An intelligent control system for coupling energy consumption of anaerobic fermentation and membrane separation

Abstract

The utility model relates to the technical field of sewage treatment especially is an intelligent regulation and control system of anaerobic fermentation and membrane separation energy consumption coupling, including: anaerobic fermentation module: carries out anaerobic fermentation to waste water, and the output biogas and anaerobic fermentation supernatant, water treatment module: is used to handle anaerobic fermentation supernatant, power generation module: uses the biogas as the energy and carries out power generation for water treatment module to provide electric energy, can through the micro gas turbine power generation of the biogas produced in anaerobic fermentation, and preferentially supplies ultrafiltration or nanofiltration membrane system, reduces the cost.

Description

Technical Field

[0001] This utility model relates to the technical field of wastewater treatment, and in particular to an intelligent control system that couples the energy consumption of anaerobic fermentation and membrane separation. Background Technology

[0002] Among various wastewater treatment technologies, ultrafiltration / nanofiltration membrane systems play a crucial role in removing pollutants and purifying water due to their high separation efficiency, and are widely used in industrial wastewater treatment, municipal sewage treatment, and other fields. However, this membrane separation process is a high-energy-consuming link in wastewater treatment, which not only significantly increases the operating cost of wastewater treatment but also contradicts the current concept of energy conservation and emission reduction, thus limiting the further promotion and application of membrane separation technology in the field of wastewater treatment.

[0003] Anaerobic fermentation technology, as a common wastewater treatment byproduct utilization method, can convert organic matter in wastewater into biogas. Biogas, as a clean energy source, has certain power generation potential. However, at present, there is a lack of linkage between the biogas energy produced by anaerobic fermentation and the high energy consumption demand of membrane separation systems. As a result, biogas energy is difficult to be fully converted and supplied to membrane separation systems, which leads to increased costs. Utility Model Content

[0004] To address the aforementioned technical problems, this utility model provides an intelligent control system that couples the energy consumption of anaerobic fermentation and membrane separation. This system can generate electricity from the biogas produced by anaerobic fermentation through a micro gas turbine and prioritize supplying it to an ultrafiltration or nanofiltration membrane system, thereby reducing costs.

[0005] This utility model discloses an intelligent control system for the coupling of energy consumption in anaerobic fermentation and membrane separation, comprising: Anaerobic fermentation module: performs anaerobic fermentation on wastewater to produce biogas and anaerobic fermentation supernatant; Water treatment module: used to treat the anaerobic fermentation supernatant; Power generation module: Uses biogas as an energy source to generate electricity to power the water treatment module.

[0006] As a preferred embodiment of this utility model, the biogas produced by the anaerobic fermentation module flows into the power generation module after passing through the desulfurization module, dehydration module, filtration module and storage module in sequence.

[0007] As a preferred embodiment of this utility model, the anaerobic fermentation supernatant is treated in a sedimentation tank and then enters the water treatment module.

[0008] As a preferred embodiment of the present invention, the water treatment module includes an ultrafiltration module, and the water source for the ultrafiltration module is the anaerobic fermentation supernatant. The ultrafiltration module's electrical energy comes from the power generation module; The ultrafiltration module produces ultrafiltration concentrate and ultrafiltration permeate, with the ultrafiltration concentrate being recycled back to the anaerobic fermentation module.

[0009] As a preferred embodiment of this utility model, the water treatment module further includes a nanofiltration module, and the ultrafiltration permeate flows into the nanofiltration module; The nanofiltration module produces nanofiltration permeate and nanofiltration concentrate; The nanofiltration module's electrical energy comes from the power generation module.

[0010] As a preferred embodiment of the present invention, it also includes a water quality monitoring module for dividing nanofiltration concentrate into primary concentrate, secondary concentrate and tertiary concentrate; The primary concentrate is used as makeup water for the cooling system of the power generation module, the secondary concentrate is used as makeup water for the anaerobic fermentation module, and the tertiary concentrate is used for irrigation.

[0011] As a preferred embodiment of this utility model, it also includes a waste heat recovery module, which is used to recover the waste heat generated by biogas combustion in the power generation module and to preheat the wastewater before it enters the anaerobic fermentation module.

[0012] As a preferred embodiment of this utility model, the power generation module is at least one of a biogas internal combustion engine, a micro gas turbine, and a biogas steam turbine.

