A device for biogas desulfurization and biogas slurry treatment

Abstract

This invention provides a device for co-treating biogas desulfurization and biogas slurry treatment. The device includes a biogas desulfurization unit and a biogas slurry treatment unit. The biogas desulfurization unit includes a desulfurization component, a reaction component, and a sedimentation component connected in a cycle. The biogas slurry treatment unit includes a first denitrification component, a nitrification component, and a second denitrification component connected in sequence, with the first denitrification component and the nitrification component connected in a cycle. The sedimentation component in the biogas desulfurization unit is connected to the second denitrification component in the biogas slurry treatment unit. This invention achieves the coupling of the biogas desulfurization unit and the biogas slurry treatment unit, while solving the problem of disposing of sulfur sludge, a byproduct of desulfurization, and the problem of carbon source shortage during biogas slurry treatment. It achieves deep desulfurization of biogas and deep denitrification of biogas slurry, reduces sludge production, and lowers the treatment cost of biogas and biogas slurry after anaerobic fermentation of organic waste.

Description

Technical Field

[0001] This utility model belongs to the field of biomass anaerobic fermentation technology, specifically relating to a device for biogas desulfurization and biogas slurry treatment, and more particularly to a device for biogas desulfurization and biogas slurry treatment after anaerobic fermentation of organic waste. Background Technology

[0002] Cities generate a large amount of organic waste during their operation, mainly including catering waste, household kitchen waste, fruit and vegetable scraps from farmers' markets, sludge from sewage treatment plants, and fecal sewage. These organic wastes have a high organic matter content (VS content generally reaches 60-85%), and improper disposal will cause multiple environmental risks: ① occupying land resources (rapid depletion of landfill volume); ② generating malodorous substances (such as hydrogen sulfide, ammonia, etc.) and leachate pollution; ③ releasing the strong greenhouse gas methane (GWP is 28 times that of CO2), etc.

[0003] Currently, the mainstream treatment process for this type of organic waste is "pretreatment + anaerobic fermentation + biogas purification and utilization". This process first pre-treats the organic waste through sorting, crushing, and pulping to improve subsequent fermentation efficiency. Then, in a closed anaerobic reactor, microorganisms decompose organic matter under anaerobic conditions, producing biogas mainly composed of methane (CH4) and carbon dioxide (CO2). Finally, the biogas needs to be purified before it can be safely and efficiently used for power generation, heating, or purified into biomethane, achieving energy recovery. However, this mainstream process presents two major problems:

[0004] One key issue is the economic viability of anaerobic digestion biogas desulfurization. The biogas produced by anaerobic digestion contains 1200-4000 ppm of hydrogen sulfide (H2S), far exceeding the tolerance limits for gas-fired equipment (typically less than 200 ppm). Existing desulfurization technologies each have their drawbacks, including: ① Alkali-based desulfurization produces sulfur sludge, with disposal costs reaching thousands of yuan per ton, and limited disposal options; ② Biological acid-based desulfurization generates 10%-15% sulfuric acid wastewater, resulting in high treatment costs; ③ Wet desulfurization produces sulfur paste, which also has high treatment costs, and the wet desulfurization process itself is also expensive; ④ Dry desulfurization requires frequent replacement of the desulfurizing agent, and the treatment cost of the replaced agent is high. Therefore, reducing the cost of biogas desulfurization is one of the most important issues facing anaerobic digestion projects involving organic waste.

[0005] Secondly, there is a shortage of carbon sources for the treatment of biogas slurry produced by anaerobic fermentation. The biogas slurry produced by the current mainstream organic waste treatment processes has a serious imbalance in the carbon-nitrogen ratio, with some projects having a carbon-nitrogen ratio as low as 1:1. The treatment of biogas slurry requires the addition of a large amount of externally purchased carbon sources (such as methanol, sodium acetate, or glucose), which significantly increases the operating cost of the project and fundamentally restricts the sustainable development potential of organic waste resource utilization projects.

