Device and method for producing hydrogen and methane by coupling rumen fluid and sludge microorganism anaerobic fermentation

Abstract

The invention relates to a device and a method for producing hydrogen and methane by coupling rumen fluid and sludge microorganism anaerobic fermentation, and the method comprises the following steps: a hydrogen production stage: mixing straws and rumen fluid microorganisms, injecting into a hydrogen production fermentation tank, pumping out air in the hydrogen production fermentation tank to enable the pressure to be less than or equal to 0.001 MPa, and continuously collecting hydrogen until the hydrogen production pressure is less than 0.1 MPa; a methane production stage: mixing the straws with sludge microorganisms, injecting the mixture into a methane production fermentation tank, pumping out air in the methane production fermentation tank to enable the pressure to be less than or equal to 0.08 MPa and the hydrogen production pressure to reach a preset pressure value, introducing liquid in the hydrogen production fermentation tank into the methane production fermentation tank, and continuously collecting methane until the methane pressure is less than 0.05 MPa; and in the cleaning stage, cleaning liquid is sprayed through the cleaning assembly, and residues are discharged through the first residue discharging opening and the second residue discharging opening. The method effectively solves the problem of unbalanced hydrogen production efficiency and methane production efficiency in the traditional technology, and realizes efficient anaerobic hydrogen production and methane production of the straws.

Description

Technical Field

[0001] The present disclosure relates to the technical field of biomass energy conversion, and in particular to a device and method for producing hydrogen and methane by coupling anaerobic fermentation of rumen fluid and sludge microorganisms. Background Art

[0002] Straw is an important renewable resource with carbon neutrality. The conversion of straw into hydrogen and methane is considered an important measure to solve my country's energy crisis and achieve the "dual carbon" goal. Among the many hydrogen and methane production technologies, anaerobic digestion technology is widely used due to its advantages such as environmental friendliness, low energy consumption, and mild operating conditions. However, due to the complexity and stubbornness of the lignocellulose structure in straw, the use of anaerobic digestion technology cannot quickly, stably, and efficiently convert straw into hydrogen and methane, and the yields of both are far from the theoretical values. Therefore, it is necessary to find practical methods to increase the hydrogen and methane production rates of straw, such as selecting microbial inoculants with the ability to degrade lignocellulose in nature.

[0003] The microorganisms in ruminant rumen fluid are by far the most capable anaerobic microbial community in nature for degrading lignocellulose, making them an ideal microbial inoculant for straw containing recalcitrant lignocellulose structures. However, when rumen fluid microorganisms are used as inoculants, their high rate of lignocellulose degradation leads to the rapid production of large amounts of hydrogen and volatile fatty acids during straw degradation. Compared to hydrogen-producing bacteria, volatile fatty acids are more detrimental to methanogens, particularly hydrogenotrophic methanogens, which account for 82% of all methanogens in rumen fluid. Consequently, when rumen fluid microorganisms are used as inoculants, straw typically exhibits higher hydrogen production and lower methane production. Compared to rumen fluid microorganisms, sludge microorganisms have a lower rate of lignocellulose degradation, resulting in lower hydrogen production when sludge microorganisms are used as inoculants for anaerobic straw digestion.

[0004] From the above, it can be seen that the traditional single-microorganism anaerobic digestion technology has the problem of imbalance between hydrogen production and methane production efficiency. That is, although rumen fluid microorganisms have strong lignocellulose degradation ability, the accumulation of volatile fatty acids will inhibit the activity of methanogens. Although sludge microorganisms can efficiently utilize fatty acids to produce methane, the lignocellulose degradation rate is low. Summary of the Invention

[0005] The purpose of the present disclosure is to provide a method for producing hydrogen and methane by coupling anaerobic fermentation of rumen fluid and sludge microorganisms. The method effectively solves the problem of imbalance in hydrogen and methane production efficiency in traditional technologies and realizes efficient anaerobic hydrogen and methane production from straw.

[0006] To achieve the above objectives, the present disclosure provides a method for producing hydrogen and methane by coupling anaerobic fermentation of rumen fluid and sludge microorganisms, comprising the following steps:

[0007] Hydrogen production stage: pretreated straw is mixed with rumen fluid microorganisms and injected into a hydrogen production fermentation tank. Air in the hydrogen production fermentation tank is extracted through the hydrogen outlet to make the pressure in the hydrogen production fermentation tank ≤ 0.001 MPa. The fermentation mixture in the hydrogen production fermentation tank continues to ferment, and hydrogen is continuously collected until the hydrogen production pressure is less than 0.1 MPa.

