A bio-fermentation hydrogen production device and a hydrogen production method thereof

Abstract

The present application relates to the technical field of bioenergy and environmental engineering, and discloses a bio-fermentation hydrogen production device and a hydrogen production method thereof. The hydrogen production device comprises a reactor main body, a three-axis orthogonal gradient magnetic field coil group, an ultrasonic transducer, a gas-liquid membrane separation module, a sensor monitoring module and a control unit. The three-axis orthogonal gradient magnetic field coil group generates a dynamic three-dimensional alternating magnetic field in the X-axis, Y-axis and Z-axis directions, drives the suspension and fluidization of magnetic biological carriers, strengthens liquid phase mass transfer and promotes the release of dissolved hydrogen; the ultrasonic transducer uses cavitation effect to remove dissolved hydrogen in situ; the gas-liquid membrane separation module continuously removes dissolved gas from the system. The control unit predicts the change trend of the hydrogen production rate based on the sensor detection data, and starts the ultrasonic hydrogen removal and / or adjusts the magnetic field parameters in advance. The present application effectively removes the thermodynamic inhibition of dissolved hydrogen through the synergy of magnetic field fluidization, ultrasonic cavitation and membrane separation, combined with prediction and control, which is beneficial to improve the hydrogen production efficiency and operation stability.

Description

Technical Field

[0001] This invention relates to the field of bioenergy and environmental engineering technology, specifically to a bio-fermentation hydrogen production device and its hydrogen production method. Background Technology

[0002] Hydrogen energy is widely regarded as an ideal energy carrier for the future due to its clean combustion products and high calorific value. Bio-fermentation for hydrogen production can directly utilize renewable raw materials such as organic wastewater and agricultural waste, achieving energy conversion under normal temperature and pressure conditions. It combines the dual benefits of waste resource utilization and clean energy production, and is considered one of the most promising hydrogen production methods.

[0003] Biological dark fermentation hydrogen production technology can directly utilize raw materials such as organic wastewater and agricultural waste to achieve energy conversion under mild conditions, making it a promising clean hydrogen production route. However, the dark fermentation hydrogen production process is constrained by product inhibition effects. Specifically, hydrogen-producing microorganisms continuously release hydrogen into the fermentation broth during metabolism. Due to the low solubility of hydrogen in water, dissolved hydrogen gradually accumulates when mass transfer in the liquid phase is hindered, leading to a continuous increase in the hydrogen partial pressure in the liquid phase. When the hydrogen partial pressure exceeds a certain threshold, the Gibbs free energy change (ΔG) of the hydrogen production reaction changes from negative to positive, and the reaction becomes thermodynamically unfavorable. At this point, the microbial metabolic pathway is forced to shift from hydrogen production to solvent production (such as ethanol, lactic acid, etc.), inhibiting hydrogenase activity, and significantly reducing the hydrogen production rate and substrate conversion rate. In continuously operating reactors, the local hydrogen partial pressure often far exceeds the inhibition level, becoming a bottleneck restricting the continuous improvement of hydrogen production efficiency.

[0004] To overcome the thermodynamic inhibition of hydrogen partial pressure, various methods for removing dissolved hydrogen have been proposed in related technologies: gas purging (such as N2 or CO2) can reduce the partial pressure of hydrogen in the liquid phase, but it will dilute the purity of hydrogen in the gas phase product and increase the cost of subsequent purification; vacuum suction method has high energy consumption and is prone to cell loss; traditional mechanical stirring has limited effect on enhancing gas-liquid mass transfer and is difficult to reduce the dissolved hydrogen concentration to the thermodynamically favorable range.

[0005] Therefore, how to achieve in-situ and efficient removal of dissolved hydrogen from the fermentation broth, while avoiding negative impacts on bacterial activity and product purity, has become a pressing problem that needs to be solved for the large-scale application of biological dark fermentation hydrogen production technology. Summary of the Invention

[0006] In view of this, the present invention provides a bio-fermentation hydrogen production device and a hydrogen production method thereof to solve the problems mentioned in the background art.

[0007] In a first aspect, the present invention provides a bio-fermentation hydrogen production apparatus, comprising: The reactor body has a reaction chamber, which is suitable for containing fermentation substrate and magnetic biological carrier loaded with hydrogen-producing bacteria. The triaxial orthogonal gradient magnetic field coil group is arranged in groups at intervals on the outside of the reactor body in the X-axis, Y-axis and Z-axis directions. The triaxial orthogonal gradient magnetic field coil group is adapted to generate a dynamic three-dimensional alternating magnetic field inside the reactor to drive the magnetic biological carrier to be in a suspended fluidized state in the fermentation broth. An ultrasonic transducer is disposed at the bottom of the reactor body and is adapted to emit ultrasonic waves toward the fermentation broth to remove dissolved hydrogen from the fermentation broth. A gas-liquid membrane separation module is disposed outside the reactor body and is connected to the reaction chamber to extract dissolved gas from the fermentation broth to the outside of the reaction chamber. A sensor monitoring module, comprising at least a dissolved hydrogen sensor, wherein the detection end of the dissolved hydrogen sensor is disposed in the fermentation broth of the reaction chamber for monitoring the dissolved hydrogen concentration in the fermentation broth; The control unit is electrically connected to the triaxial orthogonal gradient magnetic field coil group, the ultrasonic transducer, the gas-liquid film separation module, and the sensor monitoring module, respectively. The control unit is adapted to receive the detection data from the sensor monitoring module, predict the hydrogen production rate change trend based on the detection data, and start the ultrasonic transducer in advance for ultrasonic cavitation dehydrogenation based on the hydrogen production rate change trend, and / or adjust the magnetic field parameters of the triaxial orthogonal gradient magnetic field coil group in advance.

[0008] Beneficial Effects: This application aims to solve the thermodynamic inhibition problem caused by dissolved hydrogen accumulation in fermentation broth by combining multiple physical fields of magnetic field fluidization, ultrasonic cavitation, and membrane separation, and by pre-regulating based on the prediction of dissolved hydrogen concentration. Specifically, a triaxial orthogonal gradient magnetic field coil group independently generates a dynamic three-dimensional alternating magnetic field in the X, Y, and Z directions, driving the magnetic biological carrier to be in a suspended fluidized state in the fermentation broth. This suspension fluidization effect can continuously disturb the liquid phase mass transfer boundary layer on the carrier surface and around it, accelerating the diffusion of dissolved hydrogen generated by metabolism inside the carrier into the bulk liquid phase, and avoiding excessive local accumulation of dissolved hydrogen on the carrier surface. At the same time, the shuttle motion of the carrier in three-dimensional space increases the renewal frequency of the gas-liquid interface, which is also conducive to the release and escape of bubbles from the liquid phase. Ultrasonic waves are emitted into the fermentation broth through an ultrasonic transducer, and a large number of micron-sized cavitation bubbles are formed in the liquid phase by utilizing the acoustic cavitation effect. Since the partial pressure of dissolved hydrogen at the gas-liquid interface is much lower than its dissolution equilibrium partial pressure in the liquid phase, dissolved hydrogen undergoes rectification and diffusion into the cavitation bubbles and floats up with the bubbles to escape, realizing in-situ removal of dissolved hydrogen. The gas-liquid membrane separation module provides a gas-liquid separation interface, continuously extracting dissolved gases from the fermentation broth from the reaction system. This prevents the removed gases from redissolving or accumulating in the top space, which could cause a rise in the liquid-phase hydrogen partial pressure. Real-time monitoring data from the dissolved hydrogen sensor allows the control unit to dynamically sense the changing trend of the liquid-phase hydrogen concentration. Based on the detection data, the control unit predicts the direction of change in the hydrogen production rate and initiates ultrasonic dehydrogenation and / or adjusts the magnetic field parameters before the hydrogen partial pressure reaches the inhibition threshold, transforming dehydrogenation intervention from a passive response to active prevention. Through the combination of these technologies, the liquid-phase dissolved hydrogen concentration is continuously suppressed within a thermodynamically favorable range, effectively ensuring the smooth progress of the hydrogen production metabolic pathway and improving the hydrogen production efficiency and operational stability of the device.

[0009] In some embodiments, the gas-liquid membrane separation module includes a hydrophobic membrane module, a circulation pump, a circulation pipeline, and a vacuum pump. The reaction chamber is provided with an outlet and an inlet. The outlet is connected to the inlet of the hydrophobic membrane module through the circulation pipeline. The circulation pump is installed on the circulation pipeline with the outlet facing the inlet. The inlet is connected to the liquid outlet of the hydrophobic membrane module through the circulation pipeline. The vacuum pump is connected to the gas outlet of the hydrophobic membrane module and is adapted to create a negative pressure in the cavity of the hydrophobic membrane module to extract dissolved gas to the outside of the system.

[0010] Beneficial effects: The outlet of the reaction chamber is connected to the inlet of the hydrophobic membrane module via a circulation pipeline. Driven by a circulation pump, the fermentation broth flows into the hydrophobic membrane module through the circulation pipeline. A vacuum pump is connected to the gas outlet of the hydrophobic membrane module, creating a slightly negative pressure environment within the mold cavity. This slight negative pressure allows dissolved gas to permeate through the hydrophobic membrane wall from the liquid phase into the gas phase cavity under the dual drive of concentration and pressure differences, and is continuously extracted from the system by the vacuum pump. After the dissolved gas is removed, the fermentation broth flows back to the inlet of the reaction chamber through the liquid outlet of the hydrophobic membrane module and the circulation pipeline, achieving circulating degassing of the fermentation broth. This scheme utilizes a circulating degassing loop to ensure that the fermentation broth in the reaction chamber has ample opportunity to contact the hydrophobic membrane module and complete degassing, reducing the risk of dissolved hydrogen accumulation in localized dead zones. Simultaneously, efficient separation of the gas and liquid phases is achieved within the membrane module, preventing direct contact between the gaseous product and the fermentation broth, thus avoiding cell loss or secondary entrainment of product gas by the fermentation broth.

