An integrated vertical two-phase anaerobic reaction device and process

Abstract

The present invention relates to an integrated vertical two-phase anaerobic reaction device and process, the device comprises a reaction tank body, a central inner cylinder is arranged in the middle of the reaction tank body, so that a hydrolysis and acidification reaction zone located in the central inner cylinder and a methanogenic zone located between the inner wall of the reaction tank body and the outer wall of the central inner cylinder are formed in the reaction tank body, the hydrolysis and acidification reaction zone is connected to the bottom of the methanogenic zone, the top of the reaction tank body is also sealed with a reaction tank top cover, and a biogas outlet is also arranged on the reaction tank top cover. The present invention integrates two different reactors, an acidogenic phase and a methanogenic phase, into a vertical reactor to realize a two-phase process of hydrolysis and anaerobic biogas production, and solves the technical problems of low methane production efficiency and low system integration efficiency of the two-phase anaerobic reactor in the prior art.

Description

Technical Field

[0001] The invention belongs to the technical field of anaerobic reactors and relates to an integrated vertical two-phase anaerobic reaction device and process. Background Art

[0002] In recent years, the pollution of organic solid waste such as straw, organic garbage, agricultural and sideline products has gradually attracted people's attention. Conventional treatment methods such as landfill, incineration, composting, etc. have certain problems. In fact, the above waste components are mainly organic components, which have high biodegradability. The use of anaerobic digestion technology can recover biogas as biomass energy while treating organic waste, and the fermentation products can be used as fertilizers after treatment, which is very feasible.

[0003] A Chinese patent with the announcement number CN112410188A discloses a straw two-phase anaerobic fermentation biogas production device. This method divides the anaerobic biogas production process into three parts: hydrolysis, acidification and biogas production, so that acid production and gas production are carried out separately, requiring multiple tank equipment and a long anaerobic process path. At the same time, each tank of the process adopts mechanical stirring, which requires the configuration of multiple motors, making the process cumbersome and high in power consumption.

[0004] A Chinese patent with announcement number CN111762886A discloses an integrated two-phase anaerobic UITA reaction device, which adopts the method of water inlet at the bottom and water outlet at the top, and sets a hydrolysis acidification reaction zone, an anaerobic methanogenesis zone and a clean water zone in the reaction tank body in sequence along the water flow direction. Although this method can realize the acidogenesis phase and the methaneogenesis phase in the same equipment, it uses a water-passing baffle to separate the hydrolysis acidification reaction zone and the anaerobic methanogenesis zone, resulting in the difficulty in controlling the reaction process of the water flow in the acidogenesis phase and the methaneogenesis phase, and the system stability is poor. At the same time, the methaneogenesis area of ​​the reactor lacks sufficient hydraulic stirring, and the methaneogenesis effect is difficult to guarantee.

[0005] A Chinese patent with announcement number CN108179103A discloses a double-ring nested two-phase integrated anaerobic reactor, which includes an anaerobic digester with an inner and outer double-ring nested structure. The inner ring of the anaerobic digester serves as a hydrolysis acidification reactor, and the outer ring serves as a methanogenic reactor. The volume of the designed methanogenic reactor is originally larger than that of the hydrolysis acidification reactor, and it adopts a central mechanical stirring method, so that the hydraulic stirring in the outer ring methanogenic reactor is not sufficient during operation, and the mass transfer effect between the methanogens and the acidified wastewater is poor, resulting in low methanogenic reaction efficiency. Summary of the invention

[0006] The purpose of the present invention is to provide an integrated vertical two-phase anaerobic reaction device and process to solve the technical problems of low methane production efficiency and low system integration efficiency in the prior art two-phase anaerobic reactor.

[0007] The purpose of the present invention can be achieved by the following technical solutions:

[0008] One of the technical solutions of the present invention provides an integrated vertical two-phase anaerobic reaction device, including a reaction tank body, a central inner cylinder is provided in the middle position of the reaction tank body, so that a hydrolysis and acidification reaction zone located in the central inner cylinder and a methanogenic zone located between the inner wall of the reaction tank body and the outer wall of the central inner cylinder are formed in the reaction tank body, the hydrolysis and acidification reaction zone is connected to the bottom of the methanogenic zone, the top of the reaction tank body is also sealed with a reaction tank top cover, and a biogas outlet is also provided on the reaction tank top cover.

