Segmented anaerobic-aerobic combined reaction device system and application thereof

Abstract

The invention provides a segmented anaerobic-aerobic combined reaction device system and application thereof. The device system comprises an acidification hydrolysis fermentation unit, a solid-liquid separation unit, an anaerobic methanogenesis fermentation unit and an aerobic fermentation unit, wherein the acidification hydrolysis fermentation unit, the solid-liquid separation unit and the anaerobic methanogenesis fermentation unit are sequentially connected through pipelines; the aerobic fermentation unit is connected to a slag outlet of the solid-liquid separation unit through a conveying belt. The device system provided by the invention has the functions of anaerobic fermentation and aerobic fermentation, is particularly suitable for resourceful treatment of blue-green algae and reed straws, and performs resourceful treatment of the blue-green algae straws by combining the physicochemical properties of the blue-green algae and reed straws, the characteristic of methane production by anaerobic fermentation and the advantage of aerobic fermentation after dehydration of biogas residues; the efficient reutilization of blue-green algae and reed straws is realized, the treatment efficiency and the gas production rate are improved, and the stable operation of the system is ensured.

Description

Technical Field

[0001] The invention belongs to the technical field of chemical equipment, and relates to a segmented anaerobic aerobic combined reactor, in particular to a segmented anaerobic aerobic combined reaction device system and application thereof. Background Art

[0002] In recent years, with the intensification of eutrophication in some lakes in China and the advancement of lake management projects, the amount of blue algae salvaged and the amount of aquatic plants harvested have increased year by year. Blue algae not only cause water quality deterioration and damage the aquatic ecosystem, but most blue algae also release algal toxins that threaten the safety of daily drinking water in cities and public health. Aquatic plants (such as reed straw) harvested regularly by lake projects will also cause secondary pollution to the environment and waste of resources if they are not handled in time.

[0003] Accelerating the centralized treatment of blue algae and the resource utilization of aquatic plants can not only solve the problem of energy shortage, but also avoid environmental pollution, and has broad development and application prospects. As a renewable energy source, biogas not only realizes the resource utilization of organic waste, but also avoids environmental pollution, and has received widespread attention at home and abroad.

[0004] However, the use of traditional anaerobic fermentation equipment to treat blue algae and reed straw is prone to unstable gas production and low efficiency at low temperatures. There are also problems such as high warming costs, incomplete sludge disposal, ammonia inhibition and accumulation of propionic acid that can lead to unstable operation of the system. Moreover, this anaerobic fermentation equipment is not suitable for aerobic fermentation, has relatively simple functions, and still has much room for improvement.

[0005] It can be seen that how to provide an anaerobic aerobic combined reaction device system that is particularly suitable for the resource processing of cyanobacteria and reed straw, combining the physical and chemical properties of cyanobacteria and reed straw, the characteristics of anaerobic fermentation to produce methane, and the advantages of aerobic fermentation after dehydration of sludge to carry out resource processing of cyanobacteria straw, achieve efficient reuse of cyanobacteria and reed straw, improve processing efficiency and gas production rate, and ensure stable operation of the system has become a problem that technical personnel in this field urgently need to solve. Summary of the invention

[0006] The object of the present invention is to provide a device system for a segmented anaerobic-aerobic combined reaction and an application thereof. The device system takes into account the functions of anaerobic fermentation and aerobic fermentation, and is particularly suitable for the resource treatment of cyanobacteria and reed straw. The cyanobacteria straw is treated as a resource by combining the physical and chemical properties of cyanobacteria and reed straw, the characteristics of anaerobic fermentation to produce methane, and the advantages of aerobic fermentation after dehydration of biogas residue, thereby achieving efficient reuse of cyanobacteria and reed straw, improving treatment efficiency and gas production rate, and ensuring stable operation of the system.

[0007] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0008] In a first aspect, the present invention provides a staged anaerobic-aerobic combined reaction device system, the device system comprising an acidification hydrolysis fermentation unit, a solid-liquid separation unit, an anaerobic methanogenic fermentation unit and an aerobic fermentation unit.

[0009] The acidification hydrolysis fermentation unit, the solid-liquid separation unit and the anaerobic methanogenic fermentation unit are connected in sequence through pipelines; and the aerobic fermentation unit is connected to the slag outlet of the solid-liquid separation unit through a conveyor belt.

