WO2023226470A1

WO2023226470A1 - Oxygen injection desulfurization based sludge treatment method and anaerobic digester

Info

Publication number: WO2023226470A1
Application number: PCT/CN2023/074372
Authority: WO
Inventors: 胡维杰; 周友飞; 张辰
Original assignee: 上海市政工程设计研究总院（集团）有限公司
Priority date: 2022-05-23
Filing date: 2023-02-03
Publication date: 2023-11-30
Also published as: CN114853300B; CN114853300A

Abstract

The present application discloses an oxygen injection desulfurization based sludge treatment method and an anaerobic digester. The sludge treatment method comprises the following steps: S10. adjusting the sludge level in an anaerobic digester body, and further adjusting the volume of a gas phase space above the sludge in the anaerobic digester body; S20. injecting oxygen into the gas phase space and fully mixing the oxygen with biogas in the gas phase space; and S30. extending the residence time of the biogas in the anaerobic digester body by using the adjusted volume, and performing a desulfurization reaction of the biogas when the biogas stays in the anaerobic digester body until the desulfurization reaction of the biogas is completed. The volume of the gas phase space is adjusted, so that the volume meets the size required for the desulfurization reaction of the biogas, and oxygen is injected to improve the quality of the biogas after the desulfurization reaction of the biogas, thereby reducing the investment cost and operation cost of devices such as an anaerobic digester during biogas desulfurization.

Description

Oxygen injection desulfurization sludge treatment method and anaerobic digester

This application claims the priority of Chinese patent application 2022105673322 with a filing date of 2022/5/23. This application cites the full text of the above-mentioned Chinese patent application.

Technical field

This application relates to a sludge treatment method for oxygen injection desulfurization and an anaerobic digester.

Background technique

my country is currently the world's largest carbon emitter, accounting for more than 25% of the world's emissions. Among them, the carbon emissions of the sewage treatment industry account for 1% to 2% of the total emissions of the whole society, and it is an area of emission reduction that cannot be ignored. With the advancement of my country's urbanization and the improvement of sewage treatment facilities, the scale of my country's urban sewage treatment exceeds 200 million tons/day, ranking first in the world. Sludge is the final destination of organic matter energy in the sewage treatment process. The exploration and utilization of energy in the sewage treatment process must start with sludge. Similar to sludge incineration technology, anaerobic digestion technology has four major advantages: reduction, harmlessness, stabilization and resource utilization. Especially in terms of energy utilization, it uses natural biodegradation to release the energy of organic matter in sludge. To generate biogas (CH4), which can be directly utilized, and realize energy recycling, anaerobic digestion technology should become one of the inevitable trends in the development of sludge treatment and disposal technology in the future.

As a renewable energy, biogas has become an important part of my country's energy strategy. The development of efficient desulfurization technology is an important guarantee for the effective utilization of biogas. The main components of biogas produced by the anaerobic digestion process of sludge are CH4, CO2 and H2S. Among them, H2S can corrode equipment and pipelines due to its own characteristics, is highly toxic to the human body, and has an adverse impact on the operation of CHP devices. Moreover, H2S will limit the utilization potential of biogas. Therefore, H2S in biogas needs to be purified before reusing biogas. Commonly used desulfurization methods for biogas include dry desulfurization, wet desulfurization and biological desulfurization. Several desulfurization methods are relatively mature at the theoretical level and engineering application level, and each has its own advantages and disadvantages. However, the biogas desulfurization methods in the existing technology all have the same weaknesses, namely: 1. The reaction time for the desulfurization reaction between biogas and air In order to ensure sufficient desulfurization of biogas, the equipment investment cost of continuously adding chemicals and continuously injecting air into the digester is high; 2. In addition, the equipment that continuously injects air and chemicals has high operating costs during operation; 3. The equipment is relatively complex, The operation efficiency is low and operation and maintenance are difficult.

In view of the common problems of the traditional biogas desulfurization process mentioned above, it is very urgent to develop a new high-efficiency biogas desulfurization process to improve the efficiency of biogas desulfurization, reduce investment, and reduce the difficulty of system operation and maintenance.

Application content

The technical problem to be solved by this application is to provide a sludge treatment method and anaerobic digester for oxygen injection desulfurization in order to overcome the shortcomings of low biogas desulfurization efficiency and high operating cost of biogas desulfurization in the existing technology.

