A novel two-phase anaerobic reactor and treatment method

Abstract

This invention discloses a novel two-phase anaerobic reactor and treatment method. The reactor has an egg-shaped or spherical shell, within which are arranged a fermentation-acid-producing phase reaction zone, a methanogenic phase reaction zone, and a gas-liquid separation zone. The fermentation-acid-producing phase reaction zone is located in the middle of the shell, the methanogenic phase reaction zone is located in the lower half outside the fermentation-acid-producing phase reaction zone, and the gas-liquid separation zone is located in the upper half outside the fermentation-acid-producing phase reaction zone. The fermentation-acid-producing phase reaction zone is separated from the methanogenic phase reaction zone by an organic acid-selective semi-permeable membrane. The fermentation-acid-producing phase reaction zone is provided with an inlet and a slag outlet connected to the outside of the shell via pipes. A feed inlet is provided at the inlet. A control valve is installed at the slag outlet; a pneumatic peristaltic agitator is installed in the fermentation acid-producing phase reaction zone; a breathing-type air supply device is connected to the pneumatic peristaltic agitator, the feed control valve, and the slag outlet control valve via pipelines; when the breathing-type air supply device exhales to supply air to the pneumatic peristaltic agitator, the feed control valve, and the slag outlet control valve simultaneously, the feed control valve and the slag outlet control valve close the feed inlet and the slag outlet, and the pneumatic peristaltic agitator extends; when the breathing-type air supply device inhales, the feed inlet and the slag outlet open, and the pneumatic peristaltic agitator retracts.

Description

Technical Field

[0001] This invention relates to the field of anaerobic fermentation of high-organic-content solid wastes such as dewatered municipal sludge, kitchen waste, and manure straw, and particularly to a novel two-phase anaerobic reactor based on the biomimetic principle of animal rumen. Background Technology

[0002] Anaerobic technology has achieved great success in wastewater treatment, but progress has been slow in the field of high solids content materials (≥8%). Currently, high solids content materials that can be treated by anaerobic technology mainly include municipal solid waste, wastewater treatment plant sludge, kitchen waste, livestock and poultry manure, and agricultural waste straw. The main problems facing high solids content fermentation are poor fluidity, low mass transfer efficiency, the need for strict pretreatment, difficulties in feeding and discharging materials, and the fact that methanogenic bacteria are very sensitive to environmental factors, do not easily reproduce in large quantities, and have low methanogenic efficiency.

[0003] Ruminants create a microaerobic environment for fermentation, unlike traditional anaerobic fermentation which maintains the entire process under absolute anaerobic conditions. This promotes the hydrolysis and acidification of high-organic-content solid waste. Furthermore, ruminants form a long-term, stable, mutually beneficial symbiotic relationship with the microorganisms in their rumen. Ruminants provide a relatively stable, nutrient-rich internal environment for the microorganisms. The suitable pH, temperature, and redox potential in this internal environment promote the metabolism of rumen microorganisms, enabling efficient anaerobic digestion of high-organic-content solid waste.

[0004] Therefore, the digestive organs of ruminants are modeled into different types of reactors according to their functions, in order to solve the problems faced by fermentation with high solids content. Summary of the Invention

[0005] Based on the biomimetic principle of the rumen of ruminants, this invention develops a novel two-phase anaerobic reactor for the anaerobic fermentation of dehydrated municipal sludge, kitchen waste, manure, straw and other solid wastes with high organic content.

[0006] To achieve the above objectives, the present invention provides a novel two-phase anaerobic reactor, wherein the reactor has an egg-shaped or spherical shell, and the shell contains a fermentation acid-producing phase reaction zone, a methanogenic phase reaction zone, and a gas-liquid separation zone.

[0007] The fermentation acid-producing phase reaction zone is located in the middle of the shell, and the methanogenic phase reaction zone is located in the lower half of the outer part of the fermentation acid-producing phase reaction zone; the gas-liquid separation zone is located in the upper half of the outer part of the fermentation acid-producing phase reaction zone; the fermentation acid-producing phase reaction zone is separated from the methanogenic phase reaction zone by an organic acid selective semi-permeable membrane.