[0006] In response to the above situation, this utility model proposes a device for biogas desulfurization and biogas slurry treatment after anaerobic fermentation of organic waste, so as to simultaneously achieve efficient biogas desulfurization and deep denitrification of biogas slurry, reduce sludge production, solve the problem of where desulfurization by-products go and the problem of needing to purchase external carbon sources for biogas slurry treatment, and reduce treatment costs. Utility Model Content

[0007] To address the problems existing in the prior art, the purpose of this utility model is to provide a device for biogas desulfurization and biogas slurry treatment, especially a device for biogas desulfurization and biogas slurry treatment after anaerobic fermentation of organic waste. This device solves the problems of where to dispose of sulfur sludge generated from biogas desulfurization and the lack of carbon source for biogas slurry treatment, thereby reducing the cost of biogas and biogas slurry treatment after anaerobic fermentation of organic waste.

[0008] To achieve this objective, the present invention adopts the following technical solution:

[0009] This utility model provides a device for biogas desulfurization and biogas slurry treatment in conjunction with biogas desulfurization, the device including a biogas desulfurization unit and a biogas slurry treatment unit;

[0010] The biogas desulfurization unit includes a desulfurization component, a reaction component, and a sedimentation component connected in a loop; the biogas slurry treatment unit includes a first denitrification component, a nitrification component, and a second denitrification component connected in sequence, and the first denitrification component and the nitrification component are connected in a loop.

[0011] The sedimentation component in the biogas desulfurization unit is connected to the second denitrification component in the biogas slurry treatment unit.

[0012] The biogas desulfurization and biogas slurry treatment device of this invention connects the sedimentation component in the biogas desulfurization unit with the second denitrification component in the biogas slurry treatment unit, thereby achieving the coupling of the biogas desulfurization unit and the biogas slurry treatment unit. This innovatively constructs a closed-loop system of "biogas desulfurization - sulfur sludge reuse - biogas slurry treatment," effectively solving both the problem of desulfurization byproduct disposal and the carbon source shortage during biogas slurry treatment. The connection between the sedimentation component in the biogas desulfurization unit and the second denitrification component in the biogas slurry treatment unit aims to transport the sediment (containing sulfur autotrophic bacteria and elemental sulfur sludge) in the sedimentation component to the second denitrification component (sulfur autotrophic denitrification). This provides bacteria for sulfur autotrophic denitrification and energy for the denitrification reaction within the sulfur autotrophic denitrification, reducing nitrate nitrogen to nitrogen gas to achieve denitrification. The sulfur autotrophic denitrification method significantly reduces sludge production compared to conventional heterotrophic denitrification.

[0013] Meanwhile, the biogas slurry treatment unit, by coordinating the first denitrification unit and the nitrification unit before the second denitrification unit and cyclically connecting the first denitrification unit and the nitrification unit, consumes most of the carbon source in the original biogas slurry, ensuring the absolute dominance of subsequent sulfur autotrophic nitrifying bacteria; it avoids the biogas slurry entering the second denitrification unit containing a high carbon source, thus preventing competition between autotrophic denitrifying bacteria and sulfur autotrophic nitrifying bacteria. At the same time, it removes ammonia nitrogen and nitrate nitrogen from the original biogas slurry in advance, reducing the denitrification load and sludge production in the second denitrification unit, and reducing the treatment cost of biogas and biogas slurry after anaerobic fermentation of organic waste.

[0014] It is worth noting that the biogas desulfurization unit described in this utility model must use an alkaline biological desulfurization process to treat biogas. The desulfurization byproduct sulfur sludge produced by the alkaline biological desulfurization process is used as a bioenergy supplement and functional microbial carrier for biogas slurry treatment.

[0015] The following are preferred technical solutions of this utility model, but are not intended to limit the technical solutions provided by this utility model. Through the following preferred technical solutions, the purpose and beneficial effects of this utility model can be better achieved.

[0016] Preferably, the desulfurization component is provided with at least two spray components, such as two, three, four, five or six, etc.