[0011] In some embodiments, the hydrophobic membrane assembly includes a hydrophobic hollow fiber membrane and a membrane shell, wherein the hydrophobic hollow fiber membrane is encapsulated inside the membrane shell, and the hydrophobic hollow fiber membrane is a polytetrafluoroethylene membrane or a polyvinylidene fluoride membrane, and the membrane pore size of the hydrophobic hollow fiber membrane is 0.05 μm-0.2 μm; the vacuum pump is adapted to generate a negative pressure of 10 kPa-50 kPa within the mold cavity of the hydrophobic membrane assembly.

[0012] Beneficial effects: Both polytetrafluoroethylene (PTFE) and polyvinylidene fluoride (PVDF) are strongly hydrophobic materials with a contact angle greater than 90° with the aqueous phase. In aqueous fermentation broth, they effectively prevent liquid water from permeating the membrane wall while allowing dissolved gas molecules to diffuse through the membrane pores, facilitating efficient separation of the gas and liquid phases. The membrane pore size is specifically 0.05 μm-0.2 μm. This pore size range allows dissolved gas molecules to pass freely while effectively blocking suspended bacteria and carrier debris in the fermentation broth, preventing pore blockage and extending the continuous service life of the membrane module. The negative pressure within the membrane cavity is specifically 10 kPa-50 kPa, providing sufficient suction driving force to ensure efficient dissipation of dissolved gas while preventing excessive membrane wall deformation or excessive removal of water from the fermentation broth due to excessive negative pressure. This negative pressure range balances degassing efficiency and membrane structure stability.

[0013] In some embodiments, the magnetic biocarrier is a porous microsphere, comprising a magnetic core and a porous polymer coating layer arranged sequentially from the inside out. The magnetic core is a superparamagnetic Fe3O4 nanoparticle, and the porous polymer coating layer covers the periphery of the magnetic core. The porous polymer coating layer is a hybrid hydrogel framework formed by crosslinking polyvinyl alcohol, sodium alginate, and nanocellulose.

[0014] Beneficial Effects: The technical objective of this solution is to provide a porous carrier structure that combines magnetic responsiveness, biocompatibility, and high specific surface area, offering a stable attachment and colonization space for hydrogen-producing bacteria and serving as the target of magnetic field driving force. Specifically, the magnetic carrier is in the form of porous microspheres, comprising a magnetic core and a porous polymer coating layer from the inside out. The magnetic core uses superparamagnetic Fe3O4 nanoparticles. This material can be rapidly magnetized and generate magnetic response motion under the action of an external magnetic field. After the magnetic field is removed, the residual magnetism is extremely low, avoiding carrier sedimentation or uneven distribution due to magnetic agglomeration between particles, thus ensuring good dispersion and suspension fluidization performance of the carrier in a dynamic alternating magnetic field. The porous polymer coating layer consists of a hybrid hydrogel framework formed by cross-linking polyvinyl alcohol, sodium alginate, and nanocellulose. PVA provides the framework with good film-forming properties and mechanical strength, sodium alginate provides abundant carboxyl sites to facilitate electrostatic adsorption and colonization of bacteria, and nanocellulose acts as a reinforcing phase to improve the pore structure stability of the framework. The three-dimensional network structure formed by the cross-linking of the three components possesses both high porosity and suitable pore size, providing ample attachment surface area and internal habitat space for hydrogen-producing bacteria, effectively increasing the microbial population within the reactor. The composite structure of the superparamagnetic core and the porous polymer coating layer enables the carrier to achieve overall suspension under magnetic field drive, while its porous structure ensures smooth exchange of substrates and metabolites between the carrier's interior and the external liquid phase.

[0015] In some embodiments, the porous polymer coating layer is grafted with a pH-sensitive monomer, wherein the pH-sensitive monomer is at least one of acrylic acid, methacrylic acid, or 2-(dimethylamino)ethyl methacrylate; the porosity of the porous polymer coating layer is 70%-85%, and the average pore size of the porous polymer coating layer is 30μm-80μm; the porous polymer coating layer is adapted to swell and expand its pores due to electrostatic repulsion at pH < 5.0, with the average pore size expanding to 60μm-100μm.

[0016] Beneficial Effects: The technical objective of this solution is to provide the carrier with adaptive capabilities to fermentation broth acidification, mitigating the toxic effects of acid accumulation on the internal microbial community. Under normal hydrogen-producing conditions (pH 5.5-6.5), the porous polymer coating layer maintains a moderate cross-linking and shrinkage state, with an average pore size of 30μm-50μm, which is conducive to the stable attachment of hydrogen-producing bacteria within the carrier and the formation of a dense biofilm structure. When the pH of the fermentation broth drops below 5.0, the carboxyl or amino functional groups of the pH-sensitive monomers (acrylic acid, methacrylic acid, or 2-(dimethylamino)ethyl methacrylate) grafted onto the hydrogel framework undergo protonation or deprotonation, resulting in electrostatic repulsion between the polymer chains and driving the hydrogel framework to absorb water and swell, expanding the average pore size to 60μm-100μm. This enlarged pore size design allows volatile fatty acids and dissolved hydrogen, acidic metabolic products accumulated inside the carrier, to diffuse outward more quickly, alleviating the metabolic inhibition of hydrogen-producing bacteria by acid accumulation. It also facilitates the penetration of nutrient substrates in the fermentation broth into the carrier, ensuring the nutrient supply to the inner bacterial community. Furthermore, the pH-sensitive response is a reversible process; when the pH of the fermentation broth rises, electrostatic repulsion weakens, and the carrier pore size returns to normal, without causing irreversible damage to the carrier structure.

[0017] In some embodiments, the outer surface of the porous polymer coating is grafted with a thermo-responsive polymer thin layer, the phase transition temperature of which is 36°C-38°C; the thermo-responsive polymer thin layer is hydrophilic when the temperature is below the phase transition temperature, and undergoes structural collapse and becomes hydrophobic when the temperature is above the phase transition temperature.

[0018] Beneficial Effects: The technical objective of this solution is to achieve controlled detachment of the aged biofilm from the carrier surface during biofilm renewal, avoiding damage to the inner active bacterial community caused by traditional physical or chemical stripping methods. Thermosensitive polymeric thin layers (such as poly(N-isopropylacrylamide) PNIPAM) have their phase transition temperature set to 36℃-38℃ through copolymerization ratio adjustment, matching the optimal fermentation temperature (35℃-38℃). During the normal hydrogen production stage (fermentation temperature 35℃-36.5℃), the polymer chains of the thermosensitive thin layer are in an extended state, exhibiting hydrophilicity, which is beneficial for the initial adhesion and biofilm formation of hydrogen-producing bacteria, as well as the wetting and absorption of nutrient substrates, promoting the rapid formation of a highly active biofilm on the carrier surface. When the aging biofilm needs to be renewed (fermentation temperature rises to 38℃-39℃), the polymer chains of the temperature-sensitive thin layer undergo a conformational change and hydrophobic collapse, and the surface rapidly changes from hydrophilic to hydrophobic. This change causes a sharp decrease in the interfacial adhesion between the aging biofilm and the carrier surface. Combined with the carrier collision driven by the magnetic field and the cavitation loosening effect of pulsed ultrasound, the aging biofilm can be completely peeled off from the carrier surface with extremely low mechanical force, while the inner highly active dense biofilm is preserved because it is not subjected to excessive shearing.

[0019] In some embodiments, the sensor monitoring module further includes a pH sensor, an ORP sensor, and an acoustic emission sensor. The detection ends of the pH sensor and the ORP sensor are respectively disposed in the fermentation broth of the reaction chamber. The pH sensor is used to monitor the pH value of the fermentation broth, and the ORP sensor is used to monitor the redox potential of the fermentation broth. The acoustic emission sensor is attached to the outer wall of the reactor body and is electrically connected to the control unit. The acoustic emission sensor has a sampling frequency band of 100kHz-500kHz and is used to collect acoustic signals generated during biofilm peeling. The control unit is equipped with an acoustic emission signal spectrum analysis module, which is used to extract characteristic frequency band signals of biofilm rupture. The characteristic frequency band is 150kHz-250kHz.

[0020] Beneficial effects: The pH sensor is used to monitor the pH value of the fermentation broth in real time to determine whether acid accumulation has occurred in the fermentation system; the ORP sensor is used to monitor the redox potential of the fermentation broth in real time, reflecting the electronic activity and reducing atmosphere of the fermentation system. An acoustic emission sensor is attached to the outer wall of the reactor body, collecting high-frequency acoustic signals of microcracks and fractures generated during biofilm peeling in a frequency band of 100kHz-500kHz. This acoustic signal is a direct physical characterization of the fracture and peeling of the aging biofilm under carrier collision and ultrasonic loosening. The acoustic emission signal spectrum analysis module configured in the control unit extracts a characteristic frequency band signal of 150kHz-250kHz from the collected signals. This characteristic frequency band is highly correlated with the brittle fracture of the aging biofilm matrix. When the acoustic signal energy in this frequency band changes abruptly, it indicates that the aging biofilm is undergoing large-scale cracking and peeling. At this time, the control unit can determine the peeling process based on this signal to avoid over-peeling or under-peeling.

[0021] In some embodiments, the ultrasonic transducer operates at a frequency of 28kHz-50kHz.

[0022] Beneficial effects: This frequency range is in the low-frequency ultrasonic range, which can generate a stable cavitation effect in the fermentation broth to remove dissolved hydrogen, while avoiding oxidative damage to the microbial community caused by free radicals generated at excessively high frequencies, and avoiding mechanical damage to the biofilm caused by strong cavitation impacts generated at excessively low frequencies, thus balancing dehydrogenation efficiency and microbial community activity protection.

[0023] In some embodiments, the top of the reactor body is provided with a sealing cover, and the sealing cover is provided with a feed inlet, which is connected to the reaction chamber for introducing fermentation substrate into the reaction chamber.

[0024] Beneficial effects: The feed inlet on the sealed cap facilitates the periodic replenishment of fermentation substrate into the reaction chamber, enabling continuous feeding operation.

[0025] In some embodiments, a sludge discharge pipe is also included, which is connected to the bottom of the reactor body and is used to discharge the detached aged biofilm from the reaction chamber.

