Electricity-generating garbage biogas gasification treatment device

Abstract

The utility model discloses a garbage biogas gasification treatment device capable of generating electricity, which relates to the technical field of garbage treatment equipment and comprises a reaction chamber, two conductive parts and a resistor or an energy storage element, a low-oxygen or oxygen-free environment can be kept in the reaction chamber, and a liquid inlet, a liquid outlet, a gas outlet and two fixing ports are arranged on the reaction chamber; the two conductive parts respectively extend into the reaction chamber through the two fixing ports to form two electrodes; the resistor or the energy storage element is arranged outside the reaction chamber; the resistor or the energy storage element is electrically connected with the two conductive pieces and enables the two electrodes to respectively form an anode and a cathode. According to the device, a microbial fuel cell and an anaerobic fermentation process are integrated in one set of device, so that the microbial fuel cell and the anaerobic fermentation process are highly and effectively integrated, the removal rate of organic matters in garbage is high, the occupied space is small, the proportion of CH4 in biogas is high, and electric energy is generated.

Description

Technical Field

[0001] The utility model relates to the technical field of garbage processing equipment, in particular to a garbage biogasification processing device for generating electricity. Background Art

[0002] With my country's rapid economic development and accelerating urbanization, the annual generation of domestic waste in its cities has continued to rise. According to the China Statistical Yearbook, China's urban domestic waste collection and transportation volume reached 248.692 million tons in 2021, an increase of 13.575 million tons from 2020, a year-on-year growth of 5.8%. In 2020, Guangzhou proposed the goal of building a "Zero Waste City," aiming to achieve negative growth in per capita daily domestic waste production by 2035. However, the current bioresource processing capacity for domestic waste is less than 5,000 tons per day, leaving a significant market gap. my country has traditionally primarily used landfills to dispose of domestic waste, but with rising urbanization rates and land shortages, landfills have become increasingly saturated, and some cities have even run out of land for burial. Incineration of domestic waste for power generation is the most efficient way to treat domestic waste, which has the functions of reducing, harmless and resource-based treatment. However, 40-50% of domestic waste is kitchen waste, which has the characteristics of high moisture content, high salt content, high organic matter content, and rich nutrient content. Among them, it is not suitable for incineration because of its high moisture content of 70-95%. Kitchen waste is a kind of easily biodegradable organic waste because it is rich in nutrients required by microorganisms. Anaerobic fermentation is an effective means of biomass energy utilization in recent years. This technology produces renewable energy biogas and realizes energy recovery. It is one of the most ideal resource-based means of treating kitchen waste. The main components of biogas produced by anaerobic fermentation are CH4, CO2 and H2S, as well as a small amount of H2, NH3 and CO. The calorific value of CH4 is about 40MJ / m 3 , and biogas contains CO2, which leads to a decrease in energy density (calorific value is about 20MJ / m 3 ) The main methods for removing CO2 from biogas include physical absorption, chemical absorption, membrane separation, pressure swing adsorption, etc. These technologies have defects such as high energy consumption and secondary pollution, which leads to high costs for biogas upgrading and limits the development of this technology.

[0003] Microbial electrochemical systems are an emerging green environmental technology that has developed in recent years. They encompass a wide range of technologies, including microbial fuel cells, microbial electrolysis cells, and biosensors. Microbial fuel cells use microorganisms as catalysts to oxidize organic or inorganic substances, converting chemical energy into electrical energy. Given the advantages of microbial fuel cells and traditional anaerobic fermentation, combining these two technologies for treating domestic waste could create a device that occupies a small footprint, has low operating costs, and generates electricity. Utility Model Content

[0004] The purpose of the present utility model is to provide a garbage biogasification treatment device that generates electricity to solve the problems existing in the above-mentioned prior art. It integrates microbial fuel cells and anaerobic fermentation processes in a set of devices, thereby achieving a high degree of and effective integration of the two. The removal rate of organic matter in kitchen waste is high, the space occupied is small, the proportion of CH4 in biogas is high, and electricity can be generated.

