Circulating methane production device based on electro-catalysis anaerobic digestion reactor

Abstract

The utility model provides a circulating methane production device based on an electro-catalysis anaerobic digestion reactor. Comprising a control cabinet, an anaerobic fermentation tank, a feed port, a biogas outlet, an electrode anode, an electrode cathode, a controllable power supply, a pH value sensor, a temperature sensor, a discharge port, a control cabinet, a uniform gas inlet component, a circulating buffer gas bag, a three-way valve connector, a circulating gas pump, an electrochemical methane sensor, a gas collection pipeline, a gas collection piece, a gas collection control valve and a biogas flowmeter. According to the circulating methane production device, the circulating buffer gas bag and the electrochemical methane sensor are additionally arranged on the basis of an original electro-catalysis digestion reactor structure, methane with low methane content circularly returns to the anaerobic fermentation tank through the uniform gas inlet component to be fully and uniformly mixed and then is subjected to electro-catalysis, and the methane with low methane content is subjected to electro-catalysis again; the methane content of the produced methane is stably higher than 85%.

Description

TECHNICAL FIELD

[0001] The utility model relates to a kind of solid waste resource utilization technical field, specifically related to a kind of cyclic methane production device based on electrocatalytic anaerobic digestion reactor. BACKGROUND

[0002] Today's society is challenged by environmental pollution and energy shortage. According to relevant data, fossil fuels (coal, oil and natural gas) accounted for 84.7% of global primary energy consumption in 2018, while renewable energy accounted for only 4.0%. The overuse and huge consumption of fossil fuels such as coal and oil have caused serious environmental, social and economic problems, prompting a shift in energy use to less polluting, renewable, sustainable, and more efficient alternative fuels. Therefore, the use of renewable biomass resources to produce biofuels will be an important breakthrough in obtaining sustainable energy supply. Among them, the high-concentration organic waste anaerobic digestion methane production technology has been widely concerned due to its advantages of waste treatment, energy recovery and ecological benign cycle.

[0003] The utility model with the authorization announcement number CN 219861370 U in China discloses an electrocatalytic anaerobic digestion methane production system, which includes an anaerobic fermentation tank, an electric stirring rod, an electrode anode, an electrode cathode, a controllable power supply, a pH sensor, a temperature sensor, an inlet and outlet bottle, a rotary drive pump, a gas collection bag, a drying filter pipe, a biogas flowmeter, a cooling coil, a cooling water bottle, a cooling water pump, a heating pad and a control cabinet. The electrocatalytic anaerobic digestion methane production system can strengthen the activity and abundance of hydrogenophilic methanogens in the anaerobic system, ensure the smooth progress of hydrogen production and acetic acid production in the system, provide hydrogen ions or hydrogen gas for hydrogenophilic methanogens, significantly enhance the methane production efficiency, effectively balance the acidity of the anaerobic treatment system, and provide protection for the impact of external environmental factors on the anaerobic methane production system. However, there are still the following defects: first, during the early stage of digestion, the number of microbial communities is small and they have not fully adapted to the environment, resulting in low methane content in the biogas at this time. The system directly collects the biogas in the gas collection bag without upgrading, which affects the overall methane content of the biogas. Second, during the middle and late stages of digestion, the number of microbial communities is large and they have fully adapted to the environment, resulting in high methane content in the biogas. The system does not utilize this time to treat other gases with high carbon dioxide content, resulting in low utilization rate of the system. SUMMARY

[0004] In view of the deficiencies in the prior art, the utility model provides a cyclic methane production device based on electrocatalytic anaerobic digestion reactor to solve the problem of low methane content in biogas during the early stage of the existing methane production device.