[0008] Methane production stage: The pretreated straw is mixed with sludge microorganisms and injected into a methanogenic fermentation tank. The air in the methanogenic fermentation tank is extracted through the methane outlet to make the pressure in the methanogenic fermentation tank ≤ 0.08 MPa. When the hydrogen production pressure reaches a preset pressure value, the liquid in the hydrogen production fermentation tank is introduced into the methanogenic fermentation tank through the pipetting component to allow the fermentation mixture in the methanogenic fermentation tank to continue fermenting, and methane is continuously collected until the methane pressure is less than 0.05 MPa.

[0009] Cleaning stage: The cleaning liquid is sprayed through the high-pressure rotating nozzle of the cleaning component, and the residue is discharged through the first and second slag discharge ports to complete the cleaning of the device.

[0010] Optionally, in the hydrogen production stage: the straw is dried in an oven at 60-70°C, crushed and sieved, and particles with a size of 2-5 mm are taken together with rumen fluid microorganisms for anaerobic fermentation at 37-40°C and pH 6.0-6.5.

[0011] Optionally, in the methanogenesis stage, the straw is dried in an oven at 60-70°C, then crushed and sieved, and straw particles with a particle size of 2-5 mm are taken together with sludge microorganisms for anaerobic fermentation at 37-40°C and pH 6.8-7.2.

[0012] Optionally, in the methanogenic stage, when the preset pressure value is less than 0.15 MPa, the liquid in the hydrogen-producing fermentation tank is introduced into the methanogenic fermentation tank through the pipetting assembly.

[0013] On the basis of the above scheme, the present disclosure further provides a device for producing hydrogen and methane by anaerobic fermentation of rumen fluid and sludge microorganisms, which is used in the above method for producing hydrogen and methane by anaerobic fermentation of rumen fluid and sludge microorganisms. The device for producing hydrogen and methane by anaerobic fermentation of rumen fluid and sludge microorganisms comprises:

[0014] The hydrogen-producing and methane-producing assembly comprises the methane-producing fermentation tank and the hydrogen-producing fermentation tank nested in the methane-producing fermentation tank, wherein the methane-producing fermentation tank and the hydrogen-producing fermentation tank are connected via a heat pipe to transfer the heat generated in the hydrogen-producing fermentation tank to the methane-producing fermentation tank; the hydrogen-producing fermentation tank is provided with a hydrogen-producing feed inlet, the hydrogen outlet, and the first slag discharge port, and the methane-producing fermentation tank is provided with a methane-producing feed inlet, the methane outlet, and the second slag discharge port;

[0015] Liquid transfer assembly: including a liquid guide tube and a liquid pump, wherein the liquid pump is arranged on the outside of the side wall of the hydrogen production fermentation tank, one end of the liquid guide tube is located on the inside of the bottom of the hydrogen production fermentation tank and is connected to a filter screen, and the other end is connected to the liquid pump;

[0016] Cleaning assembly: comprising a plurality of the high-pressure rotating nozzles, wherein the plurality of the high-pressure rotating nozzles are distributed on the inner and outer side walls of the hydrogen-producing fermentation tank and the inner side wall and the inner side of the bottom of the methane-producing fermentation tank.

[0017] Optionally, the hydrogen outlet is embedded in the center of the hydrogen production feed inlet, and a first gas control valve is installed at the hydrogen outlet.

[0018] Optionally, the methane production feed port includes a first feed port and a second feed port, the first feed port and the second feed port are respectively arranged on the left and right sides of the hydrogen production feed port, and the methane outlet is embedded in the center position of the first feed port and the second feed port, and a second gas control valve is installed at the methane outlet.

[0019] Optionally, the side walls and bottom of the methanogenic fermentation tank are both provided with a heat insulation layer.

[0020] Optionally, the heat pipe includes a horizontal heat pipe, an inclined heat pipe and a heat collecting head, one end of the horizontal heat pipe is connected to the heat collecting head located on the inner side of the side wall of the hydrogen-producing fermentation tank, and the other end is located on the inner side of the side wall of the methane-producing fermentation tank; one end of the inclined heat pipe is connected to the heat collecting head located on the inner side of the bottom of the hydrogen-producing fermentation tank, and the other end is located on the inner side of the bottom of the methane-producing fermentation tank.

[0021] Optionally, the heat conducting tube is a hollow cylindrical tube, and the heat conducting tube is made of copper; the heat collecting head is a solid U-shaped tube, and the heat collecting head is made of stainless steel.