[0013] Compared with the prior art, the beneficial effects of this utility model are as follows: This device converts the biogas produced by anaerobic fermentation into electrical energy and supplies it to the high-energy-consuming water treatment module in a targeted manner, reducing the dependence on external energy, effectively solving the problem of high energy consumption of membrane separation system, realizing the recycling of energy, reducing the operating cost of wastewater treatment, and the anaerobic fermentation process can also remove some organic matter in wastewater, reduce the treatment load of subsequent water treatment modules, and improve treatment efficiency. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the structure of this utility model; The following modules are labeled in the attached diagram: 1. Anaerobic fermentation module; 2. Water treatment module; 21. Ultrafiltration module; 22. Ultrafiltration concentrate; 23. Ultrafiltration permeate; 24. Nanofiltration module; 25. Nanofiltration permeate; 26. Nanofiltration concentrate; 27. Secondary concentrate; 28. Primary concentrate; 29. ​​Tertiary concentrate; 3. Power generation module; 4. Desulfurization module; 5. Dehydration module; 6. Filtration module; 7. Storage module; 8. Biogas; 9. Anaerobic fermentation supernatant; 10. Waste heat recovery module; 101. Flue gas heat exchange component; 102. Circulating water system; 103. Wastewater preheating component; 11. Sedimentation tank; 12. Water quality monitoring module. Detailed Implementation

[0015] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings. Example

[0016] Reference Figure 1 This embodiment provides an intelligent control system for the coupling of energy consumption in anaerobic fermentation and membrane separation, comprising: Anaerobic fermentation module 1: Anaerobic fermentation of wastewater to produce biogas 8 and anaerobic fermentation supernatant 9; Water treatment module 2: used to treat the anaerobic fermentation supernatant 9; Power generation module 3: Uses biogas 8 as an energy source to generate electricity to supply power to water treatment module 2; The specific working process of this utility model is as follows: Wastewater first enters the anaerobic fermentation module 1, where it undergoes an anaerobic fermentation reaction to generate biogas 8 and anaerobic fermentation supernatant 9; the generated biogas 8 is transported to the power generation module 3, which uses the biogas 8 as energy to generate electricity, which is directly supplied to the water treatment module 2; at the same time, the anaerobic fermentation supernatant 9 enters the water treatment module 2, where it is treated to purify the wastewater; This device converts the biogas 8 produced by anaerobic fermentation into electrical energy and supplies it to the high-energy-consuming water treatment module 2, reducing dependence on external energy sources, effectively solving the problem of high energy consumption in membrane separation systems, realizing energy recycling, reducing the operating cost of wastewater treatment, and the anaerobic fermentation process can also remove some organic matter from the wastewater, reducing the treatment load of the subsequent water treatment module 2 and improving treatment efficiency.

[0017] In some embodiments of this utility model, the biogas 8 produced by the anaerobic fermentation module 1 flows into the power generation module 3 after passing through the desulfurization module 4, the dehydration module 5, the filtration module 6 and the storage module 7 in sequence. More specifically, desulfurization module 4 adopts a dry desulfurization process and is filled with iron oxide-based desulfurizing agent. Biogas 8 enters from the bottom of the desulfurization tower and comes into full contact with the desulfurizing agent. The hydrogen sulfide in it reacts chemically with the desulfurizing agent, reducing the H2S concentration from 500-2000 ppm produced by anaerobic fermentation to below 50 ppm. An online hydrogen sulfide detector is installed at the top of the desulfurization tower to monitor the H2S content in the outlet biogas 8 in real time. When the detected value exceeds 50 ppm, the desulfurizing agent replacement prompt is automatically triggered. Dehydration Module 5: Adopts a refrigeration dehydration process. The desulfurized biogas 8 enters the condenser, where the temperature of the biogas 8 is reduced to 2-5℃ by the refrigerant, causing the water vapor in it to condense into liquid water, which is then discharged through the separator. The dew point temperature of the dehydrated biogas 8 is controlled below 4℃ to prevent water accumulation or ice blockage in subsequent pipelines and equipment due to condensation. The dehydration module 5 is equipped with a liquid level sensor, which automatically opens the drain valve to discharge the accumulated water when the condensate reaches the set liquid level. Filter module 6: It adopts a two-stage precision filtration structure. The first stage is a 5μm metal mesh filter to remove desulfurizing agent powder and residual impurities such as condensate that may be carried in biogas 8. The second stage is a 1μm activated carbon filter to further adsorb small particles and a small amount of residual organic impurities. Pressure sensors are installed at both the inlet and outlet of filter module 6. When the pressure difference exceeds 0.05MPa, the filter element replacement alarm is triggered to ensure that the cleanliness of biogas entering storage module 7 meets the requirements of power generation equipment. Storage Module 7: A wet gas storage tank is adopted, with an effective volume designed according to the gas production fluctuation range of the anaerobic fermentation module 1. The gas storage tank is equipped with an automatic pressure regulating device, which stabilizes the pressure inside the tank at 3-5 kPa through counterweight or pneumatic valve. When the biogas production 8 exceeds the immediate demand of the power generation module 3, the gas storage tank stores the excess biogas 8; when the gas production is insufficient, the gas storage tank releases biogas 8 to supplement it, ensuring the continuous and stable operation of the power generation module 3. An overpressure protection valve is installed on the top of the gas storage tank, which automatically releases pressure when the pressure exceeds 6 kPa. Through the above processing steps, harmful components in biogas 8 are effectively removed, and the purity and stability are significantly improved. This not only reduces the corrosion and wear of power generation module 3 and extends the service life of the equipment, but also avoids the decline in power generation efficiency caused by fluctuations in the composition of biogas 8. At the same time, the buffering effect of storage module 7 resolves the contradiction between the unstable gas production of anaerobic fermentation and the continuous energy consumption of power generation module 3.