[0005] To achieve the above purpose, the utility model adopts the technical scheme of:

[0006] The circulating methane production device based on the electro-catalytic anaerobic digestion reactor has the same structure as the prior art, and comprises an electro-catalytic anaerobic digestion reactor and a control cabinet, the electro-catalytic anaerobic digestion reactor comprises an anaerobic fermentation tank in the form of a hollow sealed cavity, a feed inlet and a biogas outlet are formed at the top of the anaerobic fermentation tank, an electrode anode and an electrode cathode are vertically arranged on the two sides in the anaerobic fermentation tank, the electrode anode and the electrode cathode are electrically connected with a controllable power supply located outside the anaerobic fermentation tank, a pH sensor and a temperature sensor are arranged in the inner cavity of the anaerobic fermentation tank, a discharge port is formed at the bottom end of the anaerobic fermentation tank, and the control cabinet is a control center of the whole production device and is provided with a data acquisition module, a control module and an upper computer; the difference is that a uniform gas inlet member is arranged in the inner cavity of the anaerobic fermentation tank, the uniform gas inlet member comprises a gas inlet main pipe which is hollow and located at the axial center of the anaerobic fermentation tank and extends from the top end of the anaerobic fermentation tank, the length of the gas inlet main pipe is greater than the length of the electrode anode and the electrode cathode, a plurality of gas inlet branch pipes are arranged on the gas inlet main pipe in parallel along the axial direction and form an acute angle with the gas inlet main pipe, a plurality of end gas inlet pipes are arranged at the bottom end of the gas inlet main pipe and are arranged perpendicularly to the gas inlet main pipe, the end gas inlet pipes and the gas inlet branch pipes are communicated with the inside of the gas inlet main pipe and are uniformly provided with gas distribution holes along the length direction, a stirring member is arranged at the bottom end of the inner cavity of the anaerobic fermentation tank, a circulating gas outlet is further formed at the top of the anaerobic fermentation tank, the circulating gas outlet is connected with a gas inlet port of a circulating buffer gas bag through a pipeline, an outlet of the circulating buffer gas bag is connected with a three-way valve through a pipeline, one end of the three-way valve is connected with a circulating gas pump through a pipeline, the circulating gas pump is connected with a gas inlet end of the gas inlet main pipe through a pipeline, an electrochemical methane sensor is arranged on the biogas outlet, and the biogas outlet is further connected with a gas collecting member through a gas collecting pipeline, a gas collecting control valve and a biogas flow meter are arranged on the gas collecting pipeline.

[0007] As a preferred technical scheme, in order to improve the utilization rate of the whole production device, at the same time, the waste gas with high carbon dioxide content can be treated, and the purpose of green energy saving and emission reduction is achieved, the other end of the three-way valve is connected with a to-be-treated gas bag through a standby pipeline, the to-be-treated gas bag contains waste gas containing carbon dioxide, and a gas flow meter is arranged on the standby pipeline.

[0008] Compared with the prior art, the utility model has the beneficial effect that:

[0009] 1、The circulating methane production device, on the basis of the original electro-catalytic digestion reactor structure, adds a circulating buffer gas bag and an electrochemical methane sensor, the biogas with low methane content is circulated back to the anaerobic fermentation tank through the uniform gas inlet member, is fully mixed and then is subjected to electro-catalysis again, the biogas with low methane content is subjected to electro-catalysis again, and the output biogas with methane content higher than 85% is realized.

[0010] 2. The production device is connected with the waste gas bag containing carbon dioxide, can treat the waste gas with high carbon dioxide content when the stable production in the production device, improve the utilization rate of the circulating production device, realize the purpose of energy saving and emission reduction. BRIEF DESCRIPTION OF DRAWINGS

[0011] The utility model will be further explained in detail in combination with the drawings and specific embodiments.

