Stacking dry type straw biogas fermentation system

Abstract

The utility model belongs to the field of straw fermentation, and discloses a stacking dry type straw biogas fermentation system which comprises a greenhouse, a biogas storage device, a semi-dry type biogas digester and a dry type fermentation tank, the semi-dry type biogas digester and the dry type fermentation tank are both arranged in the greenhouse, and the semi-dry type biogas digester is communicated with the dry type fermentation tank through a material conveying device. The semi-dry biogas digester is used for culturing straw biogas strains; the dry fermentation tank comprises a sealing film, a pressing piece and a fastening piece, wherein the sealing film covers the ground so as to form a closed space for accommodating a plurality of bundles of inoculated straws with the ground. According to the utility model, the semi-dry biogas digester and the dry fermentation tank are jointly used for culturing strains and treating straws, so that the utilization rate of the straws is improved, the cost is reduced, balanced gas production is ensured, and meanwhile, the defects that diseases and pests spread, the growth of crops in season is influenced and methane gas is generated due to the fact that the straws are directly crushed and returned to the field in the field are overcome.

Description

Technical Field

[0001] The utility model belongs to the technical field of straw fermentation, and in particular relates to a stacked dry straw biogas fermentation system. Background Art

[0002] my country is one of the world's largest agricultural producers, and crop production plays a crucial role in this sector. The crop industry produces approximately 700 million tons of crop straw annually, of which approximately 50% is not effectively processed and utilized. This not only wastes resources, but also leads to serious pests and diseases and reduces the quality of agricultural products due to the crushing and return of large amounts of straw to the fields. The processing and utilization of straw is one of the major resource and environmental issues facing my country's new rural development, necessitating the urgent need to find new ways to utilize it.

[0003] (1) Domestic Straw Processing Technology. For many years, straw gasification has been a key approach to repurposing straw as a resource. Xuzhou was the first city in the province to promote straw gasification. Since 1998, over ten straw gasification stations have been established in Yangtun, Peixian County; Huangdun, Xinyi County; Bayiji, Pizhou City; Sunzhuang, Tongshan County; Qingshanquan, Jiawang County; and Daquan County. However, these stations face several challenges: first, high construction costs; second, high tar content and low calorific value; and third, the vast majority of these stations utilize wood, branches, and other materials to generate gas, rather than straw. This in turn fails to address the issue of straw burning in rural areas.

[0004] Every summer and autumn, most areas of our province resort to crushing straw and returning it directly to the fields, leading to serious pest and disease problems. In the past, pesticides cost 30-40 yuan per mu (approximately $10-$20 per acre), but now double the amount is needed to control pests and diseases. This has led to increasingly serious food safety and pesticide residue issues.

[0005] To address these challenges, experts conducted multiple in-depth investigations in biogas demonstration villages and discovered that straw-based solar biogas digesters require shredding straw to 3-5 centimeters before pumping it into the digester for fermentation. Due to the low efficiency, high cost, and poor working environment of straw shredding, many biogas demonstration villages are reluctant to use straw, opting instead for livestock and poultry manure as a biogas fermentation feedstock, severely limiting the amount of straw that can be processed.

[0006] (2) Foreign Straw Processing Technology. The issue of straw utilization is not only a major problem in my country but also exists abroad. After more than a decade of practice and development, Germany's biogas industry has achieved a mature level of technology and equipment for agricultural waste biogas projects, placing it at the forefront of the world. However, Germany's dry straw fermentation technology also requires pulverizing the straw before pumping it into the biogas digester to produce biogas.

[0007] The dry straw biogas fermentation technology used in countries like Finland is a batch dry fermentation process. This involves spreading whole bales of straw into fermentation tanks to produce biogas. While the straw does not need to be crushed, this technology still requires the construction of large, separate fermentation tanks. Furthermore, the spread of whole bales of straw cannot be compacted, increasing their volume by more than 1.5 times. Furthermore, each addition requires the purchase of bacterial strains, resulting in high investment costs and inconvenient loading and unloading. Finally, the frequent watering of the tank after biogas production is inconvenient.

