Biogas slurry energy regeneration and nutrient recovery system

Abstract

The utility model discloses a biogas slurry energy regeneration and nutrient recovery system. The system comprises a biogas slurry tank, a first water inlet pump, a self-cleaning filter, a quartz sand filter, a bag filter, an MFC reactor, a second water inlet pump, an ultrafiltration membrane assembly, an ultrafiltration water production tank, a nanofiltration pressure pump, a nanofiltration security filter, a nanofiltration high-pressure pump, a nanofiltration membrane assembly, a nanofiltration water production tank, a DTRO pressure pump, a DTRO security filter, a DTRO high-pressure pump, a DTRO and a DTRO water production tank which are connected in sequence. According to the utility model, the external pressure type ultrafiltration membrane is combined with the DTRO, so that the device is more pollution-resistant and is suitable for treating biogas slurry with high solid content. The DTRO open flow channel is more suitable for concentrating feed liquid with complex components, the problems that traditional biogas slurry concentration equipment is prone to being blocked, the later operation and maintenance cost is high and the like are fundamentally solved, and the good concentration effect is achieved.

Description

Technical Field

[0001] This utility model relates to the field of biogas slurry resource and energy treatment technology, specifically to a system that integrates microbial fuel cell (MFC) and multi-stage membrane separation technology to simultaneously realize biogas slurry energy recovery, nutrient concentration and purification. Background Technology

[0002] Biogas slurry is rich in nutrients such as nitrogen, phosphorus, and potassium, as well as trace elements such as iron, copper, and manganese. It also contains relatively abundant amino acids, humic acid, hydrolytic enzymes, vitamins, and substances that inhibit pests and diseases, making it a high-quality resource that is beneficial when used and harmful when discarded. If the nutrients in biogas slurry can be concentrated and recovered through technological means and developed into high-value products such as liquid fertilizers, the value density of biogas slurry will be effectively increased, overcoming the technical bottleneck of returning biogas slurry to the field.

[0003] Membrane concentration is a physical filtration process that can not only effectively remove pollutants to obtain high-quality permeate, but also concentrate nutrients to obtain a nutrient-rich concentrate. It has technical advantages such as simple operation, no change in the physicochemical properties of nutrients during the process, and the ability to reuse water resources. At present, biogas slurry membrane concentration has the following technical problems: (1) Single target orientation: Existing technologies mostly focus on a single target, such as pollutant removal or nutrient recovery, and lack integrated design for the coordinated recovery of energy and resources. (2) Membrane fouling problem: High suspended solids in biogas slurry can easily lead to membrane system blockage, low membrane flux, poor durability, and frequent cleaning and replacement of membrane modules significantly increase operation and maintenance costs. The above problems limit the efficient resource utilization of biogas slurry. Therefore, it is urgent to develop an integrated system that can realize the coordinated energy conversion and nutrient recovery of biogas slurry to improve resource utilization and reduce treatment costs. Summary of the Invention

[0004] The purpose of this invention is to address the aforementioned technical deficiencies by proposing a biogas slurry energy conversion and nutrient recovery system to achieve synergistic recovery of energy and resources.

[0005] To achieve the above objectives, the present invention discloses the following technical solution:

[0006] A biogas slurry energy conversion and nutrient recovery system, characterized in that the system comprises: a biogas slurry tank, a first inlet pump, a self-cleaning filter, a quartz sand filter, a bag filter, an MFC reactor, a second inlet pump, an ultrafiltration membrane module, an ultrafiltration permeate tank, a nanofiltration pressurization pump, a nanofiltration security filter, a nanofiltration high-pressure pump, a nanofiltration membrane module, a nanofiltration permeate tank, a disc tube reverse osmosis (DTRO) pressurization pump, a DTRO security filter, a DTRO high-pressure pump, a DTRO reactor, and a DTRO permeate tank connected in sequence; wherein the permeate outlet of the nanofiltration membrane module is connected to the nanofiltration permeate tank, and the concentrate outlet is connected in sequence to the nanofiltration concentrate tank and the nanofiltration reflux pump and communicates with the ultrafiltration permeate tank; the DTRO permeate outlet is connected to the DTRO permeate tank, and the concentrate outlet is connected in sequence to the DTRO concentrate tank and the DTRO reflux pump and communicates with the nanofiltration permeate tank.

[0007] The ultrafiltration membrane module in the biogas slurry energy conversion and nutrient recovery system mentioned above uses an external pressure ultrafiltration membrane.

[0008] The present invention is described in more detail below:

[0009] A biogas slurry energy conversion and nutrient recovery system, comprising: a biogas slurry tank, a first inlet pump, a self-cleaning filter, a quartz sand filter, a bag filter, an MFC reactor, a second inlet pump, an ultrafiltration membrane module, an ultrafiltration permeate tank, a nanofiltration pressurization pump, a nanofiltration security filter, a nanofiltration high-pressure pump, a nanofiltration membrane module, a nanofiltration permeate tank, a DTRO pressurization pump, a DTRO security filter, a DTRO high-pressure pump, a DTRO reactor, and a DTRO permeate tank, connected in sequence;

[0010] The self-cleaning filter, quartz sand filter, and bag filter are connected in sequence to form a pretreatment unit for biogas slurry, which is used to remove suspended solids from the biogas slurry.

[0011] The MFC reactor is a biogas slurry energy recovery unit that uses organic matter in biogas slurry to generate electricity, which powers sensors such as pH, temperature, and conductivity in the system, enabling real-time data acquisition and transmission.