[0010] The device system provided by the present invention has an anaerobic methanogenic fermentation unit and an aerobic fermentation unit, thereby taking into account the functions of anaerobic fermentation and aerobic fermentation; wherein, the anaerobic methanogenic fermentation unit can make full use of the methane gas produced by anaerobic fermentation, while reducing the emission of greenhouse gases, and has the dual advantages of environmental protection and economic benefits; the aerobic fermentation unit can promote the aerobic decomposition and mineralization of organic matter, and finally obtain high-quality organic fertilizer products, thereby improving the efficiency and value of resource utilization. At the same time, the solid-liquid separation unit can effectively separate the biogas residue and biogas liquid, which is convenient for subsequent further processing and resource utilization.

[0011] It can be seen that the device system provided by the present invention is particularly suitable for the resource processing of cyanobacteria and reed straw. The cyanobacteria straw is processed for resource processing by combining the physical and chemical properties of cyanobacteria and reed straw, the characteristics of anaerobic fermentation to produce methane, and the advantages of aerobic fermentation after dehydration of sludge, thereby achieving efficient recycling of cyanobacteria and reed straw, improving the processing efficiency and gas production rate, and ensuring the stable operation of the system.

[0012] Preferably, the acidification hydrolysis and fermentation unit comprises an acidification hydrolysis and fermentation tank.

[0013] Preferably, the height-to-diameter ratio of the acidification hydrolysis fermentation tank is (2-2.5):1, for example, it can be 2:1, 2.1:1, 2.2:1, 2.3:1, 2.4:1 or 2.5:1, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0014] Preferably, the tank body and the tank cover of the acidification and hydrolysis fermentation tank are connected by threads.

[0015] Preferably, an exhaust port is provided on the edge of the tank cover of the acidification and hydrolysis fermentation tank.

[0016] Preferably, a variable-speed agitator is disposed in the center of the tank cover of the acidification and hydrolysis fermentation tank, and the agitator rod and blades of the agitator are located in the center of the tank body.

[0017] Preferably, a feed inlet is provided at the upper portion of the tank body of the acidification and hydrolysis fermentation tank.

[0018] Preferably, a sampling port is provided at the lower part of the tank body of the acidification and hydrolysis fermentation tank.

[0019] Preferably, the bottom of the acidification and hydrolysis fermentation tank is conical, and a discharge port is provided at the bottom.

[0020] Preferably, the outer wall of the acidification and hydrolysis fermentation tank is provided with a heating layer and a heat preservation layer in sequence from the inside to the outside.

[0021] Preferably, an isolation net is provided inside the solid-liquid separation unit.

[0022] Preferably, the pipeline access port between the acidification and hydrolysis fermentation unit and the solid-liquid separation unit is located at the lower part of the isolation net.

[0023] Preferably, the pipeline access port between the solid-liquid separation unit and the anaerobic methanogenic fermentation unit is located at the upper part of the isolation net.

[0024] Preferably, the pipeline between the acidification hydrolysis fermentation unit and the solid-liquid separation unit and the pipeline between the solid-liquid separation unit and the anaerobic methanogenesis fermentation unit are independently provided with valves.

[0025] Preferably, a one-way exhaust hole is provided on the top of the solid-liquid separation unit.

[0026] Preferably, the bottom of the solid-liquid separation unit is conical, and a slag outlet is provided at the bottom.

[0027] Preferably, the anaerobic methanogenic fermentation unit comprises an anaerobic methanogenic fermentation tank.

[0028] Preferably, the height-to-diameter ratio of the anaerobic methanogenic fermentation tank is (3.5-4):1, for example, it can be 3.5:1, 3.6:1, 3.7:1, 3.8:1, 3.9:1 or 4:1, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0029] Preferably, the tank body and the tank cover of the anaerobic methanogenic fermentation tank are connected via a flange.

[0030] Preferably, a methane collecting port is provided on the edge of the tank cover of the anaerobic methanogenic fermentation tank.

[0031] Preferably, a variable-speed agitator is disposed in the center of the tank cover of the anaerobic methanogenic fermentation tank, and the agitator rod and blades of the agitator are located in the center of the tank body.

