A fully mixed decentralized anaerobic digestion treatment device and treatment method

Abstract

The application provides a full-mixing decentralized anaerobic digestion treatment device and treatment method, which comprises a decentralized tank, an anaerobic digestion assembly and a communication tank; the anaerobic digestion assembly comprises an anaerobic digestion tank and a heating and heat preservation device, and a digestion stirrer is arranged in the anaerobic digestion tank; the decentralized tank is connected with a discharge port arranged on the decentralized tank through a material conveying pipe; the communication tank contains digestion liquid, the upper portion of the communication tank is connected with the upper portion of the anaerobic digestion tank through a gas phase pipe, the lower portion of the communication tank is connected with the lower portion of the anaerobic digestion tank through a liquid phase pipe, and the bottom of the communication tank is connected with the top of the decentralized tank through a digestion liquid input pipe. The device and method can realize the decentralized treatment of various organic fertilizer raw materials through anaerobic digestion reaction, the solid content rate of the anaerobic digestion system can be more than 10% for safe and efficient reaction, the anaerobic digestion reaction can be continuously carried out, the stability of the anaerobic digestion is enhanced, and the gas production is increased.

Description

Technical Field

[0001] This invention relates to the field of organic waste resource utilization technology, and in particular to a fully mixed and dispersed anaerobic digestion treatment device and treatment method. Background Technology

[0002] Anaerobic digestion, involving facultative and anaerobic bacteria, degrades bioavailable organic matter to produce biogas (a mixture of methane, carbon dioxide, and a small amount of hydrogen). Anaerobic digestion technology achieves the goals of reducing and stabilizing food waste, while also recovering renewable energy, thus realizing both social and environmental benefits. It is currently the mainstream method for biological treatment of food waste. However, factors such as temperature, organic load, and substrate properties (e.g., C / N ratio) can all affect anaerobic digestion, leading to several problems. These include low efficiency due to nutrient imbalances and poor stability caused by acidification inhibition.

[0003] Currently, the efficiency of anaerobic digestion technology for food waste is difficult to improve, the system's buffering capacity is insufficient, it is sensitive to changes in external factors, and it is difficult to maintain stability during long-term operation. An economical, efficient, and stable anaerobic digestion technology for food waste urgently needs to be developed. Summary of the Invention

[0004] In view of this, the present invention provides a fully mixed dispersion anaerobic digestion treatment device, including a dispersion tank, an anaerobic digestion component, and a connecting tank; The dispersion tank is provided with a feed inlet and a discharge outlet at the bottom, and a dispersion stirrer is provided inside the dispersion tank; The anaerobic digestion assembly includes an anaerobic digester and a heating and insulation device. The heating and insulation device is used to control the temperature inside the anaerobic digester. The anaerobic digester is equipped with a digestion stirrer. A biogas outlet is also provided above the anaerobic digester. A dispersion tank is connected to the dispersion tank via a material conveying pipe with a discharge port. A material conveying pump is provided on the material conveying pipe. The connecting tank contains digestive fluid. The upper part of the connecting tank is connected to the upper part of the anaerobic digester via a gas phase pipe, and the lower part of the connecting tank is connected to the lower part of the anaerobic digester via a liquid phase pipe. The bottom of the connecting tank is connected to the top of the dispersion tank via a digestive fluid input pipe, and a digestive fluid delivery pump is installed on the digestive fluid input pipe.

[0005] Furthermore, the bottom of the dispersion tank is also equipped with a weighing and metering device, which is used to weigh the mass of the anaerobic digester in the dispersion tank.

[0006] Furthermore, the dispersion tank is also equipped with a liquid level control device, which is connected to the digestion liquid delivery pump. The liquid level control device is used to control the start and stop of the digestion liquid delivery pump to control the liquid level in the dispersion tank.

[0007] Furthermore, the heating and heat preservation device includes a heating coil and a heat preservation and heating layer, wherein a water bath heating pipe is provided in the heat preservation and heating layer, and the water bath heating pipe is connected to a water bath heater.