This application solves the above technical problems through the following technical solutions:

A sludge treatment method for oxygen injection desulfurization, the sludge treatment method includes the following steps:

S10. Adjust the sludge liquid level in the anaerobic digester body, and then adjust the volume of the gas phase space above the sludge in the anaerobic digester body;

S20. Inject oxygen into the gas phase space and fully mix the oxygen with the biogas in the gas phase space. The oxidation reaction of hydrogen sulfide in the biogas occurs on the inner wall of the anaerobic digester body corresponding to the gas phase space;

S30. Use the adjusted volume to extend the residence time of the biogas in the anaerobic digester body, and perform the desulfurization reaction of the biogas while the biogas remains in the anaerobic digester body until the desulfurization reaction of the biogas is completed.

In this plan, by adjusting the liquid level of the sludge in the anaerobic digester body, the volume of the gas phase space above the sludge is adjusted. This volume is used to accommodate biogas and oxygen. The biogas carries out the desulfurization reaction of biogas in the gas phase space. Oxygen is rich in oxygen. By injecting oxygen into the gas phase space, biogas and oxygen are fully mixed, relying on biochemical effects. The oxidation reaction of hydrogen sulfide in biogas is the desulfurization reaction of biogas, which mainly occurs in anaerobic digestion. The pool body corresponds to the inner wall of the gas phase space, The desulfurization reaction of biogas mainly relies on the biochemical metabolism of sulfur-oxidizing bacteria in the sludge in the anaerobic digester body. The inner wall of the anaerobic digester body provides a suitable environment for the growth and metabolism of sulfur-oxidizing bacteria - anaerobic, water vapor environment, large surface area, etc., its function is similar to the filter material biofilm. Therefore, adjusting the volume of the gas phase space is suitable for the desulfurization reaction of biogas, and injecting oxygen into the gas phase space can make the desulfurization reaction of biogas proceed more quickly and fully, reduce the desulfurization reaction time of biogas, and increase the desulfurization reaction rate of biogas.

Preferably, the following steps are also included between step S20 and step S30:

S201. Circulate biogas in the body of the anaerobic digester. The biogas flows from the gas phase space to the sludge through the biogas circulation system. The biogas enters the gas phase space again from the sludge, and further allows the biogas to flow into the gas phase space. It is fully mixed with the oxygen injected by the gas injection system and carries out the desulfurization reaction of the biogas.

In this plan, by setting up a biogas circulation system, the biogas in the anaerobic digester body flows into the sludge at the bottom of the anaerobic digester body through the gas phase space. During the flow process, the biogas and the oxygen injected by the gas injection system are fully Mix, and use the sulfur-oxidizing bacteria in the sludge in the anaerobic digester to oxidize and metabolize the hydrogen sulfide in the biogas, and then perform the desulfurization reaction of the biogas in the sludge. The desulfurization reaction carried out by the biogas circulation system and the gas injection system into the gas phase The desulfurization reaction of injecting oxygen into the space is carried out simultaneously, which is more thorough than the desulfurization reaction of only the gas phase space. At the same time, the desulfurization efficiency of the biogas is improved, the reaction time required for one desulfurization is shortened, and the operation of the equipment is reduced. cost.

Preferably, step S201 also includes the following steps:

S202. Implement steps S20 and S201 synchronously, and inject oxygen in the gas injection system into the biogas circulation system through a branch gas injection unit. The branch gas injection unit and the biogas circulation system are connected through a mixer. , and mix oxygen into the biogas circulation system through the mixer;

S203. Flow the mixed biogas into the sludge through the biogas circulation system, use the sulfur-oxidizing bacteria in the sludge to oxidize and metabolize the hydrogen sulfide in the biogas, and combine it with the gas injection system to The oxygen injected into the gas phase space performs a synchronous desulfurization reaction of the biogas.

In this solution, step S201 also includes a branch gas injection unit that injects oxygen into the biogas circulation system. The branch gas injection unit is connected to the gas injection system and can inject oxygen into the biogas circulation system and utilize the wastewater in the anaerobic digester. The sulfur-oxidizing bacteria in the mud oxidize and metabolize the hydrogen sulfide in the biogas, and then perform the desulfurization reaction of the biogas in the sludge. The branch gas injection unit injects oxygen into the biogas circulation system to solve the problem of the biogas circulation system injecting the gas injection system. When oxygen and biogas in the anaerobic digester body are circulating, the biogas and oxygen are not fully mixed and excessively high content of biogas is recycled into the sludge, which brings about the problem of insufficient oxygen during the desulfurization reaction in the sludge.