[0008] Therefore, there is a need for a straw biogas fermentation system that is easy to operate, has low straw processing cost, low straw utilization rate, and good processing effect. Utility Model Content

[0009] In view of this, the purpose of the present invention is to provide a stacked dry straw biogas fermentation system to solve the problems of high cost and low straw utilization rate of existing straw fermentation systems.

[0010] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0011] A stacked dry straw biogas fermentation system comprises a greenhouse, a biogas storage device, and a semi-dry biogas tank and a dry fermentation tank both located in the greenhouse. The semi-dry biogas tank is connected to the dry fermentation tank via a feeding device, and the semi-dry biogas tank is used to cultivate straw biogas bacteria.

[0012] The dry fermentation tank includes a sealing film, a holding member, and a fastener. The sealing film covers the ground to form a closed space for accommodating a plurality of bundles of inoculated straw. The periphery of the sealing film that contacts the ground is held by the holding member on the outside of the sealing film. The periphery of the sealing film is fixed to the ground by a plurality of fasteners.

[0013] The sealing film is connected to a biogas storage device.

[0014] In a possible implementation, the sealing film is spherical or square and covers the bundles of inoculated straw stacked in a closed space.

[0015] In a possible implementation, a plurality of dry fermentation tanks are provided, and the semi-dry biogas tank is connected in parallel and in communication with the plurality of dry fermentation tanks via a feeding device.

[0016] In a possible implementation, the sealing membrane is provided with a water inlet hole, the water inlet hole is connected to a water inlet pipe, and the water inlet pipe is connected to a water pool through a water pump.

[0017] In a possible implementation, it further includes a bacteria seed storage pool located in the greenhouse, and the bacteria seed storage is connected to the semi-dry biogas tank via a first pumping device.

[0018] In a possible implementation, a biogas exhaust connector is provided on the sealing membrane, and the biogas exhaust connector has exhaust channel one and exhaust channel two. The exhaust channel one is provided with valve one and is connected to the biogas storage device through a pipeline, and the exhaust channel two is provided with valve two and is connected to a biogas stove through a pipeline.

[0019] In a possible implementation, the biogas dehydrator is further provided on the pipeline between the exhaust channel 1 and the biogas storage device.

[0020] In a possible implementation, the semi-dry biogas tank includes a sealed tank body arranged on a reinforced concrete foundation in a greenhouse, the sealed tank body is provided with a safety manhole, a feed pipe, a discharge pipe and an outlet pipe, the outlet pipe is connected to the biogas dehydrator, and a mixer is provided in the sealed tank body.

[0021] In a possible implementation, the feeding device includes a semi-dry feeding pump; and / or the greenhouse is a solar greenhouse.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] The stacked dry straw biogas fermentation system of the present invention is equipped with a greenhouse, a semi-dry biogas tank and a dry fermentation tank. The dry fermentation tank can use the bacteria cultured in the semi-dry biogas tank for fermentation, decompose the straw and produce biogas at the same time, and through the sealed fermentation of the inoculated bundled straw, it can have a good fermentation effect without compaction and other treatments. Compared with the use of semi-dry straw solar biogas technology alone and the use of dry fermentation to treat straw alone, the utility model improves the utilization rate of the straw, reduces the cost, and ensures balanced gas production by using the semi-dry biogas tank and the dry fermentation tank together to culture bacteria to treat the straw. At the same time, it also overcomes the defects of directly crushing and returning the straw in the field, which cause the spread of pests and diseases, affect the growth of seasonal crops, and produce methane gas. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a planar connection diagram of a stacked dry straw biogas fermentation system;

[0025] Figure 2 This is a schematic diagram of the structure of a dry fermentation tank in a stacked dry straw biogas fermentation system;

[0026] Figure 3 This is a schematic diagram of the biogas exhaust connector structure of a stacked dry straw biogas fermentation system;

[0027] Figure 4 This is a structural diagram of a semi-dry biogas tank in a stacked dry straw biogas fermentation system.