[0009] Furthermore, the ratio of the inner diameter of the central inner cylinder to the inner diameter of the reaction tank body is greater than 1:2.

[0010] Furthermore, the height of the top of the central inner tube is higher than the height of the top of the inner wall of the reaction tank body.

[0011] Furthermore, a water seal ring groove is provided on the outer side of the top of the reaction tank body, and the discharge slurry in the methane production area overflows into the water seal ring groove through the top of the reaction tank body, and the reaction tank top cover is sealed and connected to the top of the water seal ring groove.

[0012] Furthermore, a discharge pipeline is provided at the bottom of the water seal ring groove to connect with the extrusion equipment, and the discharge liquid on the extrusion equipment also flows back to the upper part of the central inner cylinder through the reflux pipeline.

[0013] Furthermore, a circulation pipeline is provided outside the reaction tank body, both ends of the circulation pipeline are connected to the methane production area, and a circulation pump and a heat exchanger are provided on the circulation pipeline.

[0014] Furthermore, a three-phase separator is provided on the top of the methane producing zone.

[0015] Furthermore, the bottom of the reaction tank body adopts a conical design, and the inclination angle of the bottom plate located at the bottom of the reaction tank body is not less than 60°;

[0016] The top cover of the reaction tank is conical.

[0017] Furthermore, the bottom of the reaction tank body is preferably provided with a sand discharge port, and is connected to the external area through a sand discharge pipeline.

[0018] The second technical solution of the present invention provides an integrated vertical two-phase anaerobic reaction process, which is implemented by the reaction device as described above. The process is specifically as follows:

[0019] The reaction raw materials are fed into the center inner tube from the top through a pipeline. After being treated in the hydrolysis and acidification reaction zone, the resulting hydrolyzate is turned over to the outer methanogenic zone through the bottom of the center inner tube, where an anaerobic methanogenic reaction occurs. The resulting reaction product separates the biogas and is discharged from the biogas outlet at the top. The separated output slurry is sent out from the top of the methanogenic zone and continues to be treated.

[0020] Compared with the prior art, the present invention has the following advantages:

[0021] (1) By adding a central inner cylinder in the reaction tank, the outside of the cylinder is the methanogenic phase, so that the reaction phase can be separated in one reactor, avoiding the reactor acidification phenomenon that may be caused by the accumulation of volatile acids during anaerobic digestion in a one-way reactor, and improving the stability of the reaction system.

[0022] (2) An external circulation pump and heating system are used to heat and circulate the methanogenic phase to ensure that the anaerobic methanogenic phase is at a suitable temperature and that the materials are fully stirred, thereby improving the reaction mass transfer efficiency and greatly promoting the methane yield. At the same time, the methanogenic output is separated into solid and liquid by screw extrusion, which improves the separation efficiency, reduces the reactor volume, and greatly improves the anaerobic efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a structural schematic diagram of the present invention;

[0024] Description of the markings in the figure:

[0025] 1-reaction tank body, 2-center inner tube, 3-reaction tank top cover, 4-water seal ring groove, 5-biogas outlet, 6-discharge pipeline, 7-reflux pipeline, 8-circulation pipeline, 9-extrusion equipment, 10-sand discharge pipeline, 11-feed pipeline. DETAILED DESCRIPTION

[0026] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0027] In the description of the present invention, it should be noted that the terms "center", "inside", "outside", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limitations on the present invention.

[0028] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0029] In the following implementation manners or examples, unless otherwise specified, functional components or functional structures are conventional components or conventional structures used in the art to realize corresponding functions.

[0030] In order to solve the technical problems of low methane production efficiency and low system integration efficiency of the two-phase anaerobic reactor in the prior art, the present invention provides an integrated vertical two-phase anaerobic reaction device, the structure of which is shown in FIG. Figure 1 As shown, it includes a reaction tank body 1, and a central inner tube 2 is provided in the middle position of the reaction tank body 1, so that a hydrolysis and acidification reaction zone located in the central inner tube 2 and a methanogenic zone located between the inner wall of the reaction tank body 1 and the outer wall of the central inner tube 2 are formed in the reaction tank body 1, and the hydrolysis and acidification reaction zone is connected with the bottom of the methanogenic zone, and the top of the reaction tank body 1 is also sealed with a reaction tank top cover 3, and a biogas outlet 5 is also provided on the reaction tank top cover 3.