[0022] Through the above technical scheme, the method for coupling rumen fluid and sludge microorganisms to produce hydrogen and methane by anaerobic fermentation, in the hydrogen production stage, utilizes the high lignocellulose degradation ability of rumen fluid microorganisms, which is beneficial to improving the hydrogen yield. In the methane production stage, when the hydrogen production pressure reaches the preset pressure value, the liquid in the hydrogen production fermentation tank is introduced into the methane production fermentation tank through the pipetting component. Since the methanogens in the sludge microorganisms are mainly acetic acid-trophic methanogens, they can directly use acetic acid or indirectly use volatile fatty acids such as propionic acid and butyric acid to produce methane. Therefore, the volatile fatty acid conversion ability of sludge microorganisms can be used to improve the methane yield. Thus, the problem of imbalance between hydrogen production and methane production efficiency in traditional single microbial anaerobic digestion technology is solved, and the overall efficiency of anaerobic hydrogen and methane production from straw is significantly improved.

[0023] In addition, the present application conducts the heat released in the hydrogen production stage directly to the methane production fermentation tank through a heat pipe, maintains the temperature of the methane production fermentation tank, realizes heat recovery and utilization, and reduces energy consumption.

[0024] Other features and advantages of the present disclosure will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The accompanying drawings are used to provide a further understanding of the present disclosure and constitute a part of the specification. Together with the following detailed description, they are used to explain the present disclosure but do not constitute a limitation of the present disclosure. In the accompanying drawings:

[0026] Figure 1 Schematic diagram of the structure of the device for producing hydrogen and methane by anaerobic fermentation of coupled rumen fluid and sludge microorganisms provided in an embodiment of the present disclosure;

[0027] Figure 2 It is a schematic structural diagram of the pipetting components of the device for coupling rumen fluid and sludge microbial anaerobic fermentation to produce hydrogen and methane, provided by an embodiment of the present disclosure.

[0028] Description of Reference Numerals

[0029] 1. Hydrogen production fermentation tank; 11. Hydrogen outlet; 111. First gas control valve; 12. First slag discharge port; 13. Hydrogen production feed port; 2. Methane production fermentation tank; 21. Methane outlet; 211. Second gas control valve; 22. Second slag discharge port; 23. First feed port; 24. Second feed port; 3. Liquid transfer assembly; 31. Liquid guide tube; 32. Liquid pump; 33. Filter; 4. High-pressure rotary nozzle; 5. Heat pipe; 51. Horizontal heat pipe; 52. Inclined heat pipe; 53. Collector head; 6. Moving wheel; 7. Visual window. DETAILED DESCRIPTION

[0030] The following describes the specific embodiments of the present disclosure in detail with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present disclosure and are not intended to limit the present disclosure.

[0031] In this disclosure, unless otherwise specified, directional words such as "top, bottom, inside, outside" are used relative to the outline of the corresponding component itself. In addition, the terms "first", "second", etc. used in this disclosure are intended to distinguish one element from another and do not have sequentiality or importance. In the following description, when referring to the drawings, unless otherwise explained, the same figure numbers in different drawings represent the same or similar elements. The above definitions are only used to explain and illustrate this disclosure and should not be understood as limiting the disclosure.

[0032] According to an exemplary embodiment of the present disclosure, a method for producing hydrogen and methane by coupling anaerobic fermentation of rumen fluid and sludge microorganisms is provided, comprising the following steps:

[0033] Hydrogen production stage: the pretreated straw is mixed with rumen fluid microorganisms and injected into the hydrogen production fermentation tank 1. The air in the hydrogen production fermentation tank 1 is extracted through the hydrogen outlet 11 to make the pressure in the hydrogen production fermentation tank 1 ≤ 0.001 MPa. The fermentation mixture in the hydrogen production fermentation tank 1 continues to ferment, and hydrogen is continuously collected until the hydrogen production pressure is less than 0.1 MPa.

[0034] Methane production stage: The pretreated straw is mixed with sludge microorganisms and injected into the methanogenic fermentation tank 2. The air in the methanogenic fermentation tank 2 is extracted through the methane outlet 21 to make the pressure in the methanogenic fermentation tank 2 ≤ 0.08 MPa. When the hydrogen production pressure reaches the preset pressure value, the liquid in the hydrogen production fermentation tank 1 is introduced into the methanogenic fermentation tank 2 through the pipetting component 3. The fermentation mixture in the methanogenic fermentation tank 2 continues to ferment, and methane is continuously collected until the methane pressure is less than 0.05 MPa.