[0012] Figure 1 It is the structural diagram of the utility model;

[0013] Figure 2 It is the structural diagram of the stirring member;

[0014] Reference numeral: 1, anaerobic fermentation tank, 2, feed inlet, 3, biogas outlet, 4, electrode anode, 5, electrode cathode, 6, controllable power supply, 7, pH sensor, 8, temperature sensor, 9, uniform gas inlet member, 9-1, gas main pipe, 9-2, gas branch pipe, 9-3, end gas pipe, 9-4, diffuser, 10, stirring member, 11, circulating gas outlet, 12, circulating buffer gas bag, 13, three-way valve, 14, circulating gas pump, 15, electrochemical methane sensor, 16, gas collecting pipeline, 17, gas collecting member, 18, gas collecting control valve, 19, biogas flow meter, 20, gas bag to be treated, 21, gas flow meter, 22, discharge port. DETAILED DESCRIPTION

[0015] As Figure 1The utility model provides a specific embodiment shows a kind of methane production device of cyclic formula based on electrocatalytic anaerobic digestion reactor, and the same as existing structure is: including electrocatalytic anaerobic digestion reactor and control cabinet, the electrocatalytic anaerobic digester includes anaerobic fermentation tank 1 in hollow sealed cavity, the upper portion of anaerobic fermentation tank 1 is equipped with feed inlet 2 and marsh gas outlet 3, electrode anode 4 and electrode cathode 5 are vertically arranged in the both sides of anaerobic fermentation tank 1, electrode anode 4 and electrode cathode 5 are electrically connected with controllable power supply 6 located outside anaerobic fermentation tank 1, the effect of electrode anode 4 and electrode cathode 5 is to carry out electrocatalysis to the reaction process of organic waste, considering that anode is attached with relevant fermentation power bacteria, and provides electron for cathode, the electrode material required should have high specific area and biocompatibility, cathode is obtained electron and reduces CO2 to methane by attached methanogen, and the electrode material required has high conductivity and catalytic performance, also provides good attachment condition for microorganism, so carbon brush and foamed nickel are selected as electrode material of electrode anode 4 and electrode cathode 5 respectively, the inner chamber of anaerobic fermentation tank 1 is equipped with pH sensor 7 and temperature sensor 8, pH sensor 6 is used to detect the pH value in anaerobic fermentation tank 1, temperature sensor 7 is used to detect the temperature in anaerobic fermentation tank 1, the bottom end of anaerobic fermentation tank 1 is equipped with discharge port 22, the control cabinet is the control center of entire production device, and it is equipped with data acquisition module, control module and host computer in it;The difference is that: the inner chamber of anaerobic fermentation tank 1 is equipped with uniform air inlet component 9, the uniform air inlet component 9 includes air inlet main pipe 9-1 extending in the inner chamber from the top end of anaerobic fermentation tank 1 and being located at the axial center thereof, then air inlet main pipe 9-1 is arranged in parallel with electrode anode 4 and electrode cathode 5, the length of air inlet main pipe 9-1 is greater than the length of electrode anode 4 and electrode cathode 5, a plurality of air inlet branch pipes 9-2 are arranged in parallel along the axial direction of air inlet main pipe 9-1 and form acute angle with air inlet main pipe 9-1, in order to avoid air inlet branch pipe 9-2 and electrode anode 4 and electrode cathode 5 staggered, the present embodiment is arranged 45 ° angle between air inlet branch pipe 9-2 and air inlet main pipe 8-1, the bottom end of air inlet main pipe 9-1 is also equipped with a plurality of terminal air inlet pipes 9-3 arranged perpendicularly, the terminal air inlet pipe 9-3 and air inlet branch pipe 9-2 are communicated with the inside of air inlet main pipe 9-1 and are evenly equipped with air holes 9-4 along the length direction, as Figure 2As shown, the inner cavity bottom end of the anaerobic fermentation tank 1 is provided with a stirring member 10, the stirring member 10 is driven by a rotary drive pump located on the anaerobic fermentation tank 1, and the upper part of the anaerobic fermentation tank 1 is also provided with a circulating gas outlet 11, the circulating gas outlet 11 is connected with the gas inlet of a circulating buffer gas bag 12 through a pipeline, the outlet of the circulating buffer gas bag 12 is connected with a three-way valve 13 through a pipeline, one end of the three-way valve 13 is connected with a circulating gas pump 14 through a pipeline, the circulating gas pump 14 is connected with the gas inlet end of the gas inlet main pipe 9-1 through a pipeline, the biogas outlet 3 is provided with an electrochemical methane sensor 15, and the biogas outlet 3 is also connected with a gas collecting member 17 through a gas collecting pipeline, in order to facilitate the control of gas collection and ensure the purity of biogas, the gas collecting pipeline can filter out water vapor, hydrogen sulfide and other substances affecting biogas purification, the gas collecting pipeline is provided with a gas collecting control valve 18 and a biogas flow meter 19, in order to ensure that the temperature in the anaerobic fermentation tank 1 is at the optimum reaction temperature, the anaerobic fermentation tank 1 is connected with a heating member and a cooling member in this embodiment, the input end of the data acquisition module is connected with the controllable power supply 6, the pH value sensor 7, the temperature sensor 8, the biogas flow meter 19 and the electrochemical methane sensor 15, the output end of the data acquisition module is connected with the upper computer, the upper computer is connected with the input end of the control module, and the output end of the control module is connected with the stirring member 10, the controllable power supply 6, the rotary drive pump, the heating member and the cooling member in the anaerobic fermentation tank 1.

