is connected to the exhaust gas purification treatment device.

[0055] The sulfur-containing coal gas enters the 1# desulfurization tower 1, the 2# desulfurization tower 3 and the 3# desulfurization tower 5 in turn, and contacts with the regenerated desulfurization liquid in a countercurrent manner step by step to remove hydrogen sulfide in the coal gas; the desulfurization liquid at the bottom of the 1# desulfurization tower 1 enters the 1# regeneration tower 2 for regeneration through the 1# desulfurization liquid circulation pump, and the primary desulfurization regeneration gas discharged from the top of the 1# regeneration tower 2 is divided into two parts, most of which is used as the primary desulfurization regeneration circulating gas, and the rest enters the 2# regeneration tower 4 as the intermediate tail gas, as the renewal gas for the secondary desulfurization regeneration circulating gas; compressed air is introduced into the primary desulfurization regeneration circulating gas to supplement the air lost in the regeneration process and the external intermediate tail gas; the desulfurization liquid at the bottom of the 2# desulfurization tower 3 enters the 2# regeneration tower 4 for regeneration through the 2# desulfurization liquid circulation pump, and the secondary desulfurization regeneration gas discharged from the top of the 2# regeneration tower 4 is used as the intermediate tail gas. The desulfurization regeneration gas is also divided into two parts, most of which are used as secondary desulfurization regeneration circulating gas, and the intermediate tail gas discharged from the primary desulfurization is added to the secondary desulfurization regeneration circulating gas for regeneration of the desulfurization liquid in the 2# desulfurization tower 3; the rest of the secondary desulfurization regeneration gas enters the 3# regeneration tower 6 as the intermediate tail gas, and is used as the renewal gas for the tertiary desulfurization regeneration circulating gas; similarly, the tertiary desulfurization regeneration gas discharged from the top of the 3# regeneration tower 6 is also divided into two parts, most of which are used as tertiary desulfurization regeneration circulating gas, and the intermediate tail gas discharged from the secondary desulfurization is added to the tertiary desulfurization regeneration circulating gas for regeneration of the desulfurization liquid in the 3# desulfurization tower 5; the tail gas generated by the 3# regeneration tower 6 is the external exhaust gas of the entire desulfurization system, which is sent to the tail gas purification treatment device for purification treatment.

[0056] In the present embodiment, flow measurement control devices 12 are respectively provided on the primary desulfurization regeneration circulating gas pipeline upstream of the 1# regeneration tower 2, on the secondary desulfurization regeneration circulating gas pipeline upstream of the 2# regeneration tower 4, and on the tertiary desulfurization regeneration circulating gas pipeline upstream of the 3# regeneration tower 6; flow regulating valves 13 are respectively provided on the primary intermediate tail gas pipeline downstream of the 1# regeneration tower 2, on the secondary intermediate tail gas pipeline downstream of the 2# regeneration tower 4, and on the external exhaust gas pipeline downstream of the 3# regeneration tower 6. The flow measurement control device 12 in each stage of the desulfurization system is interlocked with the corresponding flow regulating valve 13 to control the stability of the regeneration circulating gas volume entering the regeneration towers at each stage.

[0057] In this embodiment, a flow measurement control operation device 16 and a flow regulating valve 2 17 are provided on the compressed air pipeline upstream of the 1# regeneration tower 2, and an oxygen content analysis device 18 is provided on the primary desulfurization regeneration circulating gas pipeline upstream of the 1# regeneration tower 2. The oxygen content analysis device 18 is interlocked with the flow measurement control operation device 16 and the flow regulating valve 2 17 to control the oxygen content in the primary desulfurization regeneration circulating gas entering the 1# regeneration tower 2 within the range of 5% to 18%, and oxygen is added to the primary desulfurization circulating regeneration gas as needed; the proportion of the primary desulfurization regeneration gas used as the primary desulfurization regeneration circulating gas is 80%.

[0058] In this embodiment, a pressure measuring device 14 with an overpressure alarm function is respectively provided on the top of the 1# regeneration tower 2, the 2# regeneration tower 4 and the 3# regeneration tower 6; the pressure measuring device 14 is interlocked with a pressure remote control valve 15 provided on the top of the corresponding regeneration tower and an exhaust gas booster fan (including exhaust gas booster fan 11, exhaust gas booster fan 22 and exhaust gas booster fan 3 23) provided on the corresponding desulfurization regeneration gas pipeline to ensure safe operation of the system.