[0035] Cleaning stage: The cleaning liquid is sprayed through the high-pressure rotating nozzle 4 of the cleaning component, and the residue is discharged through the first slag discharge port 12 and the second slag discharge port 22 to complete the cleaning of the device.

[0036] Through the above technical solution, the coupling rumen fluid and sludge microbial anaerobic fermentation hydrogen and methane production method of the present application utilizes the high lignocellulose degradation ability of rumen fluid microorganisms in the hydrogen production stage, which is conducive to improving the hydrogen yield. In the methane production stage, when the hydrogen production pressure reaches the preset pressure value, the liquid in the hydrogen production fermentation tank 1 is introduced into the methane production fermentation tank 2 through the pipetting component 3. Since the methanogens in the sludge microorganisms are mainly acetic acid trophic methanogens, they can directly use acetic acid or indirectly use volatile fatty acids such as propionic acid and butyric acid to produce methane. Therefore, the volatile fatty acid conversion ability of the sludge microorganisms can be used to improve the methane yield. Thus, the problem of imbalance between hydrogen production and methane production efficiency in traditional single microbial anaerobic digestion technology is solved, and the overall efficiency of straw anaerobic hydrogen and methane production is significantly improved. In addition, the present application conducts the heat released in the hydrogen production stage directly to the methane production fermentation tank 2 through the heat pipe 5, maintains the temperature of the methane production fermentation tank 2, realizes heat recovery and reduces energy consumption. Through this setting, straw is more conducive to the degradation of rumen fluid microorganisms. The appropriate temperature and pH conditions provide a suitable living environment for rumen fluid microorganisms, which is conducive to improving the degradation efficiency of rumen fluid microorganisms on straw and thus increasing the hydrogen production rate.

[0037] Among them, in the hydrogen production stage, the air in the hydrogen production fermentation tank 1 is extracted to make the pressure in the hydrogen production fermentation tank 1 ≤0.001MPa, so as to provide an anaerobic environment for the fermentation mixture in the hydrogen production fermentation tank 1; similarly, in the methane production stage, the air in the methane production fermentation tank 2 is extracted to make the pressure in the methane production fermentation tank 2 ≤0.08MPa, so as to provide an anaerobic environment for the fermentation mixture in the methane production fermentation tank 2.

[0038] According to an exemplary embodiment of the present disclosure, during the hydrogen production stage, the straw is oven-dried at 60°C-70°C, then crushed and sieved. Particles with a size of 2-5 mm are then anaerobic fermented with rumen fluid microorganisms at 37°C-40°C and a pH of 6.0-6.5. This arrangement makes the straw more conducive to rumen fluid microbial degradation. The appropriate temperature and pH conditions provide a suitable living environment for rumen fluid microorganisms, which helps improve the efficiency of rumen fluid microorganisms in straw degradation and thus increase hydrogen production. For example, during the hydrogen production stage, the oven temperature can be 60°C, 65°C, or 70°C; the anaerobic fermentation temperature can be 37°C, 39°C, or 40°C, but this disclosure does not impose specific limitations on this.

[0039] According to an exemplary embodiment of the present disclosure, in the methanogenesis stage, the straw is dried in an oven at 60°C-70°C, then crushed and sieved. Straw particles with a particle size of 2-5 mm are taken together with sludge microorganisms for anaerobic fermentation at 37°C-40°C and pH 6.8-7.2. Similar to the hydrogen production stage, the straw is pretreated to make it suitable for degradation by sludge microorganisms. The suitable temperature and pH conditions provide a good environment for sludge microorganisms, which is conducive to the sludge microorganisms utilizing the straw and substances produced in the hydrogen production stage to produce methanogens and increase the methanogenesis rate. Exemplarily, in the methanogenesis stage, the oven temperature can be 60°C, 65°C or 70°C, and the anaerobic fermentation temperature can be 37°C, 39°C or 40°C. The present disclosure does not impose any specific restrictions on this.

[0040] The particle size of the straw particles in the hydrogen production stage and the methane production stage can be set to 2 mm, 3 mm or 5 mm, and the present disclosure does not impose any specific restrictions on this.

[0041] According to an exemplary embodiment of the present disclosure, during the methane production phase, when the preset pressure is less than 0.15 MPa, the liquid in hydrogen-producing fermentation tank 1 is introduced into methane-producing fermentation tank 2 via pipetting assembly 3. By setting an appropriate preset pressure, the fermentation process in hydrogen-producing fermentation tank 1 is ensured. Liquid is introduced only when hydrogen production reaches a certain level and the pressure meets the required conditions. This prevents the adverse effects of premature or delayed introduction on the methane production phase, optimizes the connection between hydrogen and methane production, and improves overall production efficiency.