[0032] Preferably, the bottom of the anaerobic methanogenic fermentation tank is conical, and a liquid outlet is provided at the bottom.

[0033] Preferably, the outer wall of the tank body of the anaerobic methanogenic fermentation tank is provided with a heating layer and a heat preservation layer in sequence from the inside to the outside.

[0034] Preferably, the aerobic fermentation unit comprises a horizontal aerobic fermentation tank.

[0035] Preferably, a feed hopper is provided on the top of the horizontal aerobic fermentation tank, and the feed hopper is connected to the slag outlet of the solid-liquid separation unit through a conveyor belt.

[0036] Preferably, a variable-speed agitator is provided at the side end of the horizontal aerobic fermentation tank, and the agitator rod and blades of the agitator are located in the center of the tank body.

[0037] In the present invention, variable-speed agitators are independently arranged at the center of the tank cover of the acidification hydrolysis fermentation tank, the center of the tank cover of the anaerobic methanogenesis fermentation tank, and the side end of the horizontal aerobic fermentation tank, and the stirring rod and blades of the agitator are located in the center of the tank body, so that the stirring speed can be adjusted according to the different stages and characteristics of the materials during the reaction process, thereby significantly improving the reaction efficiency and effect.

[0038] In a second aspect, the present invention provides an application of the device system as described in the first aspect, wherein the device system is used for resource processing of blue algae and reed straw.

[0039] Preferably, in the resource recovery process, the inoculated bacterial liquid added to the acidification and hydrolysis fermentation unit is the bacterial liquid obtained by culturing and enriching the anaerobic fermentation liquid with an aerobic acid-producing bacteria culture medium, an anaerobic acid-producing bacteria culture medium and an anaerobic cellulose-degrading bacteria culture medium, and the bacterial liquid added to the anaerobic methanogenic fermentation unit is the bacterial liquid obtained by culturing and enriching the anaerobic fermentation liquid with a methanogenic culture medium.

[0040] The numerical range described in the present invention not only includes the point values ​​listed above, but also includes any point values ​​between the above numerical ranges that are not listed. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0041] Compared with the prior art, the present invention has the following beneficial effects:

[0042] (1) The device system provided by the present invention has an anaerobic methanogenic fermentation unit and an aerobic fermentation unit, thereby taking into account the functions of anaerobic fermentation and aerobic fermentation; wherein, the anaerobic methanogenic fermentation unit can make full use of the methane gas produced by anaerobic fermentation, while reducing the emission of greenhouse gases, and has the dual advantages of environmental protection and economic benefits; the aerobic fermentation unit can promote the aerobic decomposition and mineralization of organic matter, and finally obtain high-quality organic fertilizer products, thereby improving the efficiency and value of resource utilization; at the same time, the solid-liquid separation unit can effectively separate the biogas residue and the biogas liquid, which is convenient for subsequent further processing and resource utilization.

[0043] (2) The device system provided by the present invention is particularly suitable for the resource processing of cyanobacteria and reed straw. The cyanobacteria straw is processed for resource processing by combining the physical and chemical properties of cyanobacteria and reed straw, the characteristics of anaerobic fermentation to produce methane, and the advantages of aerobic fermentation after dehydration of sludge. This realizes the efficient recycling of cyanobacteria and reed straw, improves the processing efficiency and gas production rate, and ensures the stable operation of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 It is a schematic diagram of the structure of the device system of the segmented anaerobic and aerobic combined reaction provided by the present invention.

[0045] Among them: 10-acidification and hydrolysis fermentation tank; 11-exhaust port; 12-feed port; 13-sampling port; 14-discharge port; 20-solid-liquid separation tank; 21-isolation net; 22-one-way exhaust hole; 23-slag outlet; 30-anaerobic methanogenic fermentation tank; 31-methane collection port; 32-liquid outlet; 40-horizontal aerobic fermentation tank; 41-feed hopper; 50-conveyor belt; 60-variable speed agitator; 70-heating layer; 80-insulation layer; 90-valve. DETAILED DESCRIPTION

[0046] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0047] Example 1

[0048] This embodiment provides a device system for a staged anaerobic and aerobic combined reaction, such as Figure 1 As shown, the device system includes an acidification and hydrolysis fermentation tank 10, a solid-liquid separation tank 20, an anaerobic methanogenic fermentation tank 30 and a horizontal aerobic fermentation tank 40. The acidification and hydrolysis fermentation tank 10, the solid-liquid separation tank 20 and the anaerobic methanogenic fermentation tank 30 are sequentially connected through pipelines; the horizontal aerobic fermentation tank 40 is connected to the slag outlet 23 of the solid-liquid separation tank 20 through a conveyor belt 50.

