Stacking dry-type straw biogas fermentation method and stacking dry-type straw biogas fermentation system

Abstract

The invention belongs to the technical field of straw fermentation, and discloses a stacking dry type straw biogas fermentation method and system.The stacking dry type straw biogas fermentation method comprises the following steps that raw materials are fermented in a semi-dry type biogas digester to culture straw biogas strains, and the raw materials comprise smashed straw; a plurality of holes used for inoculation are punched in bundles of straw used for fermentation; the bundled straw obtained after punching is stacked in a space used for fermentation in a layered mode, mixed biogas bacterial liquid is injected into holes of each bundled straw of each layer in proportion when the bundled straw of each layer is placed, and the mixed biogas bacterial liquid comprises the straw biogas strains, the fermented straw and water; and sealing the fermentation space in which the bundled straws are stacked, and putting a straw biogas strain and the fermented straws for fermentation. According to the invention, the utilization rate of straws can be greatly increased, a better fermentation effect can be achieved, and balanced gas production is ensured.

Description

Technical Field

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

[0002] The planting industry produces about 700 million tons of crop straw every year, of which about 50% is not effectively processed and utilized. This not only wastes resources, but also causes serious pests and diseases and reduces the quality of agricultural products due to the crushing and return of a large amount of straw to the fields. The processing and utilization of straw is one of the main resource and environmental issues facing my country's new rural construction, so it is urgent to find new ways to utilize it.

[0003] (I) Domestic straw processing technology. For many years, one of the ways to solve the problem of straw resource utilization is straw gasification technology. Xuzhou is the first city in the province to promote straw gasification. Since 1998, more than ten straw gasification stations have been promoted in Yangtun, Peixian, Huangdun, Xinyi, Bayiji, Pizhou, Sunzhuang, Tongshan, Qingshanquan, Jiawang, Daquan and other places; but due to the following problems: first, the cost is high, second, there is a lot of tar and low calorific value. Third, most straw gasification stations do not use straw to produce gas but use wood, branches, etc. to produce gas, which cannot solve the problem of burning straw in rural areas.

[0004] Every summer and autumn, most places in our province adopt the method of breaking up straw and returning it directly to the fields to deal with straw, which brings serious problems of pests and diseases. In the past, 30-40 yuan of pesticides per mu of land was enough, but now double the amount of pesticides is needed and still can't control pests and diseases. The resulting food safety and pesticide residue problems are becoming more and more prominent.

[0005] In order to solve the above problems, relevant experts conducted in-depth research in biogas demonstration villages many times and found that when using straw solar biogas digesters to produce biogas, the straw needs to be crushed into 3-5 cm before it can be pumped into the biogas digester for fermentation. Crushing straw is inefficient, costly, and has a poor working environment. Many biogas demonstration villages are unwilling to use straw, but choose livestock and poultry manure as biogas fermentation raw materials; this seriously restricts the amount of straw that can be processed.

[0006] (II) Foreign straw processing technology. The problem of straw utilization is not only a big "problem" in my country, but also exists abroad. After more than ten years of practice and development, the German biogas industry has matured the process level and technical equipment of agricultural waste biogas projects, and the relevant technical level is in the world's leading position. However, Germany's straw dry fermentation technology also requires the straw to be crushed before it can be pumped into the biogas pool to produce biogas.

[0007] The dry straw biogas fermentation technology adopted by Finland and other countries is intermittent dry fermentation technology. This technology is to spread the whole bale of straw into the fermentation tank to ferment and produce biogas; although the straw does not need to be crushed, this technology still requires the construction of a large straw fermentation tank separately; secondly, the whole bale of straw cannot be compacted after being spread out, and the volume will increase by more than 1.5 times; thirdly, it is necessary to purchase bacteria for each feeding; the investment is large, and the feeding and unloading are inconvenient; fourthly, after the straw produces biogas, it is inconvenient to spray water into the tank frequently.