[0016] The other end of the three-way valve 13 is connected with a to-be-treated gas bag 20 through a standby pipeline, the to-be-treated gas bag 20 contains waste gas containing carbon dioxide, and the standby pipeline is provided with a gas flow meter 21, in the production device, during the later stable production, on the one hand, the utilization rate of the whole production device is improved, and on the other hand, waste gas with high carbon dioxide content can be treated, so that the purpose of green energy saving and emission reduction is realized.

[0017] When the utility model is used: the organic waste enters into the anaerobic fermentation tank 1 through the feed inlet 2, the upper computer starts the rotary drive pump to rotate and stir the organic waste through the control module, at the same time, the upper computer starts the controllable power supply 6 through the control module, the controllable power supply 6 carries out electrocatalysis to the organic waste reaction process through the electrode anode 4 and the electrode cathode 5 in the anaerobic fermentation tank 1, so as to further improve the reaction speed of the organic waste in the anaerobic fermentation tank 1, and effectively reduce the acid inhibition, the biogas outlet of the anaerobic fermentation tank 1 discharges the anaerobic fermentation tank 1, the discharged biogas is filtered to remove water vapor, hydrogen sulfide and other substances affecting biogas purification through the gas collecting pipe, and is sent into the gas collecting member 17.

[0018] During the whole reaction process: the controllable power supply 6 sends its voltage data into the host computer through the data acquisition module, and the host computer controls the voltage of the controllable power supply 6 according to the voltage data returned by the controllable power supply 6, so that the voltage between the electrode anode 4 and the electrode cathode 5 is at the set 0.6-2.0V voltage, and the controllable power supply 6 is used to give the voltage between the two electrodes, so as to domesticate the electroactive microorganism, thereby effectively improving the yield and stability of methane in the anaerobic digestion process. The pH sensor 7 sends the pH value in the anaerobic fermentation tank 1 into the host computer through the data acquisition module, and the host computer controls the stirring speed of the stirring member 10 and the voltage of the controllable power supply 6 according to the returned pH value, so as to maximize the reduction of fatty acid VFA inhibition and ammonia nitrogen inhibition in the anaerobic fermentation tank 1, so as to ensure the stability of the anaerobic digestion reaction of high-concentration organic waste. The biogas flow meter 19 sends the biogas generated by the anaerobic fermentation tank 1 into the host computer through the data acquisition module, so that the host computer can know the amount of biogas in the gas collecting member 17. The temperature sensor 8 sends the temperature in the anaerobic fermentation tank 1 into the host computer through the data acquisition module, and the host computer judges whether to start the cooling member or the heating member according to the returned temperature. The electrochemical methane sensor detects the methane content of the biogas in the anaerobic fermentation tank 1 in real time. When the monitoring value is lower than the set value, the biogas with low methane content generated in the anaerobic fermentation tank 1 enters the circulating gas buffer bag 12 through the circulating gas outlet, and the biogas generated by the organic waste in the anaerobic fermentation tank 1 returns to the anaerobic fermentation tank 1 through the uniform gas inlet member 9 for re-electrocatalysis; when the monitoring value is higher than the set value, the waste gas with high carbon dioxide content in the to-be-treated gas bag enters the anaerobic fermentation tank 1 for electrocatalysis through the three-way valve and the uniform gas inlet member in turn.