[0008] Furthermore, a safety valve is provided at the top of the connecting tank.

[0009] Furthermore, the height of the connecting tank and the dispersing tank are the same.

[0010] Furthermore, the anaerobic digester is provided with a drain outlet at the bottom for discharging the digestive liquid inside the anaerobic digester, and a slag outlet at the bottom of the anaerobic digester for discharging the treated residue.

[0011] The present invention also provides a fully mixed dispersion anaerobic digestion treatment method, which utilizes the above-mentioned fully mixed dispersion anaerobic digestion treatment device, and includes the following steps: S1: Measure the carbon-nitrogen ratio, nutrient composition, and total nitrogen ratio of each material component; calculate the proportion of each material to ensure that the carbon-nitrogen ratio, nutrient composition, and total nitrogen ratio of the total material are within a predetermined range; S2: After crushing the proportioned materials, convey them into the dispersion tank; S3: Start the digestion liquid transfer pump to deliver the digestion liquid to the dispersion tank and control the solid content in the dispersion tank within the range of 8%~25%; S4: Start the dispersing agitator to stir the material in the dispersion tank until it is homogeneous; start the material transfer pump to transfer the homogeneous material in the dispersion tank to the anaerobic digester; S5: Start the heating and heat preservation device to heat the temperature inside the anaerobic digester to 35℃-40℃ and control the temperature within this range; S6: Open the biogas outlet, which inputs the biogas produced by the anaerobic digestion reaction in the anaerobic digester into the biogas utilization equipment; after the anaerobic digestion reaction in the anaerobic digester is completed, the reaction residue is discharged.

[0012] The beneficial effects of the technical solution provided by this invention are: (1) The efficient material dispersion anaerobic digestion treatment device provided by the present invention includes anaerobic digestion dispersion equipment, metering equipment, conveying equipment, anaerobic digestion equipment, communicating vessel, heating and heat preservation equipment and control system, realizing the infinite dispersion and long-term stable system of raw materials in the anaerobic digestion life cycle, which is conducive to the full reaction of anaerobic digestion, greatly reducing the risk of system collapse caused by anaerobic digestion liquid slurry stratification, local acidification, and high solid content operation difficulty, and increasing biogas production by up to 10%.

[0013] (2) The anaerobic digestion device provided by the present invention has the characteristics of stable operation, simple operation, low cost, low energy consumption and convenient maintenance. It has huge market application prospects in the fields of urban and rural organic waste resource utilization and industrial organic wastewater treatment.

[0014] (2) The efficient material dispersion anaerobic digestion treatment method provided by the present invention can realize the single raw material and multiple raw materials such as kitchen waste, food waste, livestock and poultry manure, agricultural straw, municipal sludge, etc., and the performance and methane production of the mixed anaerobic digestion system are greatly improved, which is conducive to improving the balance of nutrients in the system and alleviating the adverse inhibitory effects caused by the accumulation of ammonia nitrogen and fatty acids. Attached Figure Description

[0015] Figure 1 This is a structural diagram of a fully mixed and dispersed anaerobic digestion treatment device according to an embodiment of the present invention.

[0016] Figure 2 This is a flowchart of a fully mixed and dispersed anaerobic digestion treatment method according to an embodiment of the present invention.

[0017] In the diagram: 1. Dispersion tank; 2. Anaerobic digester; 3. Connecting tank; 4. Liquid level control device; 5. Digestant inlet pipe; 6. Feed inlet; 7. Discharge outlet; 8. Weighing and metering device; 9. Material conveying pipe; 10. Heating coil; 11. Insulation and heating layer; 12. Raw material inlet; 13. Digestion agitator; 14. Biogas outlet; 15. Gas phase pipe; 16. Liquid phase pipe; 17. Sludge discharge port; 18. Safety valve; Detailed Implementation To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be further described below with reference to the accompanying drawings.

[0018] Please refer to Figures 1 to 2 The present invention provides a fully mixed dispersion anaerobic digestion treatment device, including a dispersion tank 1, an anaerobic digestion component and a connecting tank 3.