[0059] The supplementary renewal gas for the circulating regeneration gas of 1# regeneration tower 2 is compressed air. Part of the regeneration gas tail gas produced by each stage of desulfurization system is used as the supplementary renewal gas for the regeneration gas of the next stage of desulfurization system. The supplementary renewal gas can be connected from the upstream of the tail gas compression fan or from the downstream of the tail gas compression fan.

[0060] The first-stage desulfurization regeneration gas pipeline before the regeneration gas of the first-stage desulfurization system enters the corresponding No. 1 regeneration tower 2 is provided with an oxygen content analyzer 18, which is used to control the oxygen content of the regeneration gas entering the No. 1 regeneration tower. In this embodiment, the oxygen content is controlled at 12%. The flow rate of the compressed air for supplementary renewal is adjusted according to the set value. When the oxygen content analyzer 18 detects that the oxygen content of the regeneration gas is too low, the interlocking regulation increases the amount of compressed air entering the No. 1 regeneration tower 2, and the updated amount of compressed air is 10% to 50% of the amount of desulfurization regeneration gas. In order to ensure the oxygen content, oxygen can also be interlocked to supplement the desulfurization regeneration gas.

[0061] A pressure measuring device 14 is provided on the top of the regeneration tower of each stage of desulfurization. When the pressure is too high, an interlock alarm is sounded, and the tail gas pressurizing blower in the corresponding regeneration gas circulation system is stopped. To ensure safe production, when the pressure exceeds the maximum limit, the interlock opens the pressure remote control valve 15 on the top of the corresponding regeneration tower. An overpressure safety relief device can also be set on the desulfurization circulation regeneration gas pipeline.

[0062] [Example 2]

[0063] In this embodiment, the system for reducing the amount of regenerated tail gas from wet oxidation ammonia multi-stage desulfurization comprises a primary desulfurization system, a secondary desulfurization system and a tertiary desulfurization system; in the primary desulfurization system, the 1# desulfurization tower 1 and the 1# regeneration tower 2 are connected through a desulfurization liquid pipeline to form a desulfurization liquid circulation system; in the secondary desulfurization system, the 2# desulfurization tower 3 and the 2# regeneration tower 4 are connected through a desulfurization liquid pipeline to form a desulfurization liquid circulation system, and in the tertiary desulfurization system, the 3# desulfurization tower 5 and the 3# regeneration tower 6 are connected through a desulfurization liquid pipeline to form a desulfurization liquid circulation system; the regeneration gas outlet at the top of the 1# regeneration tower 2 and the top of the 2# regeneration tower 4 are connected through a desulfurization liquid pipeline to form a desulfurization liquid circulation system; The regeneration gas outlet at the top of the 3# regeneration tower 6 is respectively connected to the regeneration gas main pipeline; a tail gas pressurizing fan 24 is arranged on the regeneration gas main pipeline; the regeneration gas main pipeline downstream of the tail gas pressurizing fan 24 is respectively connected to the regeneration circulating gas main pipeline, the compressed air pipeline and the external exhaust gas pipeline; the regeneration circulating gas main pipeline is respectively connected to the 1# regeneration tower 2 through the primary desulfurization regeneration circulating gas pipeline, connected to the 2# regeneration tower 4 through the secondary desulfurization regeneration circulating gas pipeline, and connected to the 3# regeneration tower 6 through the tertiary desulfurization regeneration circulating gas pipeline; the external exhaust gas pipeline is connected to the exhaust gas purification treatment device.