[0005] To achieve the above purpose, the present invention provides the following solutions:

[0006] The utility model provides a garbage biogasification treatment device for generating electricity, comprising:

[0007] A reaction chamber, wherein the reaction chamber can maintain a low oxygen or oxygen-free environment, and the reaction chamber is provided with a liquid inlet and outlet, an air outlet and two fixed ports;

[0008] Two conductive members, the two conductive members respectively extending into the reaction chamber through the two fixing openings to form two electrodes; and

[0009] A resistor or energy storage element is arranged outside the reaction chamber, and the resistor or energy storage element is electrically connected to the two conductive members so that the two electrodes form an anode and a cathode respectively.

[0010] Preferably, the electrode is coated with carbon felt.

[0011] Preferably, the fixed port and the conductive part are sealed by AB glue, the liquid inlet and outlet are installed with liquid inlet and outlet rubber tubes, the liquid inlet and outlet rubber tubes can be clamped and sealed with water stop clamps, the air outlet is installed with an air outlet rubber tube, and the air outlet rubber tube is connected to an air bag.

[0012] Preferably, the liquid inlet and outlet rubber tube is inserted into the liquid inlet and outlet port, and one end of the liquid inlet and outlet rubber tube extends into the lower middle portion of the reaction chamber.

[0013] Preferably, the liquid inlet and outlet are used for adding garbage hydrolyzate in batches.

[0014] Preferably, the reaction chamber is placed in a temperature-controllable shaker or a constant temperature incubator. When placed in the constant temperature incubator, a magnetic stirrer is provided, and the stirring rod of the magnetic stirrer is placed in the reaction chamber.

[0015] Preferably, the temperature of the temperature-controllable shaker is set at 38°C and the shaker speed is set at 140 rpm;

[0016] Alternatively, the temperature of the constant temperature incubator is set at 38°C.

[0017] Preferably, the conductive member is a titanium wire with a diameter of 2 mm.

[0018] Preferably, the reaction chamber is cylindrical.

[0019] Compared with the prior art, the utility model has achieved the following technical effects:

[0020] The device provided by the present invention is used to treat garbage, such as kitchen waste. After the kitchen waste hydrolyzate enters the reaction chamber, CH4 and CO2 will be produced like the normal anaerobic fermentation process. At the same time, organic matter will also be converted into CH4 and CO2 by the electroactive anaerobic fermentation bacteria biofilm attached to the anode and cathode surfaces, and the CH4 produced in the reaction chamber will be converted into CO2 to generate electricity. Compared with the traditional anaerobic fermentation method, the use of electroactive anaerobic fermentation bacteria can promote more organic matter to be converted into CH4 and CO2, and at the same time, part of the produced CH4 will be converted into electricity, thereby achieving efficient utilization and removal of organic matter while generating electricity. The device can convert part of the CH4 produced in the reaction chamber into CO2 and oxidize part of the organic matter into CO2 and generate electricity by setting up anaerobic fermentation bacteria biofilm attached to the anode and cathode surfaces to achieve electricity production while reducing subsequent biogas upgrading consumption.

[0021] Therefore, the device integrates microbial fuel cells and anaerobic fermentation processes into one device, achieving a high degree of effective integration between the two. It has a high removal rate of organic matter in kitchen waste, occupies a small space, and has a high proportion of CH4 in biogas, generating electricity. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0023] Figure 1 This is a schematic structural diagram of a garbage biogasification treatment device for generating electricity provided in an embodiment of the utility model.

[0024] Among them, 1-liquid inlet and outlet; 2-air outlet; 3-fixing port; 4-conductive part; 5-resistor; 6-carbon felt; 7-air outlet rubber tube; 8-air bag; 9-reaction chamber. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0026] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0027] The utility model provides a garbage biogasification treatment device for generating electricity, which is used to treat kitchen waste, garden waste and agricultural waste, etc. Figure 1 As shown, it includes: a reaction chamber 9, two conductive parts 4 and a resistor 5 or an energy storage element.