[0026] Beneficial effects: The sludge discharge pipe is connected to the bottom of the reactor body and is used to discharge the peeled-off aged biofilm from the system, avoiding the accumulation of aged biofilm debris at the bottom of the reactor to form dead zones and secondary pollution, and maintaining a clean environment inside the reactor.

[0027] In some embodiments, a biogas collection device is also included, which is connected to the reaction chamber and is used to collect gaseous products generated by hydrogen-producing fermentation.

[0028] Beneficial effects: The biogas collection device is used to collect the gaseous products generated by hydrogen-producing fermentation, which facilitates the subsequent purification and utilization of the hydrogen products.

[0029] In some embodiments, a temperature control module is further included, the temperature control module including a temperature-controlled water jacket and a heat exchange unit, the temperature-controlled water jacket and the heat exchange unit being used to adjust the fermentation temperature inside the reaction chamber; the temperature-controlled water jacket is sleeved on the outside of the reactor body, the heat exchange unit is connected to the temperature-controlled water jacket through a pipeline, and the heat exchange unit is electrically connected to the control unit.

[0030] Beneficial effects: The temperature control module includes a temperature-controlled water jacket fitted on the outside of the reactor body and a heat exchange unit connected to it. The heat exchange unit delivers temperature-controlled circulating water into the temperature-controlled water jacket through pipelines, and the temperature of the fermentation broth is regulated through heat exchange between the walls. The heat exchange unit is electrically connected to the control unit, so that the temperature regulation is incorporated into the active advance regulation, and the coordinated control of multiple physical fields of heat, magnetism and sound is realized.

[0031] Secondly, the present invention also provides a method for producing hydrogen through bio-fermentation, using the above-mentioned bio-hydrogen production apparatus, comprising the following steps: Step S1: Fill the reaction chamber inside the reactor body with magnetic biological carriers at a volume ratio of 25%-40%, inoculate with hydrogen-producing bacteria, and culture them under a dynamic magnetic field. Step S2: Introduce the fermentation substrate into the reaction chamber, control the fermentation temperature to 35℃-36.5℃, and start the triaxial orthogonal gradient magnetic field coil group. The triaxial orthogonal gradient magnetic field coil group forms a dynamic three-dimensional alternating magnetic field that rotates in space, driving the magnetic biological carrier to be in a suspended fluidized state in the fermentation broth for hydrogen production fermentation. Step S3: Remove dissolved hydrogen from the fermentation broth using a gas-liquid membrane separation module; Step S4: The dissolved hydrogen sensor detects the dissolved hydrogen concentration in the fermentation broth. The control unit predicts the trend of hydrogen production rate change based on the detection data of the sensor monitoring module. When the hydrogen partial pressure is predicted to reach the preset threshold, the control unit starts the ultrasonic transducer in advance to emit ultrasonic waves to remove the dissolved hydrogen in the fermentation broth.

[0032] Beneficial Effects: The bio-fermentation hydrogen production method employs four steps: biofilm culture, fluidized bed hydrogen production, membrane separation dehydrogenation, and predictive ultrasonic dehydrogenation, enabling continuous and efficient operation of the bio-fermentation hydrogen production process. In step S1, a magnetic biological carrier is added to the reaction chamber at a loading ratio of 25%-40% and cultured under a dynamic magnetic field. This loading ratio balances the microbial population within the reactor with the fluidization space of the carrier, ensuring that the hydrogen-producing bacteria form a uniform biofilm on the carrier surface. The dynamic magnetic field provides mild fluid shear in the early stages of biofilm formation, which helps to screen for firmly adhering strains and promotes uniform biofilm growth. In step S2, a triaxial orthogonal gradient magnetic field coil group is activated at the optimal hydrogen production temperature of 35℃-36.5℃. This synthesizes a spatially rotating dynamic three-dimensional alternating magnetic field that drives the carrier in a three-dimensional helical path. This motion mode ensures that the carrier is uniformly distributed within the reactor without sedimentation or dead zones, maximizing the contact area and mass transfer efficiency of the gas-liquid-solid three-phase system, and guaranteeing sufficient contact between the hydrogen-producing bacteria and the fermentation substrate. In step S3, the gas-liquid membrane separation module continuously extracts dissolved hydrogen from the fermentation broth through circulating degassing, achieving circulating degassing of the fermentation broth between the reaction chamber and the membrane module, and maintaining the partial pressure of hydrogen in the liquid phase at a low level. In step S4, the dissolved hydrogen sensor monitors the dissolved hydrogen concentration in real time, and the control unit predicts the trend of hydrogen production rate changes based on the detection data. Before the hydrogen partial pressure reaches the inhibition threshold, ultrasonic cavitation dehydrogenation is initiated in advance for proactive prevention and adjustment, minimizing the thermodynamic reversal of the hydrogen production metabolic pathway.

[0033] In some embodiments, in step S4, the control unit predicts the hydrogen production rate after a preset time interval according to a preset time interval. When it is predicted that the hydrogen production rate after the preset time interval drops to below 80% of the maximum hydrogen production rate and is accompanied by a trend of pH decrease, the control unit enters the biofilm renewal mode in advance. The heat exchange unit is activated to raise the temperature of the fermentation broth to 38℃-39℃, causing the thermosensitive polymer thin layer of the magnetic biological carrier to undergo hydrophobic collapse. Control the ultrasonic transducer to switch to pulse mode, with a pulse duty cycle of 5%-15%, to loosen the aged biofilm on the outer layer of the magnetic biological carrier. The magnetic induction intensity of the triaxial orthogonal gradient magnetic field coil group is increased stepwise at a rate of 1mT / s-3mT / s. When the acoustic emission sensor captures a sudden change in the acoustic signal energy of the characteristic frequency band, the control unit locks the current magnetic induction intensity and maintains it for 3min-8min, causing the magnetic biological carrier to collide and peel off the aging biofilm. After the stripping is completed, the temperature of the fermentation broth is controlled to be restored to 35℃-36.5℃, the pulse mode ultrasound is turned off, and the triaxial orthogonal gradient magnetic field coil group is restored to the conventional fluidization mode.

[0034] Beneficial effects: Regarding triggering conditions, the control unit predicts the change in hydrogen production rate after a preset time interval according to the preset time interval. When both conditions are met simultaneously—the predicted hydrogen production rate dropping below 80% of its maximum value and the pH trend decreasing—it is determined that the decrease in hydrogen production rate is mainly caused by biofilm aging and mass transfer deterioration, rather than simply by dissolved hydrogen accumulation. This dual-condition judgment mechanism effectively avoids false triggering of both ultrasonic dehydrogenation and biofilm renewal interventions. In the stripping process, the fermentation broth temperature is first raised to 38℃-39℃ through the heat exchange unit, causing the temperature-sensitive polymer thin layer to collapse hydrophobically, resulting in a sharp decrease in the interfacial adhesion between the aged biofilm and the carrier surface. Then, the ultrasonic transducer is switched to a pulse mode with a duty cycle of 5%-15%, using intermittent microcavitation jets to loosen the outer layer of the aged biofilm without damaging the inner active bacterial community. Finally, the magnetic induction intensity of the triaxial orthogonal gradient magnetic field coil group is controlled to increase stepwise at a rate of 1mT / s-3mT / s, enhancing the collision intensity between the carriers. When the transmitting sensor captures a sudden change in acoustic signal energy in the characteristic frequency band of 150kHz-250kHz, it indicates that the aging biofilm is cracking and peeling off over a large area. The current magnetic induction intensity is locked and maintained for 3-8 minutes to complete the peeling. This closed-loop control design of step-by-step pressure increase and acoustic signal locking achieves reliable control to complete the peeling with minimal collision intensity, avoiding excessive peeling caused by fixing a high-intensity magnetic field. After peeling, the normal fermentation temperature of 35℃-36.5℃ and the conventional magnetic field fluidization mode are restored, allowing the new biofilm to regrow on the carrier surface. Through a four-step strategy of temperature-increased phase change to reduce viscosity, pulsed ultrasonic loosening, step-by-step magnetic field collision and acoustic signal locking peeling, efficient and directional removal of aging biofilm is achieved. The damage to the active bacterial community during the peeling process is controlled to a minimum, allowing the hydrogen production rate to recover to normal levels in a short time after biofilm renewal. Attached Figure Description

[0035] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0036] Figure 1 This is a schematic diagram of the structure of a bio-fermentation hydrogen production device according to an embodiment of the present invention; Figure 2 This is a top view schematic diagram of a bio-fermentation hydrogen production apparatus according to an embodiment of the present invention; Figure 3 This is a logical schematic diagram of an embodiment of the present invention.

[0037] Explanation of reference numerals in the attached figures: 1. Reactor body; 2. Magnetic biological carrier; 3. Triaxial orthogonal gradient magnetic field coil group; 4. Ultrasonic transducer; 5. Hydrophobic membrane module; 6. Circulation pump; 7. Circulation pipeline; 8. Vacuum pump; 9a. Dissolved hydrogen sensor; 9b. pH sensor; 9c. ORP sensor; 10. Sludge discharge pipe; 11. Control unit; 12. Feed inlet; 13. Biogas collection device; 14. Temperature-controlled water jacket; 15. Heat exchange unit. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0039] The following is combined Figures 1 to 3 The following describes embodiments of the present invention.

[0040] According to an embodiment of the present invention, this embodiment provides a bio-fermentation hydrogen production device, such as... Figure 1 and Figure 2 As shown, the reactor includes a reactor body 1, a triaxial orthogonal gradient magnetic field coil group 3, an ultrasonic transducer 4, a gas-liquid membrane separation module, a sensor monitoring module, and a control unit 11. The reactor body 1 is a cylindrical tank made of a non-magnetic and highly transparent magnetic material, preferably high-transparency borosilicate glass. The reactor body 1 has a reaction chamber inside, which is suitable for containing the fermentation substrate and a magnetic biological carrier 2 loaded with hydrogen-producing bacteria.

