Rotary solar continuous hydrogen production reactor and method with ultrasound enhanced interfacial mass transfer

Abstract

The application discloses a rotating type solar continuous hydrogen production reactor and method with ultrasonic reinforced interface mass transfer and belongs to the technical field of high-temperature solar thermochemical fuel production. In view of the problems of intermittent operation between reduction and oxidation steps of hydrogen production by a traditional reactor, slow water vapor adsorption and hydrogen desorption rate in the pores of porous ceramic reactants, and limited reaction kinetics hydrogen production rate, three innovations are provided: 1, an ultrasonic transmission system: titanium alloy waveguide is used to directionally excite the acoustic flow effect and micro disturbance in the oxidation zone; 2, rotating mesh transmission: a permanent magnet rotor is coaxially fixedly connected with a silicon carbide connecting rod, and a trapezoidal protrusion-groove structure is used to drive the periodic rotation of the foam ceramic to switch the reactor partitions (the oxidation zone and the reduction zone); and 3, a double-channel gas path: argon / water vapor is injected in the partitions to accurately control the required environment of the reaction. The application can realize continuous hydrogen production and hydrogen production rate improvement and is suitable for cerium oxide and perovskite oxygen carrier reactant systems.

Description

Technical Field

[0001] This invention belongs to the field of high-temperature solar thermochemical fuel preparation technology, specifically relating to a rotary solar continuous hydrogen production reactor and method with ultrasonically enhanced interfacial mass transfer. Background Technology

[0002] Developing clean, sustainable, and efficient new energy technologies to replace traditional fossil fuels is an inevitable choice for achieving long-term sustainable development. Solar energy, with its abundant reserves, clean and carbon-free nature, and wide distribution, is an ideal energy source, but it faces application bottlenecks such as low energy density and uneven spatial and temporal distribution. Converting solar energy into chemical fuels (such as hydrogen and syngas) enables long-term storage, low carbon emissions, and the production of high-calorific-value fuels, representing a key path to overcoming these challenges.

[0003] In high-temperature solar thermochemical fuel production technology, foam ceramic reactors have become a research hotspot due to their use of high specific surface area reactants, which enhances the hydrogen production reaction on the gas-solid surface and improves multi-cycle stability. Oxygen-carrier reactants, represented by cerium oxide (CeO2) / perovskite (ABO3), can achieve efficient hydrogen production through a two-step redox reaction. The chemical reaction equation is as follows:

[0004] ;

[0005] ;

[0006] This technology boasts three core advantages: no need for hydrogen-oxygen separation, high theoretical conversion efficiency (68%), and the ability to integrate CO2 capture to synthesize hydrocarbon fuels (such as gasoline, methane, and methanol), achieving green hydrogen production. However, existing reactor designs still suffer from two major bottlenecks: First, there is the issue of intermittent operation. Traditional reactors require separate operation of the reduction step (oxygen vacancy formation) and the oxidation step (hydrogen production via hydrolysis). High-temperature reduction (>1300℃) releases O2, followed by cooling and introducing steam to produce hydrogen (800℃), resulting in discontinuous solar energy input, frequent start-ups and shutdowns of the solar system, reduced operational reliability, and inefficient use of heat during cooling. Second, the oxidation step suffers from kinetic lag in hydrogen production. The low diffusion rate of steam to the oxygen carrier surface restricts mass transfer, and the breaking of the H2O bond requires overcoming the activation energy barrier. Increasing the specific surface area of ​​foam ceramics has reached saturation in improving hydrogen production performance.

[0007] To address existing problems, ultrasonic-enhanced mass transfer at the gas-solid interface of porous foam ceramics induces an acoustic flow effect, resolving the issues of high mass transfer diffusion resistance and slow water vapor decomposition rates within the foam ceramic material. The acoustic pressure gradient drives vapor turbulence, disrupting and renewing the boundary layer at the gas-solid interface, thus improving water vapor mass transfer efficiency. Simultaneously, ultrasound generates localized hotspots, and focused acoustic energy produces transient micro-regional high-temperature fields, reducing the activation energy required to break H₂O bonds. The synergy between directional ultrasonic enhancement of the oxidation zone and the rotating, partitioned design of the cavity can solve the problems of intermittent reactor operation and kinetic limitations. Summary of the Invention

[0008] The purpose of this invention is to provide a rotary solar-powered continuous hydrogen production reactor and method with ultrasonically enhanced interfacial mass transfer. It uses multi-stage waveguides to directionally enhance water splitting in the oxidation zone to produce hydrogen, and combines a servo motor to drive a permanent magnet rotor to achieve zone switching, thereby realizing continuous hydrogen production driven by solar thermal energy.