[0017] The spraying component described in this invention is used to spray an alkaline solution. The alkaline solution is fully mixed and reacted with the biogas produced by the anaerobic fermentation of organic waste, absorbing and purifying the H2S in the biogas to 100 ppm or less before being discharged from the top of the desulfurization component.

[0018] Preferably, the desulfurization component includes a packing zone.

[0019] The packing zone described in this invention is used to fill Pall ring packing, which catalyzes the reaction between the alkaline solution and H2S, and increases the residence time of the biogas in the desulfurization component, thereby improving the desulfurization efficiency.

[0020] Preferably, the desulfurization component has an air inlet on its side.

[0021] Preferably, the desulfurization component has an air outlet at its top.

[0022] Preferably, a first aeration component is provided at the bottom of the reaction component.

[0023] In this invention, it is further preferred that a first aeration component is provided at the bottom of the reaction component. This first aeration component provides oxygen to the desulfurization microorganisms and evenly reacts with the sprayed liquid after the H2S reaction, thereby promoting the desulfurization of sulfur dioxide. 2- The reaction that oxidizes sulfur to elemental sulfur.

[0024] Preferably, at least two aeration components are evenly distributed at the bottom of the reaction component, for example, there may be two, three, four, five, six, seven or eight such components.

[0025] It is worth noting that in the reaction component described in this invention, the pH, redox potential, conductivity, and temperature of the reaction system within the reaction component need to be adjusted in real time to ensure that the reaction environment reaches a level conducive to S. 2- It is oxidized to elemental sulfur.

[0026] Preferably, the reaction component and the precipitation component are cyclically connected.

[0027] In the biogas desulfurization unit, the supernatant in the sedimentation component overflows back to the reaction component, and elemental sulfur and some desulfurization bacteria precipitate to the sedimentation component, which can reduce the sulfur concentration and the aging degree of desulfurization bacteria in the reaction component and improve the reaction efficiency of the reaction system in the reaction component.

[0028] Preferably, the top of the reaction component is connected to the top of the desulfurization component.

[0029] Preferably, a first reflux component is provided between the top of the reaction component and the top of the desulfurization component.

[0030] Preferably, the top of the first denitrification component is provided with a first feed inlet.

[0031] It is worth noting that in this invention, the oxygen content, temperature, carbon-nitrogen ratio, and COD concentration of the reaction system within the first denitrification component need to be adjusted in a timely manner to provide an advantageous environment for heterotrophic denitrifying bacteria.

[0032] Preferably, a first stirring element is provided near the bottom of the first denitrification component.

[0033] Preferably, a first driving component is disposed on the outside of the first denitrification component, and the first driving component is electrically connected to the first stirring component.

[0034] Preferably, the first driving component includes a first motor.

[0035] Preferably, a second reflux component is provided between the nitrification component and the first denitrification component.

[0036] Preferably, a second aeration component is provided inside the nitration component.

[0037] The present invention further preferably includes a second aeration component within the nitrification component, which provides dissolved oxygen to the nitrifying bacteria and evenly distributes the biogas slurry to efficiently remove ammonia nitrogen and alleviate the pressure of subsequent denitrification.

[0038] Preferably, the reaction component is provided with at least four second aeration components that are evenly distributed, such as four, six, eight, ten, twelve, fourteen, sixteen, eighteen, or twenty.

[0039] It is worth noting that in this invention, the oxygen content (achieved by installing a dissolved oxygen meter inside the denitrification component), temperature, ammonia nitrogen, and nitrite concentration of the reaction system inside the nitrification component need to be adjusted in a timely manner to provide a favorable environment for the nitrification reaction.

[0040] Preferably, the second denitrification component is provided with a second feed inlet at its top.

[0041] Preferably, the bottom of the sedimentation component is connected to the second inlet of the second denitrification component.