[0018] In some embodiments of this utility model, the anaerobic fermentation supernatant 9 is treated by the sedimentation tank 11 and then enters the water treatment module 2; Through the treatment in sedimentation tank 11, the suspended solids in the anaerobic fermentation supernatant 9 are significantly reduced, which greatly reduces the risk of fouling of the ultrafiltration / nanofiltration membrane modules in the subsequent water treatment module 2, extends the membrane cleaning cycle, reduces the operating load of the membrane modules, and improves the stable operating efficiency of the water treatment module 2. Furthermore, the sludge from the sedimentation tank 11 can be recycled back to the anaerobic fermentation module 1, realizing the recycling of microbial resources and further enhancing the degradation efficiency of the anaerobic fermentation module 1.

[0019] In some embodiments of this utility model, the water treatment module 2 includes an ultrafiltration module 21, and the water source of the ultrafiltration module 21 is the anaerobic fermentation supernatant 9; The power for the ultrafiltration module 21 comes from the power generation module 3; Ultrafiltration module 21 produces ultrafiltration concentrate 22 and ultrafiltration permeate 23. Ultrafiltration concentrate 22 is returned to anaerobic fermentation module 1. The ultrafiltration module 21 can effectively remove more than 90% of suspended solids, colloids and macromolecular organic matter from the anaerobic fermentation supernatant 9, providing high-quality feed water for subsequent treatment; at the same time, relying on the energy supply of the power generation module 3, it reduces the operating cost compared with the traditional ultrafiltration system that relies on the mains power. The ultrafiltration concentrate 22 contains incompletely degraded organic matter, colloids, and some suspended particles. It is returned to the anaerobic fermentation module 1 through the pipeline as a supplementary substrate for the anaerobic fermentation reaction. The organic components in it can be further degraded by methanogenic bacteria and converted into biogas 8, realizing the secondary energy utilization of organic matter. This reduces wastewater discharge and improves the resource recycling efficiency of the system.

[0020] In some embodiments of this utility model, the water treatment module 2 further includes a nanofiltration module 24, and the ultrafiltration permeate 23 flows into the nanofiltration module 24; Nanofiltration module 24 produces nanofiltration permeate 25 and nanofiltration concentrate 26; The electrical energy of nanofiltration module 24 comes from power generation module 3; The nanofiltration module 24 uses ultrafiltration water 23 as feed water for deep treatment, which can further remove small molecule pollutants and salts to improve the quality of the effluent and meet the higher standards of reuse. It also relies on the biogas 8 supplied by the power generation module 3 to operate, reducing dependence on the external power grid and lowering energy costs.

[0021] In some embodiments of this utility model, a water quality monitoring module 12 is also included for dividing nanofiltration concentrate 26 into primary concentrate 28, secondary concentrate 27 and tertiary concentrate 29. Among them, primary concentrate 28 is used as makeup water for the cooling system of power generation module 3, secondary concentrate 27 is used as inlet water for anaerobic fermentation module 1, and tertiary concentrate 29 is used as irrigation water. More specifically, the water quality monitoring module 12 can adopt the following structure: it consists of an online detection unit, an automatic diversion unit and a central control unit. The nanofiltration concentrate 26 discharged from the nanofiltration module 24 first enters the buffer tank and is then transported to the online detection unit by a booster pump. This unit integrates a conductivity meter, a COD rapid detector, a turbidity meter and a pH sensor to monitor the concentrate water quality indicators in real time. Among them, Grade I concentrate 28 must meet the requirements of conductivity ≤ 800 μS / cm and turbidity ≤ 5 NTU; Grade II concentrate 27 must meet the requirements of COD ≥ 300 mg / L and pH 6.0-8.0; Grade III concentrate 29 must meet the requirements of conductivity ≤ 2000 μS / cm and heavy metal ion concentration in accordance with the "Standards for Irrigation Water Quality in Farmland". Through a tiered reuse design, the resource utilization rate of nanofiltration concentrate 26 is greatly improved. This not only reduces the consumption of fresh water, but also further enhances the material cycle efficiency of the system through the tiered utilization of organic matter and salt in the concentrate.