[0008] Therefore, there is a need for a straw biogas fermentation process and system that is easy to operate, has low straw processing cost, low straw utilization rate, and good processing effect. Summary of the invention

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

[0010] In order to achieve the above object, the present invention adopts the following technical solutions:

[0011] On the one hand, a method for biogas fermentation of stacked dry straw is provided, comprising the following steps:

[0012] fermenting raw materials in a semi-dry biogas digester to cultivate straw biogas bacteria, wherein the raw materials include crushed straw;

[0013] Punch several holes for inoculation on the straw bales used for fermentation;

[0014] The punched straw bundles are stacked in layers in a fermentation space, and mixed biogas bacteria liquid is injected into the holes of each layer of straw bundles in proportion when placing each layer of straw bundles, wherein the mixed biogas bacteria liquid includes the straw biogas bacteria, fermented straw and water;

[0015] The fermentation space where the straw bales are stacked is sealed, and straw biogas bacteria and fermented straw are placed in it for fermentation.

[0016] In a possible implementation, the weight ratio of the raw materials in the mixed biogas bacteria liquid is: straw biogas bacteria, straw and water = 2.5:1:1.

[0017] In a possible implementation, the step of fermenting raw materials in a semi-dry biogas digester to cultivate straw biogas bacteria includes the following method:

[0018] Place feces and wet biogas fermentation liquid into a semi-dry biogas digester;

[0019] Feces and crushed straw are placed in the semi-dry biogas tank, and the fermented liquid in the semi-dry biogas tank after fermentation is used as the straw biogas bacteria, and the straw residue is used as the fermented straw.

[0020] In a possible implementation, the step of punching a plurality of holes for inoculation on the bundled straw for fermentation comprises the following method:

[0021] 8 to 15 inoculation holes with a diameter of 40 mm to 60 mm are evenly punched on the whole bale of straw by a punching machine. The distribution length of the inoculation holes on the whole bale of straw is 0.5 m to 1.2 m.

[0022] In a possible implementation, the steps include sealing the fermentation space where the bundled straw is stacked, and placing straw biogas bacteria and fermented straw for fermentation, including the following methods:

[0023] Covering the outside of the stacked straw bales with a sealing film, and sealing the periphery of the sealing film with the ground to form a space for fermentation;

[0024] Straw biogas bacteria and fermented straw are placed into the sealing film, and 5-20cm deep water is placed at the same time for water sealing.

[0025] In a possible implementation, the step of covering the outer side of the stacked straw bundles with a sealing film and sealing the periphery of the sealing film with the ground to form a space for fermentation includes the following methods:

[0026] The sealing film is covered on the outside of the stacked straw bundles, and the periphery of the sealing film in contact with the ground is pressed by an annular pressing member;

[0027] The periphery of the sealing membrane is fixed to the concrete floor by expansion bolts.

[0028] In a possible implementation, the following steps are also included:

[0029] When the methane content in the biogas in the semi-dry biogas digester reaches 35%-49%, part of the biogas is discharged and burned through a biogas stove for use. When the methane content in the biogas in the semi-dry biogas digester reaches more than 50%, part of the biogas is discharged and stored in a biogas storage device through a dehydrator for use.

[0030] In a possible implementation, the following steps are also included:

[0031] After the straw bundles are fermented, the straw bundles in the fermentation space are taken out and used to make organic fertilizer, and at the same time, the straw bundles inoculated with the mixed biogas bacteria liquid and stacked in layers are re-placed into the fermentation space for fermentation.

[0032] On the other hand, a stacked dry straw biogas fermentation system is also provided, which uses any of the stacked dry straw biogas fermentation methods described above, comprising a greenhouse, a biogas storage device, and a semi-dry biogas tank and a dry fermentation tank both arranged in the greenhouse, wherein 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;

[0033] The dry fermentation tank comprises a sealing film, a holding piece and a fastener, wherein the sealing film covers the ground to form a closed space for accommodating a plurality of bundles of inoculated straws, the periphery of the sealing film in contact with the ground is held by the holding piece on the outside of the sealing film, and the periphery of the sealing film is fixed to the ground by a plurality of fasteners;

[0034] The sealing film is connected to a biogas storage device.