[0019] The dispersion tank 1 is a closed container with a volume of 0.2 m³. 3 ~10m 3 The dispersion tank 1 is equipped with a feed inlet 6 at the top, which is used to allow the material to be treated to enter the dispersion tank 1. The material to be treated is kitchen waste, food waste, livestock and poultry manure, agricultural straw, municipal sludge, etc. The dispersion tank 1 is equipped with a dispersion agitator, which is a stirring shaft with stirring blades. The upper end of the stirring shaft extends outside the dispersion tank 1 and is connected to a dispersion stirring motor. The stirring speed of the dispersion agitator is 10r / min to 2000r / min. The dispersion agitator is used to stir the material to be treated and the digestion liquid to a homogeneous state. The bottom of the dispersion tank 1 is equipped with a discharge port 7.

[0020] The anaerobic digestion assembly includes an anaerobic digester 2 and a heating and insulation device. The anaerobic digester 2 is a prestressed reinforced concrete assembled tank with a height-to-diameter ratio of 1:1 to 1:2 and a volume of 1000 m³. 3 ~5000m 3 It is equipped with a digestion stirrer 13, which has the same structure as the dispersion stirrer. Its stirring speed is 15r / min to 30r / min. The digestion stirrer 13 is used to accelerate the anaerobic digestion reaction rate between the material to be treated and the digestion liquid inside.

[0021] The heating and heat preservation device includes a heating coil 10 and a heat preservation and heating layer 11. The heat preservation and heating layer 11 is provided with a water bath heating pipe, which is connected to a water bath heater. The heating coil 11 is used to raise the temperature inside the anaerobic digester 2 to the required temperature (35℃-40℃). The heat preservation and heating layer 11 is used to keep the temperature inside the anaerobic digester 2 within the required temperature range.

[0022] The anaerobic digester 2 is also provided with a biogas outlet 14 at the top, which is used to discharge the biogas produced by the anaerobic digestion reaction in the anaerobic digester 2 for utilization; the dispersion tank 2 is provided with a raw material inlet 12, which is connected to the discharge outlet 7 on the dispersion tank 2 through a material conveying pipe 9; a material conveying pump is provided on the material conveying pipe 9; the material conveying pump is used to input the reaction raw materials (materials to be processed and digestion liquid) dispersed in the dispersion tank 1 into the anaerobic digester 2 for reaction; a liquid discharge outlet 7 is provided at the bottom of the anaerobic digester 2, which is used to discharge the digestion liquid in the anaerobic digester 2; a slag discharge outlet 17 is provided at the bottom of the anaerobic digester 2, which is used to discharge the reaction residue.

[0023] The top of the connecting tank 3 is equipped with a safety valve 18; the connecting tank 3 is at the same height as the dispersion tank 2; the connecting tank 3 contains digestive liquid, which also contains a large number of anaerobic digestive bacteria; the top of the connecting tank 3 is connected to the top of the anaerobic digestion tank 2 via a gas phase pipe 15, and the bottom of the connecting tank 3 is connected to the bottom of the anaerobic digestion tank 2 via a liquid phase pipe 16. The gas phase pipe 15 and the liquid phase pipe 16 are used to balance the gas pressure and liquid level in the connecting tank 3 and the anaerobic digestion tank 3, and to store the digestive liquid in the anaerobic digestion tank 3; the bottom of the connecting tank 3 is connected to the top of the dispersion tank 1 via a digestive liquid inlet pipe 5, and a digestive liquid delivery pump is provided on the digestive liquid inlet pipe 5. The digestive liquid delivery pump is used to input the digestive liquid in the connecting tank 3 into the dispersion tank 1 and adjust its solid-liquid ratio.

