A photocatalytic hydrogen production reaction system capable of separating and storing hydrogen

Abstract

A photocatalytic hydrogen production reaction system capable of separating and storing hydrogen, which relates to the field of hydrogen production. In order to solve the problem that most of the working modes of various reactors are relatively simple and mainly tend to produce hydrogen, and there is still a lack of effective reaction systems in the two links of gas separation and storage, the present invention introduces piezoelectric effect and photovoltaic technology into the PAEC system, and adopts a unique design to develop a "multi-energy complementary" water decomposition hydrogen production system. The system is equipped with a gas separation speed measurement and a hydrogen storage device, thereby opening up the "hydrogen production-separation-hydrogen storage" and other links, and has good innovation and practicality. In addition, the water decomposition system greatly reduces the excessive dependence on electrical energy, realizes an efficient "solar hydrogen" production process, and meets zero-carbon emission standards.

Description

Technical Field

[0001] The present invention belongs to the field of hydrogen production, and in particular relates to a photocatalytic hydrogen production reaction system capable of separating and storing hydrogen. Background Art

[0002] Currently, the mainstream "green hydrogen" production methods on the market include alkaline electrolysis, proton exchange membrane electrolysis, and solid oxide electrolysis, all of which rely on electricity. Known solar hydrogen production projects that have been put into operation use photovoltaics to convert solar energy into electricity, which is then used to produce hydrogen through hydrolysis. This process involves multiple energy conversions, resulting in low overall energy conversion efficiency. Furthermore, some key components of hydrogen electrolysis equipment are subject to technical barriers such as foreign patents, resulting in high equipment costs.

[0003] Photocatalytic hydrogen production is a novel method for generating hydrogen energy. This technology directly utilizes solar energy to split water to produce hydrogen. Due to its simplicity and low cost, it has high potential for commercial application. However, compared to water electrolysis, current photocatalytic hydrogen production efficiency still lags behind. In recent years, researchers have proposed various modification strategies, including the introduction of the piezoelectric effect, heterojunction structure construction, co-catalyst loading, and surface defect engineering, to improve the separation and transfer of photogenerated charges in the catalyst, effectively increasing its photocatalytic efficiency. Currently, the University of Tokyo and Xi'an Jiaotong University are actively developing photocatalyst materials for commercial application. It is expected that a variety of commercial hydrogen production photocatalysts will be commercially available in the near future. However, current reactors tend to be small and designed for research purposes. Furthermore, most reactors operate in a single mode, primarily focusing on hydrogen production. Effective reaction systems for gas separation and storage are still lacking. Summary of the Invention

[0004] In light of the above, the present invention provides a photocatalytic hydrogen production reaction system capable of separating and storing hydrogen. This invention addresses the low solar energy utilization efficiency and high energy consumption of current photo-assisted electrocatalytic (PAEC) water splitting systems. By innovatively integrating piezoelectric effects and photovoltaic technologies into the PAEC system, the present invention employs a uniquely designed, "multi-energy complementary" photocatalytic hydrogen production reaction system for both water splitting, hydrogen production, and hydrogen storage.

[0005] The present invention proposes a photocatalytic hydrogen production reaction system capable of separating and storing hydrogen. The reaction system includes a photocatalytic reactor, an oxygen separation purifier and a hydrogen storage tank;

[0006] The photocatalytic reactor includes a top light incident port, a pressure gauge head, a gas sampling port, a reactor outer tube circulating water inlet, a reactor outer tube circulating water outlet, a reactor inner tube gas inlet, a reactor inner tube liquid inlet, a pulley bracket and a piezoelectric reaction accessory;

[0007] The photocatalytic reactor is a double-layered cylinder consisting of an inner cylinder and an outer cylinder. The reactor's inner cylinder gas inlet is connected to the photocatalytic reactor's inner cylinder and is also connected to the hydrogen storage tank via a pipeline. The reactor's inner cylinder liquid inlet is connected to the photocatalytic reactor's inner cylinder, and the reactor's outer cylinder circulating water inlet is connected to the photocatalytic reactor's outer cylinder. The top of the photocatalytic reactor's inner cylinder is provided with a top incident light port. The pressure gauge head and gas sampling port are respectively provided at the top of the photocatalytic reactor's inner cylinder. The photocatalytic reactor and hydrogen storage tank are both provided on a pulley bracket. The piezoelectric reaction accessory is provided at the bottom of the photocatalytic reactor. The oxygen separation purifier is respectively connected to the gas sampling port and the nitrogen tank. A magnetic stirrer is also provided below the photocatalytic reactor.