[0042] It is worth noting that in this invention, the oxygen content, temperature, pH and nitrogen concentration of the reaction system in the second denitrification component need to be adjusted in a timely manner to provide an advantageous environment for the sulfur autotrophic denitrification reaction.

[0043] Preferably, a second stirring element is provided near the bottom of the second denitrification component.

[0044] Preferably, a second driving component is provided on the outside of the second denitrification component, and the second driving component is electrically connected to the second stirring component.

[0045] Preferably, the second drive component includes a second motor.

[0046] Preferably, the biogas slurry treatment unit further includes an ultrafiltration component, and the second denitrification component is cyclically connected to the ultrafiltration component.

[0047] Preferably, the ultrafiltration assembly includes at least two ultrafiltration components connected in parallel, such as 2, 4, 6, 8, 10, 12, 14, 16, 18 or 20, preferably 8 to 16.

[0048] Preferably, the biogas slurry treatment unit further includes a sludge treatment component.

[0049] Preferably, the sludge treatment component is connected to the ultrafiltration assembly.

[0050] The numerical range described in this utility model includes not only the point values ​​listed above, but also any point values ​​within the numerical range that are not listed. Due to space limitations and for the sake of brevity, this utility model will not exhaustively list all the specific point values ​​included in the range.

[0051] The operation method of the biogas desulfurization and biogas slurry treatment device provided by this utility model specifically includes the following steps:

[0052] H2S-containing biogas produced by the anaerobic fermentation of organic waste enters the desulfurization unit through the inlet. Pollutants such as H2S in the biogas are thoroughly mixed and reacted with the alkaline spray solution, purifying the H2S in the biogas to 100 ppm or less, and then discharged through the outlet. Subsequently, the alkaline spray solution, having absorbed H2S and other pollutants, flows by gravity from the bottom of the desulfurization unit into the reaction unit. A first aeration unit within the reaction unit provides oxygen to the desulfurizing bacteria and evenly sprays the solution. The pH, oxidation-reduction potential, conductivity, and temperature within the reaction unit are controlled at 7.5–9.5, -340–-400 mV, and 40–60 mS / cm, respectively, and the temperature is approximately 37°C. This allows the desulfurizing bacteria to remove the H2S from the reaction unit. 2- The primary oxidation process produces elemental sulfur, i.e., sulfur mud. Subsequently, the mixture from the reaction unit is pumped to the sedimentation unit, where the supernatant overflows and flows back to the reaction unit to continue oxidizing sulfur. 2- Elemental sulfur and some desulfurizing bacteria precipitate into the precipitation component for subsequent biogas slurry treatment;

[0053] The biogas slurry from the anaerobic fermentation of organic waste is first transported from the first inlet to the first denitrification unit. The first drive unit is activated to drive the first agitator to stir the system. Simultaneously, the first denitrification unit is controlled to be an oxygen-deficient environment at a temperature of 20-40℃. The biogas slurry in the first denitrification unit flows by gravity into the nitrification unit. The second aeration unit is activated, controlling the dissolved oxygen content in the nitrification unit to be 2-4 mg / L and the temperature to be 25-40℃ (preferably 37℃). This completely oxidizes the remaining ammonia nitrogen and nitrite in the nitrification unit to nitrate, with a residence time of 8-48 hours, adjusted according to the ammonia nitrogen and nitrite concentrations. Then, the first reflux unit, i.e., the reflux pump, is activated to return the biogas slurry from the nitrification unit, providing nitrate (NO3) for the heterotrophic denitrification reaction in the first denitrification unit. - The reflux ratio is determined based on the carbon content in the biogas slurry, and the carbon:nitrogen (referring to nitrate nitrogen) ratio is controlled at (2-3):1. This process utilizes the energy provided by the COD in the biogas slurry to convert some of the nitrate nitrogen into nitrogen gas, achieving partial denitrification and reducing the denitrification pressure at the downstream end; at the same time, it removes most of the carbon source in the biogas slurry, providing a favorable environment for the subsequent sulfur autotrophic denitrification reaction; the residence time is 12-48 hours, adjusted according to the COD concentration in the biogas slurry.