Preferably, the following steps are also included between step S10 and step S20:

S11. Before the oxygen is injected into the gas phase space, use a detection mechanism to check the initial concentration of oxygen and the content of biogas in the gas phase space, and adjust the amount of oxygen injected into the gas phase space according to the initial concentration of oxygen and the content of biogas. Air intake volume.

In this plan, by setting up a detection mechanism and determining the initial concentration of oxygen in the anaerobic digester body and the biogas content in the anaerobic digester body before injecting oxygen into the gas phase space, the injection to be injected can be further accurately adjusted. The amount of oxygen in the gas phase space can not only ensure the full progress of the desulfurization reaction of biogas, but also reduce the waste of oxygen.

Preferably, the anaerobic digester body also includes an air distribution mechanism. There are two air distribution mechanisms, one of which is disposed in the gas phase space and communicates with the air injection system. , the other gas distribution mechanism is arranged in the sludge and communicates with the biogas circulation system.

In this plan, the anaerobic digester body is also equipped with a gas distribution mechanism. There are two gas distribution mechanisms that are connected to the gas injection system and the biogas circulation system respectively. The gas distribution mechanism connected to the gas injection system is used to supply gas to the gas phase space. Oxygen is injected into the sludge. The gas distribution mechanism can increase the diffusion area of oxygen and quickly mix it with the biogas in the gas phase space. The gas distribution mechanism connected with the biogas circulation system is used to inject the mixed gas of oxygen and biogas into the sludge. The purpose is also to increase the contact area between the mixed gas and sludge, thereby improving the desulfurization reaction efficiency of biogas.

Preferably, after step S30, the following steps are also included: S31. After the oxygen and biogas are fully mixed, After the desulfurization reaction is carried out, the valve mechanisms on the gas injection system and the branch gas injection unit are closed and the valve mechanisms on the biogas output system are opened.

In this plan, a valve mechanism is set up to control the on/off of the gas injection system, branch gas injection unit, biogas circulation system and biogas output system. The valve mechanism is also connected to the detection mechanism. Before the desulfurization reaction of the biogas is completed, the detection mechanism passes The signal closes the valve mechanism on the biogas output system to ensure the safety of the anaerobic digester operation. The detection mechanism and the valve mechanism cooperate with each other. After the biogas desulfurization reaction is completed, the detection mechanism detects this situation and Correspondingly close the valve mechanism on the gas injection system and branch gas injection unit, open the valve mechanism on the biogas output system and discharge the desulfurized biogas out of the anaerobic digester.

Preferably, the sludge treatment method further includes the following steps after step S31:

S32. Discharge the desulfurized biogas from the anaerobic digester body through the biogas output system and collect it.

In this plan, by closing the valve mechanism on the gas injection system and branch gas injection unit and opening the valve on the biogas output system, the desulfurized biogas is discharged from the anaerobic digester body, and the other end of the biogas output system is set to collect The device effectively collects biogas. The nitrogen content in the desulfurized biogas is reduced compared to air desulfurization, and the quality of the desulfurized biogas is higher.

Preferably, the following steps are also included after step S32: S33. After the desulfurized biogas is discharged from the anaerobic digester body, the valve mechanism of the biogas output system is closed, and the waste gas is passed through the anaerobic digester body. The mud generates biogas again to repeat the desulfurization reaction of biogas for the next time.

In this plan, the desulfurized biogas is discharged from the anaerobic digester body, new sludge is injected into the anaerobic digester body, and the valve mechanism on the biogas output system is closed, and then the undesulfurized biogas is regenerated through the gas phase space. The reacted biogas is used for the next biogas desulfurization treatment, thereby improving the reuse rate of this solution and further reducing the cost of the biogas desulfurization reaction.

An anaerobic digester, which uses the sludge treatment method of oxygen injection and desulfurization as described in any one of the above to treat sludge.

In this plan, the anaerobic digester uses the above sludge treatment method to make oxygen and biogas The gas is fully mixed and the desulfurization reaction of the biogas is fully carried out in the gas phase space. At the same time, the biogas circulation system allows the biogas to mix with oxygen and carry out the desulfurization reaction of the biogas with the sludge. The desulfurization reaction of the biogas in the gas phase space and the sludge is further improved at the same time. It improves the quality of biogas after desulfurization, shortens the desulfurization reaction time, and improves the efficiency of the anaerobic digestion process.