[0028] In the figure: 1-greenhouse; 2-dry fermentation tank; 21-ground; 22-sealing membrane; 23-biogas exhaust connector; 231-exhaust channel 1; 232-valve 1; 233-exhaust channel 2; 234-valve 2; 24-holding piece; 25-water seal; 26-water inlet; 27-fastener; 28-feeding port; 3-semi-dry biogas tank; 31-sealed tank body; 32-safety manhole; 33-feeding pipe; 34-exhaust pipe; 35-discharge pipe; 36-reinforced concrete foundation; 4-feeding device; 5-bacteria storage tank; 6-first pumping device; 7-biogas dehydrator; 8-biogas storage device; 9-biogas stove; 10-water tank; 11-water pump; 12-fertilizer workshop; 13-punching workshop; 14-baled inoculated straw. DETAILED DESCRIPTION

[0029] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described in detail below in conjunction with specific implementation methods.

[0030] Please refer to Figure 1 As shown, an embodiment of the present application provides a stacked dry straw biogas fermentation system, comprising a greenhouse 1, a biogas storage device 8, and a semi-dry biogas tank 3 and a dry fermentation tank 2 both arranged in the greenhouse 1, the semi-dry biogas tank 3 being connected to the dry fermentation tank 2 through a feeding device 4, and the semi-dry biogas tank 3 being used to cultivate straw biogas bacteria.

[0031] Among them, the greenhouse 1 can provide a relatively stable greenhouse environment, which is conducive to the fermentation and gas production of straw. The semi-dry biogas tank 3 is used to cultivate straw biogas bacteria. Excrement and wet biogas fermentation liquid are placed in it. After a period of time, excrement and crushed waste biomass are placed in it to cultivate straw biogas bacteria. The dry fermentation tank 2 is used to ferment straw under the action of the straw biogas bacteria and produce biogas through fermentation. The semi-dry biogas tank 3 is connected to the dry fermentation tank 2 through a feeding device 4 such as a dry feed pump, so that the biomass and / or fermentation bacteria (i.e., straw biogas bacteria) in the semi-dry biogas tank 3 that are conducive to fermentation can be transported to the dry fermentation tank 2 to promote fermentation. By combining the semi-dry biogas tank 3 and the dry fermentation tank 2, straw can be used for the cultivation of bacteria and fermentation to produce biogas, respectively, thereby improving the utilization rate of straw.

[0032] Please refer to Figure 2As shown, in an embodiment of the present application, the dry fermentation tank 2 includes a sealing film 22, a holding member 24 and a fastener 27. The sealing film 22 covers the ground 21 to form a closed space with the ground 21 for accommodating a number of bundled inoculated straw 14. The periphery of the sealing film 22 that is in contact with the ground 21 is held by the holding member 24 on the outside of the sealing film. The periphery of the sealing film 22 is fixed to the ground 21 by a number of fasteners 27; the sealing film 22 is connected to the biogas storage device 8.

[0033] The sealing film 22 is used to cover the bundles of inoculated straw 14 stacked on the ground 21. The periphery of the sealing film 22 is sealed against the ground 21, thus forming a closed space conducive to fermentation. The sealing film 22 can expand to a certain extent as the internal gas pressure increases. Compared with the methane tank formed by traditional masonry, the sealing film 22 is low in cost and easy to install. The sealing film 22 is a sealing film with a certain thickness to be able to withstand the high pressure of the internal gas. It is used to cover the bundles of inoculated straw 14 stacked on the ground 21 to cooperate with the ground 21 for sealing. The sealing of the sealing film 22 is mainly achieved by a pressing member 24 and a fastener 27. The pressing member 24 presses from the outside of the sealing film 22 so that the periphery thereof in contact with the ground 21 can be pressed and fixed relatively stably. Then, the periphery thereof is fixedly connected to the ground 21 by a fastener 27 such as an expansion bolt, thus achieving a better seal. In the specific implementation process, the holding member 24 can be a component with a relatively large weight, such as a ring-shaped metal component. Such a metal component can be uniformly pressed from the outside. Preferably, the cross-section of the metal component is L-shaped, and its bottom surface can have a certain pressing area with the ground 21 to play a better pressing role. Its upper part can provide a certain resistance to the outer wall of the sealing film 22, so that the bending angle of the outer wall of the sealing film 22 is more gentle, which is more conducive to the long-term use of the sealing film 22. During the specific sealing, water and straw biogas bacteria are also injected into the inner side of the sealing film 22 to a depth of about 10 cm for water sealing, that is, a water seal 25 is formed at the bottom of the inner side of the sealing film 22. Such a seal can meet the sealing requirements of fermentation. The ground 21 is preferably a flat concrete floor, so that they can cooperate with each other to play a better sealing role.