[0035] In a possible implementation, the sealing film is spherical or square and covers the bundles of inoculated straw stacked in a closed space;

[0036] The dry fermentation tanks are provided in plurality, and the semi-dry biogas tank is connected in parallel and in communication with the plurality of dry fermentation tanks via a feeding device;

[0037] 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;

[0038] It also includes a bacteria storage tank arranged in the greenhouse, and the bacteria storage tank is connected to the semi-dry biogas tank through a first pumping device;

[0039] The sealing film is provided with a biogas exhaust joint, which has an exhaust channel 1 and an exhaust channel 2, wherein the exhaust channel 1 is provided with a valve 1 and is connected to the biogas storage device through a pipeline, and the exhaust channel 2 is provided with a valve 2 and is connected to a biogas stove through a pipeline;

[0040] The biogas dehydrator is also provided on the pipeline between the exhaust channel 1 and the biogas storage device;

[0041] The semi-dry biogas tank comprises 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 arranged in the sealed tank body;

[0042] The feeding device comprises a semi-dry feeding pump; and / or the greenhouse is a solar greenhouse.

[0043] Compared with the prior art, the present invention has the following beneficial effects:

[0044] The stacked dry straw biogas fermentation method of the present invention can obtain straw biogas bacteria and straw for inoculation by fermenting straw as one of the raw materials in a semi-dry biogas pool, and inject the obtained straw biogas bacteria and straw into the holes of the punched straw bundles to form a mixed biogas solution containing straw biogas bacteria and straw, so that each bundle of straw can be fermented from the inside in the fermentation space, and at the same time, the straw biogas bacteria and the fermented straw in the external fermentation space are sealed and fermented, which can greatly improve the utilization rate of the straw, have a better fermentation effect, ensure balanced gas production, and overcome the defects of directly crushing and returning the straw in the field, which may cause the spread of pests and diseases, affect the growth of seasonal crops, and produce methane gas.

[0045] The stacked dry straw biogas fermentation system of the present invention comprises a greenhouse, a semi-dry biogas tank and a dry fermentation tank. The dry fermentation tank can utilize the bacteria cultured in the semi-dry biogas tank for fermentation to decompose the straw and generate biogas at the same time. Moreover, by sealing the inoculated bundled straw for fermentation, a good fermentation effect can be achieved without compaction or other treatments. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 A flowchart of a stacked dry straw biogas fermentation method

[0047] Figure 2 It is a planar connection block diagram of a stacked dry straw biogas fermentation system;

[0048] Figure 3 It is a structural schematic diagram of a dry fermentation tank of a stacked dry straw biogas fermentation system;

[0049] Figure 4 A schematic diagram of the structure of a biogas exhaust joint of a stacked dry straw biogas fermentation system;

[0050] Figure 5 The schematic diagram of the structure of a semi-dry biogas tank of a stacked dry straw biogas fermentation system.

[0051] In the figure: 1-greenhouse; 2-dry fermentation tank; 21-ground; 22-sealing film; 23-biogas exhaust joint; 231-exhaust channel one; 232-valve one; 233-exhaust channel two; 234-valve two; 24-holding piece; 25-water seal; 26-water inlet; 27-fastener; 28-feeding port; 3-semi-dry biogas tank; 31-sealed tank; 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

[0052] 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.

[0053] Please refer to Figure 1 As shown, the embodiment of the present application provides a stacked dry straw biogas fermentation method, comprising the following steps:

[0054] Step S100: fermenting raw materials in a semi-dry biogas digester to cultivate straw biogas bacteria, wherein the raw materials include crushed straw.

[0055] In this step, the semi-dry biogas digester is used to cultivate straw biogas bacteria, which uses raw materials including crushed straw for fermentation, and can ferment to obtain straw biogas bacteria and straw for inoculation, and can also be used as fermentation materials required for space fermentation.