[0049] In this embodiment, the height-to-diameter ratio of the acidification and hydrolysis fermentation tank 10 is 2.2:1, and the tank body and the tank cover are connected by threads; an exhaust port 11 is provided on the edge of the tank cover, a variable-speed agitator 60 is provided in the center of the tank cover, and the stirring rod and blades of the agitator are located in the center of the tank body; a feed port 12 is provided on the upper part of the tank body, a sampling port 13 is provided on the lower part of the tank body, the bottom is conical, and a discharge port 14 is provided at the bottom; a heating layer 70 and a heat-insulating layer 80 are provided on the outer wall of the tank from the inside to the outside.

[0050] In this embodiment, an isolation net 21 is provided inside the solid-liquid separation tank 20; the pipeline access port between the acidification hydrolysis fermentation tank 10 and the solid-liquid separation tank 20 is located at the lower part of the isolation net 21, and the pipeline access port between the solid-liquid separation tank 20 and the anaerobic methanogenic fermentation tank 30 is located at the upper part of the isolation net 21; the pipeline between the acidification hydrolysis fermentation tank 10 and the solid-liquid separation tank 20 and the pipeline between the solid-liquid separation tank 20 and the anaerobic methanogenic fermentation tank 30 are respectively and independently provided with valves 90; the top of the solid-liquid separation tank 20 is provided with a one-way exhaust hole 22, the bottom is conical, and a slag outlet 23 is provided at the bottom.

[0051] In this embodiment, the height-to-diameter ratio of the anaerobic methanogenic fermentation tank 30 is 3.6:1, and the tank body and the tank cover are connected by a flange; a methane collecting port 31 is provided on the edge of the tank cover, a variable-speed agitator 60 is provided in the center of the tank cover, and the agitator rod and blades of the agitator are located in the center of the tank body; the bottom is conical, and a liquid outlet 32 ​​is provided at the bottom; a heating layer 70 and a heat-insulating layer 80 are provided on the outer wall of the tank from the inside to the outside.

[0052] In this embodiment, a feed hopper 41 is provided on the top of the horizontal aerobic fermentation tank 40, and the feed hopper 41 is connected to the slag outlet 23 of the solid-liquid separation tank 20 through a conveyor belt 50; a variable-speed agitator 60 is provided on the side end of the horizontal aerobic fermentation tank 40, and the agitator rod and blades of the agitator are located in the center of the tank body.

[0053] In this embodiment, the acidification and hydrolysis fermentation tank 10, the solid-liquid separation tank 20, the anaerobic methanogenic fermentation tank 30 and the horizontal aerobic fermentation tank 40 are all made of corrosion-resistant stainless steel.

[0054] Example 2

[0055] This embodiment provides a device system for a staged anaerobic-aerobic combined reaction. Except that the height-to-diameter ratio of the acidification and hydrolysis fermentation tank 10 is changed to 2:1, and the height-to-diameter ratio of the anaerobic methanogenic fermentation tank 30 is changed to 3.5:1, the remaining structures and conditions are the same as those in Embodiment 1, and thus will not be described in detail herein.

[0056] Example 3

[0057] This embodiment provides a device system for a staged anaerobic-aerobic combined reaction. Except that the height-to-diameter ratio of the acidification and hydrolysis fermentation tank 10 is changed to 2.5:1, and the height-to-diameter ratio of the anaerobic methanogenic fermentation tank 30 is changed to 4:1, the remaining structures and conditions are the same as those in Embodiment 1, and thus will not be described in detail here.