The positive progressive effect of this application is to adjust the volume of the gas phase space so that the volume of the gas phase space meets the size required for the desulfurization reaction of the biogas, and inject oxygen into the gas phase space to improve the quality of the biogas after the desulfurization reaction of the biogas. At the same time, the reaction time of the biogas desulfurization reaction is shortened, the efficiency of the biogas desulfurization reaction is improved, and the investment and operating costs of other equipment such as anaerobic digesters during biogas desulfurization are further reduced.

Description of the drawings

Figure 1 is a flow chart of the sludge treatment method for oxygen injection desulfurization provided by the embodiment of the present application.

Figure 2 is a flow chart of step S201 of the sludge treatment method for oxygen injection desulfurization provided by the embodiment of the present application.

Figure 3 is a schematic structural diagram of an anaerobic digester provided by an embodiment of the present application.

Explanation of reference symbols:
Anaerobic digester body 1
Gas phase space 11
Biogas output system 3
Biogas circulation system 4
Mixer 5
Power components 6
Air distribution mechanism 7
Valve mechanism 8
Testing agency 9

Detailed ways

The present application is further described below by means of examples, but the present application is not limited to the scope of the described examples.

This embodiment provides an anaerobic digester as shown in Figure 3. By using this anaerobic digester, the sludge treatment method in this embodiment can be realized. Specifically, the anaerobic digester includes an anaerobic digester body 1. The anaerobic digester body 1 is provided with a gas phase space 11. The anaerobic digester body 1 is connected to a gas injection system 2, and the gas injection system 2 is connected to the gas phase. In space 11, the anaerobic digester body 1 is also connected to a biogas output system 3 and a biogas circulation system 4. The gas injection system 2 is provided with a branch gas injection unit 21, and one end of the branch gas injection unit 21 is connected to the gas injection system 2. , the other end is connected to the biogas circulation system 4. The branch gas injection unit 21 is connected to the biogas circulation system 4 through the mixer 5. The anaerobic digester body 1 is also equipped with a gas distribution mechanism 7 and a detection mechanism 9. The gas injection system 2. The branch gas injection unit 21, the biogas output system 3 and the biogas circulation system 4 are respectively provided with valve mechanisms 8. The valve mechanism 8 and the detection mechanism 9 control the gas injection system 2, the branch gas injection unit 21, the biogas output system 3 and On and off of biogas circulation system 4.

In addition, the gas injection system 2, branch gas injection unit 21, biogas output system 3 and biogas circulation system 4 on the anaerobic digester in this embodiment are mainly composed of pipelines, and the main power-consuming equipment is used to inject gas into the gas injection system 2 Oxygen preparation equipment that provides oxygen, while other equipment in this embodiment, such as the valve mechanism 8 and the detection mechanism 9, have low power consumption, thereby making the anaerobic digester consume less power during operation and comply with energy conservation. the need to reduce emissions.

As shown in Figure 1, this embodiment provides a sludge treatment method for oxygen injection desulfurization. The sludge treatment method includes the following steps:

S10. Adjust the sludge liquid level in the anaerobic digester body 1, and then adjust the volume of the gas phase space 11 above the sludge in the anaerobic digester body 1;

S20. Inject oxygen into the gas phase space 11 and fully mix the oxygen with the biogas in the gas phase space 11. The oxidation reaction of hydrogen sulfide in the biogas occurs on the inner wall of the anaerobic digester body 1 corresponding to the gas phase space 11;

S30. Use the adjusted volume to extend the residence time of the biogas in the anaerobic digester body 1, and perform the desulfurization reaction of the biogas while the biogas remains in the anaerobic digester body 1 until the desulfurization reaction of the biogas is completed.