[0028] The reaction chamber 9 is capable of maintaining a low-oxygen or oxygen-free environment and is provided with a liquid inlet and outlet 1, an air outlet 2, and two fixed ports 3. The liquid inlet and outlet 1 is used to introduce waste hydrolyzed liquid into the reaction chamber 9 and to extract muddy, liquid, or gel-like reaction products from the reaction chamber 9 for sludge removal and sampling.

[0029] Two conductive members 4 extend into the reaction chamber 9 through the two fixing openings 3 to form two electrodes. The conductive members 4 can be in the form of wires, rods, etc., which is not limited in this embodiment, as long as they can form conductive electrodes.

[0030] The resistor 5 or the energy storage element is disposed outside the reaction chamber 9 . The resistor 5 or the energy storage element is electrically connected to the two conductive members 4 so that the two electrodes form an anode and a cathode respectively.

[0031] When the device provided by the present invention is used to treat food waste, after the food waste hydrolyzate enters the reaction chamber 9, CH4 and CO2 will be produced like the normal anaerobic fermentation process. At the same time, organic matter will also be converted into CH4 and CO2 by the electroactive anaerobic fermentation bacteria biofilm attached to the anode and cathode surfaces, and the CH4 produced in the reaction chamber 9 will be converted into CO2 to generate electricity. Compared with the traditional anaerobic fermentation method, the use of electroactive anaerobic fermentation bacteria can promote more organic matter to be converted into CH4 and CO2, and at the same time, part of the produced CH4 will be converted into electricity, thereby achieving efficient utilization and removal of organic matter while generating electricity; the device can convert part of the CH4 produced in the reaction chamber 9 into CO2 and oxidize part of the organic matter into CO2 and generate electricity by setting up anaerobic fermentation bacteria biofilm attached to the anode and cathode surfaces to achieve electricity generation while reducing subsequent biogas upgrading consumption.

[0032] Therefore, the device integrates microbial fuel cells and anaerobic fermentation processes into one device, achieving a high degree of effective integration between the two. It has a high removal rate of organic matter in kitchen waste, occupies a small space, and has a high proportion of CH4 in biogas, generating electricity.

[0033] Considering that metal electrode surfaces are typically smooth, which is not conducive to the attachment of anaerobic fermentation bacteria biofilms, to overcome this drawback, in some embodiments, the electrodes are coated with carbon felt 6. Specifically, carbon felt 6 is porous. Carbon felt 6 has numerous pores and a rough surface, resulting in a large specific surface area and providing excellent attachment points for microorganisms. As the reaction chamber 9 is stirred, some anaerobic fermentation bacteria are trapped and adhere to the surface of carbon felt 6. They then grow and multiply on the surface of carbon felt 6, secreting extracellular polymers to strengthen their adhesion. Under the continuous operation of the reactor, the microbial fuel cell will gradually generate electricity to form an electrical circuit. The generated voltage will stimulate the anaerobic fermentation bacteria that are not adapted to the voltage and cause them to fall off, while the anaerobic fermentation bacteria that use the voltage can gradually be enriched on the surface of the carbon felt 6. The biofilm on the surface of the carbon felt 6 will participate in the conversion of organic matter into CH4 and CO2. At the same time, it can also convert part of the CH4 produced by the anaerobic fermentation sludge in the reaction chamber 9 into CO2 and oxidize part of the organic matter into CO2 to generate electricity. The generated electricity will be directly consumed by the resistor 5. If electricity needs to be stored, the resistor 5 will be replaced by an energy storage element, specifically a supercapacitor energy storage element.

[0034] The conversion mentioned here is the same as the existing anaerobic digestion technology, that is, the process of producing methane conforms to the three-stage four-group theory. However, after the microbial fuel cell is coupled with the anaerobic digestion technology, there may be other ways to produce CH4. When generating electricity, hydrogen ions will be generated (Formula 1), and the hydrogen ions can be directly used by carbon dioxide-reducing methanogens and reduce CO2 to CH4 (Formula 2). There may also be hydrogen-producing bacteria that convert the produced hydrogen ions into H2 (Formula 3) and then reduce CO2 to CH4 (Formula 4).