[0034] The bundled inoculated straw 14 is a plurality of straws tied into bundles, each bundle being placed vertically and stacked layer by layer on the ground 21. The bundled inoculated straw 14 refers to the bundled straw filled with straw biogas bacteria, water and / or fermented straw after inoculation. In this way, the inoculated bundled straw can gradually ferment from the inside outward during the fermentation process in a closed space, which can achieve a good fermentation effect, avoid the problem of needing to compact the straw, and is more convenient for operation. The biogas generated by the fermentation can be discharged through the biogas discharge portion on the sealing membrane 22, and after being dehydrated by the biogas dehydrator 7, enter the biogas storage device 8 such as the biogas cabinet for storage for easy use.

[0035] Prior to inoculation, a punching machine is used in a punching workshop 13 within the greenhouse 1 to uniformly punch multiple holes with a diameter of 40-60 mm on the entire straw bale. The number of holes can be 8-15. The straw bales are then inoculated. The punched straw bales are placed in a first layer on the ground 21. Straw biogas bacteria cultured in a semi-dry biogas digester 3 and fermented straw are placed in proportion. At the same time, straw biogas bacteria and fermented straw are injected into the holes of the entire straw bale. Clean water is then pumped in with a high-pressure water gun to mix them. The specific ratio is: fermented straw: straw biogas bacteria: water = 1:2.5:1 (weight ratio). The clean water allows the biogas bacteria to penetrate the straw bales.

[0036] In one embodiment, the sealing film 22 is spherical or square and covers the bundles of inoculated straw 14 stacked in a closed space.

[0037] The shape of the sealing film 22 can be spherical or square. Specifically, the corresponding pressing piece can be selected according to the stacking shape of the bundled inoculated straw 14 to match it, so that the sealing film can be sealed in a shape close to square or close to circular.

[0038] In one embodiment, a plurality of dry fermentation tanks 2 are provided, and the semi-dry biogas tank 3 is connected in parallel and communicated with the plurality of dry fermentation tanks 2 via a feeding device 4 .

[0039] In this way, the straw processing capacity and biogas production can be increased through multiple dry fermentation tanks 2, and it is also convenient for the remaining dry fermentation tanks 2 to ferment and produce gas when several dry fermentation tanks 2 are changing materials. Moreover, by connecting with the semi-dry biogas tanks 3 in parallel, it is convenient for one semi-dry biogas tank 3 to transport materials to the dry fermentation tanks 2 that need to be fed, so as to provide the biomass and / or fermentation bacteria required for fermentation.

[0040] In a specific implementation, the feeding device 4 can be a semi-dry feeding pump, which can deliver the biomass and / or fermentation bacteria to the dry fermentation tank 2 by pumping. The semi-dry feeding pump can be connected to the feeding port 28 of each dry fermentation tank 2 through a parallel pipeline, and each branch of the pipeline can be equipped with a valve for control.

[0041] In order to better facilitate the fermentation of bundled straw in the dry fermentation tank 2 , the sealing membrane 22 is further provided with a water inlet hole 26 , and the water inlet hole 26 is connected to a water inlet pipe, which is connected to a water tank 10 through a water pump 11 .