[0041] In a specific embodiment, the top of the reactor body 1 is equipped with a sealing cap, and the sealing cap has a feed inlet 12. The feed inlet 12 is connected to the reaction chamber and is used to introduce fermentation substrate into the reaction chamber. The feed inlet 12 on the sealing cap facilitates the periodic replenishment of fermentation substrate into the reaction chamber, enabling continuous feeding operation. The bottom of the reactor body 1 is equipped with a sludge discharge pipe 10, which is connected to the bottom of the reactor body 1. The sludge discharge pipe 10 is used to discharge the detached aged biofilm from the reaction chamber. The sludge discharge pipe 10 is connected to the bottom of the reactor body 1 to discharge the detached aged biofilm from the system, preventing the accumulation of aged biofilm debris at the bottom of the reactor, which would create a dead zone and cause secondary pollution, thus maintaining a clean environment inside the reactor.

[0042] In a specific embodiment, the hydrogen production device further includes a biogas collection device 13, which is connected to the reaction chamber and used to collect the gaseous products generated by hydrogen-producing fermentation. The biogas collection device 13 is used to collect the gaseous products generated by hydrogen-producing fermentation, facilitating subsequent purification and utilization of the hydrogen products.

[0043] In a specific embodiment, a temperature control module is also included. This module regulates the fermentation broth temperature, enabling precise fine-tuning and rapid response (heating rate ≥ 0.5℃ / min) within the range of 35℃-39℃ based on sensor feedback or biofilm renewal instructions. The temperature control module specifically includes a temperature-controlled water jacket 14 and a heat exchange unit 15. These components are used to adjust the fermentation temperature within the reaction chamber. The temperature-controlled water jacket 14 is fitted onto the outside of the reactor body 1. The heat exchange unit 15 is connected to the temperature-controlled water jacket 14 via a pipeline and is electrically connected to the control unit 11. The heat exchange unit 15 delivers temperature-controlled circulating water to the temperature-controlled water jacket 14 via a pipeline, achieving temperature regulation through heat exchange between the jacket and the control unit 11. The electrical connection between the heat exchange unit 15 and the control unit 11 allows for proactive pre-regulation of temperature control, achieving coordinated control of multiple physical fields including heat, magnetism, and sound.

[0044] In one alternative implementation, the heat exchange unit 15 incorporates a heater and a cooling medium switching valve to achieve rapid heating and rapid cooling, meeting the requirements of heating to trigger phase change during biofilm renewal and rapidly restoring fermentation temperature after renewal.

[0045] In this embodiment, the reactor body 1 is a high-transparency, high-borosilicate glass cylinder with an inner diameter D=60mm and a height H=200mm, to facilitate observation of the internal fluidization state. The top of the reactor body 1 is equipped with a sealing cap, on which is a feed inlet 12 connected to the reaction chamber for introducing the fermentation substrate. The sealing cap also has a pre-installed sensor mounting port and a biogas collection device 13, which is connected to the reaction chamber and used to collect the gaseous products generated during hydrogen-producing fermentation. The bottom of the reactor body 1 is connected to a sludge discharge pipe 10, which is used to discharge the detached, aged biofilm from the reaction chamber, preventing the accumulation of aged biofilm debris at the bottom of the reactor and the formation of a dead zone.

[0046] like Figure 1 and Figure 2As shown, three-axis orthogonal gradient magnetic field coil groups 3 are respectively arranged in groups at intervals on the outer side of the reactor body 1 in the X-axis, Y-axis and Z-axis directions. The three groups of coils are connected to a multiphase adjustable power drive power supply. The control unit 11 independently adjusts the current amplitude, AC frequency and phase difference of the three groups of coils to synthesize a three-dimensional dynamic vector magnetic field in real time in the three-dimensional space inside the reactor using the principle of spatial magnetic field superposition. The magnetic field is used to drive the magnetic biological carrier 2 to be in a suspended fluidized state in the fermentation broth. The three-axis orthogonal gradient magnetic field coil groups 3 are specifically connected to an external multiphase adjustable power drive control cabinet. By controlling the amplitude, frequency and phase difference of the three-axis current, a three-dimensional dynamic vector magnetic field with a maximum intensity of 60mT is generated in the tank. In the conventional mixing mode, the three-axis coils output an AC signal with orthogonal phase and low-frequency modulation to generate a synthesized magnetic field that rotates around the reactor axis and simultaneously reciprocates up and down along the Z-axis. The excitation current controls the magnetic force intensity to be 5-25mT and the magnetic field alternation frequency to be 0.1-1.0Hz, driving the carrier to rotate, drift and spin. In the adaptive biomembrane renewal mode, the electromagnetic coil group outputs a high-frequency pulse current, which starts with a preset initial magnetic force intensity such as 30mT and an alternating frequency of 10-30Hz, and increases the magnetic field intensity in a stepwise manner at a set change rate ΔB / Δt such as 1-3mT / s.

[0047] An ultrasonic transducer 4 is located at the bottom of the reactor body 1. The ultrasonic transducer 4 is adapted to emit ultrasonic waves toward the fermentation broth to remove dissolved hydrogen. In this embodiment, eight ultrasonic transducers 4 are arranged in a ring at the bottom of the reactor body 1, and the power supply is integrated into the external control cabinet. The ultrasonic transducer 4 operates at a frequency of 28kHz-50kHz, with continuously adjustable output power from 0-150W, and supports a low duty cycle pulse mode of 5%-15%. During normal hydrogen production, the control unit 11 controls the ultrasonic transducers 4 to emit low-intensity ultrasonic waves (sound intensity 0.2-1.5W / cm²) in continuous mode. 2 The system utilizes acoustic cavitation to form micro- and nano-sized bubbles, removing dissolved hydrogen from the fermentation broth in situ. During the biofilm renewal stage, the control unit 11 is equipped with a micro-area positioning pulse mode, controlling the ultrasonic waves to emit pulsed ultrasonic waves with a duty cycle of 5%-15%, which is used to loosen the aging biofilm on the outermost layer of the magnetic biological carrier 2.

[0048] In a specific embodiment, the gas-liquid membrane separation module is located outside the reactor body 1 and is connected to the reaction chamber to extract dissolved gas from the fermentation broth to the outside of the reaction chamber. The gas-liquid membrane separation module includes a hydrophobic membrane module 5, a circulation pump 6, a circulation pipeline 7, and a vacuum pump 8. The reaction chamber is provided with an outlet and an inlet. The outlet is connected to the inlet of the hydrophobic membrane module 5 through the circulation pipeline 7. The circulation pump 6 is installed on the circulation pipeline 7 with the outlet facing the inlet. The inlet is connected to the liquid outlet of the hydrophobic membrane module 5 through the circulation pipeline 7. The vacuum pump 8 is connected to the gas outlet of the hydrophobic membrane module 5 and is adapted to form a slight negative pressure in the cavity of the hydrophobic membrane module 5 to extract dissolved gas to the outside of the system.

[0049] The outlet of the reaction chamber is connected to the inlet of the hydrophobic membrane module 5 via the circulation pipe 7. Driven by the circulation pump 6, the fermentation broth flows into the hydrophobic membrane module 5 through the circulation pipe 7. A vacuum pump 8 is connected to the gas outlet of the hydrophobic membrane module 5, creating a slightly negative pressure environment within the mold cavity. This slight negative pressure allows dissolved gas to pass through the hydrophobic membrane wall from the liquid phase into the gas phase cavity under the dual drive of concentration and pressure differences, and is continuously extracted from the system by the vacuum pump 8. After the dissolved gas is removed, the fermentation broth flows back to the inlet of the reaction chamber through the liquid outlet of the hydrophobic membrane module 5 and the circulation pipe 7, achieving circulating degassing of the fermentation broth. This scheme utilizes a circulating degassing loop to ensure that the fermentation broth in the reaction chamber has ample opportunity to contact the hydrophobic membrane module 5 and complete degassing, reducing the risk of dissolved hydrogen accumulation in localized dead zones. Simultaneously, the gas and liquid phases achieve efficient separation within the membrane module, preventing direct contact between the gaseous product and the fermentation broth, thus avoiding cell loss or secondary entrainment of product gas by the fermentation broth.

[0050] In a specific embodiment, the hydrophobic membrane module 5 includes a hydrophobic hollow fiber membrane and a membrane shell. The hydrophobic hollow fiber membrane is encapsulated inside the membrane shell. The liquid outlet is specifically connected to the space between the membrane shell and the hydrophobic hollow fiber membrane, and the gas outlet is connected to the inner cavity of the hydrophobic hollow fiber membrane. The hydrophobic hollow fiber membrane is a polytetrafluoroethylene membrane or a polyvinylidene fluoride membrane, and the pore size of the hydrophobic hollow fiber membrane is 0.05μm-0.2μm. The vacuum pump 8 is adapted to form a negative pressure of 10kPa-50kPa within the cavity of the hydrophobic membrane module 5.

[0051] Both polytetrafluoroethylene (PTFE) and polyvinylidene fluoride (PVDF) are strongly hydrophobic materials with a contact angle greater than 90° with the aqueous phase. In aqueous fermentation broths, they effectively prevent liquid water from permeating the membrane wall while allowing dissolved gas molecules to diffuse through the membrane pores, facilitating efficient separation of the gas and liquid phases. The membrane pore size is specifically 0.05μm-0.2μm. This pore size range allows dissolved gas molecules to pass freely while effectively blocking suspended bacteria and carrier debris in the fermentation broth, preventing pore blockage and extending the continuous service life of the membrane module. The negative pressure within the membrane cavity is specifically 10kPa-50kPa, providing sufficient suction driving force to ensure efficient dissipation of dissolved gas while preventing excessive membrane wall deformation or excessive removal of water from the fermentation broth due to excessive negative pressure. This negative pressure range balances degassing efficiency and membrane structure stability.

[0052] The sensor monitoring module includes a dissolved hydrogen sensor 9a. The detection end of the dissolved hydrogen sensor 9a is placed in the fermentation broth of the reaction chamber to monitor the concentration of dissolved hydrogen in the fermentation broth. The concentration value measured by the dissolved hydrogen sensor 9a is converted into the equivalent hydrogen partial pressure using Henry's Law for calculation and threshold judgment.

[0053] The control unit 11 is electrically connected to the triaxial orthogonal gradient magnetic field coil group 3, the ultrasonic transducer 4, the gas-liquid film separation module, and the sensor monitoring module, respectively. The control unit 11 is adapted to receive the detection data from the sensor monitoring module, predict the trend of hydrogen production rate change based on the detection data, and start the ultrasonic transducer 4 in advance for ultrasonic cavitation dehydrogenation based on the trend of hydrogen production rate change, and / or adjust the magnetic field parameters of the triaxial orthogonal gradient magnetic field coil group 3 in advance.