[0056] Step S200: punching a plurality of holes for inoculation on the bundled straw for fermentation.

[0057] In this step, a number of holes are punched on the straw bales, and the holes can extend inside the straw bales, so that the mixed biogas bacteria liquid can be fermented from the inside out, which can not only achieve better fermentation effects, but also avoid the problem of uneven and unstable gas production caused by uneven fermentation of stacked straw.

[0058] Step S300: stack the punched straw bundles in layers in a fermentation space, and inject mixed biogas bacteria liquid into the holes of each layer of straw bundles in proportion when placing each layer of straw bundles. The mixed biogas bacteria liquid includes the straw biogas bacteria, the fermented straw and water.

[0059] In this step, the fermentation space can be a traditional tank structure or a closed space structure formed by a sealing membrane, and there is no limitation. Several bundles of straw are stacked in layers in the fermentation space, and preferably are stacked in layers vertically, and mixed biogas bacteria liquid is injected for inoculation when each layer is placed, so that each bundle of straw can meet the fermentation conditions, and the straw biogas bacteria species, straw and water cultured in a semi-dry biogas tank contained in the mixed biogas bacteria liquid can be used as a carrier for storage, so that it can be fermented more stably, and the addition of water can make the bundles of straw easy to penetrate and ferment better, and each bundle of straw can be penetrated and immersed from the inside to the outside by the mixed biogas bacteria liquid, so as to obtain a better fermentation effect and achieve inoculation at the same time, which can not only facilitate fermentation, but also simplify the process, make it easier to operate, and reduce costs. Specifically, the straw biogas bacteria and the fermented straw in the mixed biogas bacteria liquid can be injected into the hole by a pump, and water can be pumped in by a high-pressure water gun to mix the straw biogas bacteria and the fermented straw with each other.

[0060] Step S400: The fermentation space where the straw bundles are stacked is sealed, and straw biogas bacteria and fermented straw are placed therein for fermentation.

[0061] In this step, the fermentation space after inoculation and stacking is sealed, and at the same time, a fermentation environment can be constructed from the outside through the straw biogas bacteria and the fermented straw.

[0062] Through the above technical scheme, straw is used as one of the raw materials for fermentation in a semi-dry biogas digester to obtain straw biogas bacteria and straw for inoculation, and the obtained straw biogas bacteria and straw are injected into the holes of the punched straw bundles into a mixed biogas solution containing straw biogas bacteria and straw, so that each bundle of straw can be fermented from the inside in the fermentation space, and at the same time, the straw biogas bacteria and the fermented straw in the external fermentation space are sealed and fermented, which can greatly improve the utilization rate of the straw, have a better fermentation effect, ensure balanced gas production, and overcome the defects of directly crushing and returning the straw in the field, which may cause the spread of pests and diseases, affect the growth of seasonal crops, and produce methane gas.

[0063] In one embodiment, the weight ratio of the raw materials in the mixed biogas bacteria liquid is: straw biogas bacteria, straw and water = 2.5:1:1.

[0064] By mixing the biogas bacteria liquid in such a proportion, the straw biogas bacteria can better ferment the bundles of straw, and a more sufficient fermentation effect can be obtained for the bundles of straw.

[0065] In an embodiment of the present application, step S100: fermenting raw materials in a semi-dry biogas digester to cultivate straw biogas bacteria may include the following methods:

[0066] Step S101: placing feces and wet biogas fermentation liquid into a semi-dry biogas digester.

[0067] Step S102: placing feces and crushed straw into the semi-dry biogas tank, and the fermented liquid in the semi-dry biogas tank after fermentation is used as straw biogas bacteria, and the straw residue is used as straw.

[0068] In this way, the crushed straw can be fermented by feces and wet biogas fermentation liquid, and the straw biogas bacteria and straw can be obtained by fermentation. At the same time, biogas can also be produced, and the produced biogas can be collected by the biogas storage device through the pipeline.