[0024] Furthermore, a weighing device 8 is also provided at the bottom of the dispersion tank 1, which is used to weigh the mass of the material to be processed in the dispersion tank 1. A liquid level control device 4 is also provided in the dispersion tank 1, which is connected to the digestion liquid transfer pump. The liquid level control device 4 is used to control the start and stop of the digestion liquid transfer pump to control the liquid level in the dispersion tank 1, thereby adjusting the solid-liquid ratio in the dispersion tank 1.

[0025] Furthermore, the feed inlet 6 is connected to a screw conveyor, which is used to transport the material to be processed into the dispersion tank 1.

[0026] Furthermore, the anaerobic digester 2 is also equipped with an online monitoring component (the online monitoring component is not shown in the figure). The online monitoring component includes a comprehensive sensor and a signal transmitter connected to the comprehensive sensor. The comprehensive sensor is a vertically installed rod inside the anaerobic digester 2, with its lower end located inside the reaction material inside the anaerobic digester 2. The lower end of the comprehensive sensor is equipped with a pH sensor and a temperature sensor, which are used to sense the pH value and temperature of the reaction material inside the anaerobic digester 2, respectively. The upper end of the comprehensive sensor is located above the liquid surface of the reaction material, and a pressure sensor is installed at the upper end of the comprehensive sensor. The pressure sensor is used to sense the biogas pressure inside the anaerobic digester 2. The signal transmitter is used to transmit the pH value, temperature, and pressure signals sensed by the comprehensive sensor to the monitoring terminal, so that the monitoring terminal staff can monitor the anaerobic digestion environment of the anaerobic digester 2 in real time.

[0027] The anaerobic digestion method of the fully mixed dispersion anaerobic digestion device of the present invention includes the following steps: S1: Measure the carbon-nitrogen ratio, nutrient composition, total nitrogen content, and moisture content of each material to be treated (food waste, kitchen waste, livestock and poultry manure, agricultural straw, municipal sludge, etc.); calculate the proportion of each material to ensure that the carbon-nitrogen ratio, nutrient composition, and total nitrogen content of the total material are within the predetermined range. S2: The proportioned materials are fed into the dispersion tank 1 (for some materials, such as agricultural straw, kitchen waste, and food waste, which have poor flowability, they need to be crushed before being fed into the dispersion tank).

[0028] S3: Start the digestion liquid transfer pump to deliver the digestion liquid to the dispersion tank 1, and control the amount of digestion liquid delivered to the dispersion tank 1 by the liquid level control device 4 to ensure that the solid content in the dispersion tank 1 is controlled within the range of 8%~25%. S4: Start the dispersing agitator to stir the material in the dispersion tank until it is homogeneous; start the material conveying pump to convey the homogeneous material in the dispersion tank to the anaerobic digester 2; S5: Start the heating and heat preservation device to heat the temperature inside the anaerobic digester to 35℃-40℃ and control the temperature within this range; specifically, first heat the temperature inside the anaerobic digester 2 to 38℃ through the heating coil 10, and then start the water bath heater to control the temperature inside the anaerobic digester 2 within the range of 35℃-40℃. S6: Open biogas outlet 14 (biogas outlet 14 is connected to biogas utilization equipment). Biogas outlet 14 inputs the biogas produced by the anaerobic digestion reaction in anaerobic digester 2 into the biogas utilization equipment for utilization until the anaerobic digestion reaction in anaerobic digester 2 is completed. After the anaerobic digestion reaction in anaerobic digester 2 is completed, the reaction residue is discharged. The digestion liquid in anaerobic digester 2 is discharged from the liquid phase pipe into the connecting tank 3, and then enters the disperser 1 to prepare the raw materials for the next round of reaction.

[0029] The anaerobic digestion method of this invention can achieve co-dispersed treatment of raw materials such as kitchen waste, food waste, livestock and poultry manure, agricultural straw, and municipal sludge. It can be used for wet, semi-dry, and dry anaerobic digestion reactions. Simultaneously, the anaerobic digestion system can safely and efficiently react with a solids content of over 10%. The communicating vessel ensures continuous anaerobic digestion, enhances the stability of anaerobic digestion, and increases gas production.