[0042] On the basis of the above scheme, the present disclosure also provides a device for producing hydrogen and methane by anaerobic fermentation of rumen fluid and sludge microorganisms, which is used for the above method for producing hydrogen and methane by anaerobic fermentation of rumen fluid and sludge microorganisms. Figure 1 and Figure 2 As shown in the figure, the device for producing hydrogen and methane by coupling anaerobic fermentation of rumen fluid and sludge microorganisms includes: a hydrogen-producing and methane-producing component: including a methane-producing fermentation tank 2 and a hydrogen-producing fermentation tank 1 nested in the methane-producing fermentation tank 2, the methane-producing fermentation tank 2 and the hydrogen-producing fermentation tank 1 are connected by a heat pipe 5 to transfer the heat generated in the hydrogen-producing fermentation tank 1 to the methane-producing fermentation tank 2; the hydrogen-producing fermentation tank 1 is provided with a hydrogen-producing feed port 13, a hydrogen outlet 11 and a first slag outlet 12, and the methane-producing fermentation tank 2 is provided with a methane-producing alkane feed port, methane outlet 21 and second slag discharge port 22; pipetting component 3: including a liquid guide tube 31 and a liquid pump 32, the liquid pump 32 is arranged on the outside of the side wall of the hydrogen-producing fermentation tank 1, one end of the liquid guide tube 31 is located on the inner side of the bottom of the hydrogen-producing fermentation tank 1 and is connected to a filter screen 33, and the other end is connected to the liquid pump 32; cleaning component: including multiple high-pressure rotary nozzles 4, multiple high-pressure rotary nozzles 4 are distributed on the inner and outer walls of the hydrogen-producing fermentation tank 1 and the inner wall and inner side of the bottom of the methane-producing fermentation tank 2.

[0043] In the above technical solution, the hydrogen-producing fermentation tank 1 is nested in the methane-producing fermentation tank 2 and connected through the heat pipe 5, which can effectively utilize the heat generated in the hydrogen production stage to provide heat for the methane production stage, saving energy; the pipetting component 3 can realize the transfer of liquid in the hydrogen-producing fermentation tank 1 to the methane-producing fermentation tank 2; the cleaning component can effectively clean the device. The overall device provides hardware support for the method of coupling rumen fluid and sludge microorganisms to produce hydrogen and methane through anaerobic fermentation, ensuring the implementation of the method.

[0044] According to an exemplary embodiment of the present disclosure, referring to Figure 1 As shown, the hydrogen outlet 11 can be embedded in the center of the hydrogen production feed port 13, and a first gas control valve 111 is installed at the hydrogen outlet 11. This arrangement makes the device structure more compact and reasonable. Among them, the first gas control valve 111 can control the discharge of hydrogen, ensuring the pressure and anaerobic environment in the hydrogen production fermentation tank 1, which is conducive to the hydrogen production reaction.

[0045] According to an exemplary embodiment of the present disclosure, referring to Figure 1 As shown, the methanogenic feed port may include a first feed port 23 and a second feed port 24, which are respectively arranged on the left and right sides of the hydrogen production feed port 13, and a methane outlet 21 is embedded in the center of the first feed port 23 and the second feed port 24, and a second gas control valve 211 is installed at the methane outlet 21. The first feed port 23 and the second feed port 24 can be arranged symmetrically to facilitate the addition of materials. The position of the methane outlet 21 and the setting of the second gas control valve 211 can control the discharge of methane, facilitate collection, and ensure the pressure and anaerobic environment in the methanogenic fermentation tank 2, which is conducive to the progress of the methanogenic reaction.

[0046] In the present disclosure, sealing covers can be provided at the hydrogen production feed port 13, the first feed port 23 and the second feed port 24, and a hydrogen outlet 11 and a methane outlet 21 can be provided on the corresponding covers, so that the feeding operation can be carried out by opening the covers, and when the feeding is completed, the covers are closed to put the device in a sealed state.

[0047] According to an exemplary embodiment of the present disclosure, referring to Figure 1 As shown, the sidewalls and bottom of the methanogenic fermentation tank 2 are provided with an insulation layer. The insulation layer is made of glass wool. The insulation layer can reduce heat loss in the methanogenic fermentation tank 2, maintain a stable temperature inside the tank, provide a stable temperature environment for the methanogenic reaction, and help improve the efficiency of methanogenesis.