[0031] In some specific embodiments, the ratio of the inner diameter of the central inner cylinder 2 to the inner diameter of the reaction tank body 1 is greater than 1:2.

[0032] In some specific embodiments, the height of the top of the central inner tube 2 is higher than the height of the top of the inner wall of the reaction tank body 1 .

[0033] In some specific embodiments, a water seal ring groove 4 is provided on the outer side of the top of the reaction tank body 1, and the discharge slurry in the methane production area overflows into the water seal ring groove 4 through the top of the reaction tank body 1, and the reaction tank top cover 3 is sealed and connected to the top of the water seal ring groove 4.

[0034] Furthermore, a discharge pipeline 6 is provided at the bottom of the water seal ring groove 4 to connect to the extrusion device 9 , and the discharge liquid on the extrusion device 9 also returns to the upper part of the central inner tube 2 through the reflux pipeline 7 .

[0035] In some specific embodiments, a circulation pipeline 8 is further provided on the outside of the reaction tank body 1, and both ends of the circulation pipeline 8 are connected to the methane production zone. A circulation pump and a heat exchanger are provided on the circulation pipeline 8. The anaerobic equipment is provided with a circulation water collecting pipe, which is arranged at 1 / 4 of the distance from the top of the equipment. The circulation water collecting pipe is connected from one side of the equipment, and is connected to the inside of the equipment from the outside of the lower part of the equipment after being pressurized by the circulation pump, so as to complete the liquid circulation of the methane production zone.

[0036] In some specific embodiments, a three-phase separator is provided at the top of the methanogenic zone.

[0037] The equipment uses a conventional three-phase separator, which is arranged at the top of the methane-producing area, above the circulating water collection ring pipe, and is arranged in a ring shape to separate the gas, solid and liquid three phases.

[0038] In some specific embodiments, the bottom of the reaction tank body 1 adopts a conical design, and the inclination angle of the bottom plate located at the bottom of the reaction tank body 1 is not less than 60°;

[0039] The reaction tank top cover 3 is conical.

[0040] In some specific embodiments, a sand discharge port is further provided at the bottom of the reaction tank body 1 and is connected to the external area via a sand discharge pipeline 10 .

[0041] The hydrolysis zone and methanogenic zone designed by the present invention have different volumes, so that the hydraulic retention time of water in the hydrolysis zone and the methanogenic zone is different, thereby controlling the formation of specific dominant bacteria in different areas for hydrolysis acidification reaction and methanogenic reaction, and at the same time, increasing the circulation pipeline in the methanogenic zone to strengthen the material transfer rate of the methanogenic zone, and controlling the reaction process of the acidogenic phase and the methanogenic phase to be carried out efficiently. The diameter ratio of the central inner cylinder 2 and the reaction tank body 1 is limited to be greater than 1:2, and the volume ratio of the hydrolysis zone and the methanogenic zone can be controlled to be greater than 1:4. The hydrolysis zone is connected to the bottom of the methanogenic zone, and the water flows from top to bottom in the hydrolysis zone, and enters the methanogenic zone around the bottom. The liquid hydraulic retention time of the hydrolysis zone is designed to be 2 to 4 days, and the liquid hydraulic retention time of the methanogenic zone is about 15 to 20 days, and the economic performance is optimal. The water flow fully reacts in the methanogenic zone, and after three-phase separation, the clear liquid flows into the water seal ring groove around and is sent to the next process section through the pipeline.

[0042] In addition, the present invention also provides an integrated vertical two-phase anaerobic reaction process, which is implemented using the reaction device as described above. The process is specifically as follows:

[0043] The reaction raw materials are fed into the top of the central inner tube 2 through a pipeline. After being treated in the hydrolysis and acidification reaction zone, the resulting hydrolyzate is turned over to the outer methanogenic zone through the bottom of the central inner tube 2, where an anaerobic methanogenic reaction occurs. The resulting reaction product separates the biogas and is discharged from the biogas outlet 5 at the top. The separated output slurry is sent out from the top of the methanogenic zone and continues to be treated.