[0009] To achieve the above objectives, the present invention adopts the following technical solution:

[0010] An ultrasonically enhanced interfacial mass transfer rotary solar continuous hydrogen production reactor includes:

[0011] Ultrasonic enhancement module: An external ultrasonic generator is connected to a piezoelectric transducer, which transmits acoustic energy to the oxide zone through a multi-stage titanium alloy waveguide. The waveguide surface is coated with a yttrium-stabilized zirconia coating with a thickness of 150-250 μm, and the end is equipped with a porous alumina fiber felt heat buffer layer with a thickness of 8-12 mm and a porosity >85%.

[0012] Rotary meshing module: A magnetic rotor is driven by a servo motor. A silicon carbide connecting rod fixed coaxially with the rotor meshes with the foam ceramic reactant through a trapezoidal protrusion-groove structure at an inclination angle of 30°±2°, realizing the periodic switching between a high-temperature reduction zone at 1400±50℃ and a hydrolysis oxidation zone at 800±50℃.

[0013] Dual-channel gas path system: The oxidation zone is equipped with a radial inlet for water vapor, the reduction zone is equipped with a radial inlet for high-purity argon, and the outlet channel is arranged axially.

[0014] In the above technical solution, the multi-stage titanium alloy waveguide includes:

[0015] The large end has a diameter of 50mm, the radius of curvature of the tapered transition section is ≥15mm, and the small end has a diameter of 22mm.

[0016] Amplitude ratio ≥ 5:1, surface roughness Ra < 0.8 μm;

[0017] The total length L satisfies the condition of being an integer multiple of half the wavelength of the sound wave: Where c is the sound velocity of titanium alloy and f is the ultrasonic frequency of 20-40kHz.

[0018] In the above technical solution, the foam ceramic reactant is composed of CeO2 or ABO3 type perovskite material with a porosity of 70%-90% and a specific surface area ≥20m². 2 / g.

[0019] In the above technical solution, the silicon carbide connecting rod of the rotary engagement module:

[0020] The height of the trapezoidal protrusion is 3-5mm, and the depth tolerance of the groove is ≤0.05mm;

[0021] Apply 50-200 through the ceramic lock nut. Preload;

[0022] The dynamic sealing structure includes a graphite packing layer, a water-cooling jacket, and double O-rings.

[0023] In the above technical solution, the flange-type water-cooled sealing sleeve between the heat buffer layer and the waveguide includes:

[0024] The inner layer of expanded graphite gasket has a compression rate of 15±2%.

[0025] The outer high-temperature silicone ring has a Shore hardness of 80A±5.

[0026] Cooling water flow rate ≥ 5L / min, ensuring waveguide end temperature ≤ 800℃.

[0027] In the above technical solution, the argon gas inlet is:

[0028] The incident light is incident radially along the quartz glass window, with the angle between the incident light and the horizontal plane of the glass being ≤5°;

[0029] Gas flow rate 2-4 L / min, maintaining oxygen partial pressure P in the reaction chamber O2 ≤10 -5 atm.

[0030] In the above technical solution, the ultrasonic enhancement module:

[0031] It induces acoustic flow effects, disrupting the steam boundary layer;

[0032] This generates micro-region hotspots and reduces the activation energy for HO bond breaking;

[0033] Ultrasonic frequency 20-40kHz, power 0-1.5kW, terminal amplitude ≥50μm.

[0034] In the above technical solution, the reactor body:

[0035] The top is fitted with a high-transmittance quartz glass window with a light transmittance of ≥92%;

[0036] The secondary concentrator focuses sunlight onto the reduction zone, with a concentration ratio ≥1000 suns;

[0037] The cavity is covered with multiple layers of insulation material, with a heat loss of ≤10%.

[0038] In the above technical solution, the rotation switching cycle is:

[0039] The dwell time in the reduction zone is 30-60 minutes, and the dwell time in the oxidation zone is 20-40 minutes; the servo motor speed is 0.5-2 rpm.

[0040] A solar-powered hydrogen production method, using the above-mentioned reactor, includes the following steps:

[0041] Reduction stage: The surface of the foam ceramic in the reduction zone is directly irradiated by solar energy at a temperature of 1400±50℃. Argon gas is used to purge and reduce the oxygen bias, and oxygen vacancies are formed in the material at high temperature.

[0042] Oxidation stage: The foam ceramic material after high-temperature reduction is rotated to the oxidation zone at a temperature of 800±50℃. Mass transfer in the oxidation zone is enhanced by ultrasound to achieve "instant production and removal" of hydrogen.