[0042] In this way, the water in the water pool 10 can be transported to the enclosed space in the sealing membrane 22 through the water pump 11 and the water inlet pipe, so as to be adaptively adjusted according to the fermentation situation.

[0043] In the specific implementation process, in order to facilitate inoculation, a bacterial strain storage tank 5 is also included in the greenhouse 1. The bacterial strain storage tank is connected to the semi-dry biogas tank 3 via a first pumping device 6. The bacterial strain storage tank 5 stores straw biogas bacteria delivered from the semi-dry biogas tank 3 via the first pumping device 6. As a preparation for inoculation, it is more convenient to directly deliver the bacterial strain from the bacterial strain storage tank 5 to the punched holes of the bundled straw via a second pumping device (not shown) for inoculation.

[0044] Please refer to Figure 3 As shown, in a preferred embodiment of the biogas discharge part, a biogas exhaust connector 23 is provided on the sealing membrane, and the biogas exhaust connector 23 has an exhaust channel 1 231 and an exhaust channel 2 233. The exhaust channel 1 231 is provided with a valve 1 232 and is connected to the biogas storage device 8 through a pipeline. The exhaust channel 2 233 is provided with a valve 234 and is connected to the biogas stove 9 through a pipeline.

[0045] The biogas exhaust connector 23 can be used to promptly discharge unusable biogas generated after the dry fermentation tank 2 is started, through valve 1 232 provided in exhaust channel 1 231. When the methane content in the biogas reaches approximately 40%, the exhaust is performed by controlling valve 2 234 of exhaust channel 2 233 to open, and the discharged biogas is promptly burned and used by adjusting the damper of the biogas stove 9. When the methane content in the biogas reaches above 50%, the exhaust is performed by controlling valve 1 232 of exhaust channel 1 231 to open, and the discharged biogas is stored in the biogas storage device 8. This exhaust structure facilitates flexible exhaust according to actual conditions and is more convenient to operate. Specifically, valve 1 232 and valve 2 234 can be solenoid valves, or valve 1 232 and valve 2 234 can be located at the far end of the pipeline for easier control.

[0046] Specifically, the biogas dehydrator 7 is further provided on the pipeline between the exhaust channel 1 and the biogas storage device 8. The biogas dehydrator 7 is used to dehydrate the output biogas. In the specific implementation process, a biogas dehydrator 7 capable of desulfurization can also be used.

[0047] Please refer to Figure 4 As shown, in a preferred embodiment of the semi-dry biogas tank 3, the semi-dry biogas tank 3 may include a sealed tank body 31 arranged in the greenhouse 1 and buried on the reinforced concrete foundation 36, and the sealed tank body 31 is provided with a safety manhole 32, a feed pipe 33, a discharge pipe 35 and an outlet pipe 34, and the outlet pipe 34 is connected to the biogas dehydrator 7, and a mixer is provided in the sealed tank body 31.

[0048] Among them, the closed environment of the sealed tank body 31 can be conducive to the cultivation of bacterial strains, and its arrangement on the upper shell of the reinforced concrete foundation 36 provides more stable support. The safety manhole 32 on the sealed tank body 31 can be opened and closed to facilitate maintenance personnel to enter for cleaning or modification. The feed pipe 33 can be used to place feces and wet biogas fermentation liquid. After a period of time, feces and crushed straw can be placed to cultivate dry biogas bacteria; the discharge pipe 35 can facilitate the discharge of fermented bacteria, and the outlet pipe 34 can facilitate the discharge of biogas produced by fermentation. Of course, the feed pipe 33, the discharge pipe 35, and the outlet pipe 34 are all provided with valves. The mixer provided in the sealed tank body 31 can facilitate the promotion of fermentation.

[0049] Specifically, the feeding device 4 includes a semi-dry feed pump; and / or the greenhouse 1 is a solar greenhouse. Solar greenhouses can utilize solar energy to generate electricity, and the generated electricity can be used by other electrical devices. Solar greenhouses are already existing technology and no improvements are involved, so they will not be described in detail here.