[0048] According to an exemplary embodiment of the present disclosure, referring to Figure 1As shown, the heat pipe 5 may include a horizontal heat pipe 51, an inclined heat pipe 52 and a heat collecting head 53. One end of the horizontal heat pipe 51 is connected to the heat collecting head 53 provided on the inner side of the side wall of the hydrogen-producing fermentation tank 1, and the other end is located on the inner side of the side wall of the methane-producing fermentation tank 2; one end of the inclined heat pipe 52 is connected to the heat collecting head 53 provided on the inner side of the bottom of the hydrogen-producing fermentation tank 1, and the other end is located on the inner side of the bottom of the methane-producing fermentation tank 2. The structural design of the heat pipe 5 can more effectively transfer the heat in the hydrogen-producing fermentation tank 1 to the methane-producing fermentation tank 2, improve the heat transfer efficiency, further utilize the heat in the hydrogen production stage, and save energy. According to the exemplary embodiment of the present disclosure, with reference to Figure 1 As shown, the heat pipe 5 is a hollow cylindrical tube made of copper; the heat collecting head 53 is a solid U-shaped tube made of stainless steel. The copper heat pipe 5 has excellent thermal conductivity, which improves heat transfer efficiency; the stainless steel heat collecting head 53 has good corrosion resistance and strength, ensuring stable heat collection and conduction, further optimizing the device's heat transfer function.

[0049] In order to facilitate the transfer of the device for producing hydrogen and methane by coupled anaerobic fermentation of rumen fluid and sludge microorganisms, a plurality of moving wheels 6 may be provided at the bottom of the methane fermentation tank.

[0050] Reference Figure 1 and Figure 2 , the implementation process of this application is detailed as follows:

[0051] 1. Implementation process of hydrogen production stage

[0052] Take an appropriate amount of straw and put it into a 60℃-70℃ oven to dry. The drying time is determined according to the moisture content and quantity of the straw.

[0053] The dried straw is crushed using a crusher and then sieved to select straw particles with a particle size of 2-5 mm;

[0054] Collect rumen fluid, treat it appropriately to remove impurities and harmful microorganisms, and obtain pure rumen fluid microorganisms;

[0055] The selected straw particles are mixed with rumen fluid microorganisms in a certain ratio. The mixing ratio can be determined based on experimental optimization. The cover of the hydrogen production feed port 13 is opened, and the mixed materials are injected into the hydrogen production fermentation tank 1 through the hydrogen production feed port 13. The hydrogen production feed port 13 is closed.

[0056] Connect a vacuum pump through the hydrogen outlet 11 to extract the air in the hydrogen production fermentation tank 1 until the pressure in the tank is ≤ 0.001 MPa, thereby forming an anaerobic environment;

[0057] The temperature of the hydrogen production fermentation tank 1 is controlled at 37°C-40°C, and the pH value in the tank is maintained in the range of 6.0-6.5 by a pH adjustment device;

[0058] The hydrogen collecting device is started to continuously collect the generated hydrogen through the hydrogen outlet 11, and the hydrogen production pressure is monitored in real time. When the hydrogen production pressure is less than 0.1 MPa, the hydrogen production process is stopped.

[0059] 2. Implementation Process of Methane Production

[0060] Similarly, take an appropriate amount of straw, and follow the same pretreatment method as the hydrogen production stage, dry it in an oven at 60℃-70℃, then crush and sieve it to obtain straw particles with a particle size of 2-5mm;

[0061] Collect sludge, treat the sludge, and separate sludge microorganisms;

[0062] The straw particles and the sludge microorganisms are mixed in a certain ratio, which can be determined by experimental optimization. The lids of the first feed port 23 and the second feed port 24 are opened, and the mixed materials are injected into the methanogenic fermentation tank 2 through the first feed port 23 and the second feed port 24. The first feed port 23 and the second feed port 24 are closed.

[0063] Connect a vacuum pump through the methane outlet 21 to extract the air in the methanogenic fermentation tank 2 until the pressure in the tank is ≤ 0.08 MPa, thereby forming an anaerobic environment;

[0064] The temperature of the methanogenic fermentation tank 2 is controlled at 37°C-40°C, and the pH value in the tank is maintained in the range of 6.8-7.2 by a pH adjustment device;

[0065] When the hydrogen production pressure in the hydrogen production fermentation tank 1 reaches a preset pressure value less than 0.15 MPa, the liquid pump 32 is started to introduce the liquid in the hydrogen production fermentation tank 1 into the methane production fermentation tank 2 through the liquid transfer component 3;

[0066] The methane collection device is started to continuously collect the generated methane through the methane outlet 21, and the methane pressure is monitored in real time. When the methane pressure is less than 0.05 MPa, the methane production process is stopped.