[0043] Cycle cycle: The reduction / oxidation zone is continuously switched by meshing rotation under the control of a servo motor.

[0044] Compared with the prior art, the present invention has the following beneficial technical effects:

[0045] First, ultrasonic oxidation zone directionally enhances mass transfer: it excites the acoustic flow effect, and high-frequency ultrasound arouses microscale turbulence (Re>3000) at the gas-solid interface, destroying the boundary layer of the gas-solid interface and enhancing the adsorption of water vapor at oxygen vacancy active sites and the immediate desorption of hydrogen; it generates local hot spots, and the acoustic energy is concentrated and dissipated at material defects, generating micro-region high temperature, activating oxygen vacancy migration and HO bond breaking; at the same time, the high-frequency ultrasonic vibration delays grain agglomeration, maintains the density of surface active sites, and inhibits the sintering of the material.

[0046] Second, continuous hydrogen production by rotating partitions: The magnetic drive rotating device, combined with the trapezoidal meshing transmission design, can achieve synchronous operation of the reduction zone (>1300℃) and the oxidation zone (800℃) in the reaction chamber. Some heat can be recovered between the two different zones through solid heat conduction. Attached Figure Description

[0047] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below:

[0048] Figure 1 This is a schematic diagram of the ultrasonically enhanced interfacial mass transfer rotary solar continuous hydrogen production reactor system described in this invention.

[0049] Figure 2 This is a structural cross-sectional view of the ultrasonically enhanced interfacial mass transfer rotary solar continuous hydrogen production reactor system described in this invention.

[0050] Figure 3 This is a top view of the rotary solar continuous hydrogen production reactor with ultrasonic-enhanced interfacial mass transfer as described in this invention.

[0051] Wherein: 1 is the high-concentration solar simulator, 2 is the quartz glass window, 3 is the argon inlet A, 4 is the argon inlet B, 5 is the insulation material layer, 6 is the secondary concentrating section, 7 is the secondary concentrating port, 8 is the continuous hydrogen production reactor, 9 is the small end, 10 is the conical transition section, 11 is the large end, 12 is the alumina fiber felt heat buffer layer, 13 is the flange-type water-cooled sealing sleeve, 14 is the cerium oxide foam ceramic ring, 15 is the steam inlet, 16 is the water-cooling jacket, and 17 is the silicon carbide connecting rod. 18 is a permanent magnet rotor, 19 is a servo motor, 20 is a piezoelectric transducer, 21 is an ultrasonic generator, 22 is a dynamic sealing structure, 23 is a ceramic locking nut, 24 is a reaction chamber, 25 is a product outlet, 26 is a multi-stage titanium alloy waveguide, 27 is the reactor body, 28 is the front end cover, 29 is a high-temperature sealing ring, 30 is a high-temperature resistant bolt, 31 is the first type B thermocouple, 32 is the second type B thermocouple, 33 is the argon inlet C, and 34 is the argon outlet. Detailed Implementation

[0052] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. However, the following embodiments are only for explaining the present invention, and the scope of protection of the present invention should include all the contents of the claims. Moreover, through the description of the following embodiments, those skilled in the art can fully implement all the contents of the claims of the present invention.

[0053] This invention provides a rotary solar-powered continuous hydrogen production reactor and method with ultrasonically enhanced interfacial mass transfer, which solves the problems of discontinuous hydrogen production in the oxidation step and slow surface reaction kinetics in solar thermochemical hydrogen production. Details are provided below with reference to the accompanying drawings:

[0054] like Figure 1 As shown, the ultrasonically enhanced interfacial mass transfer rotary solar continuous hydrogen production reactor includes a foam ceramic reactor body 27; a high-concentration solar simulator 1; an ultrasonically enhanced mass transfer subsystem in the oxidation zone; and a servo motor 19 magnetically driven rotary meshing subsystem.

[0055] Specifically, the ultrasonic enhanced proton transfer system in the oxide zone comprises an ultrasonic generator 21, a piezoelectric transducer 20, a water-cooled jacket 16, and a multi-stage titanium alloy waveguide 26. Further, the multi-stage titanium alloy waveguide 26 includes a large end 11, a tapered transition section 10, and a small end 9; specifically, the large end 11 has a diameter of 50 mm, the tapered transition section 10 has a cone angle of 15°, the small end 9 has a diameter of 22 mm, and the amplitude amplification ratio is 5:1. Preferably, the waveguide surface is plasma-sprayed with a yttrium-stabilized zirconia coating with a thickness of 200 μm and a surface emissivity of less than 0.3.