[0050] In addition, a fertilizer workshop 12 can be provided in the greenhouse 1. The fertilizer workshop 12 is provided with additional equipment such as an organic fertilizer production machine for making organic fertilizer from waste residue.

[0051] The above are merely preferred embodiments of the present invention. It should be noted that the above preferred embodiments should not be construed as limiting the present invention. The scope of protection of the present invention shall be determined by the scope defined in the claims. Persons skilled in the art will appreciate that improvements and modifications may be made without departing from the spirit and scope of the present invention, and such improvements and modifications shall also be considered within the scope of protection of the present invention.

Claims

1. A stacked dry straw biogas fermentation system, characterized in that: The invention comprises a greenhouse (1), a biogas storage device (8), and a semi-dry biogas tank (3) and a dry fermentation tank (2) both of which are arranged in the greenhouse (1); the semi-dry biogas tank (3) is connected to the dry fermentation tank (2) via a feeding device (4); and the semi-dry biogas tank (3) is used for cultivating straw biogas bacteria; The dry fermentation tank (2) comprises a sealing film (22), a holding member (24) and a fastener (27); the sealing film (22) covers the ground (21) to form a closed space with the ground (21) for accommodating a plurality of bundled inoculated straws (14); the periphery of the sealing film (22) in contact with the ground (21) is held by the holding member (24) on the outside of the sealing film; the periphery of the sealing film (22) is fixed to the ground (21) by a plurality of fasteners (27); and the inside of the sealing film (22) is connected to a biogas storage device (8).

2. A stacked dry straw biogas fermentation system according to claim 1, characterized in that: The sealing film (22) is spherical or square and covers the bundled inoculated straw (14) stacked in layers in a closed space.

3. The stacked dry straw biogas fermentation system according to claim 1, characterized in that: There are multiple dry fermentation tanks (2), and the semi-dry biogas tank (3) is connected in parallel and communicated with the multiple dry fermentation tanks (2) via a feeding device (4).

4. The stacked dry straw biogas fermentation system according to claim 1, characterized in that: The sealing membrane (22) is provided with a water inlet hole (26), the water inlet hole (26) is connected to a water inlet pipe, and the water inlet pipe is connected to a water pool (10) through a water pump (11).

5. The stacked dry straw biogas fermentation system according to claim 1, characterized in that: It also includes a bacterial strain storage tank (5) arranged in the greenhouse (1), and the bacterial strain storage is connected to the semi-dry biogas tank (3) through a first pumping device (6).

6. A stacked dry straw biogas fermentation system according to any one of claims 1 to 5, characterized in that: A biogas exhaust connector (23) is provided on the sealing film (22), and the biogas exhaust connector (23) has an exhaust channel 1 (231) and an exhaust channel 2 (233). The exhaust channel 1 (231) is provided with a valve 1 (232) and is connected to the biogas storage device (8) via a pipeline. The exhaust channel 2 (233) is provided with a valve 2 (234) and is connected to a biogas stove (9) via a pipeline.

7. A stacked dry straw biogas fermentation system according to claim 6, characterized in that: A biogas dehydrator (7) is also provided on the pipeline between the exhaust channel 1 and the biogas storage device (8).

8. The stacked dry straw biogas fermentation system according to claim 7, characterized in that: The semi-dry biogas tank (3) comprises a sealed tank body (31) arranged on a reinforced concrete foundation (36) in a greenhouse (1); the sealed tank body (31) is provided with a safety manhole (32), a feed pipe (33), a discharge pipe (35) and an outlet pipe (34); the outlet pipe (34) is communicated with the biogas dehydrator (7); and a mixer is provided in the sealed tank body (31).

9. The stacked dry straw biogas fermentation system according to claim 1, characterized in that: The feeding device (4) includes a semi-dry feeding pump; and / or the greenhouse (1) is a solar greenhouse.

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