[0067] In order to facilitate observation of whether the liquid in the hydrogen-producing fermentation tank 1 smoothly enters the methane-producing fermentation tank 2 , a visual window 7 can be provided on the methane-producing fermentation tank 2 . Specifically, a hole can be opened on the methane-producing fermentation tank 2 and quartz glass can be installed to form the visual window 7 .

[0068] 3. Implementation process of the cleaning stage

[0069] Inject cleaning fluid (such as clean water or cleaning agent of appropriate concentration) into the storage tank of the cleaning component;

[0070] The high-pressure rotating nozzle 4 is started to clean the hydrogen-producing fermentation tank 1 and the methane-producing fermentation tank 2 by spraying the cleaning liquid at high pressure;

[0071] During the cleaning process, the residue is flushed by the cleaning liquid and discharged from the device through the first slag discharge port 12 and the second slag discharge port 22;

[0072] Continue cleaning until the discharged cleaning fluid is clear and free of impurities, close the high-pressure rotating nozzle 4, and complete the device cleaning.

[0073] Through the above-mentioned specific implementation methods, the method for producing hydrogen and methane by coupling anaerobic fermentation of rumen fluid and sludge microorganisms as described in this application can be realized. The device of the present invention can efficiently and stably convert straw into hydrogen and methane, effectively solving the problem of imbalance in hydrogen production and methane production efficiency in traditional technologies, and has good application prospects and economic benefits.

[0074] The preferred embodiments of the present disclosure are described in detail above in conjunction with the accompanying drawings. However, the present disclosure is not limited to the specific details of the above embodiments. Within the technical concept of the present disclosure, various simple modifications can be made to the technical solutions of the present disclosure, and these simple modifications all fall within the scope of protection of the present disclosure.

[0075] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any appropriate manner without contradiction. In order to avoid unnecessary repetition, the present disclosure will not further describe various possible combinations.

[0076] In addition, the various embodiments of the present disclosure may be arbitrarily combined, and as long as they do not violate the concept of the present disclosure, they should also be regarded as the contents disclosed by the present disclosure.

Claims

1. A method for producing hydrogen and methane by coupling anaerobic fermentation of rumen fluid and sludge microorganisms, characterized in that: The following steps are involved: Hydrogen production stage: pretreated straw is mixed with rumen fluid microorganisms and injected into a hydrogen production fermentation tank (1); air in the hydrogen production fermentation tank (1) is extracted through a hydrogen outlet (11) to make the pressure in the hydrogen production fermentation tank (1) ≤ 0.001 MPa; the fermentation mixture in the hydrogen production fermentation tank (1) continues to ferment, and hydrogen is continuously collected until the hydrogen production pressure is less than 0.1 MPa; Methane production stage: pre-treated straw is mixed with sludge microorganisms and injected into a methanogenic fermentation tank (2); air in the methanogenic fermentation tank (2) is extracted through a methane outlet (21) to make the pressure in the methanogenic fermentation tank (2) ≤ 0.08 MPa; when the hydrogen production pressure reaches a preset pressure value, the liquid in the hydrogen production fermentation tank (1) is introduced into the methanogenic fermentation tank (2) through a pipetting assembly (3); the fermentation mixture in the methanogenic fermentation tank (2) continues to ferment, and methane is continuously collected until the methane pressure is less than 0.05 MPa; Cleaning stage: the cleaning liquid is sprayed through the high-pressure rotating nozzle (4) of the cleaning component, and the residue is discharged through the first slag discharge port (12) and the second slag discharge port (22), thereby completing the cleaning of the device.

2. The method for producing hydrogen and methane by coupling rumen fluid and sludge microbial anaerobic fermentation according to claim 1, characterized in that: In the hydrogen production stage: the straw is dried in an oven at 60℃-70℃ and then crushed and sieved. Particles with a particle size of 2-5mm are taken together with rumen fluid microorganisms for anaerobically fermented at 37℃-40℃ and pH 6.0-6.

5.