[0044] In specific treatment, the residence time of the material in the hydrolysis and acidification reaction zone is controlled to be about 2 to 4 days, and the residence time in the methanogenic zone is about 15 to 20 days. If the diameter ratio of the central inner tube 2 to the reaction tank body 1 is greater than 1:2, the volume ratio of the hydrolysis zone and the methanogenic zone can be controlled to be greater than 1:4. The hydrolysis zone is connected to the bottom of the methanogenic zone, and the water flows from top to bottom in the hydrolysis zone and enters the methanogenic zone around the bottom. The designed liquid hydraulic retention time of the hydrolysis zone is 2 to 4 days, and the liquid hydraulic retention time of the methanogenic zone is about 15 to 20 days, which has the best economic performance.

[0045] The above embodiments may be implemented individually or in any combination of two or more.

[0046] The above implementation is described in more detail below in conjunction with specific examples.

[0047] Embodiment 1:

[0048] This embodiment provides an integrated vertical two-phase anaerobic reaction device, the structure of which is shown in FIG. Figure 1 As shown, it includes a reaction tank body 1, and a central inner tube 2 is provided in the middle position of the reaction tank body 1, so that a hydrolysis and acidification reaction zone located in the central inner tube 2 and a methanogenic zone located between the inner wall of the reaction tank body 1 and the outer wall of the central inner tube 2 are formed in the reaction tank body 1, and the hydrolysis and acidification reaction zone is connected to the bottom of the methanogenic zone, and the top of the reaction tank body 1 is also sealed with a reaction tank top cover 3, and a biogas outlet 5 is also provided on the reaction tank top cover 3. The ratio of the inner diameter of the central inner tube 2 to the inner diameter of the reaction tank body 1 is greater than 1:2. The height of the top of the central inner tube 2 is higher than the top height of the inner wall of the reaction tank body 1, at least higher than the overflow port set at the top of the reaction tank body 1.

[0049] At the same time, a water seal ring groove 4 is provided on the outer side of the top of the reaction tank body 1, and the discharge slurry in the methane production area overflows into the water seal ring groove 4 through the top of the reaction tank body 1, and the reaction tank top cover 3 is sealed and connected to the top of the water seal ring groove 4. The bottom of the water seal ring groove 4 is also provided with a discharge pipeline 6 connected to the extrusion device 9, and the liquid outlet on the extrusion device 9 is also returned to the upper part of the central inner tube 2 through the reflux pipeline 7. The extrusion device 9 here can adopt the screw extrusion equipment commonly used in this field, and the discharge slurry can be processed to obtain biogas slurry and anaerobic sludge, wherein the obtained biogas slurry can be discharged for subsequent treatment, or returned to the central inner tube 2 through the reflux pipeline 7 for circulation treatment, and the anaerobic sludge can be further composted or pyrolyzed.

[0050] Please see again Figure 1 As shown, a circulation pipeline 8 is further provided outside the reaction tank body 1 , both ends of the circulation pipeline 8 are connected to the methane production area, and a circulation pump and a heat exchanger are provided on the circulation pipeline 8 .

[0051] A three-phase separator is provided in the upper region of the methane-producing zone.

[0052] The bottom of the reaction tank body 1 is conical, and the inclination angle of the bottom plate at the bottom of the reaction tank body 1 is not less than 60°; the reaction tank top cover 3 is conical. The bottom of the reaction tank body 1 is preferably provided with a sand discharge port, and connected to the outside area through a sand discharge pipeline 10, and the sand in the reaction tank body 1 can be discharged to the outside through the sand discharge pipeline 10.