[0022] In some embodiments of this utility model, a waste heat recovery module 10 is also included, which is used to recover the waste heat generated by the combustion of biogas 8 in the power generation module 3, and to preheat the wastewater before it enters the anaerobic fermentation module 1. More specifically, the waste heat recovery module 10 includes a flue gas heat exchange component 101, a circulating water system 102, and a wastewater preheating component 103. The high-temperature flue gas generated by the combustion of biogas 8 in the power generation module 3 is introduced into the flue gas heat exchange component 101 and exchanges heat with the circulating medium in the circulating water system 102 to realize the recovery of waste heat from the combustion of biogas 8. The circulating water system 102 transports the circulating medium after absorbing waste heat to the wastewater preheating component 103. The wastewater preheating component 103 is installed on the wastewater conveying pipeline entering the anaerobic fermentation module 1 and transfers the waste heat in the circulating medium to the wastewater to be entered into the anaerobic fermentation module 1 through heat exchange to complete the preheating of the wastewater.

[0023] In some embodiments of this utility model, the power generation module 3 is at least one of a biogas internal combustion engine, a micro gas turbine, and a biogas steam turbine.

[0024] It should be noted that the above embodiments are only used to illustrate the technical solution of this utility model and are not intended to limit it. Although this utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solution of this utility model without departing from the spirit and scope of the technical solution of this utility model, and all such modifications or substitutions should be covered within the scope of the claims of this utility model.

Claims

1. A smart control system for energy consumption coupling anaerobic fermentation and membrane separation, characterized in that, include: Anaerobic fermentation module (1): Anaerobic fermentation of wastewater to produce biogas (8) and anaerobic fermentation supernatant (9); Water treatment module (2): used to treat the anaerobic fermentation supernatant (9); Power generation module (3): Uses biogas (8) as an energy source to generate electricity to provide power to the water treatment module (2).

2. The intelligent control system for energy consumption coupling of anaerobic fermentation and membrane separation as described in claim 1, characterized in that, The biogas (8) produced by the anaerobic fermentation module (1) flows into the power generation module (3) after passing through the desulfurization module (4), dehydration module (5), filtration module (6) and storage module (7).

3. The intelligent control system for energy consumption coupling of anaerobic fermentation and membrane separation as described in claim 1, characterized in that, The anaerobic fermentation supernatant (9) is treated in a sedimentation tank (11) and then enters the water treatment module (2).

4. The intelligent control system for energy consumption coupling of anaerobic fermentation and membrane separation as described in claim 3, characterized in that, The water treatment module (2) includes an ultrafiltration module (21), and the water source of the ultrafiltration module (21) is the anaerobic fermentation supernatant (9). The power of the ultrafiltration module (21) comes from the power generation module (3); The ultrafiltration module (21) produces ultrafiltration concentrate (22) and ultrafiltration permeate (23), and the ultrafiltration concentrate (22) is returned to the anaerobic fermentation module (1).

5. The intelligent control system for energy consumption coupling of anaerobic fermentation and membrane separation as described in claim 4, characterized in that, The water treatment module (2) also includes a nanofiltration module (24), and the ultrafiltration permeate (23) flows into the nanofiltration module (24). The nanofiltration module (24) produces nanofiltration permeate (25) and nanofiltration concentrate (26). The electrical energy of the nanofiltration module (24) comes from the power generation module (3).

6. The intelligent control system for energy consumption coupling of anaerobic fermentation and membrane separation as described in claim 5, characterized in that, It also includes a water quality monitoring module (12) for dividing the nanofiltration concentrate (26) into primary concentrate (28), secondary concentrate (27) and tertiary concentrate (29); Among them, the primary concentrate (28) is used as the cooling system water for the power generation module (3), the secondary concentrate (27) is used as the inlet water for the anaerobic fermentation module (1), and the tertiary concentrate (29) is used as irrigation water.

7. The intelligent control system for energy consumption coupling of anaerobic fermentation and membrane separation as described in claim 1, characterized in that, It also includes a waste heat recovery module (10) for recovering the waste heat generated by the combustion of biogas (8) in the power generation module (3) and using the waste heat to preheat the wastewater before it enters the anaerobic fermentation module (1).

8. The intelligent control system for energy consumption coupling of anaerobic fermentation and membrane separation as described in claim 1, characterized in that, The power generation module (3) is at least one of a biogas internal combustion engine, a micro gas turbine, and a biogas steam turbine.

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