Anaerobic digestion device with high methane yield

Abstract

The utility model relates to the technical field of organic solid waste resource utilization, and discloses an anaerobic digestion device for high-yield methane, which comprises an anaerobic reactor, a feed port and a discharge port are respectively arranged at the lower end and the upper end of the side wall of the anaerobic reactor, and an exhaust port is arranged at the top of the anaerobic reactor. A plurality of layers of electrodes which are horizontally arranged are arranged at the upper end in the anaerobic reactor, the electrodes are silk screen filler electrodes, the electrodes comprise positive electrodes and negative electrodes, and the positive electrodes and the negative electrodes are connected with an external power supply through wires. The water electrolysis device is arranged in the anaerobic reactor, the positive electrode generates oxygen, a micro-oxygen-consumption environment is generated around the positive electrode, hydrolytic bacteria are promoted to convert organic matter into low-molecular organic acid, a substrate is provided for methanogens, and methane generation is promoted; the negative electrode produces hydrogen, a hydrogen environment is generated around the negative electrode, hydrogen nutrition type methanogens are promoted to convert hydrogen and CO2 dissolved in the system into methane, and the purposes of reducing the carbon dioxide and improving the methane yield are achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of organic solid waste resource utilization, in particular to an anaerobic digestion device with high methane production. Background Art

[0002] Organic solid waste generally refers to biodegradable organic waste, including but not limited to kitchen waste, organic components of municipal waste, residual sludge, crop straw, livestock and poultry manure, etc. Organic solid waste is rich in organic matter, easy to hydrolyze, contains a large amount of biomass energy, and is an important energy source in solid waste. At present, the treatment methods of organic solid waste are generally landfill, incineration, aerobic fermentation, anaerobic digestion, etc.

[0003] Anaerobic digestion refers to the process of decomposing organic matter into methane, carbon dioxide, inorganic nutrients and humus with the help of various microbial flora in an oxygen-deficient environment. Anaerobic digestion includes three stages: the first stage is the hydrolysis and acidification stage, in which macromolecular organic matter such as carbohydrates, proteins and fats are converted into monosaccharides, amino acids, fatty acids, glycerol, carbon dioxide, hydrogen, etc. through hydrolysis and fermentation by hydrolytic bacteria and fermentation bacteria (including hydrolytic and fermentation bacteria, protozoa and fungi); the second stage is the acid production stage, in which the products of the first stage except acetic acid, formic acid and methanol are converted into hydrogen, carbon dioxide and acetic acid under the action of hydrogen-producing and acetic acid-producing bacteria and homoacetic acid bacteria; the third stage is the methanogenesis stage, in which hydrogen and carbon dioxide are converted into methane through the action of two different groups of methanogens.

[0004] Anaerobic digestion technology can achieve resource utilization, reduction and high efficiency. However, traditional anaerobic technology has low methane production, low organic matter utilization efficiency and unstable operation. Utility Model Content

[0005] The utility model aims to overcome the shortcomings of the prior art and provide an anaerobic digestion device with high methane production.

[0006] In order to achieve the above-mentioned purpose, the technical solution of the utility model is: an anaerobic digestion device with high methane production, comprising an anaerobic reactor, wherein the lower end and the upper end of the side wall of the anaerobic reactor are respectively provided with a feed port and a discharge port, the top of the anaerobic reactor is provided with an exhaust port, and the upper end of the interior of the anaerobic reactor is provided with multiple layers of horizontally arranged electrodes, the electrodes are wire mesh filler electrodes, the electrodes include a positive electrode and a negative electrode, and the positive electrode and the negative electrode are connected to an external power supply through a wire.

[0007] Furthermore, the wire mesh filler electrode is a stainless steel wire mesh filler electrode.

[0008] Furthermore, four layers of horizontally arranged electrodes are provided at the upper end of the interior of the anaerobic reactor, wherein from top to bottom, the first layer of electrodes and the third layer of electrodes are connected to the first external power supply through wires, and the second layer of electrodes and the fourth layer of electrodes are connected to the second external power supply through wires.

[0009] Furthermore, the distance between two adjacent layers of horizontally arranged electrodes is 20-60 cm.

[0010] Furthermore, a stirrer is provided at the bottom of the anaerobic reactor.

[0011] Beneficial effects of the utility model:

[0012] (1) By setting up an electrolytic water device in the anaerobic reactor, the positive electrode produces oxygen, creating a micro-oxygen-consuming environment around the positive electrode, promoting hydrolytic bacteria to convert organic matter into low-molecular organic acids, providing substrates for methanogens, and promoting methane production; the negative electrode produces hydrogen, creating a hydrogen environment around the negative electrode, promoting hydrogenotrophic methanogens to use hydrogen and dissolved CO2 in the system to convert into methane, thereby achieving the purpose of reducing carbon dioxide and increasing methane yield.

[0013] (2) Use stainless steel wire mesh filler as electrode: (a) It can filter the sludge, increase the bottom sludge concentration, and promote anaerobic fermentation reaction; (b) It can provide a large surface area, which is conducive to the attachment and growth of microorganisms, as well as the mass transfer and reaction rate of substances in the electrolyte, thereby improving the efficiency of the electrode; (c) It has good corrosion resistance, which can extend the service life of the electrode, and is easy to clean and maintain, so that the electrode maintains good performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the structure of the utility model.