[0008] The fermentation acid-producing phase reaction zone is equipped with a feed inlet and a slag outlet connected to the outside of the shell via pipelines. A feed control valve is installed at the feed inlet, and a slag outlet control valve is installed at the slag outlet. A pneumatic peristaltic stirring device is installed in the fermentation acid-producing phase reaction zone.

[0009] A breathing-type air supply device is connected to a pneumatic peristaltic agitator, a feed control valve, and a slag discharge control valve via pipelines. When the breathing-type air supply device exhales to supply air to the pneumatic peristaltic agitator, the feed control valve, and the slag discharge control valve simultaneously, the feed control valve and the slag discharge control valve close the feed inlet and the slag outlet, and the pneumatic peristaltic agitator extends. When the breathing-type air supply device inhales, the feed inlet and the slag outlet open, and the pneumatic peristaltic agitator retracts.

[0010] Furthermore, the methanogenic phase reaction zone is equipped with suspended ball packing material.

[0011] Furthermore, it also includes an organic solid waste pulverizer, wherein the discharge port of the pulverizer is connected to the feed pipe of the inlet.

[0012] Furthermore, the pneumatic peristaltic stirring device includes: a flexible main airbag is provided in the fermentation acid-producing phase reaction zone, and the flexible main airbag is connected to several strip-shaped flexible branch airbags. The strip-shaped flexible branch airbags are in an "S" shape, and the expansion and contraction of the airbags are driven by an integrated blower; the upper end of the flexible main airbag is connected to the feed control air valve through a rigid air pipe, and the lower end is connected to the slag discharge control air valve through a rigid air pipe.

[0013] Furthermore, the flexible main airbag is connected to the feed control air valve and the slag discharge control air valve via pipes.

[0014] Furthermore, a packing screen is installed at the outlet of the methanogenic phase reaction zone.

[0015] Furthermore, a bowl-shaped gas-blocking and water-collecting shell is provided outside the fermentation acid-producing phase reaction zone along the organic acid selective semi-permeable membrane, and a flow guide groove is provided on the inner surface of the bowl-shaped gas-blocking and water-collecting shell; a water outlet is provided at the center of the bottom of the bowl-shaped gas-blocking and water-collecting shell.

[0016] Furthermore, an overflow weir plate is installed on the shell corresponding to the outlet of the methanogenic phase reaction zone, and a drainage pipe is installed on the shell corresponding to the overflow weir plate.

[0017] Furthermore, a gaseous membrane is provided on the upper shell of the gas-water separation zone, and a gas collection zone is formed between the gaseous membrane and the shell; a vacuum pump tube is connected to the shell corresponding to the gas collection zone.

[0018] To achieve the above objectives, the present invention provides a novel two-phase anaerobic reactor treatment method, which utilizes the aforementioned reactor and includes the following steps:

[0019] The breathing-type air supply device performs the following actions at a predetermined breathing frequency: When the breathing-type air supply device exhales to simultaneously supply air to the pneumatic peristaltic agitator, the feed control valve, and the slag discharge control valve, the feed control valve and the slag discharge control valve close the feed port and the slag discharge port, and the pneumatic peristaltic agitator extends to agitate the organic solid waste in the fermentation acid-producing phase reaction zone; when the breathing-type air supply device inhales, the feed port and the slag discharge port open, and slag discharge is completed simultaneously with feeding. At the same time, the pneumatic peristaltic agitator retracts to agitate the organic solid waste in the fermentation acid-producing phase reaction zone again.

[0020] Furthermore, it also includes:

[0021] Water from the organic solid waste entering the fermentation acid-producing phase reaction zone enters the methanogenic phase reaction zone through an organic acid-selective semi-permeable membrane; under vacuum, it enters the gas collection zone through a gas membrane.

[0022] Wastewater from the methanogenic reaction zone is discharged through an overflow weir.

[0023] This invention utilizes a breathing-type air supply device to control a pneumatic peristaltic stirring device, a feed control valve, and a slag discharge control valve at a predetermined breathing frequency to simultaneously complete feeding, slag discharge, and peristalsis. This overcomes the problems of poor fluidity, low mass transfer efficiency, difficult pretreatment, and difficult feeding and discharging that exist in traditional anaerobic reactors when treating high-content organic solid waste, and can effectively improve methane yield. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the structure of a novel two-phase anaerobic reactor according to the present invention.