In specific implementation, by adjusting the liquid level of the sludge in the anaerobic digester body 1, the volume of the gas phase space 11 above the sludge is adjusted. This volume is used to accommodate biogas and oxygen, and the biogas is evaporated in the gas phase space 11. For the desulfurization reaction, oxygen is rich in oxygen. It is better to use pure oxygen with 95% oxygen. By injecting oxygen into the gas phase space 11, the biogas and oxygen are fully mixed. The oxidation reaction of hydrogen sulfide in the biogas is the desulfurization of the biogas. The reaction mainly occurs on the inner wall of the anaerobic digester body 1 corresponding to the gas phase space 11. Among them, taking the diameter of the anaerobic digester body 1 as 28m, the height as 27m, and the effective volume as 14000m3 as an example, the corresponding anaerobic digestion The biogas output is 1400m3/h. Among them, the volume of the gas phase space 11 is set according to the biogas residence time of 3 hours, which is 4200m3. The total oxygen injection volume of the gas injection system 2 is designed to be 3% of the anaerobic digestion biogas volume, and is taken to be 50m3/h. By adjusting the volume of the gas phase space 11 to adapt to the desulfurization reaction of biogas, and injecting oxygen into the gas phase space 11, the anaerobic digester body 1 is sealed after the oxygen is injected. The oxygen stays in the gas phase space 11 and the purity of the oxygen itself is high, so that the biogas and oxygen The mixed desulfurization reaction can proceed more quickly and fully, reducing the desulfurization reaction time of biogas to increase the desulfurization reaction rate of biogas.

In another implementation of this embodiment, the volume of the gas phase space 11 can be set according to the biogas residence time of 1.5h-5h, and the sludge liquid level in the anaerobic digester body 1 can be adjusted accordingly, so that the anaerobic digester body 1 Adapt to the needs of different biogas production.

In this embodiment, the following steps are also included between step S20 and step S30:

S201. The biogas is circulated in the anaerobic digester body 1, and the biogas flows from the gas phase space 11 to the sludge through the biogas circulation system 4. The biogas enters the gas phase space 11 from the sludge again, and further combines the biogas with the gas injection. The oxygen injected into system 2 is fully mixed and the desulfurization reaction of biogas is carried out.

Specifically, a biogas circulation system 4 is provided outside the anaerobic digester body 1. One end of the biogas circulation system 4 is connected to the bottom of the anaerobic digester body 1, and the other end is connected to the gas phase space 11. The anaerobic digester body 1 is injected with After the oxygen is released, the biogas circulation system 4 is closed and kept smooth, and the oxygen and biogas are The anaerobic digester body 1 and the biogas circulation system 4 are relatively closed, and the mixing rate of oxygen and biogas is accelerated through the biogas circulation system 4, so that the biogas in the anaerobic digester body 1 flows into the anaerobic digester body 1 through the gas phase space 11 In the sludge at the bottom end of the interior, during the flow process, the biogas is fully mixed with the oxygen injected by the gas injection system 2, and the sulfur-oxidizing bacteria in the sludge are used to oxidize and metabolize the hydrogen sulfide in the biogas, and then in the sludge The desulfurization reaction of biogas, the desulfurization reaction carried out by the biogas circulation system 4 and the desulfurization reaction of the gas injection system 2 injecting oxygen into the gas phase space 11 are synchronized, which is more thorough than the desulfurization reaction of biogas that only carries out the desulfurization reaction in the gas phase space 11. At the same time It improves the desulfurization efficiency of biogas and shortens the reaction time required for primary desulfurization, thereby reducing the operating cost of the equipment.

In this embodiment, step S201 also includes the following steps:

S202. Implement step S20 and step S201 synchronously, and inject oxygen in the gas injection system 2 into the biogas circulation system 4 through the branch gas injection unit 21. The branch gas injection unit 21 and the biogas circulation system 4 are connected through the mixer 5, and Mix oxygen into the biogas circulation system 4 through the mixer 5;

S203. Flow the mixed biogas into the sludge through the biogas circulation system 4, use the sulfur-oxidizing bacteria in the sludge to oxidize and metabolize the hydrogen sulfide in the biogas, and combine it with the oxygen injected into the gas phase space 11 by the gas injection system 2. Synchronized biogas desulfurization reaction.

As shown in Figure 2, step S201 also includes a branch gas injection unit 21 that injects oxygen into the biogas circulation system 4. The branch gas injection unit 21 is connected with the gas injection system 2 and can inject oxygen into the biogas circulation system 4. The gas injection unit 21 stops gas injection after injecting oxygen into the biogas circulation system 4. The oxygen injected by the branch gas injection unit 21 is mixed with the biogas in the pipeline of the biogas circulation system 4, so that the oxygen in the biogas circulation system 4 is mixed with the biogas. The mixing ratio of the biogas is uniform and meets the content required for the biogas desulfurization reaction. The sulfur-oxidizing bacteria in the sludge in the anaerobic digester body 1 are used to oxidize and metabolize the hydrogen sulfide in the biogas, and then desulfurize the biogas in the sludge. reaction, the branch gas injection unit 21 injects oxygen into the biogas circulation system 4, which can solve the problem of insufficient mixing of biogas and oxygen when the biogas circulation system 4 circulates the oxygen injected by the gas injection system 2 and the biogas in the anaerobic digester body 1 However, recycling the biogas with excessive content into the sludge will cause the problem of insufficient oxygen during the desulfurization reaction in the sludge.