3. The method for producing hydrogen and methane by coupling rumen fluid and sludge microbial anaerobic fermentation according to claim 1, characterized in that: In the methanogenesis stage, the straw is dried in an oven at 60-70°C and then crushed and sieved. The straw particles with a particle size of 2-5 mm are taken together with sludge microorganisms for anaerobically fermented at 37-40°C and pH 6.8-7.

2.

4. The method for producing hydrogen and methane by coupling rumen fluid and sludge microbial anaerobic fermentation according to claim 1, characterized in that: In the methanogenic stage, when the preset pressure value is less than 0.15 MPa, the liquid in the hydrogen-producing fermentation tank (1) is introduced into the methanogenic fermentation tank (2) through the liquid transfer component (3).

5. A device for producing hydrogen and methane by coupling rumen fluid and sludge microbial anaerobic fermentation, characterized in that: The method for producing hydrogen and methane by anaerobic fermentation of rumen fluid and sludge microorganisms according to any one of claims 1 to 4, wherein the device for producing hydrogen and methane by anaerobic fermentation of rumen fluid and sludge microorganisms comprises: A hydrogen-producing and methane-producing component comprises a methane-producing fermentation tank (2) and a hydrogen-producing fermentation tank (1) nested in the methane-producing fermentation tank (2), wherein the methane-producing fermentation tank (2) is connected to the hydrogen-producing fermentation tank (1) via a heat conducting pipe (5) so as to transfer heat generated in the hydrogen-producing fermentation tank (1) to the methane-producing fermentation tank (2); the hydrogen-producing fermentation tank (1) is provided with a hydrogen-producing feed inlet (13), a hydrogen outlet (11) and the first slag discharge port (12), and the methane-producing fermentation tank (2) is provided with a methane-producing feed inlet, the methane outlet (21) and the second slag discharge port (22); A liquid transfer assembly (3): comprising a liquid guide tube (31) and a liquid pump (32), wherein the liquid pump (32) is arranged on the outside of the side wall of the hydrogen production fermentation tank (2), one end of the liquid guide tube (31) is located on the inside of the bottom of the hydrogen production fermentation tank (1) and is connected to a filter (33), and the other end is connected to the liquid pump (32); The cleaning component comprises a plurality of the high-pressure rotating nozzles (4), wherein the plurality of the high-pressure rotating nozzles (4) are distributed on the inner and outer walls of the hydrogen-producing fermentation tank (1) and the inner wall and the inner side of the bottom of the methane-producing fermentation tank (2).

6. The device for producing hydrogen and methane by coupling rumen fluid and sludge microbial anaerobic fermentation according to claim 5, characterized in that: The hydrogen outlet (11) is embedded in the center of the hydrogen production feed port (13), and a first gas control valve (111) is installed at the hydrogen outlet (11).

7. The device for producing hydrogen and methane by coupling rumen fluid and sludge microbial anaerobic fermentation according to claim 5, characterized in that: The methane production feed port comprises a first feed port (23) and a second feed port (24), wherein the first feed port (23) and the second feed port (24) are respectively arranged on the left and right sides of the hydrogen production feed port (13), and the methane outlet (21) is embedded in the center of the first feed port (23) and the second feed port (24), and a second gas control valve (211) is installed at the methane outlet (21).

8. The device for producing hydrogen and methane by coupling rumen fluid and sludge microbial anaerobic fermentation according to claim 5, characterized in that: The side walls and bottom of the methane-producing fermentation tank (2) are both provided with a heat insulation layer (8).

9. The device for producing hydrogen and methane by coupling rumen fluid and sludge microbial anaerobic fermentation according to claim 5, characterized in that: The heat conducting pipe (5) comprises a horizontal heat conducting pipe (51), an inclined heat conducting pipe (52) and a heat collecting head (53); one end of the horizontal heat conducting pipe (51) is connected to the heat collecting head (53) provided on the inner side of the side wall of the hydrogen-producing fermentation tank (1), and the other end is located on the inner side of the side wall of the methane-producing fermentation tank (2); one end of the inclined heat conducting pipe (52) is connected to the heat collecting head (53) provided on the inner side of the bottom of the hydrogen-producing fermentation tank (1), and the other end is located on the inner side of the bottom of the methane-producing fermentation tank (2).

10. The device for producing hydrogen and methane by coupling rumen fluid and sludge microbial anaerobic fermentation according to claim 9, characterized in that: The heat conducting pipe (5) is constructed as a hollow cylindrical pipe, and the heat conducting pipe (5) is made of copper; the heat collecting head (53) is constructed as a solid U-shaped pipe, and the heat collecting head (53) is made of stainless steel.

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