[0056] like Figure 1 As shown, the continuous hydrogen production reactor 8 includes a rotary meshing transmission subsystem. This subsystem achieves power transmission through the meshing structure of a reaction-sintered silicon carbide connecting rod 17 and a cerium oxide foam ceramic ring 14. The connecting rod has a trapezoidal protrusion with an inclination angle of 30°, and the foam ceramic ring has a matching groove. A ceramic locking nut 23 is used to apply a preload torque of 80-150 N·m. The connecting rod is coaxially fixedly connected to a permanent magnet rotor 18, and a servo motor 19 drives the permanent magnet rotor 18 to drive the foam ceramic material to achieve periodic rotation.

[0057] Furthermore, the reactor body 27 includes a quartz glass window 2, and the reduction zone is provided with tangential gas inlets, including argon inlet A3, argon inlet B4, and argon inlet C33. The product outlet 25 and argon outlet 34 in the reduction zone are used to remove the generated oxygen. The axial product outlet 25 is arranged at the bottom of the reactor, and the oxidation zone is provided with an independent water vapor inlet 15.

[0058] This invention designs a rotary solar continuous hydrogen production reactor with ultrasonically enhanced interfacial mass transfer. The reaction chamber 24 is divided into a reduction zone and an oxidation zone by a rotating structure. The oxidation and reduction reactions of the materials are carried out continuously by the trapezoidal meshing and rotation of the silicon carbide connecting rod 17 and the cerium oxide foam ceramic ring 14, thereby realizing continuous hydrogen production.

[0059] The reduction reaction proceeds as follows: Concentrated solar energy enters the reaction chamber 24 through the quartz glass window 2. The sunlight entering the reactor is focused onto the secondary concentrator 7 via the secondary concentrator section 6, resulting in high-concentration solar irradiation on the surface of the cerium oxide foam ceramic ring 14 in the upper reduction zone inside the reaction chamber 24. High-purity inert argon gas is introduced radially through argon inlets A3, B4, and C33 to maintain a low-oxygen bias environment inside the reactor, which helps enhance oxygen exchange in the reduction reaction. The oxygen generated by the reduction reaction is discharged from the reactor chamber through the product outlet 25 and the argon outlet 34 via pipes.

[0060] To ensure the reactor operates stably under high-temperature conditions, such as Figure 3As shown, the edge of the quartz glass window 2 is provided with a high-temperature sealing ring 29, the front cover 28 is provided with a water cooling device, and the glass and the front cover 28 are fixed by 7 high-temperature resistant bolts 30, so that the reactor chamber has high sealing performance.

[0061] pass Figure 2 In the cross-sectional view, the first type B thermocouple 31 and the second type B thermocouple 32 in the reduction zone measure the surface temperature of the material. The thermocouples are inserted from the side of the reactor cavity. After the temperature of the foam ceramic material in the reduction zone reaches the reaction value of 1300–1500℃, the ceramic connecting rod rotates to switch the foam ceramic material in the reduction zone to the oxidation zone below. Water vapor is injected through the water vapor inlet 15. The water vapor and the foam ceramic material containing oxygen vacancies undergo an oxidation reaction, and the oxygen vacancies inside the oxygen carrier material are filled to generate hydrogen gas.

[0062] This invention also provides a method for directional ultrasonic enhancement of the reaction in an oxide zone. High-frequency ultrasonic waves are input into the oxide zone within the reaction chamber 24 via a multi-stage titanium alloy waveguide 26, and the water splitting reaction is synergistically enhanced through the acoustic flow effect and local hotspot effect of the ultrasonic waves.

[0063] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A rotary solar-powered continuous hydrogen production reactor with ultrasonic-enhanced interfacial mass transfer, characterized in that, include: Ultrasonic enhancement module: An external ultrasonic generator (21) is connected to a piezoelectric transducer (20), and the acoustic energy is transmitted to the oxide zone in the reaction cavity through a multi-stage titanium alloy waveguide (26). The waveguide surface is provided with a yttrium oxide-stabilized zirconium oxide coating with a thickness of 150-250μm, and a porous alumina fiber felt heat buffer layer (12) with a thickness of 8-12mm and a porosity >85% is provided at the end. Rotary meshing module: The permanent magnet rotor (18) is driven by a servo motor (19) through a coupling. The permanent magnet rotor is coaxially fixed with the silicon carbide connecting rod (17). The silicon carbide connecting rod (17) meshes with the cerium oxide foam ceramic ring (14) through a trapezoidal protrusion-groove structure with an inclination angle of 30°±2°. This enables the periodic rotational switching between the high-temperature reduction zone at the upper end of the reactor cavity with a temperature of 1400±50℃ and the oxidation zone at the lower end with a temperature of 800±50℃. The rotational speed depends on the reaction rate of the material used. Dual-channel gas path system: The reduction zone is equipped with an argon inlet A (3) with a diameter of 10 mm, an argon inlet B (4) with a diameter of 5 mm, and an argon inlet C (33) with a diameter of 5 mm. The high-purity argon outlet (34) of the reduction zone has a diameter of 5 mm. The oxidation zone in the reactor is equipped with a water vapor inlet (15) with a diameter of 10 mm. The product outlet (25) is arranged axially with a diameter of 15 mm.