[0025] 1. Crusher; 2. Flexible main airbag; 3. Fermentation acid-producing phase reaction zone; 4. Methanogenic phase reaction zone; 5. Methane collection zone; 6. Feed control valve; 7. Slag discharge control valve; 8. Strip-shaped flexible support airbag; 9. Strip-shaped semi-flexible airbag 1; 10. Check valve duckbill tube; 11. Strip-shaped semi-flexible airbag 2; 12. Suspended ball packing; 13. Feed pipe; 14. Slag discharge pipe; 15. Organic acid selective semi-permeable membrane; 16. Packing interception net; 17. Egg-shaped shell; 18. Sludge discharge pipe; 19. Air pipe; 20. Slag storage tank; 21. Vacuum pump; 22. Support; 23. Suction (breathing) compressed air pump; 24. Gas-liquid separation zone; 25. Gaseous membrane; 26. Overflow weir plate Detailed Implementation

[0026] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0027] In the description of this invention, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0028] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0029] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0030] Example 1

[0031] like Figure 1 As shown, the reactor is designed in an egg shape, including an organic solid waste crushing zone, a fermentation acid production reaction zone 3, a methanogenic reaction zone 4, and a gas-liquid separation zone 24.

[0032] The fermentation acid-producing phase reaction zone is located within the reactor via a support structure. This zone includes a support frame, and an upper portion corresponding to the gas-water separation zone outside the support frame is a gas-tight shell. The lower portion corresponding to the methanogenic phase reaction zone is covered with an organic acid-selective semi-permeable membrane, forming a container. Inside the fermentation acid-producing phase reaction zone, a flexible main air bladder 2 is installed to provide peristaltic stirring for the high-organic-content solid waste. The flexible main air bladder is connected to several strip-shaped flexible support air bladders 8, which are S-shaped. The expansion and contraction of the air bladders are controlled by a breathing-type air supply device, which is a suction (breathing) compressed air pump 24. This pump can control the exhalation and inhalation actions at a predetermined breathing frequency (2-20 times per minute). The breathing frequency is designed based on the size of the reactor, the size of the inlet and outlet, and the amount of organic solid waste to be processed, and is generally 2-20 times per minute.

[0033] When the breathing-type air supply device exhales, the flexible main air bladder 2 is filled with gas and expands. At the same time, the "S"-shaped flexible branch air bladders become longer, thicker, and straighter under the pressure of the gas, which can agitate, compress, and mix the organic solid waste in the fermentation acid-producing phase reaction zone. When the breathing-type air supply device inhales, the gas in the flexible main air bladder 2 is drawn away, and the flexible main air bladder and branch air bladders expand and contract. Under the gravity of the organic solid waste, they become shorter, thinner, and more curved, thereby further increasing the agitation and mixing effect on the organic solid waste in the fermentation acid-producing phase reaction zone.

[0034] The upper end of the flexible main airbag is connected to the feed control air valve 6 via a pipe, and the lower end is connected to the slag discharge control air valve 7 via a pipe. When the slag discharge control air valve is filled with gas, the slag discharge pipe is closed. When the gas is discharged from the slag discharge control air valve, the slag discharge pipe is opened and slag discharge begins.

[0035] The expansion of the air bladder can squeeze out the pore water and capillary water in the organic solid waste. The organic acids produced by hydrolysis and acidification in the fermentation acid production reaction zone dissolve into the pore water and capillary water, which then pass through the organic acid selective semipermeable membrane 15 and enter the methanogenic reaction zone. The organic acid selective semipermeable membrane can play a role in uniformly distributing water.

[0036] Example 2

[0037] Based on the above embodiments, the methanogenic phase reaction zone is located outside the fermentation acid-producing phase reaction zone. It contains suspended ball packing material 12, selected with a density close to that of water. The suspended ball packing material should fill the entire fermentation acid-producing phase reaction zone. The methane produced in the methanogenic phase can disturb the suspended ball packing material, increasing the contact between the organic acid and the biofilm on the packing material, thus improving reaction efficiency. A packing interception net is installed at the outlet of the methanogenic phase reaction zone. The net only allows water and gases such as methane to enter the gas-liquid separation zone. A temperature control device and a pH meter are installed within the methanogenic phase reaction zone. The temperature is maintained at approximately 35°C, and the pH is controlled between 6.6 and 7.5. When the pH buffer balance established during the microbial metabolism is disrupted, an artificial pH buffer can be added.