[0035] Organic matter + nH2O → mCO2 + nH + +ne - (Formula 1)

[0036] CO2+4H + +4e - →CH4+2H2O (Formula 2)

[0037] 2H + +2e - →H2 (Formula 3)

[0038] CO2+4H2→CH4+H2O (Formula 4)

[0039] In some embodiments, the fixed port 3 and the conductive part 4 are sealed by AB glue, and the liquid inlet and outlet ports 1 are equipped with liquid inlet and outlet rubber tubes, which can be clamped and sealed with water stop clamps to maintain the anaerobic environment in the reaction chamber 9. The air outlet 2 is equipped with an air outlet rubber tube 7, and the air outlet rubber tube 7 is connected to an air bag 8, which is used to collect biogas generated by anaerobic fermentation sludge.

[0040] In some embodiments, a liquid inlet and outlet rubber tube is installed in the liquid inlet and outlet port 1, and one end of the liquid inlet and outlet rubber tube extends into the middle and lower part of the reaction chamber 9. This facilitates the extraction of muddy, liquid or gel-like reaction products at the bottom of the reaction chamber 9.

[0041] In some embodiments, the liquid inlet and outlet 1 is used for adding garbage hydrolyzed liquid in a sequential batch manner.

[0042] Specifically, the startup process is performed under sequencing batch operation conditions. Anaerobic fermentation sludge is added to the reaction chamber 9. After connecting the resistor 5 or energy storage element, garbage hydrolyzate is added in a sequencing batch manner to cultivate the anaerobic fermentation sludge to gradually enrich the electroactive anaerobic fermentation bacteria biofilm on the surface of the carbon felt 6.

[0043] In some embodiments, the reaction chamber 9 is placed in a temperature-controlled shaker or a constant temperature incubator. When placed in a constant temperature incubator, a magnetic stirrer is provided, and the stirring bar of the magnetic stirrer is placed in the reaction chamber.

[0044] Specifically, when placed on a temperature-controlled shaker, the temperature of the temperature-controlled shaker is set at 38° C. and the shaker speed is set at 140 rpm;

[0045] When placed in a constant temperature incubator, the temperature is set at 38°C.

[0046] In some embodiments, the conductive member 4 is preferably a titanium wire, specifically a titanium wire with a diameter of 2 mm. Titanium wire can be used for a long time and has little toxicity to microorganisms.

[0047] If iron wire is used, it will be corroded and fall into the solution during long-term operation, which will prevent the formation of a loop in the reactor. Therefore, the iron wire needs to be replaced frequently. When the iron wire is replaced, the reactor will be in an aerobic environment, which is toxic to anaerobic microorganisms. In addition, copper wire, platinum wire, silver wire, and gold wire can also be selected, but copper wire has the same problem as iron wire, that is, it will be corroded, and copper wire will gradually precipitate copper ions, which are toxic to microorganisms. Therefore, copper wire is not selected; as for other platinum wire, silver wire, and gold wire, they all have the problem of high prices and are therefore not considered.

[0048] In some embodiments, the reaction chamber 9 is cylindrical.

[0049] The power-generating garbage gasification treatment device provided in the present application processes garbage as follows: the garbage hydrolyzate enters from the liquid inlet and outlet 1, and the organic matter in the garbage hydrolyzate is converted into CH4 and CO2 after being treated by anaerobic fermentation sludge and the electroactive anaerobic fermentation bacteria biofilm attached to the surface of the carbon felt 6. At the same time, the electroactive anaerobic fermentation bacteria biofilm will convert CH4 into CO2 and part of the organic matter into CO2 and generate electricity. The gas generated in the reaction chamber 9 will enter the air bag 8 through the air outlet 2, and the final treated liquid will be discharged from the liquid inlet and outlet 1.