[0069] Furthermore, step S200 of punching a plurality of holes for inoculation on the bundled straw for fermentation may include the following method:

[0070] Step S201: 8 to 15 inoculation holes with a diameter of 40 mm to 60 mm are evenly punched on the whole bale of straw by a punching machine, and the distribution length of the inoculation holes on the whole bale of straw is 0.5 m to 1.2 m.

[0071] With such inoculation hole distribution, the mixed biogas bacteria liquid can effectively penetrate into the interior of the straw bundles, thereby achieving a better fermentation effect.

[0072] Furthermore, in step S400, the fermentation space where the bundled straw is stacked is sealed, and straw biogas bacteria and fermented straw are placed therein for fermentation, which may include the following methods:

[0073] Step S401: Cover the outside of the stacked straw bundles with a sealing film, and seal the periphery of the sealing film with the ground to form a fermentation space. The sealing film is a special sealing film for biogas sealing. By covering the outside of the stacked straw bundles and sealing the periphery of the sealing film with the ground, a closed fermentation space can be formed.

[0074] Step S402: inserting straw biogas bacteria and fermented straw into the sealing film, and simultaneously inserting 5-20cm deep water for water sealing. In this way, the straw biogas bacteria and fermented straw can be mixed with water, and water sealing can be performed from the inside, thereby forming a closed environment for fermentation.

[0075] Preferably, in step S401, the outer side of the stacked straw bundles is covered with a sealing film, and the periphery of the sealing film is sealed with the ground to form a space for fermentation, which may include the following methods:

[0076] S4011: Cover the outside of the stacked straw bundles with a sealing film, and use an annular pressing piece to press the periphery of the sealing film that fits the ground. The annular pressing piece can press and fix the edge of the sealing film from the outside, so that it can maintain good fixity even after the internal biogas expands, which is more conducive to sealing.

[0077] S4012: Use expansion bolts to fix the edge of the sealing membrane to the concrete floor. The use of expansion bolts can fix the edge of the sealing membrane to the ground, making the sealing membrane more stable.

[0078] In an embodiment of the present application, the following steps may also be included:

[0079] S500: When the methane content in the biogas in the semi-dry biogas digester reaches 35%-49%, part of the biogas is discharged and burned through a biogas stove for use; when the methane content in the biogas in the semi-dry biogas digester reaches more than 50%, part of the biogas is discharged and stored in a biogas storage device through a dehydrator for use.

[0080] In this step, when the methane content in the biogas reaches 35%-49%, such as about 40%, the unusable biogas generated after the fermentation begins can be discharged in time and safely by discharging it at this time. When the methane content in the biogas reaches more than 50%, such as about 50%, discharging it at this time can make the discharged biogas basically usable, which is safer and more convenient.

[0081] In the specific implementation process, the following steps may also be included:

[0082] S600: After the straw bundles are fermented, the straw bundles in the fermentation space are taken out and used to make organic fertilizer, and at the same time, the straw bundles stacked in layers and inoculated with the mixed biogas bacteria liquid are re-placed into the fermentation space for fermentation.

[0083] After the fermentation is completed, which is about 3 months, the bundles of straw in the fermentation space can be taken out and used to make organic fertilizer for further utilization. At the same time, the inoculated bundles of straw can be replaced for material replacement.

[0084] Please refer to Figure 2-5 As shown, an embodiment of the present application also provides a stacked dry straw biogas fermentation system, including 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 is connected to the dry fermentation tank 2 through a feeding device 4, and the semi-dry biogas tank 3 is used to cultivate straw biogas bacteria.

[0085] 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. Feces and wet biogas fermentation liquid are placed in it. After a period of time, feces and crushed waste biomass are placed in it, and straw biogas bacteria can be cultivated. The dry fermentation tank 2 is used to ferment straw under the action of 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 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, the straw can be used for the cultivation of bacteria and fermentation to produce biogas, respectively, so that the utilization rate of the straw can be improved.

[0086] Please refer to Figure 3 As shown, in an embodiment of the present application, the dry fermentation tank 2 includes a sealing film 22, a holding piece 24 and a fastener 27. The sealing film 22 covers the ground 21 to form an enclosed 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 piece 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.