[0054] Subsequently, the biogas slurry in the nitrification unit flows by gravity to the second denitrification unit, and the precipitate (elemental sulfur) and some desulfurizing bacteria in the precipitation reaction unit are pumped into the second denitrification unit through the second inlet. At the same time, the second drive unit is activated to drive the second agitator to stir the system. The desulfurizing bacteria continue to grow and multiply, oxidizing elemental sulfur to SO4. 2- It generates energy and provides electron donors; at the same time, it uses nitrates (NO3) in the second denitrification unit. - Using an electron acceptor, nitrates are gradually reduced to nitrogen (N2) to achieve denitrification. During this process, the temperature inside the second denitrification unit is controlled at 20-40℃ (preferably 37℃); an oxygen-deficient environment is maintained, with dissolved oxygen concentration controlled at 0.2-0.5 mg / L and pH at 6.5-8.0. Simultaneously, the amount of sulfur sludge added is controlled, with a sulfur-to-nitrogen mass ratio of (3-5):1, to ensure that most nitrates are converted to nitrogen; the residence time is 6-48 hours, adjusted according to the nitrogen concentration.

[0055] Then, the biogas slurry in the second denitrification unit is pumped into the ultrafiltration unit and undergoes ultrafiltration treatment through each ultrafiltration unit in sequence. Part of the ultrafiltration concentrate is returned to the second denitrification unit, and part is pumped to the downstream sludge treatment unit. The ultrafiltration clear liquid is denitrified purified water, which is discharged in compliance with standards or further downstream treatment.

[0056] The biogas desulfurization and biogas slurry treatment device of this utility model is suitable for the comprehensive treatment of organic waste such as kitchen waste, manure and biochemical sludge. It is suitable for treatment processes that do not have strict requirements for sulfate ions in the downstream biogas slurry. If there is no biogas desulfurization unit at the front end, elemental sulfur mud can be purchased directly to replace the carbon source.

[0057] Compared with the prior art, the present invention has the following beneficial effects:

[0058] (1) The present invention provides a biogas desulfurization and biogas slurry treatment device, which innovatively constructs a closed-loop system of "biogas desulfurization-sulfur sludge reuse-biogas slurry treatment" by connecting the sedimentation component in the biogas desulfurization unit with the second denitrification component in the biogas slurry treatment unit, thereby realizing the coupling of the biogas desulfurization unit and the biogas slurry treatment unit, and simultaneously solving the problem of disposal of sulfur sludge byproduct of biogas desulfurization and the problem of carbon source shortage in the biogas slurry treatment process.

[0059] (2) The present invention provides a biogas desulfurization and biogas slurry treatment device, which simultaneously adds a first denitrification component and a nitrification component in the biogas slurry treatment unit and designs the first denitrification component and the nitrification component to be circulatedly connected, removes ammonia nitrogen and nitrate nitrogen in the original biogas slurry in advance, reduces the denitrification load in the second denitrification component, and consumes most of the carbon source in the original biogas slurry, ensuring the absolute advantage of subsequent sulfur autotrophic nitrifying bacteria, achieving deep denitrification of biogas slurry while reducing sludge production and reducing treatment costs. Attached Figure Description

[0060] Figure 1 This is a schematic diagram of the structure and connection relationship of the biogas desulfurization and biogas slurry treatment device provided in Embodiment 1 of this utility model;

[0061] Explanation of reference numerals in the attached drawings: 1. Biogas desulfurization unit; 11. Desulfurization component; 12. Reaction component; 13. Sedimentation component; 14. Spraying component; 15. Packing zone; 16. Air inlet; 17. Air outlet; 18. First aeration component; 2. Biogas slurry treatment unit; 201. First denitrification component; 202. Nitrification component; 203. Second denitrification component; 204. Ultrafiltration assembly; 205. Sludge treatment component; 206. First agitator; 207. First drive component; 208. Second agitator; 209. Second drive component; 210. Second aeration component; 211. First feed inlet; 212. Second feed inlet. Detailed Implementation

[0062] The technical solution of this utility model will be further described below with reference to the accompanying drawings and specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of this utility model and should not be considered as specific limitations thereof.