[0054] The bio-fermentation hydrogen production device provided in this embodiment aims to solve the thermodynamic inhibition problem caused by dissolved hydrogen accumulation in the fermentation broth by combining multiple physical fields such as magnetic field fluidization, ultrasonic cavitation, and membrane separation, and by pre-regulating based on the prediction of dissolved hydrogen concentration. Specifically, the triaxial orthogonal gradient magnetic field coil group 3 independently generates a dynamic three-dimensional alternating magnetic field in the X, Y, and Z directions, driving the magnetic biological carrier 2 to be in a suspended fluidized state in the fermentation broth. This suspension fluidization effect can continuously disturb the liquid phase mass transfer boundary layer on the surface of the carrier and the surrounding liquid phase, accelerating the diffusion of dissolved hydrogen generated by metabolism inside the carrier to the bulk liquid phase, and avoiding excessive local accumulation of dissolved hydrogen on the carrier surface. At the same time, the shuttle motion of the carrier in three-dimensional space increases the renewal frequency of the gas-liquid interface, which is also conducive to the release and escape of bubbles from the liquid phase. Ultrasonic waves are emitted into the fermentation broth via ultrasonic transducer 4, generating numerous micron-sized cavitation bubbles in the liquid phase through acoustic cavitation. Since the partial pressure of dissolved hydrogen at the gas-liquid interface is much lower than its equilibrium partial pressure in the liquid phase, dissolved hydrogen undergoes rectification and diffusion into the cavitation bubbles and escapes with them, achieving in-situ removal of dissolved hydrogen. A gas-liquid membrane separation module provides the gas-liquid separation interface, continuously extracting dissolved gas from the fermentation broth from the reaction system, preventing the removed gas from redissolving or accumulating in the top space, which could cause the partial pressure of hydrogen in the liquid phase to rise again. Real-time monitoring data from the dissolved hydrogen sensor 9a allows the control unit 11 to dynamically sense the changing trend of the hydrogen concentration in the liquid phase. Based on the detection data, the control unit 11 predicts the direction of change in the hydrogen production rate and initiates ultrasonic dehydrogenation and / or adjusts the magnetic field parameters before the hydrogen partial pressure reaches the suppression threshold, transforming dehydrogenation intervention from a passive response to active prevention. Through the combination of these technologies, the dissolved hydrogen concentration in the liquid phase is continuously suppressed within a thermodynamically favorable range, effectively ensuring the smooth progress of the hydrogen production metabolic pathway and improving the hydrogen production efficiency and operational stability of the device.

[0055] In an optional embodiment, the sensor monitoring module further includes a pH sensor 9b, an ORP sensor 9c, and an acoustic emission sensor. The detection ends of the pH sensor 9b and the ORP sensor 9c are respectively disposed in the fermentation broth of the reaction chamber. The pH sensor 9b is used to monitor the pH value of the fermentation broth to determine whether acid accumulation occurs in the fermentation system. The ORP sensor 9c is used to monitor the redox potential of the fermentation broth to reflect the electronic activity and reducing atmosphere of the fermentation system.

[0056] An acoustic emission sensor is attached to the outer wall of the reactor body 1 and is electrically connected to the control unit 11. The acoustic emission sensor has a sampling frequency band of 100kHz-500kHz and is used to collect acoustic signals generated during the biofilm peeling process. The high-frequency acoustic signals of microcracks and fractures generated during biofilm peeling are collected in the 100kHz-500kHz sampling frequency band. These acoustic signals are a direct physical characterization of the fracture and peeling of the aging biofilm under carrier collision and ultrasonic loosening. The control unit 11 is equipped with an acoustic emission signal spectrum analysis module, which is used to extract the characteristic frequency band signal of biofilm fracture; the characteristic frequency band is 150kHz-250kHz. Specifically, the acoustic emission signal spectrum analysis module has a built-in mutation judgment algorithm, adopts a sliding window baseline comparison method, sets the time window length to 100ms, and calculates the root mean square (RMS) value of the signal in the 150-250kHz frequency band within the window. When the RMS value of three consecutive windows exceeds 300% of the moving average of RMS in the previous 30 seconds, it is determined that the energy mutation has occurred, and the control unit locks the current magnetic induction intensity.

[0057] The acoustic emission signal spectrum analysis module configured in the control unit 11 extracts a characteristic frequency band signal of 150kHz-250kHz from the acquired signal. This characteristic frequency band is highly correlated with the brittle fracture of the aging biofilm matrix. When the acoustic signal energy in this frequency band changes abruptly, it indicates that the aging biofilm is undergoing large-scale cracking and peeling. At this time, the control unit 11 can determine the peeling process based on this signal to avoid over-peeling or under-peeling.

[0058] In this embodiment, the magnetic biocarrier 2 is a porous microsphere. The magnetic biocarrier 2 includes a magnetic core and a porous polymer coating layer arranged sequentially from the inside out. The magnetic core is a superparamagnetic Fe3O4 nanoparticle. The porous polymer coating layer covers the periphery of the magnetic core and is a hybrid hydrogel framework formed by crosslinking polyvinyl alcohol, sodium alginate and nanocellulose.

[0059] The technical objective of this solution is to provide a porous carrier structure that combines magnetic responsiveness, biocompatibility, and high specific surface area, offering a stable attachment and colonization space for hydrogen-producing bacteria and serving as the target of magnetic field driving force. Specifically, the magnetic carrier is in the form of porous microspheres, comprising a magnetic core and a porous polymer coating layer from the inside out. The magnetic core uses superparamagnetic Fe3O4 nanoparticles. This material can be rapidly magnetized and generate magnetic response motion under the action of an external magnetic field. After the magnetic field is removed, the residual magnetism is extremely low, avoiding carrier sedimentation or uneven distribution due to magnetic agglomeration between particles, thus ensuring good dispersibility and suspension fluidization performance of the carrier in a dynamic alternating magnetic field. The porous polymer coating layer consists of a hybrid hydrogel framework formed by cross-linking polyvinyl alcohol (PVA), sodium alginate (SA), and cellulose nanofiber (CNC). PVA provides the framework with good film-forming properties and mechanical strength, sodium alginate provides abundant carboxyl sites to facilitate electrostatic adsorption and colonization of bacteria, and cellulose nanofiber acts as a reinforcing phase to improve the pore structure stability of the framework. The three-dimensional network structure formed by the cross-linking of the three components possesses both high porosity and suitable pore size, providing ample attachment surface area and internal habitat space for hydrogen-producing bacteria, effectively increasing the microbial population within the reactor. The composite structure of the superparamagnetic core and the porous polymer coating layer enables the carrier to achieve overall suspension under magnetic field drive, while its porous structure ensures smooth exchange of substrates and metabolites between the carrier's interior and the external liquid phase.

[0060] In a further embodiment, the porous polymer coating layer is grafted with a pH-sensitive monomer, which is at least one of acrylic acid, methacrylic acid, or 2-(dimethylamino)ethyl methacrylate; the porosity of the porous polymer coating layer is 70%-85%, and the average pore size of the porous polymer coating layer is 30μm-80μm; the porous polymer coating layer is suitable for swelling and pore expansion due to electrostatic repulsion at pH < 5.0, with the average pore size expanding to 60μm-100μm.

[0061] The technical objective of this solution is to provide the carrier with adaptive capabilities to fermentation broth acidification, mitigating the toxic effects of acid accumulation on the internal microbial community. Under normal hydrogen-producing conditions (pH 5.5-6.5), the porous polymer coating layer maintains a moderate cross-linked shrinkage state, with an average pore size of 30μm-50μm, which is conducive to the stable attachment of hydrogen-producing bacteria within the carrier and the formation of a dense biofilm structure. When the pH of the fermentation broth drops below 5.0, the carboxyl or amino functional groups of the pH-sensitive monomers (acrylic acid, methacrylic acid, or 2-(dimethylamino)ethyl methacrylate) grafted onto the hydrogel framework undergo protonation or deprotonation, resulting in electrostatic repulsion between the polymer chains and driving the hydrogel framework to absorb water and swell, expanding the average pore size to 60μm-100μm. This enlarged pore size design allows volatile fatty acids and dissolved hydrogen, acidic metabolic products accumulated inside the carrier, to diffuse outward more quickly, alleviating the metabolic inhibition of hydrogen-producing bacteria by acid accumulation. It also facilitates the penetration of nutrient substrates in the fermentation broth into the carrier, ensuring the nutrient supply to the inner bacterial community. Furthermore, the pH-sensitive response is a reversible process; when the pH of the fermentation broth rises, electrostatic repulsion weakens, and the carrier pore size returns to normal, without causing irreversible damage to the carrier structure.

[0062] In a specific embodiment, the outer surface of the porous polymer coating is grafted with a thermo-responsive polymer thin layer, the phase transition temperature of which is 36°C-38°C; the thermo-responsive polymer thin layer is hydrophilic when the temperature is below the phase transition temperature, and undergoes structural collapse and becomes hydrophobic when the temperature is above the phase transition temperature.

[0063] The technical objective of this solution is to achieve controlled detachment of the aged biofilm from the carrier surface during biofilm renewal, avoiding damage to the inner active bacterial community caused by traditional physical or chemical stripping methods. Thermosensitive polymeric thin layers (such as poly(N-isopropylacrylamide) PNIPAM) have their phase transition temperature set to 36℃-38℃ through copolymerization ratio adjustment, matching the optimal fermentation temperature (35℃-38℃). During the normal hydrogen production stage (fermentation temperature 35℃-36.5℃), the polymer chains of the thermosensitive thin layer are in an extended state, exhibiting hydrophilicity, which is beneficial for the initial adhesion and biofilm formation of hydrogen-producing bacteria, as well as the wetting and absorption of nutrient substrates, promoting the rapid formation of a highly active biofilm on the carrier surface. When the aging biofilm needs to be renewed (fermentation temperature rises to 38℃-39℃), the polymer chains of the temperature-sensitive thin layer undergo a conformational change and hydrophobic collapse, and the surface rapidly changes from hydrophilic to hydrophobic. This change causes a sharp decrease in the interfacial adhesion between the aging biofilm and the carrier surface. Combined with the carrier collision driven by the magnetic field and the cavitation loosening effect of pulsed ultrasound, the aging biofilm can be completely peeled off from the carrier surface with extremely low mechanical force, while the inner highly active dense biofilm is preserved because it is not subjected to excessive shearing.