[0087] The sealing film 22 is used to cover a number of bundles of inoculated straw 14 stacked on the ground 21, and its periphery is sealed with the ground 21, so that a closed space conducive to fermentation can be formed, and 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 cost is low and it is easy to install. The sealing film 22 is a sealing film with a certain thickness to be able to withstand the large internal gas pressure. 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 through the pressing member 24 and the fastener 27. The pressing member 24 is pressed from the outside of the sealing film 22, so that the periphery that fits the ground 21 can be pressed and fixed more stably, and then the periphery is fixedly connected to the ground 21 by fasteners 27 such as expansion bolts, so that a better seal can be achieved. 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 evenly 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 resist the outer wall of the sealing film 22 to a certain extent, 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. When sealing specifically, water and fermentation bacteria (i.e., 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, and 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 achieve better sealing cooperation.

[0088] 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, so that the inoculated bundled straw can be gradually fermented from the inside to the outside during the fermentation process in a closed space, which can have a good fermentation effect, avoids the problem of needing to compact the straw, and is more conducive to operation. The biogas generated by the fermentation can be discharged through the biogas discharge part on the sealing film 22, and after being dehydrated by the biogas dehydrator 7, enters the biogas storage device 8 such as the biogas cabinet for storage, so as to facilitate use.

[0089] Before inoculation, a punching machine is used in the punching workshop 13 in the greenhouse 1 to evenly punch a plurality of holes with a diameter of 40-60 mm on the whole bundle of straw. The number of holes can be 8-15. Then, the bundle of straw is inoculated. The punched whole bundle of straw is placed in the first layer on the ground 21. Straw biogas bacteria and fermented straw are cultured in a semi-dry biogas digester 3 in proportion. Water is pumped into the whole bundle of straw with a high-pressure water gun to mix the biogas bacteria. The specific ratio is: straw: bacteria: water = 1:2.5:1 (weight ratio).

[0090] In one embodiment, the sealing film 22) is spherical or square and covers the outside of the bundled inoculated straw 14 stacked in a closed space.

[0091] The shape of the sealing film 22 can be spherical or square. Specifically, the corresponding holding piece can be selected according to the stacking shape of the bales of inoculated straw 14 to match it, so that the sealing film can be sealed in a shape close to a square or a circle.

[0092] In one embodiment, a plurality of dry fermentation tanks 2 are provided, and the semi-dry biogas digester 3 is connected in parallel and communicated with the plurality of dry fermentation tanks 2 via a feeding device 4 .

[0093] 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 some of the dry fermentation tanks 2 are changing materials. Moreover, by connecting with the semi-dry biogas tanks 3 in parallel, one semi-dry biogas tank 3 can 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.

[0094] In the specific implementation process, the feeding device 4 can adopt a semi-dry feeding pump, and the biomass and / or fermentation bacteria can be pumped into the dry fermentation tank 2. The semi-dry feeding pump can be connected to the feeding port 28 of each dry fermentation tank 2 through a parallel pipeline, and the branch of each pipeline can be provided with a valve for control.

[0095] In order to better facilitate the fermentation of the bundled straw in the dry fermentation tank 2, the sealing film 22 is further provided with a water inlet hole 26, and the water inlet hole 26 is connected to a water inlet pipe, and the water inlet pipe is connected to a water tank 10 through a water pump 11.

[0096] 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 perform adaptive adjustment according to the fermentation situation.

[0097] In the specific implementation process, in order to facilitate inoculation, a strain storage pool 5 is also included in the greenhouse 1, and the strain storage is connected to the semi-dry biogas tank 3 through a first pumping device 6. The strain storage pool 5 stores straw biogas strains transported from the semi-dry biogas tank 3 through the first pumping device 6, as a preparation for inoculation, so as to facilitate direct inoculation from the strain storage pool 5 through a second pumping device (not shown in the figure) to the punched holes of the bundled straw, which is more convenient.