[0064] In this embodiment, a flow measurement control device 12 and a flow regulating valve 13 are interlockedly arranged on the first-stage desulfurization regeneration circulating gas pipeline, the second-stage desulfurization regeneration circulating gas pipeline and the third-stage desulfurization regeneration circulating gas pipeline respectively; the flow measurement control device 12 arranged on the regeneration gas main pipeline is interlocked with the flow regulating valve 13 arranged on the exhaust tail gas pipeline; a flow measurement control operation device 16 and a flow regulating valve 2 17 are arranged on the compressed air pipeline; an oxygen content analysis device 18 is arranged on the regeneration circulating gas main pipeline, and the oxygen content analysis device 18 is interlocked with the flow measurement control operation device 16 and the flow regulating valve 2 17; a pressure measuring device 14 with an overpressure alarm function is respectively arranged on the top of the 1# regeneration tower 2, the 2# regeneration tower 4 and the 3# regeneration tower 6; the pressure measuring device 14 is interlocked with the pressure remote control valve 15 arranged on the corresponding regeneration tower top and the tail gas pressurizing fan 24 arranged on the regeneration gas main pipeline.

[0065] The sulfur-containing coal gas enters the 1# desulfurization tower 1, 2# desulfurization tower 3 and 3# desulfurization tower 5 in turn, and contacts with the regenerated desulfurization liquid in a countercurrent manner step by step to remove hydrogen sulfide in the coal gas; the desulfurization liquid at the bottom of the 1# desulfurization tower enters the 1# regeneration tower 2 for regeneration through the 1# desulfurization liquid circulation pump, the desulfurization liquid at the bottom of the 2# desulfurization tower enters the 2# regeneration tower 4 for regeneration through the 2# desulfurization liquid circulation pump, and the desulfurization liquid at the bottom of the 3# desulfurization tower enters the 3# regeneration tower 6 for regeneration through the 3# desulfurization liquid circulation pump; the primary desulfurization regeneration gas discharged from the top of the 1# regeneration tower 2, the secondary desulfurization regeneration gas discharged from the top of the 2# regeneration tower 4, and the top of the 3# regeneration tower 6 are discharged from the 3# regeneration tower 6. The discharged tertiary desulfurization regeneration gas is merged into the regeneration gas main pipeline, and most of the mixed regeneration gas pressurized by the tail gas compression fan 24 is used as the regeneration circulating gas, which is respectively sent to the 1# regeneration tower 2 through the primary desulfurization regeneration circulating gas pipeline, to the 2# regeneration tower 4 through the secondary desulfurization regeneration circulating gas pipeline, and to the 3# regeneration tower 6 through the tertiary desulfurization regeneration circulating gas pipeline; compressed air is introduced into the desulfurization regeneration circulating gas to supplement the air lost in the regeneration process; a small part of the mixed regeneration gas is sent to the tail gas purification treatment device for purification as the external tail gas of the entire desulfurization system.

[0066] In this embodiment, a flow measurement control device 12 and a flow regulating valve 13 are interlockedly arranged on the first-stage desulfurization regeneration circulating gas pipeline upstream of the 1# regeneration tower 2, on the second-stage desulfurization regeneration circulating gas pipeline upstream of the 2# regeneration tower 4, and on the third-stage desulfurization regeneration circulating gas pipeline upstream of the 3# regeneration tower 6, respectively, to control the stability of the regeneration circulating gas volume entering the corresponding regeneration tower.

[0067] A flow measurement control operation device 16 and a flow regulating valve 2 17 are arranged on the compressed air pipeline; an oxygen content analysis device 18 is arranged on the regeneration circulating gas main pipeline downstream of the compressed air pipeline, and the oxygen content analysis device 18 is interlocked with the flow measurement control operation device 16 and the flow regulating valve 2 17 to control the oxygen content in the regeneration circulating gas entering each level of regeneration tower to be within the range of 5% to 18%; the proportion of the mixed regeneration gas used as regeneration circulating gas is 70% to 90%; a pressure measuring device 14 with an overpressure alarm function is arranged on the top of the 1# regeneration tower 2, the 2# regeneration tower 4 and the 3# regeneration tower 6 respectively; the pressure measuring device 14 is interlocked with the pressure remote control valve 15 arranged on the top of the corresponding regeneration tower and the tail gas pressurizing fan 24 arranged on the regeneration gas main pipeline to ensure the safe operation of the system.