[0053] In specific operation, the raw materials enter the central inner tube 2 from the top through the feed pipeline 11 after pretreatment. A valve is set on the pipeline to control the feed. The material stays in the central inner tube 2 for about 2 to 4 days, and the hydrolysis reaction mainly occurs. The hydrolyzate flows from the bottom of the central inner tube 2 to the outer methanogenic zone, and the residence time is about 15 to 20 days, and the anaerobic methanogenic reaction mainly occurs. A circulation pipeline 8 is set in the methanogenic zone, and a circulation pump is set outside the tank body to circulate the material in the methanogenic zone to play a role in stirring and homogenizing. The circulation pump is controlled by a variable frequency pump. The circulation pipeline 8 of the biogas slurry outside the tank is also equipped with a heat exchanger and a hot water exchange system to heat the circulating liquid in the methanogenic zone, while maintaining the temperature in the tank at 35.5℃~39.5℃. A three-phase separator is arranged on the top of the reaction tank 1. The biogas separated by the three-phase separator is collected in the biogas collection area on the top of the tank and discharged from the biogas outlet 5. The discharged liquid flows into the overflow port on the outside of the tank wall after passing through the three-phase separator and is collected and then transported to the screw extruder through a pipeline for solid-liquid separation. The separated biogas liquid can be returned to the reactor through the reflux pipeline 7 or enter the water treatment system for further treatment. The dehydrated anaerobic sludge can be further composted or pyrolyzed. The bottom of the tank is designed to be conical, with a bottom plate inclination angle of not less than 60°. A sand discharge port is left in the center of the tank bottom, and a sand discharge pipeline 10 is configured. The settled sand is discharged through the sand discharge pipeline 10.

[0054] The above description of the embodiments is to facilitate the understanding and use of the invention by those skilled in the art. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the present invention is not limited to the above embodiments, and improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the present invention should be within the scope of protection of the present invention.

Claims

1. An integrated vertical two-phase anaerobic reaction process, It is characterized in that The two-phase anaerobic reaction device based on the process includes a reaction tank body, a central inner cylinder is provided in the middle of the reaction tank body, so that a hydrolysis and acidification reaction zone located in the central inner cylinder and a methanogenic zone located between the inner wall of the reaction tank body and the outer wall of the central inner cylinder are formed in the reaction tank body, the hydrolysis and acidification reaction zone is connected to the bottom of the methanogenic zone, the top of the reaction tank body is also sealed with a reaction tank top cover, and a biogas outlet is also provided on the reaction tank top cover; The ratio of the inner diameter of the central inner cylinder to the inner diameter of the reaction tank body is greater than 1:2; The height of the top of the central inner cylinder is higher than the height of the top of the inner wall of the reaction tank body; The specific process is: The reaction raw materials are fed into the top of the central inner cylinder through a pipeline. After being treated in the hydrolysis and acidification reaction zone, the obtained hydrolyzate is turned over to the outer methanogenic zone through the bottom of the central inner cylinder to produce anaerobic methanogenesis. The obtained reaction products are separated at the three-phase separator arranged on the upper part of the reaction tank body. The separated biogas is discharged from the biogas outlet at the top. The separated output slurry is discharged from the top of the methanogenic zone and enters the next step of treatment. A circulation pipeline is also provided outside the reaction tank body, both ends of which are connected to the methane production area. A circulation pump and a heat exchanger are provided on the circulation pipeline. The circulating liquid in the methane production area is heated and maintained at a temperature of 35.5°C to 39.5°C through a hot water exchange system.

2. The integrated vertical two-phase anaerobic reaction process according to claim 1, It is characterized in that A water seal ring groove is arranged on the outer side of the top of the reaction tank body, and the discharge slurry in the methane production area overflows into the water seal ring groove through the top of the reaction tank body, and the top cover of the reaction tank is sealed and connected to the top of the water seal ring groove.

3. The integrated vertical two-phase anaerobic reaction process according to claim 2, It is characterized in that A discharge pipeline is also provided at the bottom of the water seal ring groove to connect the extrusion equipment, and the liquid outlet on the extrusion equipment is also returned to the upper part of the central inner cylinder through a reflux pipeline.

4. The integrated vertical two-phase anaerobic reaction process according to claim 1, It is characterized in that A three-phase separator is arranged on the top of the methane producing zone.

5. The integrated vertical two-phase anaerobic reaction process according to claim 1, It is characterized in that The bottom of the reaction tank body adopts a conical design, and the inclination angle of the bottom plate located at the bottom of the reaction tank body is not less than 60°; The top cover of the reaction tank is conical.

6. The integrated vertical two-phase anaerobic reaction process according to claim 1, It is characterized in that The bottom of the reaction tank is also provided with a sand discharge port, which is connected to the outside area through a sand discharge pipeline.

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