[0098] Please refer to Figure 4As 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, and the exhaust channel 2 233 is provided with a valve 234 and is connected to the biogas stove 9 through a pipeline.

[0099] The biogas exhaust connector 23 can timely discharge the unusable biogas generated after the dry fermentation tank 2 is started through the valve 232 set in the exhaust channel 231. When the methane content in the biogas reaches about 40%, the exhaust is carried out by controlling the valve 234 of the exhaust channel 233 to open, and the discharged biogas is burned and used in time by adjusting the air door of the biogas stove 9; when the methane content in the biogas reaches more than 50%, the exhaust is carried out by controlling the valve 232 of the exhaust channel 231 to open, and the discharged biogas enters the biogas storage device 8 for storage. Such an exhaust structure is more convenient for flexible exhaust according to actual conditions and more convenient to operate. Specifically, the valve 1 232 and the valve 2 234 can be solenoid valves, or the valve 1 232 and the valve 2 234 can be set at the far end of the pipeline for easy control.

[0100] 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, and in the specific implementation process, a biogas dehydrator 7 capable of desulfurization can also be used.

[0101] Please refer to Figure 5 As shown, in a preferred embodiment of the semi-dry biogas digester 3, the semi-dry biogas digester 3 may include a sealed tank body 31 arranged in the greenhouse 1 and buried in 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.

[0102] Among them, the closed environment of the sealed tank body 31 can be conducive to the cultivation of bacterial strains, and the upper shell of the sealed tank body 31 is provided with a more stable support on the reinforced concrete foundation 36. 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 are placed to cultivate dry biogas strains; the discharge pipe 35 can facilitate the discharge of straw biogas strains and fermented straw, 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 fermentation.

[0103] Specifically, the feeding device 4 includes a semi-dry feed pump; and / or, the greenhouse 1 is a solar greenhouse. The solar greenhouse can be used to generate electricity using solar energy, and the generated electricity can be used by other electrical equipment. The solar greenhouse is already an existing technology and does not involve improvement thereof, so it will not be described in detail here.

[0104] In addition, a fertilizer workshop 12 may be provided in the greenhouse 1, and additional equipment such as an organic fertilizer production machine for making organic fertilizer from waste residue may be provided in the fertilizer workshop 12. The ground 21 is a concrete ground 21.

[0105] The above are only preferred embodiments of the present invention. It should be noted that the above preferred embodiments should not be regarded as limiting the present invention, and the protection scope of the present invention should be based on the scope defined by the claims. For ordinary technicians in this technical field, several improvements and modifications can be made without departing from the spirit and scope of the present invention, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A stacked dry straw biogas fermentation method, characterized in that: The following steps are involved: fermenting raw materials in a semi-dry biogas digester to cultivate straw biogas bacteria, wherein the raw materials include crushed straw; Punch several holes for inoculation on the straw bales used for fermentation; The punched straw bundles are stacked in layers in a fermentation space, and mixed biogas bacteria liquid is injected into the holes of each layer of straw bundles in proportion when placing each layer of straw bundles, wherein the mixed biogas bacteria liquid includes the straw biogas bacteria, fermented straw and water; The fermentation space where the straw bales are stacked is sealed, and straw biogas bacteria and fermented straw are placed in it for fermentation.

2. A stacked dry straw biogas fermentation method as claimed in claim 1, characterized in that: The weight ratio of the raw materials in the mixed biogas bacteria liquid is: straw biogas bacteria, straw and water = 2.5:1:

1.

3. A stacked dry straw biogas fermentation method as claimed in claim 1, characterized in that: The step is to ferment raw materials in a semi-dry biogas digester to cultivate straw biogas bacteria, including the following methods: Place feces and wet biogas fermentation liquid into a semi-dry biogas digester; Feces and crushed straw are placed in the semi-dry biogas tank, and the fermented liquid in the semi-dry biogas tank after fermentation is used as the straw biogas bacteria, and the straw residue is used as the fermented straw.