[0064] In this embodiment, the preparation steps of the pH / temperature-responsive magnetic biological carrier 2 are as follows: Preparation and grafting of pH-sensitive sol: 8.0 g polyvinyl alcohol (PVA), 1.5 g sodium alginate (SA), and 0.5 g cellulose nanoparticles (CNC) were dissolved in 90 mL of deionized water and stirred at 95 °C for 3 h to form a homogeneous sol. The mixture was then cooled to 50 °C, and 0.6 g acrylic acid (AA, pH-sensitive monomer), 0.05 g potassium persulfate (initiator), and 3.0 g of the modified Fe3O4-NH2 nanoparticles were added. Grafting was completed by stirring under nitrogen protection for 2 h, followed by ultrasonic dispersion for 20 min.

[0065] Droplet crosslinking and curing: The mixed sol was dropped into a crosslinking curing solution (containing 2.0 wt% CaCl2 and 3.0 wt% boric acid, pH 4.5) cooled to 4°C using a syringe pump at a rate of 1.5 mL / min, and allowed to stand for crosslinking for 12 hours. After washing, particles with an average particle size of 3.5-4.2 mm and a density of 1.06 g / cm³ were obtained. 3 Porous magnetic hydrogel spheres with a saturation magnetization of 18.4 emu / g and a porosity of 78.5%.

[0066] Thermosensitive phase change outer membrane grafting: The above hydrogel spheres were immersed in an alcohol-free solution containing 2.0 wt% poly(N-isopropylacrylamide) (PNIPAM, phase change temperature 37.0℃) and 0.1 wt% ethylene glycol dimethacrylate (crosslinking agent) to initiate interfacial polymerization, covalently grafting a thermosensitive phase change thin layer with a thickness of 200-300 nm onto the outermost layer of the carrier. After washing, a magnetic biological carrier 2 with dual pH / thermosensitive response function was obtained.

[0067] In a specific embodiment, the ultrasonic transducer 4 operates at a frequency of 28kHz-50kHz. This frequency range falls within the low-frequency ultrasonic range, enabling the generation of a stable cavitation effect in the fermentation broth to remove dissolved hydrogen. Simultaneously, it avoids oxidative damage to the microbial community caused by free radicals generated at excessively high frequencies, and also avoids mechanical damage to the biofilm caused by strong cavitation impacts generated at excessively low frequencies, thus balancing dehydrogenation efficiency with microbial activity protection.

[0068] In this embodiment, the control unit 11 has a built-in hydrogen production kinetic prediction model, which is configured to predict the trend of hydrogen production rate based on multi-dimensional sensor data, and adjust the magnetic field fluidization mode, ultrasonic emission power and fermentation temperature in advance according to the prediction results.

[0069] The hydrogen production kinetics prediction model is expressed as follows:

[0070] In the formula, the current time is t, the predicted duration is τ, and a future time is t + τ. rmax is the baseline coefficient in the model, representing the theoretical maximum hydrogen production rate that the fermentation system can achieve under ideal conditions; f ( S Using the baseline and substrate factor as references, according to the Monod equation, , S Substrate concentration, K s It is the half-saturation constant; g ( T () represents the temperature effect factor, indicating the influence of temperature on enzyme activity; in, ; In the formula: This is the current measured temperature. T opt For the optimal hydrogen production temperature, T opt =36.5℃; This is the temperature tolerance coefficient, which can be set according to the specific bacterial species used or calibrated through experiments during implementation.

[0071] h (pH) is the pH deviation factor, which represents the inhibitory effect of fermentation broth acidification on the hydrogen production metabolic pathway. in, ; In the formula: This is the current real-time pH value; The optimal pH value for hydrogen production; Φ( P H2 ) is a thermodynamic inhibitor of dissolved oxygen; in, ; In the formula: The equivalent hydrogen partial pressure is calculated from the dissolved hydrogen concentration. The rate of change of dissolved hydrogen, The critical thermodynamic inhibition threshold is 0.04 MPa. Ψ(ORP, δ ) is a biomembrane activity and ORP attenuation factor; in, ; In the formula: This is the current measured ORP value. For optimal hydrogen production ORP, This is an estimate of biofilm thickness, calculated cumulatively over time and with substrate consumption. The aging growth rate; k 1 represents ORP bias sensitivity. k 2 represents the sensitivity to biofilm aging.

[0072] The control unit 11 collects multi-dimensional sensor data in real time at preset time intervals, preferably at equal time intervals Δt=5min, and substitutes the data into the above model to calculate the predicted hydrogen production rate after a preset time period (preferably τ=1h). H2 (t+1h).

[0073] Control unit 11 predicts the hydrogen production rate for the next hour every 5 minutes. H2 (t+1h). When predicted H2 (t+1h)≤80% r max At that time, the control unit 11 further determines the dominant inhibitory factor and initiates corresponding response measures in advance: Early initiation of ultrasonic cavitation dehydrogenation: When the predictive model determines that the main dominant factor in the decrease in hydrogen production rate is Φ( P H2 This refers to predicting the equivalent hydrogen partial pressure within the next hour. P H2 When the pressure is ≥0.04MPa, the control unit 11 starts the ultrasonic transducer 4 in advance. The specific control method is: an incremental PID algorithm is used to automatically adjust the ultrasonic power. P H2 Dissolved hydrogen is pre-removed using low-power microcavitation before the pressure reaches 0.04 MPa, suppressing the dissolved hydrogen concentration at a low level and preventing the hydrogen production rate from continuing to decrease. In a preferred embodiment, the control unit 11 pre-controls the dissolved hydrogen concentration to a level below the equivalent hydrogen partial pressure of 0.02 MPa.

[0074] Early initiation of adaptive biofilm renewal: When the predictive model determines that the main dominant factor in the decline in hydrogen production rate is... h (pH) and Ψ(ORP, δ When it is predicted that the pH will drop below 5.0 and the biofilm mass transfer resistance will be too high, the control unit 11 will initiate the biofilm renewal program in advance. For details of the response process, please refer to step S5 below.

[0075] In the adaptive biofilm renewal mode, the acoustic emission sensor, with a acquisition frequency band of 100-500kHz, is attached to the outer wall of the reactor body 1 to collect high-frequency acoustic signals of microcracks and fractures generated during biofilm peeling. The control unit 11 is equipped with an acoustic emission signal spectrum analysis module to extract characteristic frequency band signals (preferably 150-250kHz) of the fractured aging biofilm matrix and use them as the basis for locking the magnetic field strength.

[0076] The specific control logic is as follows: In biofilm renewal mode, the triaxial orthogonal gradient magnetic field coil group 3 is started with a preset initial magnetic intensity (e.g., 30mT), and the magnetic induction intensity is increased in steps at a set change rate ΔB / Δt (e.g., 1-3mT / s). Acoustic emission sensors collect acoustic signals in real time and upload them to the spectrum analysis module of the control unit 11. When the module detects a sudden change in the energy spectral density of the acoustic signal in the 150-250kHz characteristic frequency band (i.e., reaching a preset energy threshold), indicating that the aging biofilm matrix is ​​undergoing large-area brittle fracture and peeling, the control unit 11 immediately stops the voltage increase and locks the current magnetic induction intensity, maintaining this intensity for 3-8 minutes to complete adaptive peeling. This closed-loop control strategy avoids excessive peeling that may be caused by a fixed high-intensity magnetic field, achieving the technical effect of precise peeling with minimal impact intensity.

[0077] The present invention provides a method for bio-hydrogen production using the above-mentioned reaction apparatus, comprising the following steps: Step S1: Regarding carrier loading and biofilm formation: The magnetic biological carrier 2 is loaded into the reactor body 1 at a volume ratio of 25%-40%. Hydrogen-producing bacteria (such as heat-treated Clostridium species enriched) are inoculated and cultured under a weak dynamic magnetic field (such as 10mT) for 3-5 days to allow the hydrogen-producing bacteria to form a uniform biofilm on the carrier surface.

[0078] Step S2: Stable hydrogen production mode: Fermentation substrate (such as glucose wastewater, concentration 20g / L) is introduced into the reaction chamber through feed inlet 12. The fermentation temperature is controlled at 35℃-36.5℃. The three-dimensional magnetic field fluidization module is turned on in the conventional mixing mode: the triaxial orthogonal gradient magnetic field coil group 3 outputs a low-frequency alternating current with orthogonal phase, generating a synthetic spatial rotating dynamic magnetic field with a magnetic induction intensity of 5-25mT and an alternating frequency of 0.1-1.0Hz, driving the magnetic biological carrier 2 to be suspended in a three-dimensional spiral path in the fermentation broth for hydrogen production fermentation.

[0079] Step S3: Membrane separation and circulating dehydrogenation: Turn on the circulating pump 6 and vacuum pump 8 in the gas-liquid membrane separation circulation system to generate a micro negative pressure of 10-50 kPa in the cavity of the hydrophobic membrane module 5. The fermentation broth flows through the hydrophobic hollow fiber membrane module under the drive of the circulating pump 6. The dissolved gas permeates through the hydrophobic membrane wall under the dual drive of concentration difference and pressure difference and is extracted to the outside of the system by the vacuum pump 8, realizing online circulating dehydrogenation of the fermentation broth.

[0080] Step S4: In-situ ultrasonic dehydrogenation: as follows Figure 3As shown, the hydrogen production kinetic prediction model built into the control unit 11 is used to predict the hydrogen partial pressure change trend in real time over the next 1 hour. When the equivalent hydrogen partial pressure is predicted to reach 0.04 MPa, the ultrasonic cavitation dehydrogenation module is activated in advance, with the frequency set to 28kHz-50kHz (preferably 40kHz) and the sound intensity to 0.2-1.5 W / cm². 2 (Preferred value: 0.5-0.8 W / cm) 2 The acoustic cavitation effect is used to form micro- and nano-sized bubbles, which capture and remove dissolved hydrogen from the fermentation broth in situ, thus suppressing the hydrogen partial pressure within a thermodynamically favorable range.