[0019] Of course, the above is only a detailed description of the preferred specific embodiments of the present application combined with the drawings, and is not intended to limit the scope of the present application. Any equivalent changes made in accordance with the principles, structure and structure of the present application shall be covered within the scope of the present application.

Claims

1. A circulating methane production device based on an electro-catalytic anaerobic digestion reactor, comprising an electro-catalytic anaerobic digestion reactor and a control cabinet, the electro-catalytic anaerobic digestion reactor comprising an anaerobic fermentation tank (1) in the form of a hollow sealed cavity, a feed inlet (2) and a biogas outlet (3) being formed at the upper portion of the anaerobic fermentation tank (1), an electrode anode (4) and an electrode cathode (5) being vertically arranged on both sides of the anaerobic fermentation tank (1), the electrode anode (4) and the electrode cathode (5) being electrically connected to a controllable power supply (6) located outside the anaerobic fermentation tank (1), a pH sensor (7) and a temperature sensor (8) being arranged in the inner cavity of the anaerobic fermentation tank (1), a discharge outlet (22) being formed at the bottom end of the anaerobic fermentation tank (1), and the control cabinet being the control center of the entire production device and comprising a data acquisition module, a control module and an upper computer; characterized in that: The inner cavity of the anaerobic fermentation tank (1) is provided with a uniform gas inlet member, the uniform gas inlet member (9) comprises a gas inlet main pipe (9-1) extending in the inner cavity of the anaerobic fermentation tank (1) from the top end and located at the axial center, the length of the gas inlet main pipe (9-1) is greater than the length of the electrode anode (4) and the electrode cathode (5), a plurality of gas inlet branch pipes (9-2) are provided on the gas inlet main pipe (9-1) in parallel along the axial direction and form an acute angle with the gas inlet main pipe (9-1), the bottom end of the gas inlet main pipe (9-1) is further provided with a plurality of terminal gas inlet pipes (9-3) arranged perpendicularly, the terminal gas inlet pipes (9-3) and the gas inlet branch pipes (9-2) are both communicated with the inner cavity of the gas inlet main pipe (9-1) and are uniformly provided with gas distribution holes (9-4) along the length direction, the inner cavity of the anaerobic fermentation tank (1) is provided with a stirring member (10) at the bottom end, the upper part of the anaerobic fermentation tank (1) is further provided with a circulating gas outlet (11), the circulating gas outlet (11) is connected with the gas inlet port of a circulating buffer gas bag (12) through a pipeline, the outlet of the circulating buffer gas bag (12) is connected with a three-way valve (13) through a pipeline, one end of the three-way valve (13) is connected with a circulating gas pump (14) through a pipeline, the circulating gas pump (14) is connected with the gas inlet end of the gas inlet main pipe (9-1) through a pipeline, an electrochemical methane sensor (15) is arranged on the biogas outlet (3), the biogas outlet (3) is further connected with a gas collecting member (17) through a gas collecting pipeline (16), a gas collecting control valve (18) and a biogas flow meter (19) are arranged on the gas collecting pipeline (16).

2. The cyclic methane production apparatus based on an electrocatalytic anaerobic digestion reactor according to claim 1, characterized in that: The other end of the three-way valve (13) is connected with a to-be-treated gas bag (20) through a standby pipeline, the to-be-treated gas bag (20) contains waste gas containing carbon dioxide, and a gas flow meter (21) is arranged on the standby pipeline.

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