4. A stacked dry straw biogas fermentation method as claimed in claim 1, characterized in that: The steps include punching a plurality of holes for inoculation on the straw bundles for fermentation, comprising the following method: 8 to 15 inoculation holes with a diameter of 40 mm to 60 mm are evenly punched on the whole bale of straw by a punching machine. The distribution length of the inoculation holes on the whole bale of straw is 0.5 m to 1.2 m.

5. A stacked dry straw biogas fermentation method according to any one of claims 1 to 4, characterized in that: The step is to seal the fermentation space where the bundled straw is stacked, and place straw biogas bacteria and fermented straw for fermentation, including the following methods: Covering the outside of the stacked straw bales with a sealing film, and sealing the periphery of the sealing film with the ground to form a space for fermentation; Straw biogas bacteria and fermented straw are placed into the sealing film, and 5-20cm deep water is placed at the same time for water sealing.

6. A stacked dry straw biogas fermentation method as claimed in claim 5, characterized in that: The step includes covering the outer side of the stacked straw bundles with a sealing film, and sealing the periphery of the sealing film with the ground to form a space for fermentation, comprising the following methods: The sealing film is covered on the outside of the stacked straw bundles, and the periphery of the sealing film in contact with the ground is pressed by an annular pressing member; The periphery of the sealing membrane is fixed to the concrete floor by expansion bolts.

7. A stacked dry straw biogas fermentation method as claimed in claim 1, characterized in that: The following steps are also included: When the methane content in the biogas in the semi-dry biogas digester reaches 35%-49%, part of the biogas is discharged and burned through a biogas stove for use. When the methane content in the biogas in the semi-dry biogas digester reaches more than 50%, part of the biogas is discharged and stored in a biogas storage device through a dehydrator for use.

8. The method for biogas fermentation of stacked dry straw according to claim 1, characterized in that: The following steps are also included: After the straw bundles are fermented, the straw bundles in the fermentation space are taken out and used to make organic fertilizer, and at the same time, the straw bundles inoculated with the mixed biogas bacteria liquid and stacked in layers are re-placed into the fermentation space for fermentation.

9. A stacked dry straw biogas fermentation system, using the stacked dry straw biogas fermentation method according to any one of claims 1 to 8, characterized in that: It comprises a greenhouse, a biogas storage device, and a semi-dry biogas tank and a dry fermentation tank both arranged in the greenhouse, wherein the semi-dry biogas tank is connected with the dry fermentation tank through a feeding device, and the semi-dry biogas tank is used to cultivate straw biogas bacteria; The dry fermentation tank comprises a sealing film, a holding piece and a fastener, wherein the sealing film covers the ground to form a closed space for accommodating a plurality of bundles of inoculated straws, the periphery of the sealing film in contact with the ground is held by the holding piece on the outside of the sealing film, and the periphery of the sealing film is fixed to the ground by a plurality of fasteners; The sealing film is connected to a biogas storage device.

10. A stacked dry straw biogas fermentation system as claimed in claim 9, characterized in that: The sealing film is spherical or square and covers the bundles of inoculated straw stacked in a closed space; The dry fermentation tanks are provided in plurality, and the semi-dry biogas tank is connected in parallel and in communication with the plurality of dry fermentation tanks via a feeding device; 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; It also includes a bacteria storage tank arranged in the greenhouse, and the bacteria storage tank is connected to the semi-dry biogas tank through a first pumping device; The sealing film is provided with a biogas exhaust joint, which has an exhaust channel 1 and an exhaust channel 2, wherein the exhaust channel 1 is provided with a valve 1 and is connected to the biogas storage device through a pipeline, and the exhaust channel 2 is provided with a valve 2 and is connected to a biogas stove through a pipeline; The biogas dehydrator is also provided on the pipeline between the exhaust channel 1 and the biogas storage device; The semi-dry biogas tank comprises 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 arranged in the sealed tank body; The feeding device comprises a semi-dry feeding pump; and / or the greenhouse is a solar greenhouse.

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