[0012] The ultrafiltration membrane module, nanofiltration membrane module, and DTRO are membrane separation units that progressively concentrate nutrients in the biogas slurry and produce reclaimed water, which can be used for agricultural irrigation or landscaping. The ultrafiltration membrane module uses an external pressure ultrafiltration membrane. The permeate from the nanofiltration membrane enters the nanofiltration permeate tank, and the concentrate enters the nanofiltration concentrate tank, which is then returned to the ultrafiltration permeate tank via a nanofiltration reflux pump. The permeate from the DTRO membrane enters the DTRO permeate tank, and the concentrate enters the DTRO concentrate tank, which is then returned to the nanofiltration permeate tank via a DTRO reflux pump. When the nanofiltration and DTRO concentrates reach the set concentration requirements, they are output as concentrated liquid and processed into liquid fertilizer.

[0013] The advantages of the biogas slurry treatment and nutrient recovery system disclosed in this utility model compared with the prior art are as follows:

[0014] (1) Integrated design for energy and resource recovery, utilizing MFC to degrade organic matter in biogas slurry and generate electricity to power sensors such as pH, temperature, and conductivity, thereby reducing system energy consumption.

[0015] (2) The combination of external pressure ultrafiltration membrane and DTRO is more resistant to pollution and suitable for treating biogas slurry with high solid content; the open flow channel of DTRO is more suitable for concentrating complex components of the liquid, fundamentally alleviating the problems of easy clogging and high maintenance costs of traditional biogas slurry concentration equipment, and achieving good concentration effect. Attached Figure Description

[0016] Figure 1 This is a process flow diagram of the present invention; the reference numerals in the diagram are as follows:

[0017] 1. Biogas slurry tank; 2. First inlet pump; 3. Self-cleaning filter; 4. Quartz sand filter;

[0018] 5. Bag filter; 6. MFC reactor; 7. Second feed pump; 8. Ultrafiltration membrane module;

[0019] 9. Ultrafiltration permeate tank; 10. Nanofiltration booster pump; 11. Nanofiltration security filter; 12. Nanofiltration high-pressure pump;

[0020] 13 Nanofiltration membrane module; 14 Nanofiltration permeate tank; 15 DTRO booster pump; 16 DTRO security filter; 17 DTRO high-pressure pump; 18 DTRO; 19 DTRO permeate tank; 20 Nanofiltration concentrate tank;

[0021] 21 Nanofiltration reflux pump; 22 DTRO concentrate tank; 23 DTRO reflux pump. Detailed Implementation

[0022] The present invention will now be described through specific embodiments. Unless otherwise specified, all technical means used in this invention are methods known to those skilled in the art. Furthermore, the embodiments should be understood as illustrative, not limiting, of the scope of this invention; the essence and scope of this invention are defined only by the claims. Example

[0023] A biogas slurry energy conversion and nutrient recovery system is used to treat biogas slurry discharged from a large-scale dairy farm in North China. The system includes: a biogas slurry tank 1, a first inlet pump 2, a self-cleaning filter 3, a quartz sand filter 4, a bag filter 5, an MFC reactor 6, a second inlet pump 7, an ultrafiltration membrane module 8, an ultrafiltration permeate tank 9, a nanofiltration pressurization pump 10, a nanofiltration security filter 11, a nanofiltration high-pressure pump 12, a nanofiltration membrane module 13, a nanofiltration permeate tank 14, a DTRO pressurization pump 15, a DTRO security filter 16, a DTRO high-pressure pump 17, and a DTRO... 18. DTRO permeate tank 19 are connected in sequence; the ultrafiltration membrane module adopts an external pressure ultrafiltration membrane; the permeate from the nanofiltration membrane module 13 enters the nanofiltration permeate tank 14, and the concentrate enters the nanofiltration concentrate tank 20, which is then returned to the ultrafiltration permeate tank 9 via the nanofiltration return pump 21; the permeate from the DTRO 18 membrane enters the DTRO permeate tank 19, and the concentrate enters the DTRO concentrate tank 22, which is then returned to the nanofiltration permeate tank 14 via the DTRO return pump 23; when the nanofiltration and DTRO concentrates reach the set concentration requirements, they are output as concentrated liquid and processed into liquid fertilizer. The DTRO permeate meets the "Standards for Irrigation Water Quality" (GB 5084-2021) and is used for agricultural irrigation.

Claims

1. A biogas slurry energy production and nutrient recovery system, characterized by The system comprises, in sequence, a biogas slurry tank, a first water inlet pump, a self-cleaning filter, a quartz sand filter, a bag filter, an MFC reactor, a second water inlet pump, an ultrafiltration membrane assembly, an ultrafiltration water tank, a nanofiltration pressure pump, a nanofiltration security filter, a nanofiltration high-pressure pump, a nanofiltration membrane assembly, a nanofiltration water tank, a DTRO pressure pump, a DTRO security filter, a DTRO high-pressure pump, a DTRO, and a DTRO water tank; wherein the nanofiltration membrane assembly water outlet is connected with the nanofiltration water tank, the concentrated water outlet is connected with the nanofiltration concentrated water tank and the nanofiltration backflow pump in sequence and is communicated with the ultrafiltration water tank; the DTRO water outlet is connected with the DTRO water tank, the concentrated water outlet is connected with the DTRO concentrated water tank and the DTRO backflow pump in sequence and is communicated with the nanofiltration water tank.

2. The biogas energy and nutrient recovery system according to claim 1, wherein The ultrafiltration membrane assembly adopts an external pressure type ultrafiltration membrane.

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