[0063] It should be understood that in the description of this utility model, the terms "inner," "outer," "side," "top," "bottom," "between," and "parallel," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These are used only for the convenience of describing this utility model and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. The terms "first," "second," "third," and "fourth," etc., do not indicate the importance of the components and therefore should not be construed as limitations on this utility model. The specific dimensions used in this embodiment are only for illustrating the technical solution and do not limit the scope of protection of this utility model.

[0064] I. Implementation Examples

[0065] Example 1

[0066] This embodiment provides a device for biogas desulfurization and biogas slurry treatment in conjunction, such as... Figure 1 As shown, the device includes a biogas desulfurization unit 1 and a biogas slurry treatment unit 2;

[0067] The biogas desulfurization unit 1 includes a desulfurization component 11, a reaction component 12, and a sedimentation component 13 connected in a loop. The desulfurization component 11 contains three spray components 14. The desulfurization component 11 also contains a packing zone 15 (filled with Pall ring packing). An air inlet 16 is located on the side of the desulfurization component 11. An air outlet 17 is located at the top of the desulfurization component 11. The bottom of the reaction component 12 contains four evenly distributed first aeration components 18. The reaction component 12 and the sedimentation component 13 are connected in a loop. The top of the reaction component 12 is connected to the top of the desulfurization component 11. A first reflux component, i.e., a reflux pump, is located between the tops of the reaction component 12 and the tops of the desulfurization component 11.

[0068] The biogas slurry treatment unit 2 includes a first denitrification component 201, a nitrification component 202, a second denitrification component 203, an ultrafiltration component 204, and a sludge treatment component 205 connected in sequence, with the first denitrification component 201 and the nitrification component 202 being cyclically connected; the second denitrification component 203 and the ultrafiltration component 204 being cyclically connected.

[0069] The first denitrification component 201 has a first feed inlet 211 at its top; a first stirring element 206 is located near the bottom inside the first denitrification component 201; a first driving component 207, i.e., a first motor, is located outside the first denitrification component 201, and the first driving component 207 is electrically connected to the first stirring element 206; a second reflux component, i.e., a reflux pump, is located between the nitrification component 202 and the first denitrification component 201; and 30 evenly distributed second aeration components are located inside the nitrification component 202. 210; The top of the second denitrification component 203 is provided with a second feed inlet 212; The bottom of the sedimentation component 13 is connected to the second feed inlet 212 of the second denitrification component 203; A second stirring component 208 is provided inside the second denitrification component 203 near the bottom; A second driving component 209, i.e., a second motor, is provided outside the second denitrification component 203, and the second driving component 209 is electrically connected to the second stirring component 208; The ultrafiltration assembly 204 includes 12 ultrafiltration components connected in parallel.

[0070] The device described in this embodiment simultaneously achieves efficient desulfurization of biogas and deep denitrification of biogas slurry, with a desulfurization efficiency of over 90% and a denitrification efficiency of over 90%, and also achieves sludge reduction.

[0071] Example 2

[0072] This embodiment provides a device for biogas desulfurization and biogas slurry treatment in conjunction with biogas desulfurization, the device including a biogas desulfurization unit and a biogas slurry treatment unit;

[0073] The biogas desulfurization unit includes a desulfurization component, a reaction component, and a sedimentation component connected in a loop. The desulfurization component contains four spray components and a packing zone (filled with Pall ring packing). An air inlet is located on the side of the desulfurization component, and an air outlet is located at the top. Six evenly distributed first aeration components are located at the bottom of the reaction component. The reaction component and the sedimentation component are connected in a loop. The top of the reaction component is connected to the top of the desulfurization component. A first reflux component, i.e., a reflux pump, is located between the tops of the reaction component and the tops of the desulfurization component.