2. The reactor according to claim 1, characterized in that, The multi-stage titanium alloy waveguide (26) includes: a large end (11) with a diameter of 50 mm, a tapered transition section (10) with a radius of curvature ≥ 15 mm, and a small end (9) with a diameter of 22 mm; Amplitude ratio ≥ 5:1, surface roughness Ra < 0.8 μm; The total length L satisfies the condition that it is an integer multiple of the half wavelength of the sound wave, n: Where c is the sound velocity of titanium alloy, n is a multiple, and f is the ultrasonic frequency, which is taken as 20-40kHz.

3. The reactor according to claim 1, characterized in that, The cerium oxide foam ceramic ring (14) is composed of cerium oxide or ABO3 type perovskite material with a porosity of 70%-90% and a specific surface area ≥20m² / g.

4. The reactor according to claim 1, characterized in that, The silicon carbide connecting rod (17) of the rotary engagement module: The height of the trapezoidal protrusion is 3-5mm, and the depth tolerance of the groove is ≤0.05mm; Apply 50-200 through the ceramic lock nut (23). Preload; The dynamic sealing structure (22) includes a graphite packing layer, a water cooling jacket (16), and double O-rings.

5. The reactor according to claim 1, characterized in that, The alumina fiber felt heat buffer layer (12) and the waveguide are connected by a flange-type water-cooled sealing sleeve (13), including: The inner layer of expanded graphite gasket has a compression rate of 15±2%. The outer high-temperature silicone ring has a Shore hardness of 80A±5. Cooling water flow rate ≥ 5L / min, ensuring waveguide end temperature ≤ 800℃.

6. The reactor according to claim 1, characterized in that, The argon gas inlet: The incident light is incident radially along the quartz glass window (2), with the angle between the incident angle and the horizontal plane of the glass being ≤5°; Gas flow rate 2-4 L / min, maintaining oxygen partial pressure P in the reaction chamber O2 ≤10 -5 atm.

7. The reactor according to claim 1, characterized in that, The ultrasonic enhancement module: Excite the acoustic flow effect to enhance the mass transfer of water vapor at the gas-solid interface of porous foam ceramics; Local micro-perturbations are generated, updating the interface mass transfer boundary layer; Ultrasonic frequency 20-40kHz, power (sound pressure amplitude) 0-1.5kW, and end amplitude of multi-stage waveguide ≥50μm.

8. The reactor according to claim 1, characterized in that, The reactor body (27): The top is equipped with a high-transmittance quartz glass window (2), with a glass window radius of 89mm and a light transmittance of ≥92%; The secondary concentrator (7) focuses sunlight onto the reduction zone, with a concentration ratio ≥ 1000 suns (1 sun = 1000 W / m²). 2 ); The cavity is covered with multiple layers of thermal insulation material (5), and the thermal loss is ≤10%.

9. The reactor according to claim 1, characterized in that, The switching cycle of the rotary engagement module: The dwell time in the reduction zone is 30-60 minutes, and the dwell time in the oxidation zone is 20-40 minutes; the servo motor (19) speed is 0.5-2 rpm.

10. A solar-powered hydrogen production method, using the reactor described in any one of claims 1-9, characterized in that... Including the following steps: Reduction stage: Sunlight shines directly on the upper part of the porous foam ceramic material, and heat is transferred to the interior of the reaction material through thermal conduction. The reaction temperature is 1400±50℃. Argon gas is purged to reduce the oxygen bias in the reaction reduction area. Under the high temperature thermal drive, oxygen vacancies are formed in the material, releasing oxygen. Oxidation stage: The silicon carbide connecting rod (17) rotates to switch the porous foam ceramic material to the oxidation zone at a temperature of 800±50℃. The ultrasonic strengthening of the water vapor adsorption and hydrogen desorption at the porous foam ceramic interface achieves the immediate production and removal of hydrogen. Cycle cycle: The permanent magnet rotor (18) is coaxially fixedly connected with the connecting rod, and drives the connecting rod to mesh and rotate to realize the continuous switching of the reduction / oxidation zone.

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