[0081] Step S5: Adaptive Biofilm Renewal: When the control unit 11 predicts that the hydrogen production rate will decrease to below 80% of its maximum value within the next 1 hour, accompanied by a trend of pH decline, it indicates that the decrease in the hydrogen production rate is mainly caused by biofilm aging and mass transfer deterioration (rather than simply by dissolved hydrogen accumulation). The control unit 11 enters the adaptive biofilm renewal mode in advance. S51: Heating and hydrophobic collapse: The heat exchange unit 15 of the temperature control module raises the temperature of the fermentation broth to 38℃-39℃ (preferably 38.5℃), causing the outermost thermosensitive polymer thin layer of the magnetic biological carrier 2 to undergo a conformational change and hydrophobic collapse. The surface rapidly changes from hydrophilic to hydrophobic, and the interfacial adhesion between the aged biofilm and the carrier surface decreases sharply. S52: Pulsed Ultrasonic Loosening: The ultrasonic cavitation dehydrogenation module is activated in pulse mode, emitting high-frequency short pulse ultrasound with a duty cycle of 5%-15% (preferably 10%). The microcavitation jet is precisely positioned on the outermost layer of the magnetic biological carrier 2 to loosen the outer layer of the aged biofilm without damaging the inner layer of highly active dense biofilm. S53: Stepped voltage increase and acoustic signal locking: Drive the three-dimensional magnetic field fluidization module to increase the magnetic induction intensity of the triaxial orthogonal gradient magnetic field coil group 3 in steps from a preset initial value (e.g., 30mT) at a rate of 1-3mT / s (preferably 2mT / s). When the acoustic emission sensor detects a sudden change in acoustic signal energy in the characteristic frequency band of 150-250kHz, indicating large-area cracking and peeling of the aging biofilm, the control unit 11 immediately locks the current magnetic field intensity and maintains the collision for 3-8 minutes (preferably 5 minutes). S54: Recovery and Sludge Removal: After the stripping is completed, the temperature control module restores the fermentation broth temperature to 35℃-36.5℃, turns off the pulsed ultrasound, switches the magnetic field back to the conventional mixing mode, and the stripped aging biofilm is discharged from the system through the sludge removal pipe 10.

[0082] The bio-fermentation hydrogen production method provided in this embodiment adopts the steps of biofilm culture, hydrogen production fluidization, membrane separation dehydrogenation, and predictive ultrasonic dehydrogenation, which can realize the continuous and efficient operation of the bio-fermentation hydrogen production process. In step S1, the magnetic biological carrier 2 is put into the reaction chamber at a filling volume ratio of 25%-40% and biofilm culture is carried out under a dynamic magnetic field. This filling ratio takes into account the microbial content in the reactor and the fluidization space of the carrier, ensuring that the hydrogen-producing bacteria form a uniform biofilm on the carrier surface. The dynamic magnetic field provides mild fluid shear in the early stage of biofilm formation, which helps to screen for firmly adhered strains and promotes uniform growth of the biofilm. In step S2, the triaxial orthogonal gradient magnetic field coil group 3 is activated at the optimal hydrogen production temperature of 35℃-36.5℃. The dynamic three-dimensional alternating magnetic field driving the carrier to move in a three-dimensional helical path by synthesizing a spatially rotating dynamic three-dimensional alternating magnetic field. This movement mode enables the carrier to be uniformly distributed in the reactor without sedimentation or dead zones, maximizing the contact area and mass transfer efficiency of the gas-liquid-solid three phases, and ensuring sufficient contact between the hydrogen-producing bacteria and the fermentation substrate. In step S3, the gas-liquid membrane separation module continuously extracts dissolved hydrogen from the fermentation broth through circulating degassing, achieving circulating degassing of the fermentation broth between the reaction chamber and the membrane module, and maintaining the partial pressure of hydrogen in the liquid phase at a low level. In step S4, the dissolved hydrogen sensor 9a monitors the dissolved hydrogen concentration in real time, and the control unit 11 predicts the trend of hydrogen production rate changes based on the detection data. Before the hydrogen partial pressure reaches the inhibition threshold, ultrasonic cavitation dehydrogenation is initiated in advance for proactive prevention and adjustment, minimizing the thermodynamic reversal of the hydrogen production metabolic pathway.

[0083] Regarding the triggering conditions, the control unit 11 predicts the change in hydrogen production rate after a preset time interval according to the preset time interval. When both conditions are met simultaneously—the predicted hydrogen production rate dropping below 80% of its maximum value and the pH trend decreasing—it is determined that the decrease in hydrogen production rate is mainly caused by biofilm aging and mass transfer deterioration, rather than simply by dissolved hydrogen accumulation. This dual-condition judgment mechanism effectively avoids false triggering of both ultrasonic dehydrogenation and biofilm renewal interventions. In the stripping process, the fermentation broth temperature is first raised to 38℃-39℃ via the heat exchange unit 15, causing the temperature-sensitive polymer thin layer to collapse hydrophobically, resulting in a sharp decrease in the interfacial adhesion between the aged biofilm and the carrier surface. Then, the ultrasonic transducer 4 is switched to a pulse mode with a duty cycle of 5%-15%, using intermittent microcavitation jets to loosen the outer layer of the aged biofilm without damaging the inner active bacterial community. Finally, the magnetic induction intensity of the triaxial orthogonal gradient magnetic field coil group 3 is controlled to increase stepwise at a rate of 1mT / s-3mT / s to enhance the collision intensity between the carriers. When the acoustic emission sensor detects a sudden change in acoustic signal energy in the characteristic frequency band of 150kHz-250kHz, it indicates that the aging biofilm is cracking and peeling off over a large area. The current magnetic induction intensity is locked and maintained for 3-8 minutes to complete the peeling. This closed-loop control design of step-by-step pressure increase and acoustic signal locking achieves reliable control to complete the peeling with minimal collision intensity, avoiding excessive peeling caused by a fixed high-intensity magnetic field. After peeling, the normal fermentation temperature of 35℃-36.5℃ and the conventional magnetic field fluidization mode are restored, allowing the new biofilm to regrow on the carrier surface. Through a four-step strategy of temperature-increased phase change to reduce viscosity, pulsed ultrasonic loosening, step-by-step magnetic field collision and acoustic signal locking peeling, efficient and directional removal of aging biofilm is achieved. The damage to the active bacterial community during the peeling process is controlled to a minimum, allowing the hydrogen production rate to recover to normal levels in a short time after biofilm renewal.

[0084] In this embodiment, the comparative verification of the hydrogen production effect by fermentation is as follows: A 20-day continuous comparative experiment on hydrogen production through dark fermentation was conducted using a reactor with an effective volume of 5L.

[0085] Inoculation sludge: Clostridium species enriched by heat treatment at 100℃ for 30 min to remove methanogens and domestication and propagation.

[0086] Fermentation substrate: simulated glucose wastewater with a concentration of 20 g / L, supplemented with inorganic nutrients, and the influent pH was controlled at 6.0.

[0087] Experimental Groups: Experimental Group A (this invention): The above-mentioned pH / temperature-sensitive magnetic biocarrier 2 (filling rate 30%) was filled, and three-dimensional magnetic field spiral fluidization, ultrasonic cavitation / membrane separation dual dehydrogenation, temperature-controlled phase change and acoustic signal-controlled biofilm renewal, and kinetic prediction control were activated.

[0088] Control group B (traditional mechanical stirring group): The same tank was used, and the inside was continuously mechanically stirred by an impeller (speed 120 r / min). It was filled with non-magnetic porous biological carrier (filling rate 30%), without external magnetic field, ultrasound and predictive control.

[0089] Control group C (magnetic field fluidization group only): The device structure is the same as that of experimental group A, but the separation mode of ultrasonic cavitation dehydrogenation and intelligent temperature control and acoustic signal control is not activated. Only conventional three-dimensional magnetic field suspension fluidization is performed.

[0090] Control group D (traditional hysteresis response group): The structure is the same as that of experimental group A, but the kinetic prediction model is not run. Only the traditional threshold triggering method is used, and the response is performed after the hydrogen production rate decreases or the dissolved hydrogen reaches the threshold.

[0091] Test results: The fermentation temperature was controlled at 36.0±0.5℃, and the hydraulic retention time (HRT) was 8h. After 20 days of continuous operation, the key performance indicators of the four reactors are summarized in the table below.

[0092] Comparison of the operational performance of the four reactor groups

[0093] Experimental data analysis: Hydrogen production efficiency analysis: The average daily hydrogen production rate of experimental group A was 3.85 L / (L·d), which was 3.35 times that of control group B (1.15 L / (L·d)). Thanks to the early intervention of the hydrogen production kinetic prediction model, the hydrogen production rate fluctuation coefficient of experimental group A was only 4.2%, far lower than that of control group D (15.2%) which responded after the fact, and hydrogen production fluctuations were basically eliminated, achieving stable and efficient operation.

[0094] Dehydrogenation efficiency analysis: The average dissolved hydrogen concentration in the fermentation broth of experimental group A was controlled at 12.3 μmol / L (equivalent hydrogen partial pressure below 0.02 MPa), which was 82.0% lower than that of control group B. This effectively relieved the thermodynamic limitation of hydrogen production metabolism, increasing the glucose conversion rate to 3.58 mol H2 / mol glucose, close to the theoretical limit of 4.0 mol / mol.

[0095] Analysis of biofilm peeling effect: On days 8 and 15, experimental group A triggered the biofilm renewal program through a predictive model, employing a four-step strategy of temperature-induced phase change to reduce viscosity, pulsed ultrasonic loosening, stepped magnetic field collision, and acoustic signal locking peeling. This achieved precise peeling without damaging the inner layer of active bacteria, with a hydrogen production recovery time of only 0.5 hours after biofilm renewal. In contrast, control group C, lacking temperature-sensitive phase change and acoustic signal control, experienced excessive or uneven peeling of the carrier, resulting in a hydrogen production recovery period as long as 12 hours. Control group D, due to its delayed response, also required a recovery time of 5 hours.