[0074] The biogas slurry treatment unit includes a first denitrification unit, a nitrification unit, a second denitrification unit, an ultrafiltration unit, and a sludge treatment unit connected in sequence, with the first denitrification unit and the nitrification unit being cyclically connected; the second denitrification unit and the ultrafiltration unit are also cyclically connected.

[0075] The first denitrification component has a first feed inlet at its top; a first stirring element is located near the bottom inside the first denitrification component; a first driving component, i.e., a first motor, is located outside the first denitrification component, and the first driving component is electrically connected to the first stirring element; a second reflux component, i.e., a reflux pump, is located between the nitrification component and the first denitrification component; 24 evenly distributed second aeration components are located inside the nitrification component; a second feed inlet is located at the top of the second denitrification component; the bottom of the sedimentation component is connected to the second feed inlet of the second denitrification component; a second stirring element is located near the bottom inside the second denitrification component; a second driving component, i.e., a second motor, is located outside the second denitrification component, and the second driving component is electrically connected to the second stirring element; the ultrafiltration assembly includes 10 ultrafiltration components connected in parallel.

[0076] The biogas desulfurization efficiency, biogas slurry denitrification, and sludge reduction effects described in this embodiment are comparable to those in Embodiment 1.

[0077] Example 3

[0078] This embodiment provides a device for biogas desulfurization and biogas slurry treatment. Except that the second denitrification component does not have a second stirring element and the first denitrification component does not have a second motor, the device is the same as that in Embodiment 1.

[0079] In this embodiment, because the second denitrification component does not have a second stirring element, the biogas slurry, sulfur sludge, and sulfur autotrophic nitrifying bacteria are unevenly distributed and not mixed sufficiently, resulting in reduced denitrification efficiency and increased sludge production.

[0080] Example 4

[0081] This embodiment provides a device for biogas desulfurization and biogas slurry treatment. Except for the absence of a second aeration component in the nitrification component, the device is the same as that in Embodiment 1.

[0082] In this embodiment, since the second aeration component is not installed in the nitrification component, dissolved oxygen cannot be provided and the biogas slurry cannot be uniformly distributed. This results in a reduced reaction efficiency of ammonia nitrogen in the biogas slurry being oxidized to nitrate nitrogen, leading to a high ammonia nitrogen content entering the second denitrification component and increasing the denitrification load.

[0083] II. Comparative Example

[0084] Comparative Example 1

[0085] This comparative example provides a device for biogas desulfurization and biogas slurry treatment. Except that the first denitrification component and the nitrification component are not cyclically connected, but are unidirectionally connected, the device is the same as that in Example 1.

[0086] In this comparative example, because the first denitrification unit and the nitrification unit are not circulated but unidirectionally connected, the biogas slurry in the nitrification unit cannot flow back to the first denitrification unit, thus failing to initially remove nitrogen. The subsequent nitrogen removal load is large, consuming most of the carbon source in the original biogas slurry. Subsequently, the sulfur autotrophic nitrifying bacteria in the second denitrification unit lose their competitive advantage, resulting in reduced nitrogen removal efficiency and increased sludge production.

[0087] Comparative Example 2

[0088] This comparative example provides a device for biogas desulfurization and biogas slurry treatment. The device is the same as that in Example 1 except that the first denitrification component is not provided and the first feed inlet is located on the top of the nitrification component.

[0089] Because the first denitrification component was not installed in this comparative example, it was unable to perform preliminary denitrification and could not consume carbon sources. As a result, the second denitrification component bore the entire denitrification load. Moreover, the presence of a large amount of carbon sources was not conducive to the survival of sulfur-autotrophic nitrifying bacteria, resulting in poor denitrification effect of biogas slurry and a large amount of sludge production.