[0015] In the figure: 1, anaerobic reactor; 2, feed inlet; 3, agitator; 4, discharge port; 5, exhaust port; 6, first positive electrode; 7, second positive electrode; 8, first negative electrode; 9, second negative electrode; 10, first external power supply; 11, second external power supply. DETAILED DESCRIPTION

[0016] Example:

[0017] like Figure 1As shown, a high-yield methane anaerobic digestion device includes an anaerobic reactor 1, wherein the lower end and the upper end of the side wall of the anaerobic reactor 1 are respectively provided with a feed port 2 and a discharge port 4, and the top of the anaerobic reactor 1 is provided with an exhaust port 5. The upper end of the interior of the anaerobic reactor 1 is provided with four layers of horizontally arranged electrodes, and the distance between two adjacent layers of electrodes is 40 cm. The electrodes are stainless steel wire mesh filler electrodes. The four layers of electrodes are, from top to bottom, a first positive electrode 6, a second positive electrode 7, a first negative electrode 8, and a second negative electrode 9. The first positive electrode 6 and the first negative electrode 8 are connected to a first external power supply 10 through a wire, and the second positive electrode 7 and the second negative electrode 9 are connected to a second external power supply 11 through a wire. A stirrer 3 is provided at the bottom of the anaerobic reactor 1.

[0018] Electrochemical electrodes promote the production of methane from anaerobic sludge by using external current or the potential provided by the electrode to regulate the kinetic process of methane generation during anaerobic digestion, thereby enhancing the efficiency and total amount of methane production. Based on the integrated technology of energy, resource utilization and carbon emission reduction of organic solid wastes from anaerobic digestion, water electrolysis produces hydrogen and oxygen for subsequent processes, solving the problems of low methane production, low organic matter utilization efficiency and unstable operation of traditional anaerobic technology.

[0019] Electrolytic hydrogen and oxygen production technology refers to the reaction that occurs at the negative electrode when electricity is applied to the aqueous solution: 2H2O+2e - →H2+2OH- produces hydrogen, and reacts at the positive electrode: 2H2O→O2+4H + +4e- produces oxygen, and by turning the power on and off to adjust the oxygen content in the system, it achieves the purpose of regulating a series of microbial metabolism in aerobic digestion (including the metabolism of methanogens), and ultimately promotes the anaerobic digestion process of waste.

[0020] The utility model sets a stainless steel wire mesh filler as an electrode in the anaerobic reactor 1, which can filter the sludge in the anaerobic reactor 1, not only increasing the bottom sludge concentration and promoting the anaerobic fermentation reaction, but also attaching microorganisms. The wire mesh filler can provide a large surface area, which is conducive to the attachment and growth of microorganisms. Microorganisms attach to the wire mesh filler in the following ways: (a) Surface adsorption: Some microorganisms have some affinity groups on their cell surfaces, which can adsorb to the surface of the wire mesh filler, thereby achieving the attachment of microorganisms; (b) Bio-glue attachment: Some microorganisms can produce extracellular polymers to form bio-glue fixed on the surface of the wire mesh filler, thereby attaching to the electrode; (c) Spontaneous deposition: Under suitable environmental conditions, some microorganisms can spontaneously deposit on the surface of the wire mesh filler to form a biofilm, thereby completing the attachment process.

[0021] During operation, the time interval for the motor to be powered on can be selected according to the situation. After power is turned on, the positive electrode produces oxygen, and a micro-oxygen-consuming environment is generated around the positive electrode, which promotes hydrolytic bacteria to convert organic matter into low-molecular organic acids, provides substrates for methanogens, and promotes methane production; the negative electrode produces hydrogen, and a hydrogen environment is generated around the negative electrode, which promotes hydrogenotrophic methanogens to use hydrogen and dissolved CO2 in the system to convert into methane, thereby achieving the purpose of reducing carbon dioxide and increasing methane yield.

[0022] The above-described embodiments are only preferred solutions of the present invention and are not intended to limit the present invention in any form. Other variations and modifications are possible without exceeding the technical solutions described in the claims.

[0023] In the description of the present invention, it is necessary to understand that the terms indicating orientation or positional relationship are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

Claims

1. An anaerobic digestion device with high methane production, characterized in that: An anaerobic reactor is included, wherein the lower end and the upper end of the side wall of the anaerobic reactor are respectively provided with a feed port and a discharge port, the top of the anaerobic reactor is provided with an exhaust port, and the upper end of the interior of the anaerobic reactor is provided with multiple layers of horizontally arranged electrodes, the electrodes are wire mesh filler electrodes, the electrodes include a positive electrode and a negative electrode, and the positive electrode and the negative electrode are connected to an external power supply through a wire.

2. The high methane-producing anaerobic digestion device according to claim 1, characterized in that: The wire mesh filler electrode is a stainless steel wire mesh filler electrode.

3. The high methane-producing anaerobic digestion device according to claim 1, characterized in that: The upper end of the anaerobic reactor is provided with four layers of horizontally arranged electrodes, wherein from top to bottom, the first layer of electrodes and the third layer of electrodes are connected to the first external power supply through wires, and the second layer of electrodes and the fourth layer of electrodes are connected to the second external power supply through wires.

4. The high methane-producing anaerobic digestion device according to claim 1, characterized in that: The distance between two adjacent layers of horizontally arranged electrodes is 20-60 cm.

5. The high methane-producing anaerobic digestion device according to claim 1, characterized in that: A stirrer is arranged at the bottom of the anaerobic reactor.

Images