[0058] Application Example 1

[0059] This application example uses the device system provided in Example 1 to process blue algae and reed straw, which specifically includes the following steps:

[0060] (1) mixing dehydrated blue algae with a moisture content of 85% with crushed reed straw, and then adding water to adjust the moisture content of the mixture to 90%;

[0061] (2) pumping the mixture into the acid hydrolysis fermentation tank 10, controlling the pumping volume to be 80% of the tank volume, adding the inoculated bacterial solution, introducing nitrogen into the tank for 1 hour, and closing all valves 90 to carry out acid hydrolysis fermentation;

[0062] (3) When the pH value of the fermented material in step (2) is lower than 6.5 and the volume content of acetic acid reaches more than 70%, the valve 90 and the exhaust port 11 are opened, and the biogas slurry in the acidified hydrolysis fermentation tank 10 enters the solid-liquid separation tank 20 through the pipeline, and the biogas slurry separated by the isolation net 21 enters the anaerobic methanogenic fermentation tank 30, and the bacterial liquid is added and nitrogen is introduced for 1 hour to carry out methanogenic fermentation;

[0063] (4) The separated biogas residue falls into the conveyor belt 50 through the residue outlet 23 and is then conveyed to the horizontal aerobic fermentation tank 40, where aerobic fermentation bacteria are added to perform aerobic fermentation;

[0064] (5) The methane produced is collected through the methane collecting port 31, and the finished organic fertilizer is collected through the horizontal aerobic fermentation tank 40.

[0065] Among them, the inoculated bacterial liquid in step (2) is the bacterial liquid obtained by culturing and enriching the anaerobic fermentation liquid with an aerobic acid-producing bacteria culture medium, an anaerobic acid-producing bacteria culture medium and an anaerobic cellulose-degrading bacteria culture medium; the bacterial liquid in step (3) is the bacterial liquid obtained by culturing and enriching the anaerobic fermentation liquid with a methanogenic culture medium.

[0066] Application Example 2

[0067] This application example uses the device system provided in Example 2 to process blue algae and reed straw for resource recovery. The specific steps are the same as those in Application Example 1, so they will not be repeated here.

[0068] Application Example 3

[0069] This application example uses the device system provided in Example 3 to process blue algae and reed straw for resource recovery. The specific steps are the same as those in Application Example 1, so they will not be repeated here.

[0070] The results showed that the resource recovery treatment provided by Application Examples 1-3 was fermented continuously for 10 days with a stable operation status, and finally achieved full fermentation of cyanobacteria and reed straw, converting low value-added biomass into high value-added methane gas and finished organic fertilizer.

[0071] It can be seen that the device system provided by the present invention has an anaerobic methanogenic fermentation unit and an aerobic fermentation unit, thereby taking into account the functions of anaerobic fermentation and aerobic fermentation; wherein, the anaerobic methanogenic fermentation unit can make full use of the methane gas produced by anaerobic fermentation, while reducing the emission of greenhouse gases, and has the dual advantages of environmental protection and economic benefits; the aerobic fermentation unit can promote the aerobic decomposition and mineralization of organic matter, and finally obtain high-quality organic fertilizer products, thereby improving the efficiency and value of resource utilization; at the same time, the solid-liquid separation unit can effectively separate the sludge and the liquid biogas, which is convenient for subsequent further processing and resource utilization.

[0072] In addition, the device system provided by the present invention is particularly suitable for the resource processing of cyanobacteria and reed straw. The cyanobacteria straw is processed for resource processing by combining the physical and chemical properties of cyanobacteria and reed straw, the characteristics of anaerobic fermentation to produce methane, and the advantages of aerobic fermentation after dehydration of sludge, thereby achieving efficient recycling of cyanobacteria and reed straw, improving processing efficiency and gas production rate, and ensuring stable operation of the system.

[0073] The applicant declares that the above is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention shall fall within the protection scope and disclosure scope of the present invention.

Claims

1. A device system for staged anaerobic and aerobic combined reaction, characterized in that: The device system includes an acidification hydrolysis fermentation unit, a solid-liquid separation unit, an anaerobic methanogenic fermentation unit and an aerobic fermentation unit; The acidification hydrolysis fermentation unit, the solid-liquid separation unit and the anaerobic methanogenic fermentation unit are connected in sequence through pipelines; and the aerobic fermentation unit is connected to the slag outlet of the solid-liquid separation unit through a conveyor belt.