[0096] Mass transfer and stability analysis: Experimental group A was driven by a triaxial orthogonal gradient magnetic field, and the magnetic biological carrier 2 moved in a three-dimensional spiral path. No bottom sedimentation or sidewall retention was observed inside the reactor. The gas-liquid-solid three-phase contact was sufficient, and the COD removal rate of the effluent reached 88.2%. The system's mass transfer efficiency and overall operational stability were significantly better than those of the traditional mechanical stirring group B and the magnetic field fluidization group C.

[0097] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A bio-fermentation hydrogen production device, characterized in that, include: The reactor body (1) has a reaction chamber, which is suitable for containing the fermentation substrate and a magnetic biological carrier (2) loaded with hydrogen-producing bacteria. The triaxial orthogonal gradient magnetic field coil group (3) is arranged in groups at intervals on the outside of the reactor body (1) in the X-axis direction, Y-axis direction and Z-axis direction. The triaxial orthogonal gradient magnetic field coil group (3) is adapted to generate a dynamic three-dimensional alternating magnetic field inside the reactor to drive the magnetic biological carrier (2) to be in a suspended fluidized state in the fermentation broth. An ultrasonic transducer (4) is disposed at the bottom of the reactor body (1). The ultrasonic transducer (4) is adapted to emit ultrasonic waves toward the fermentation broth to remove dissolved hydrogen from the fermentation broth. A gas-liquid membrane separation module is disposed outside the reactor body (1). The gas-liquid membrane separation module is connected to the reaction chamber and is used to extract dissolved gas in the fermentation broth to the outside of the reaction chamber. The sensor monitoring module includes at least a dissolved hydrogen sensor (9a), the detection end of which is disposed in the fermentation broth of the reaction chamber for monitoring the dissolved hydrogen concentration in the fermentation broth; The control unit (11) is electrically connected to the triaxial orthogonal gradient magnetic field coil group (3), the ultrasonic transducer (4), the gas-liquid film separation module and the sensor monitoring module, respectively. The control unit (11) is adapted to receive the detection data of the sensor monitoring module, predict the hydrogen production rate change trend based on the detection data, and start the ultrasonic transducer (4) in advance to perform ultrasonic cavitation dehydrogenation based on the hydrogen production rate change trend, and / or adjust the magnetic field parameters of the triaxial orthogonal gradient magnetic field coil group (3) in advance.

2. The bio-fermentation hydrogen production apparatus according to claim 1, characterized in that, The gas-liquid membrane separation module includes a hydrophobic membrane module (5), a circulation pump (6), a circulation pipeline (7), and a vacuum pump (8). The reaction chamber is connected to an outlet and an inlet. The outlet is connected to the inlet of the hydrophobic membrane module (5) through the circulation pipeline (7). The circulation pump (6) is installed on the circulation pipeline (7) with the outlet facing the inlet. The inlet is connected to the liquid outlet of the hydrophobic membrane module (5) through the circulation pipeline (7). The vacuum pump (8) is connected to the gas outlet of the hydrophobic membrane module (5). The vacuum pump (8) is adapted to form a negative pressure in the cavity of the hydrophobic membrane module (5) to extract the dissolved gas to the outside of the system.

3. The bio-fermentation hydrogen production apparatus according to claim 2, characterized in that, The hydrophobic membrane module (5) includes a hydrophobic hollow fiber membrane and a membrane shell. The hydrophobic hollow fiber membrane is encapsulated inside the membrane shell. The hydrophobic hollow fiber membrane is a polytetrafluoroethylene membrane or a polyvinylidene fluoride membrane. The membrane pore size of the hydrophobic hollow fiber membrane is 0.05μm-0.2μm. The vacuum pump (8) is adapted to form a negative pressure of 10kPa-50kPa in the mold cavity of the hydrophobic membrane module (5).

4. The bio-fermentation hydrogen production apparatus according to claim 1, characterized in that, The magnetic biocarrier (2) is a porous microsphere. The magnetic biocarrier (2) includes a magnetic core and a porous polymer coating layer arranged sequentially from the inside out. The magnetic core is a superparamagnetic Fe3O4 nanoparticle. The porous polymer coating layer covers the periphery of the magnetic core. The porous polymer coating layer is a hybrid hydrogel framework formed by crosslinking polyvinyl alcohol, sodium alginate and nanocellulose.

5. The bio-fermentation hydrogen production apparatus according to claim 4, characterized in that, The porous polymer coating layer is grafted with a pH-sensitive monomer, which is at least one of acrylic acid, methacrylic acid, or 2-(dimethylamino)ethyl methacrylate; the porosity of the porous polymer coating layer is 70%-85%, and the average pore size of the porous polymer coating layer is 30μm-80μm; the porous polymer coating layer is suitable for swelling and pore expansion due to electrostatic repulsion at pH < 5.0, with the average pore size expanding to 60μm-100μm.

6. The bio-fermentation hydrogen production apparatus according to claim 5, characterized in that, The outer surface of the porous polymer coating is grafted with a thermo-responsive polymer thin layer, the phase transition temperature of which is 36℃-38℃; the thermo-responsive polymer thin layer is hydrophilic when the temperature is below the phase transition temperature, and undergoes structural collapse and becomes hydrophobic when the temperature is above the phase transition temperature.

7. The bio-fermentation hydrogen production apparatus according to claim 1, characterized in that, The sensor monitoring module further includes a pH sensor (9b), an ORP sensor (9c), and an acoustic emission sensor. The detection ends of the pH sensor (9b) and the ORP sensor (9c) are respectively located in the fermentation broth of the reaction chamber. The pH sensor (9b) is used to monitor the pH value of the fermentation broth, and the ORP sensor (9c) is used to monitor the redox potential of the fermentation broth. The acoustic emission sensor is attached to the outer wall of the reactor body (1) and is electrically connected to the control unit (11). The acoustic emission sensor has a sampling frequency band of 100kHz-500kHz and is used to collect acoustic signals generated during biofilm peeling. The control unit (11) is equipped with an acoustic emission signal spectrum analysis module, which is used to extract the characteristic frequency band signal of biofilm rupture. The characteristic frequency band is 150kHz-250kHz.

8. The bio-fermentation hydrogen production apparatus according to claim 1, characterized in that, The ultrasonic transducer (4) operates at a frequency of 28kHz-50kHz; and / or; The reactor body (1) is provided with a sealing cover at the top, and the sealing cover is provided with a feed inlet (12), which is connected to the reaction chamber and is used to feed the fermentation substrate into the reaction chamber; and / or; It also includes a sludge discharge pipe (10) connected to the bottom of the reactor body (1), the sludge discharge pipe (10) being used to discharge the detached aged biofilm from the reaction chamber; and / or; It also includes a biogas collection device (13), which is connected to the reaction chamber and is used to collect gaseous products generated by hydrogen-producing fermentation; and / or; It also includes a temperature control module, which includes a temperature control water jacket (14) and a heat exchange unit (15). The temperature control water jacket (14) and the heat exchange unit (15) are used to adjust the fermentation temperature in the reaction chamber. The temperature control water jacket (14) is sleeved on the outside of the reactor body (1). The heat exchange unit (15) is connected to the temperature control water jacket (14) through a pipeline. The heat exchange unit (15) is electrically connected to the control unit (11).

9. A method for producing hydrogen through bio-fermentation, using the bio-fermentation hydrogen production apparatus according to any one of claims 1-8, characterized in that, Includes the following steps: Step S1: Fill the reaction chamber inside the reactor body (1) with magnetic biological carrier (2) at a volume ratio of 25%-40%, inoculate with hydrogen-producing bacteria, and culture them under a dynamic magnetic field. Step S2: Introduce the fermentation substrate into the reaction chamber, control the fermentation temperature to 35℃-36.5℃, start the triaxial orthogonal gradient magnetic field coil group (3), the triaxial orthogonal gradient magnetic field coil group (3) synthesizes a dynamic three-dimensional alternating magnetic field that rotates in space, driving the magnetic biological carrier (2) to be in a suspended fluidized state in the fermentation liquid for hydrogen production fermentation; Step S3: Remove dissolved hydrogen from the fermentation broth using a gas-liquid membrane separation module; Step S4: The dissolved hydrogen sensor (9a) detects the dissolved hydrogen concentration in the fermentation broth. The control unit (11) predicts the trend of hydrogen production rate change based on the detection data of the sensor monitoring module. When the hydrogen partial pressure is predicted to reach the preset threshold, the control unit (11) starts the ultrasonic transducer (4) in advance to emit ultrasonic waves to remove the dissolved hydrogen in the fermentation broth.

10. The method for producing hydrogen through bio-fermentation according to claim 9, characterized in that: In step S4, the control unit (11) predicts the hydrogen production rate after a preset time interval according to the preset time interval. When the predicted hydrogen production rate after the preset time interval drops to below 80% of the maximum hydrogen production rate and is accompanied by a trend of pH decrease, the control unit (11) enters the biofilm renewal mode in advance. Start the heat exchange unit (15) to raise the temperature of the fermentation broth to 38℃-39℃, causing the thermosensitive polymer thin layer of the magnetic biological carrier (2) to undergo hydrophobic collapse; Control the ultrasonic transducer (4) to switch to pulse mode, with a pulse duty cycle of 5%-15%, to loosen the aging biofilm on the outer layer of the magnetic biocarrier (2); The magnetic induction intensity of the triaxial orthogonal gradient magnetic field coil group (3) is increased stepwise at a rate of 1mT / s-3mT / s. When the acoustic emission sensor captures the sudden change in acoustic signal energy in the characteristic frequency band, the control unit (11) locks the current magnetic induction intensity and maintains it for 3min-8min, so that the magnetic biological carrier (2) will collide and peel off the aging biofilm. After the stripping is completed, the temperature of the fermentation broth is controlled to be restored to 35℃-36.5℃, the pulse mode ultrasound is turned off, and the triaxial orthogonal gradient magnetic field coil group (3) is restored to the conventional fluidization mode.

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