[0050] Application Effect

[0051] The results of using the power-generating garbage biogasification treatment device of this embodiment to treat kitchen waste hydrolyzate are as follows:

[0052] (1) The waste gasification treatment device for power generation in this embodiment has an effective volume of 0.7 L and is used to treat an influent organic load of 4 kg / (m 3 d) The kitchen waste hydrolyzate has a COD of more than 190,000 mg / L, a COD removal rate of 93.1-98.3%, a biogas output of 0.55-0.7 L, and biogas compositions of 61-64% CH4 and 20.7-32.28% CO2. The generated electricity is

[0053] The power-generating garbage biogasification treatment device of this embodiment controls the effluent COD below 13000 mg / L, the biogas production is above 0.55 L, the methane content in the biogas is above 61%, it has a simple structure, strong impact load resistance, high processing efficiency, and generates 1.9 mV of electricity.

[0054] (2) The waste gasification treatment device for power generation in this embodiment has an effective volume of 1.5L and is used to treat an influent organic load of 8kg / (m 3 d) The kitchen waste hydrolyzate has a COD of >220,000 mg / L, a COD removal rate of 91.8-96.4%, a biogas output of 2.53-3.13 L, and biogas compositions of 60.7-63.42% CH4 and 31.8-33.7% CO2.

[0055] The power-generating garbage biogasification treatment device of this embodiment controls the effluent COD below 18000 mg / L, the biogas production is above 2.53 L, the methane content in the biogas is above 60.7%, has a simple structure, strong impact load resistance, high processing efficiency, and generates 3.1 mV of electricity.

[0056] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only intended to help understand the method and core concept of the present invention. At the same time, those skilled in the art will find that the specific implementation methods and application scopes may vary based on the concept of the present invention. In summary, the contents of this specification should not be construed as limiting the present invention.

Claims

1. A garbage biogasification treatment device for generating electricity, characterized by: include: A reaction chamber, wherein the reaction chamber can maintain a low oxygen or oxygen-free environment, and the reaction chamber is provided with a liquid inlet and outlet, an air outlet and two fixed ports; Two conductive members, the two conductive members respectively extending into the reaction chamber through the two fixing openings to form two electrodes; as well as A resistor or energy storage element is arranged outside the reaction chamber, and the resistor or energy storage element is electrically connected to the two conductive members so that the two electrodes form an anode and a cathode respectively.

2. The garbage biogasification treatment device for generating electricity according to claim 1, characterized in that: The electrodes are coated with carbon felt.

3. The garbage biogasification device for generating electricity according to claim 1, characterized in that: The fixing port and the conductive part are sealed by AB glue, the liquid inlet and outlet are installed with liquid inlet and outlet rubber tubes, and the liquid inlet and outlet rubber tubes can be clamped and sealed with water stop clamps, and the air outlet is installed with an air outlet rubber tube, and the air outlet rubber tube is connected to an air bag.

4. The garbage biogasification device for generating electricity according to claim 3 is characterized in that: The liquid inlet and outlet rubber tube is inserted into the liquid inlet and outlet port, and one end of the liquid inlet and outlet rubber tube extends into the middle and lower part of the reaction chamber.

5. The garbage biogasification device for generating electricity according to claim 1, characterized in that: The liquid inlet and outlet are used for adding garbage hydrolyzate in batches.

6. The garbage biogasification device for generating electricity according to claim 1, characterized in that: The reaction chamber is placed in a temperature-controllable shaker or a constant temperature incubator. When placed in the constant temperature incubator, a magnetic stirrer is provided, and a stirring rod of the magnetic stirrer is placed in the reaction chamber.

7. The garbage biogasification device for generating electricity according to claim 6, characterized in that: The temperature of the temperature-controlled shaker was set at 38°C and the shaker speed was set at 140 rpm; Alternatively, the temperature of the constant temperature incubator is set at 38°C.

8. The garbage biogasification device for generating electricity according to claim 1, characterized in that: The conductive member is a titanium wire with a diameter of 2 mm.

9. The garbage biogasification device for generating electricity according to claim 1, characterized in that: The reaction chamber is cylindrical.

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