[0038] Example 3

[0039] Based on the above embodiment, a gaseous membrane is provided above the gas-water separation zone; a gas collection zone is formed between the gaseous membrane and the shell; the gaseous membrane only allows gas to pass through while water cannot. The gas collection zone is connected to a vacuum pump through a pipe, and the gas collection zone completes the gas collection through the negative pressure generated by the vacuum pump.

[0040] Example 4

[0041] Based on the above embodiments, the high organic solid waste crushing zone consists of a crusher 1 and a feeding pipe 13. The feeding pipe is connected to the fermentation acid-producing phase reaction zone, and a feeding control air valve 6 is provided at the connection. When the air valve is full of gas, the feeding pipe is closed. When the gas in the air valve is vented, the feeding pipe is opened, and the high organic solid waste crushed by the crusher falls into the fermentation acid-producing phase reaction zone. At the same time, the crushed material will bring in some air, so that the fermentation acid-producing phase reaction zone maintains a micro-oxygen environment, which is conducive to the hydrolysis and acidification of organic solid waste.

[0042] Example 5

[0043] Based on the above embodiments, the upper part of the methanogenic reaction zone is a gas-water separation zone. The methane produced by the reaction enters the gas-water separation zone together with water. A gaseous membrane is set in the upper part of the gas-water separation zone. In the gas-water separation zone, water and gases such as methane are separated. The water is discharged through the overflow weir plate, and the gases such as methane pass through the gaseous membrane into the gas collection zone. Under the suction of the vacuum pump, the methane concentration on both sides of the gaseous membrane always maintains a certain gradient, which promotes the continuous separation of methane gas from the water.

[0044] Example 6

[0045] Based on the above embodiments, a bowl-shaped gas-blocking and water-collecting shell (not shown in the figure) is provided outside the organic acid-selective semi-permeable membrane in the fermentation acid-producing phase reaction zone. A flow guide groove is provided on the inner surface of the bowl-shaped gas-blocking and water-collecting shell; an outlet is provided at the center of the bottom of the bowl-shaped gas-blocking and water-collecting shell. The bowl-shaped gas-blocking and water-collecting shell can prevent methane and other gases generated in the methanogenic phase reaction zone from passing through the organic acid-selective semi-permeable membrane into the fermentation acid-producing phase reaction zone; simultaneously, it can collect the organic acid-containing pore water and capillary water that pass through the organic acid-selective semi-permeable membrane and allow it to enter the lower part of the methanogenic phase reaction zone, thereby facilitating the renewal of the methanogenic phase reaction zone.

[0046] Example 7

[0047] The novel two-phase anaerobic reactor treatment method of the present invention includes the following steps:

[0048] The breathing-type air supply device performs the following actions at a predetermined breathing frequency: When the breathing-type air supply device exhales to simultaneously supply air to the pneumatic peristaltic agitator, the feed control valve, and the slag discharge control valve, the feed control valve and the slag discharge control valve close the feed port and the slag discharge port, and the pneumatic peristaltic agitator extends to agitate the organic solid waste in the fermentation acid-producing phase reaction zone; when the breathing-type air supply device inhales, the feed port and the slag discharge port open, and slag discharge is completed simultaneously with feeding. At the same time, the pneumatic peristaltic agitator retracts to agitate the organic solid waste in the fermentation acid-producing phase reaction zone again.

[0049] The breathing frequency mentioned above is designed based on the size of the reactor, the size of the feed inlet and discharge outlet, and the amount of organic solid waste to be processed, and is generally 2-20 times per minute.