In this embodiment, the following steps are also included between step S10 and step S20:

S11. Before oxygen is injected into the gas phase space 11, the initial concentration of oxygen and the content of biogas in the gas phase space 11 are checked by the detection mechanism 9, and the amount of oxygen injected into the gas phase space 11 is adjusted according to the initial concentration of oxygen and the content of biogas.

Specifically, the detection mechanism 9 is arranged at the top of the interior of the anaerobic digester body 1 and is located close to the connection between the gas injection system 2 and the gas phase space 11. The detection mechanism 9 is used to detect the progress of the desulfurization reaction of the biogas in the anaerobic digester body 1. , for example, when the desulfurization reaction of the biogas is completed, the detection mechanism 9 detects and transmits the signal to the biogas output system 3 so that the desulfurized biogas can be discharged from the anaerobic digester body 1; before injecting oxygen into the gas phase space 11, the detection mechanism 9 Determine the initial concentration of oxygen in the anaerobic digester body 1 and the biogas content in the anaerobic digester body 1, and then accurately adjust the amount of oxygen to be injected into the gas phase space 11, which not only ensures the desulfurization reaction of the biogas It can be fully carried out and can reduce the waste of oxygen and further reduce the operating cost of anaerobic digester.

In this embodiment, the anaerobic digester body 1 also includes an air distribution mechanism 7. There are two air distribution mechanisms 7. One of the air distribution mechanisms 7 is provided in the gas phase space 11 and is connected to the gas injection system 2. The other is A gas distribution mechanism 7 is arranged in the sludge and communicates with the biogas circulation system 4 .

As shown in Figure 3, the anaerobic digester body 1 is also equipped with a gas distribution mechanism 7. There are two gas distribution mechanisms 7 and they are connected to the gas injection system 2 and the biogas circulation system 4 respectively. The gas distribution mechanism 7 is a ring. shaped pipeline, and the gas distribution mechanism 7 is provided with multiple nozzles or gas distribution holes. The gas distribution mechanism 7 connected with the gas injection system 2 is used to inject oxygen into the gas phase space 11. The gas distribution mechanism 7 can increase the diffusion of oxygen. area, and quickly mixes with the biogas in the gas phase space 11. The gas distribution mechanism 7 connected to the biogas circulation system 4 is used to inject a mixed gas of oxygen and biogas into the sludge, and its purpose is also to improve the efficiency of the mixed gas and sludge. contact area, thereby improving the desulfurization reaction efficiency of biogas.

In this embodiment, starting from step S10 to step S30 also includes the following steps: closing the valve mechanism 8 on the biogas output system 3 connected to the anaerobic digester body 1 before the desulfurization reaction between oxygen and biogas is fully carried out.

As shown in Figure 3, the anaerobic digester body 1 is equipped with a biogas output system 3. The biogas output system 3 and the biogas circulation system 4 share a common path from the top of the anaerobic digester body 1 to the biogas output system 3 and the biogas circulation system. The pipelines at the branches between the gas circulation systems 4 further reduce the investment cost of the anaerobic digester equipment. In addition, the biogas output system 3 and the biogas circulation system 4 are provided with a valve mechanism 8 for controlling the biogas output system 3 and the biogas circulation. When the system 4 is on and off, the detection mechanism 9 is electrically connected to the valve mechanism 8. The desulfurization reaction progress of the biogas in the anaerobic digester body 1 is detected by the detection mechanism 9, and then the corresponding valve mechanism 8 is opened or closed in sequence, so as to To adapt to the different steps of the desulfurization reaction of biogas, at the same time, the gas injection system 2 and the branch gas injection unit 21 are also provided with a valve mechanism 8, whose purpose is the same as the valve mechanism 8 provided on the biogas output system 3 and the biogas circulation system 4; in When oxygen is injected into the anaerobic digester body 1, the detection mechanism 9 detects the initial oxygen concentration and biogas content in the anaerobic digester body 1, and feeds the signal back to the valve mechanism 8, which opens the gas injection system 2 and branch gas injection. Unit 21, and promptly close the valve mechanism 8 on the gas injection system 2 and the branch gas injection unit 21 after the oxygen intake meets the amount required for the biogas desulfurization reaction. At the same time, the valve mechanism 8 on the biogas output system 3 is closed, To prevent oxygen from flowing out; when the biogas undergoes desulfurization reaction, close the valve mechanism 8 on the biogas output system 4, close the valve mechanism 8 on the gas injection system 2 and branch gas injection unit 21, close the valve on the biogas circulation system 4 The mechanism 8 remains on, and the detection mechanism 9 determines whether the desulfurization reaction of the biogas has been completed. Before the desulfurization reaction of the biogas is completed, the valve mechanism 8 on the biogas output system 3 is closed to ensure the safety of the anaerobic digester operation.