[0090] In summary, the biogas desulfurization and biogas slurry treatment device provided by this utility model connects the sedimentation component in the biogas desulfurization unit to the second denitrification component in the biogas slurry treatment unit, and sets the first denitrification component and the nitrification component in coordination before the second denitrification component, and circulates the first denitrification component and the nitrification component, thereby achieving the coupling of the biogas desulfurization unit and the biogas slurry treatment unit. At the same time, it solves the problem of disposing of sulfur sludge, a by-product of desulfurization, and the problem of carbon source shortage in the biogas slurry treatment process, achieving deep desulfurization of biogas and deep denitrification of biogas slurry, reducing the amount of sludge generated, and reducing the treatment cost of biogas and biogas slurry after anaerobic fermentation of organic waste.

[0091] The applicant declares that the detailed structural features of this utility model are illustrated through the above embodiments, but this utility model is not limited to the above detailed structural features, that is, it does not mean that this utility model must rely on the above detailed structural features to be implemented. Those skilled in the art should understand that any improvements to this utility model, equivalent substitutions of selected components, additions of auxiliary components, and selection of specific methods, etc., all fall within the protection and disclosure scope of this utility model.

Claims

1. A device for biogas desulfurization and synergistic biogas slurry treatment, characterized in that, The device includes a biogas desulfurization unit and a biogas slurry treatment unit; The biogas desulfurization unit includes a desulfurization component, a reaction component, and a sedimentation component connected in a loop; the biogas slurry treatment unit includes a first denitrification component, a nitrification component, and a second denitrification component connected in sequence, and the first denitrification component and the nitrification component are connected in a loop. The sedimentation component in the biogas desulfurization unit is connected to the second denitrification component in the biogas slurry treatment unit.

2. The apparatus for biogas desulfurization and synergistic biogas slurry treatment according to claim 1, characterized in that, The desulfurization unit is equipped with at least two spray components; The desulfurization component is equipped with a packing zone; An air inlet is provided on the side of the desulfurization component; The desulfurization component is provided with an air outlet at its top.

3. The apparatus for biogas desulfurization and synergistic biogas slurry treatment according to claim 2, characterized in that, The reaction component is equipped with a first aeration component at its bottom.

4. The apparatus for biogas desulfurization and synergistic biogas slurry treatment according to claim 3, characterized in that, The reaction component and the precipitation component are connected in a loop; The top of the reaction component is connected to the top of the desulfurization component; A first reflux component is provided between the top of the reaction component and the top of the desulfurization component.

5. The apparatus for biogas desulfurization and synergistic biogas slurry treatment according to claim 1, characterized in that, The first denitrification unit is provided with a first feed inlet at its top.

6. The apparatus for biogas desulfurization and synergistic biogas slurry treatment according to claim 5, characterized in that, A first stirring element is provided near the bottom of the first denitrification component; The first denitrification component is externally provided with a first driving component, and the first driving component is electrically connected to the first stirring component.

7. The apparatus for biogas desulfurization and synergistic biogas slurry treatment according to claim 6, characterized in that, A second reflux component is provided between the nitration component and the first denitration component; The nitration component is equipped with a second aeration component.

8. The apparatus for biogas desulfurization and synergistic biogas slurry treatment according to claim 7, characterized in that, The second denitrification unit is provided with a second feed inlet at its top; The bottom of the sedimentation component is connected to the second inlet of the second denitrification component.

9. The apparatus for biogas desulfurization and synergistic biogas slurry treatment according to claim 8, characterized in that, A second stirring element is provided near the bottom of the second denitrification component; The second denitrification component is externally provided with a second driving component, and the second driving component is electrically connected to the second stirring component.

10. The apparatus for biogas desulfurization and synergistic biogas slurry treatment according to claim 1, characterized in that, The biogas slurry treatment unit further includes an ultrafiltration component, and the second denitrification component is circulatedly connected to the ultrafiltration component; The ultrafiltration assembly includes at least two ultrafiltration components connected in parallel; The biogas slurry treatment unit also includes a sludge treatment component; The sludge treatment component is connected to the ultrafiltration assembly.

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