2. The device system according to claim 1, characterized in that: The acidification hydrolysis and fermentation unit comprises an acidification hydrolysis and fermentation tank; Preferably, the height-to-diameter ratio of the acidification and hydrolysis fermentation tank is (2-2.5):1; Preferably, the tank body and the tank cover of the acidification and hydrolysis fermentation tank are connected by threads; Preferably, the edge of the tank cover of the acidification and hydrolysis fermentation tank is provided with an exhaust port; Preferably, a variable-speed agitator is disposed in the center of the tank cover of the acidification and hydrolysis fermentation tank, and the agitator rod and blades of the agitator are located in the center of the tank body.

3. The device system according to claim 2, characterized in that: The upper part of the tank body of the acidification and hydrolysis fermentation tank is provided with a feed inlet; Preferably, a sampling port is provided at the lower part of the tank body of the acidification and hydrolysis fermentation tank; Preferably, the bottom of the acidification and hydrolysis fermentation tank is conical, and a discharge port is provided at the bottom; Preferably, the outer wall of the acidification and hydrolysis fermentation tank is provided with a heating layer and a heat preservation layer in sequence from the inside to the outside.

4. The device system according to any one of claims 1 to 3, characterized in that: An isolation net is provided inside the solid-liquid separation unit; Preferably, the pipeline access port between the acidification hydrolysis fermentation unit and the solid-liquid separation unit is located at the lower part of the isolation net; Preferably, the pipeline access port between the solid-liquid separation unit and the anaerobic methanogenic fermentation unit is located at the upper part of the isolation net; Preferably, the pipeline between the acidification hydrolysis fermentation unit and the solid-liquid separation unit and the pipeline between the solid-liquid separation unit and the anaerobic methanogenesis fermentation unit are independently provided with valves.

5. The device system according to any one of claims 1 to 4, characterized in that: A one-way exhaust hole is provided on the top of the solid-liquid separation unit; Preferably, the bottom of the solid-liquid separation unit is conical, and a slag outlet is provided at the bottom.

6. The device system according to any one of claims 1 to 5, characterized in that: The anaerobic methanogenic fermentation unit comprises an anaerobic methanogenic fermentation tank; Preferably, the height-to-diameter ratio of the anaerobic methanogenic fermentation tank is (3.5-4):1; Preferably, the tank body and the tank cover of the anaerobic methanogenic fermentation tank are connected via a flange; Preferably, a methane collecting port is provided on the edge of the tank cover of the anaerobic methanogenic fermentation tank; Preferably, a variable-speed agitator is disposed in the center of the tank cover of the anaerobic methanogenic fermentation tank, and the agitator rod and blades of the agitator are located in the center of the tank body.

7. The device system according to claim 6, characterized in that: The bottom of the anaerobic methanogenic fermentation tank is conical, and a liquid outlet is provided at the bottom; Preferably, the outer wall of the tank body of the anaerobic methanogenic fermentation tank is provided with a heating layer and a heat preservation layer in sequence from the inside to the outside.

8. The device system according to any one of claims 1 to 7, characterized in that: The aerobic fermentation unit comprises a horizontal aerobic fermentation tank; Preferably, a feed hopper is provided on the top of the horizontal aerobic fermentation tank, and the feed hopper is connected to the slag outlet of the solid-liquid separation unit through a conveyor belt; Preferably, a variable-speed agitator is provided at the side end of the horizontal aerobic fermentation tank, and the agitator rod and blades of the agitator are located in the center of the tank body.

9. An application of the device system according to any one of claims 1 to 8, characterized in that: The device system is used for resource processing of blue algae and reed straw.

10. The use according to claim 9, characterized in that:In the resource recovery process, the inoculated bacterial liquid added to the acidification hydrolysis fermentation unit is the bacterial liquid obtained by culturing and enriching the anaerobic fermentation liquid with an aerobic acid-producing bacteria culture medium, an anaerobic acid-producing bacteria culture medium and an anaerobic cellulose-degrading bacteria culture medium, and the bacterial liquid added to the anaerobic methanogenic fermentation unit is the bacterial liquid obtained by culturing and enriching the anaerobic fermentation liquid with a methanogenic culture medium.

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