[0068] The above is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent substitutions or changes within the technical scope disclosed by the present invention according to the technical solution and inventive concept of the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A system for reducing the amount of regenerated tail gas in a wet oxidation ammonia process multi-stage desulfurization, comprising a multi-stage desulfurization system; a desulfurization tower and a corresponding regeneration tower in each stage of the desulfurization system are connected through a desulfurization liquid pipeline to form a desulfurization liquid circulation system; characterized in that: In each stage of the desulfurization system, the top of the regeneration tower is connected to the bottom of the regeneration tower through a regeneration circulating gas pipeline, and the regeneration circulating gas pipeline of each stage of the desulfurization system is connected to the regeneration circulating gas pipeline of the next stage of the desulfurization system through the corresponding intermediate tail gas pipeline; the regeneration circulating gas pipeline of the first stage of the desulfurization system is additionally connected to a compressed air pipeline, and the regeneration circulating gas pipeline of the last stage of the desulfurization system is additionally connected to an external exhaust gas pipeline; or, as an alternative, in each stage of the desulfurization system, the regeneration gas pipelines at the top of the regeneration tower are respectively connected to the regeneration gas main pipeline, the regeneration gas main pipelines are connected to the regeneration towers of the desulfurization systems of each stage through the regeneration circulating gas pipeline, and the regeneration gas main pipeline is additionally connected to a compressed air pipeline and an external exhaust gas pipeline.

2. A system for reducing the amount of regenerated tail gas in wet oxidation ammonia multi-stage desulfurization according to claim 1, characterized in that: It includes a primary desulfurization system, a secondary desulfurization system and a tertiary desulfurization system; in the primary desulfurization system, the 1# desulfurization tower and the 1# regeneration tower are connected through a desulfurization liquid pipeline to form a desulfurization liquid circulation system; in the secondary desulfurization system, the 2# desulfurization tower and the 2# regeneration tower are connected through a desulfurization liquid pipeline to form a desulfurization liquid circulation system, and in the tertiary desulfurization system, the 3# desulfurization tower and the 3# regeneration tower are connected through a desulfurization liquid pipeline to form a desulfurization liquid circulation system; the regeneration gas outlet at the top of the 1# regeneration tower is connected to the primary desulfurization regeneration circulation gas pipeline and the primary intermediate tail gas pipeline through the primary desulfurization regeneration gas pipeline, and the primary desulfurization regeneration circulation gas pipeline is also connected to the compressed air pipeline and the 1# regeneration tower The desulfurization regeneration circulating gas inlet at the bottom of the tower; the regeneration gas outlet at the top of the 2# regeneration tower is connected to the secondary desulfurization regeneration circulating gas pipeline and the secondary intermediate tail gas pipeline through the secondary desulfurization regeneration gas pipeline, and the secondary desulfurization regeneration circulating gas pipeline is additionally connected to the primary intermediate tail gas pipeline and the desulfurization regeneration circulating gas inlet at the bottom of the 2# regeneration tower; the regeneration gas outlet at the top of the 3# regeneration tower is connected to the tertiary desulfurization regeneration circulating gas pipeline and the external tail gas pipeline through the tertiary desulfurization regeneration gas pipeline, and the tertiary desulfurization regeneration circulating gas pipeline is additionally connected to the secondary intermediate tail gas pipeline and the desulfurization regeneration circulating gas inlet at the bottom of the 3# regeneration tower; the external tail gas pipeline is connected to the tail gas purification treatment device.

3. A system for reducing the amount of regenerated tail gas in wet oxidation ammonia multi-stage desulfurization according to claim 2, characterized in that: A tail gas pressurizing fan 1 is arranged on the first-stage desulfurization regeneration gas pipeline, a tail gas pressurizing fan 2 is arranged on the second-stage desulfurization regeneration gas pipeline, and a tail gas pressurizing fan 3 is arranged on the tertiary desulfurization regeneration gas pipeline; a pressure measuring device 1 with an overpressure alarm function is respectively arranged on the top of the 1# regeneration tower, the 2# regeneration tower and the 3# regeneration tower; the pressure measuring device 1 is interlocked with the pressure remote control valve arranged on the top of the corresponding regeneration tower and the tail gas pressurizing fan arranged on the corresponding desulfurization regeneration gas pipeline; or an overpressure safety relief device is respectively arranged on the circulating regeneration gas pipeline of each stage of the desulfurization system.