In addition, the biogas output system 3 and the biogas circulation system 4 are also provided with a power component 6. The power component 6 is a booster pump. The power component 6 is used to provide power for the flow of biogas. The power component 6 is electrically connected to the detection mechanism 9 and the control valve 8. Sexual connection, through the signal detected by the detection mechanism 9, the corresponding valve mechanism 8 is opened or closed, and at the same time, the corresponding power component 6 is connected, and the operating efficiency of the anaerobic digester is improved.

In another preferred implementation of this embodiment, the gas injection system 2 is provided with two valve mechanisms 8, and a branch gas injection unit 21 is connected between the two valve mechanisms 8. When gas is injected into the gas phase space 11 , the different connection states of the two valve mechanisms 8 can be controlled by the detection mechanism 9 to achieve synchronous control of the gas injection system 2 and the branch gas injection unit 21, or to individually control the air intake amount of oxygen flowing into the branch gas injection unit 21, Then, the rate of biogas desulfurization reaction in the anaerobic digester body 1 is accurately adjusted.

In this embodiment, the following steps are included after step S30: S31. After the desulfurization reaction between oxygen and biogas is fully carried out, the valve mechanism 8 on the gas injection system 2 and the branch gas injection unit 21 is closed and the valve mechanism 8 on the biogas output system 3 is opened. The valve mechanism 8.

Specifically, through the mutual cooperation of the detection mechanism 9 and the valve mechanism 8, and after oxygen is injected into the anaerobic digester body 1, the detection mechanism 9 detects this situation and accordingly closes the gas injection system 2 and the branch gas injection unit 21 The valve mechanism 8. At this time, oxygen is no longer injected into the anaerobic digester body 1. After the desulfurization reaction of the biogas is completed, the value of the desulfurized biogas is detected through the detection mechanism 9, and the valve mechanism on the biogas output system 3 is opened. 8. Discharging the desulfurized biogas out of the anaerobic digester not only improves the operating efficiency of the anaerobic digester, but also timely closing the gas injection system 2 and the branch gas injection unit 21 can further reduce the operating energy consumption of the anaerobic digester.

In this embodiment, the sludge treatment method also includes the following steps after step S31:

S32. Discharge the desulfurized biogas from the anaerobic digester body 1 through the biogas output system 3 and collect it.

Specifically, the anaerobic digester body 1 is connected to a biogas output system 3, and the other end of the biogas output system 3 is connected to a collection device. By closing the gas injection system 2, the branch gas injection unit 21 and the valve mechanism 8 on the biogas circulation system 4 And open the valve mechanism 8 on the biogas output system 3, and then the desulfurized biogas is discharged from the anaerobic digester body 1, flows through the biogas output system 3, and finally flows into the collection device. A collection device is set at the other end of the biogas output system 3 Through effective collection of biogas, the nitrogen content in the desulfurized biogas is reduced compared to the nitrogen content in the desulfurization reaction using air, and the quality of the desulfurized biogas is higher.

In this embodiment, the following steps are included after step S32: S33. After the desulfurized biogas is discharged from the anaerobic digester body 1, the valve mechanism 8 of the biogas output system 3 is closed and passed through the anaerobic digester body 1. The sludge inside produces biogas again to repeat the next biogas desulfurization reaction.