[0050] In the description of this specification, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0051] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A novel two-phase anaerobic reactor, characterized in that: The reactor has an egg-shaped or spherical shell, and inside the shell are a fermentation acid-producing phase reaction zone, a methanogenic phase reaction zone, and a gas-liquid separation zone. The fermentation acid-producing phase reaction zone is located in the middle of the shell, and the methanogenic phase reaction zone is located in the lower half of the outer part of the fermentation acid-producing phase reaction zone; the gas-liquid separation zone is located in the upper half of the outer part of the fermentation acid-producing phase reaction zone; the fermentation acid-producing phase reaction zone is separated from the methanogenic phase reaction zone by an organic acid selective semi-permeable membrane. The fermentation acid-producing phase reaction zone is equipped with a feed inlet and a slag outlet connected to the outside of the shell via pipelines. A feed control valve is installed at the feed inlet, and a slag outlet control valve is installed at the slag outlet. A pneumatic peristaltic stirring device is installed in the fermentation acid-producing phase reaction zone. A breathing-type air supply device is connected via pipeline to a pneumatic peristaltic agitator, a feed control valve, and a slag discharge control valve. When the breathing-type air supply device exhales to simultaneously supply air to the pneumatic peristaltic agitator, the feed control valve, and the slag discharge control valve, the feed control valve and the slag discharge control valve close the feed inlet and the slag outlet, and the pneumatic peristaltic agitator extends. When the breathing-type air supply device inhales, the feed inlet and the slag outlet open, and the pneumatic peristaltic agitator retracts. A gaseous membrane is provided on the upper shell of the gas-liquid separation zone, and a gas collection zone is formed between the gaseous membrane and the shell; a vacuum pump tube is connected to the shell corresponding to the gas collection zone.

2. The novel two-phase anaerobic reactor as described in claim 1, characterized in that: The methanogenic phase reaction zone is equipped with suspended ball packing material.

3. The novel two-phase anaerobic reactor according to claim 1, characterized in that: It also includes an organic solid waste pulverizer, wherein the discharge port of the pulverizer is connected to the feed pipe of the inlet.

4. A novel two-phase anaerobic reactor according to claim 1, characterized in that: The pneumatic peristaltic stirring device includes: a flexible main airbag in the fermentation acid production phase reaction zone, the flexible main airbag being connected to several strip-shaped flexible branch airbags, the strip-shaped flexible branch airbags being "S" shaped, the expansion and contraction of the airbags being driven by an integrated blower; the upper end of the flexible main airbag is connected to the feed control air valve through a rigid air pipe, and the lower end is connected to the slag discharge control air valve through a rigid air pipe.

5. A novel two-phase anaerobic reactor according to claim 4, characterized in that: The flexible main airbag is connected to the feed control air valve and the slag discharge control air valve through a pipeline.

6. A novel two-phase anaerobic reactor according to claim 2, characterized in that: Outside the fermentation acid-producing phase reaction zone, a bowl-shaped gas-blocking and water-collecting shell is provided on the organic acid-selective semi-permeable membrane. A flow guide groove is provided on the inner surface of the bowl-shaped gas-blocking and water-collecting shell. A water outlet is provided at the center of the bottom of the bowl-shaped gas-blocking and water-collecting shell.

7. A novel two-phase anaerobic reactor according to claim 2, characterized in that: An overflow weir is installed on the shell corresponding to the outlet of the methanogenic phase reaction zone, and a drainage pipe is installed on the shell corresponding to the overflow weir.

8. A novel two-phase anaerobic reactor treatment method, characterized in that: The method is performed using the reactor as described in claim 1, and includes the following steps: The breathing-type air supply device performs the following actions at a predetermined breathing frequency: When the breathing-type air supply device exhales to simultaneously supply air to the pneumatic peristaltic agitator, the feed control valve, and the slag discharge control valve, the feed control valve and the slag discharge control valve close the feed port and the slag discharge port, and the pneumatic peristaltic agitator extends to agitate the organic solid waste in the fermentation acid-producing phase reaction zone; when the breathing-type air supply device inhales, the feed port and the slag discharge port open, and slag discharge is completed simultaneously with feeding. At the same time, the pneumatic peristaltic agitator retracts to agitate the organic solid waste in the fermentation acid-producing phase reaction zone again.

9. The two-phase anaerobic reactor treatment method as described in claim 8, characterized in that: Also includes: The organic acid solution in the organic solid waste entering the fermentation acid-producing phase reaction zone enters the methanogenic phase reaction zone through the organic acid selective semi-permeable membrane, and the methane gas rises to the gas-liquid separation zone. Under vacuum, it enters the gas collection area through the gas membrane; Wastewater from the methanogenic reaction zone is discharged through an overflow weir.

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