4. A system for reducing the amount of regenerated tail gas in wet oxidation ammonia multi-stage desulfurization according to claim 2, characterized in that: Flow measurement control devices are respectively arranged on the first-stage desulfurization regeneration circulating gas pipeline, the second-stage desulfurization regeneration circulating gas pipeline and the third-stage desulfurization regeneration circulating gas pipeline; flow regulating valves 1 are respectively arranged on the first-stage intermediate tail gas pipeline, the second-stage intermediate tail gas pipeline and the external exhaust tail gas pipeline; the flow measurement control device in each stage of the desulfurization system is interlocked with the corresponding flow regulating valve 1 for control.

5. A system for reducing the amount of regenerated tail gas in wet oxidation ammonia multi-stage desulfurization according to claim 2, characterized in that: The compressed air pipeline is provided with a flow measurement control operation device 1 and a flow regulating valve 2, and the primary desulfurization regeneration circulating gas pipeline upstream of the 1# regeneration tower is provided with an oxygen content analysis device, which is interlocked with the flow measurement control operation device 1 and the flow regulating valve 2.

6. A system for reducing the amount of regenerated tail gas in wet oxidation ammonia multi-stage desulfurization according to claim 1, characterized in that: It includes a primary desulfurization system, a secondary desulfurization system and a tertiary desulfurization system; in the primary desulfurization system, the 1# desulfurization tower and the 1# regeneration tower are connected through a desulfurization liquid pipeline to form a desulfurization liquid circulation system; in the secondary desulfurization system, the 2# desulfurization tower and the 2# regeneration tower are connected through a desulfurization liquid pipeline to form a desulfurization liquid circulation system, and in the tertiary desulfurization system, the 3# desulfurization tower and the 3# regeneration tower are connected through a desulfurization liquid pipeline to form a desulfurization liquid circulation system; it is characterized in that the regeneration gas outlet at the top of the 1# regeneration tower, the regeneration gas outlet at the top of the 2# regeneration tower, and the regeneration gas outlet at the top of the 3# regeneration tower are respectively connected to the regeneration gas main pipeline; an exhaust gas pressurizing fan is arranged on the regeneration gas main pipeline; the regeneration gas main pipeline downstream of the exhaust gas pressurizing fan is respectively connected to the regeneration circulation gas main pipeline, the compressed air pipeline and the external exhaust gas pipeline; the regeneration circulation gas main pipeline is respectively connected to the 1# regeneration tower through the primary desulfurization regeneration circulation gas pipeline, connected to the 2# regeneration tower through the secondary desulfurization regeneration circulation gas pipeline, and connected to the 3# regeneration tower through the tertiary desulfurization regeneration circulation gas pipeline; the external exhaust gas pipeline is connected to the exhaust gas purification treatment device.

7. A system for reducing the amount of regenerated tail gas in wet oxidation ammonia multi-stage desulfurization according to claim 6, characterized in that: The first-stage desulfurization regeneration circulating gas pipeline, the second-stage desulfurization regeneration circulating gas pipeline and the third-stage desulfurization regeneration circulating gas pipeline are interlockedly provided with a flow measurement control device and a flow regulating valve 1.

8. A system for reducing the amount of regenerated tail gas in wet oxidation ammonia multi-stage desulfurization according to claim 6, characterized in that: A flow measurement control device is arranged on the regeneration gas main pipeline, and is interlocked with a flow regulating valve arranged on the exhaust gas pipeline for control.

9. A system for reducing the amount of regenerated tail gas in wet oxidation ammonia multi-stage desulfurization according to claim 6, characterized in that: The compressed air pipeline is provided with a flow measurement control operation device 1 and a flow control valve 2; the regeneration circulation gas main pipeline is provided with an oxygen content analysis device, and the oxygen content analysis device is interlocked with the flow measurement control operation device 1 and the flow control valve 2 for control.

10. A system for reducing the amount of regenerated tail gas in wet oxidation ammonia multi-stage desulfurization according to claim 6, characterized in that: A pressure measuring device with an overpressure alarm function is respectively arranged on the top of the 1# regeneration tower, the 2# regeneration tower and the 3# regeneration tower; the pressure measuring device is interlocked with the pressure remote control valve arranged on the top of the corresponding regeneration tower and the tail gas pressurizing fan arranged on the regeneration gas main pipeline; or an overpressure safety relief device is respectively arranged on the circulating regeneration gas pipeline of each level of the desulfurization system.

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