Specifically, the bottom of the anaerobic digester body 1 is provided with a pipeline for sludge to enter. The sludge can generate biogas in the anaerobic digester body 1. The generated biogas is used to mix with oxygen and perform a desulfurization reaction of the biogas. , when the primary desulfurization reaction is completed, the desulfurized biogas will be discharged from the anaerobic digester body 1, By injecting new sludge into the anaerobic digester body 1 and closing the valve mechanism 8 on the biogas output system 3, biogas without desulfurization reaction is regenerated through the gas phase space 11 for use in the next biogas desulfurization treatment. , thereby improving the reuse rate of this solution and further reducing the cost of biogas desulfurization reaction.

Although specific embodiments of the present application have been described above, those skilled in the art will understand that these are only examples, and the protection scope of the present application is defined by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principles and essence of the present application, but these changes and modifications all fall within the protection scope of the present application.

Claims

A sludge treatment method for oxygen injection desulfurization, characterized in that the sludge treatment method includes the following steps:

S10. Adjust the liquid level of the sludge in the anaerobic digester body, and then adjust the volume of the gas phase space above the sludge in the anaerobic digester body;

S20. Inject oxygen into the gas phase space and fully mix the oxygen with the biogas in the gas phase space. The oxidation reaction of hydrogen sulfide in the biogas occurs on the inner wall of the anaerobic digester body corresponding to the gas phase space;

S30. Use the adjusted volume to extend the residence time of the biogas in the anaerobic digester body, and perform the desulfurization reaction of the biogas while the biogas remains in the anaerobic digester body until the desulfurization reaction of the biogas is completed.
The sludge treatment method for oxygen injection desulfurization according to claim 1, characterized in that the following steps are further included between step S20 and step S30:

S201. Circulate biogas in the body of the anaerobic digester. The biogas flows from the gas phase space to the sludge through the biogas circulation system. The biogas enters the gas phase space again from the sludge, and further allows the biogas to flow into the gas phase space. It is fully mixed with the oxygen injected by the gas injection system and carries out the desulfurization reaction of the biogas.
The sludge treatment method for oxygen injection desulfurization according to claim 2, characterized in that step S201 further includes the following steps:

S202. Implement steps S20 and S201 synchronously, and inject oxygen in the gas injection system into the biogas circulation system through a branch gas injection unit. The branch gas injection unit and the biogas circulation system are connected through a mixer. , and mix oxygen into the biogas circulation system through the mixer;

S203. Flow the mixed biogas into the sludge through the biogas circulation system, use the sulfur-oxidizing bacteria in the sludge to oxidize and metabolize the hydrogen sulfide in the biogas, and combine it with the gas injection system to The oxygen injected into the gas phase space performs a synchronous desulfurization reaction of the biogas.
The sludge treatment method for oxygen injection desulfurization according to any one of claims 1 to 3, characterized in that the following steps are further included between step S10 and step S20:

S11. Before the oxygen is injected into the gas phase space, use a detection mechanism to check the initial concentration of oxygen and the content of biogas in the gas phase space, and adjust the amount of oxygen injected into the gas phase space according to the initial concentration of oxygen and the content of biogas. Air intake volume.
The sludge treatment method for oxygen injection desulfurization according to claim 3 or 4, characterized in that the anaerobic digester body further includes a gas distribution mechanism, and there are two gas distribution mechanisms, one of which is The gas distribution mechanism is arranged in the gas phase space and communicates with the gas injection system, and the other gas distribution mechanism is arranged in the sludge and communicates with the biogas circulation system.
The sludge treatment method for oxygen injection and desulfurization according to any one of claims 1 to 5, characterized in that, after step S30, it also includes the following steps: S31, after oxygen and biogas have fully carried out desulfurization reaction, gas injection The valve mechanism on the system and branch gas injection units closes and the valve mechanism on the biogas output system opens.
The sludge treatment method for oxygen injection desulfurization according to claim 6, wherein the sludge treatment method further includes the following steps after step S31:

S32. Discharge the desulfurized biogas from the anaerobic digester body through the biogas output system and collect it.
The sludge treatment method of oxygen injection desulfurization according to claim 7, characterized in that, after step S32, it also includes the following steps: S33. After the desulfurized biogas is discharged from the anaerobic digester body, the biogas output system The valve mechanism is closed, and biogas is generated again through the sludge in the anaerobic digester body to repeat the next biogas desulfurization reaction.
An anaerobic digester, characterized in that the anaerobic digester uses the sludge treatment method of oxygen injection and desulfurization as described in any one of claims 1-8 to treat sludge.