[0030] In this document, the directional terms such as front, back, top, and bottom are defined based on the location of the components in the accompanying drawings and their relative positions to each other, solely for the purpose of clarity and convenience in expressing the technical solution. It should be understood that the use of these directional terms should not limit the scope of protection claimed in this application.

[0031] Where there is no conflict, the above embodiments and features described herein can be combined with each other.

[0032] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for treating anaerobic digestion using a fully mixed dispersion anaerobic digestion device, characterized in that: The method includes the following steps: S1: Measure the carbon-nitrogen ratio, nutrient composition, and total nitrogen ratio of each material component; calculate the proportion of each material to ensure that the carbon-nitrogen ratio, nutrient composition, and total nitrogen ratio of the total material are within a predetermined range; S2: After crushing the proportioned materials, convey them into the dispersion tank; S3: Start the digestion liquid transfer pump to deliver the digestion liquid to the dispersion tank and control the solid content in the dispersion tank within the range of 8%~25%; S4: Start the dispersing agitator to stir the material in the dispersion tank until it is homogeneous; start the material transfer pump to transfer the homogeneous material in the dispersion tank to the anaerobic digester; S5: Start the heating and heat preservation device to heat the temperature inside the anaerobic digester to 35℃-40℃ and control the temperature within this range; S6: Open the biogas outlet, which inputs the biogas produced by the anaerobic digestion reaction in the anaerobic digester into the biogas utilization equipment; after the anaerobic digestion reaction in the anaerobic digester is completed, the reaction residue is discharged. The fully mixed dispersion anaerobic digestion treatment device includes a dispersion tank, an anaerobic digestion component, and a connecting tank; The dispersion tank is provided with a feed inlet and a discharge outlet at the bottom, and a dispersion stirrer is provided inside the dispersion tank; The anaerobic digestion assembly includes an anaerobic digester and a heating and insulation device. The heating and insulation device is used to control the temperature inside the anaerobic digester. The anaerobic digester is equipped with a digestion stirrer. A biogas outlet is also provided above the anaerobic digester. The dispersion tank is connected to the dispersion tank via a material conveying pipe with a discharge port. A material conveying pump is provided on the material conveying pipe. The connecting tank contains digestive fluid. The upper part of the connecting tank is connected to the upper part of the anaerobic digester via a gas phase pipe, and the lower part of the connecting tank is connected to the lower part of the anaerobic digester via a liquid phase pipe. The bottom of the connecting tank is connected to the top of the dispersion tank via a digestive fluid input pipe, and a digestive fluid delivery pump is installed on the digestive fluid input pipe.

2. The method for a fully mixed and dispersed anaerobic digestion process according to claim 1, characterized in that: The bottom of the dispersion tank is also equipped with a weighing and metering device, which is used to weigh the mass of the anaerobic digester in the dispersion tank.

3. The method for a fully mixed and dispersed anaerobic digestion process according to claim 1, characterized in that: The dispersion tank is also equipped with a liquid level control device, which is connected to the digestion liquid delivery pump. The liquid level control device is used to control the start and stop of the digestion liquid delivery pump to control the liquid level in the dispersion tank.

4. The method for a fully mixed dispersion anaerobic digestion process according to claim 1, characterized in that: The heating and heat preservation device includes a heating coil and a heat preservation and heating layer. A water bath heating pipe is provided in the heat preservation and heating layer, and the water bath heating pipe is connected to a water bath heater.

5. The method for a fully mixed and dispersed anaerobic digestion process according to claim 1, characterized in that: The top of the connecting tank is equipped with a safety valve.

6. The method for a fully mixed and dispersed anaerobic digestion process according to claim 1, characterized in that: The connecting tank and the dispersing tank have the same height.

7. The method for a fully mixed and dispersed anaerobic digestion process according to claim 1, characterized in that: The anaerobic digester is provided with a drain outlet at the bottom for discharging the digestive liquid inside the anaerobic digester. The slag outlet at the bottom of the anaerobic digester is provided for discharging the treated residue.

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