[0008] Furthermore, the photocatalytic reactor has a cylindrical body with a height of 40-60 cm, an inner diameter of 20-30 cm, and an outer diameter of 25-35 cm.

[0009] Furthermore, when the top light incident port receives sunlight, a circular condenser with a diameter of 5-20 cm is placed at the light incident port.

[0010] Furthermore, the piezoelectric reaction accessory consists of an acrylic glass plate, 6 ultrasonic vibrators, 4 brackets, a piezoelectric ceramic circuit board and a power switch; the 4 brackets are respectively arranged at the four corners of the bottom of the photocatalytic reactor; the 6 ultrasonic vibrators are arranged at the bottom of the acrylic glass plate; the piezoelectric ceramic circuit board and the power switch are electrically connected; and the leads on the piezoelectric ceramic circuit board are respectively electrically connected to the 6 ultrasonic vibrators.

[0011] Furthermore, the output power of the piezoelectric reaction accessory is 250-320W.

[0012] Furthermore, the oxygen separation purifier is connected to the gas sampling port; a dissolved oxygen exchange membrane is placed at the lower opening of the oxygen separation purifier and placed inside the aqueous solution, and an inert gas inlet and exhaust port are opened at the upper narrow end of the oxygen separation purifier.

[0013] Furthermore, the oxygen separation purifier is in the shape of a thin tube at the upper end and a three-headed shape at the lower end.

[0014] Furthermore, the air inlet of the vacuum pump is communicated with the air intake port of the inner cylinder of the photocatalytic reactor, and the air outlet of the vacuum pump is communicated with the air inlet of the hydrogen storage tank.

[0015] Furthermore, the catalyst used in the hydrogen production process of the photocatalytic reactor is a ZCS / PO / Ni3Pi2 catalyst or a ZCS / PO / FCNPi-MnO catalyst.

[0016] Furthermore, the preparation method of the ZCS / PO / Ni3Pi2 catalyst or the ZCS / PO / FCNPi-MnO catalyst comprises the following steps:

[0017] 1) dissolving the mixed metal salt in a mixed solvent to form a suspension;

[0018] 2) adding the mixed sulfur source to the above suspension, stirring after ultrasonication until the solution is transparent;

[0019] 3) transferring the clear solution into a polytetrafluoroethylene-lined stainless steel autoclave for reaction;

[0020] 4) The precipitate after the reaction was recovered by centrifugation using deionized water and anhydrous ethanol respectively, and then the precipitate was vacuum dried to obtain Zn x Cd 1-x S material;

[0021] 5) Zn x Cd 1-x The S material is put into an aqueous solution containing sodium hypophosphite and ultrasonically stirred under argon to form a suspension;

[0022] 6) transferring the suspension obtained in step 5) into a photocatalytic reactor, sealing the container, evacuating the entire reaction system with a vacuum pump, irradiating the reactor with a visible light source, and maintaining room temperature with continuous stirring;

[0023] 7) After the photochemical modification reaction is completed, the reactor is opened, the supernatant is removed, the precipitate is recovered by centrifugation, and the ZCS / PO is recovered after drying;

[0024] 8) A ZCS / PO sample is dispersed in a mixed aqueous solution of nickel sulfate and sodium hypophosphite or a mixed aqueous solution containing ferric nitrate, cobalt nitrate, nickel sulfate, manganese sulfate, and sodium hypophosphite, and ultrasonically treated under the protection of an inert gas. The sample is then transferred to a photocatalytic reactor, the container is sealed, and the entire reaction system is evacuated with a vacuum pump. The reactor is irradiated with a visible light source and maintained at room temperature with continuous stirring. After the photochemical modification reaction is completed, the reactor is opened, the supernatant is removed, and the precipitate is recovered by centrifugation and oven-dried to obtain the ZCS / PO / Ni3Pi2 catalyst or ZCS / PO / FCNPi-MnO catalyst.

[0025] Furthermore, in step 5), Zn x Cd 1-xS material is dispersed in a sodium hypophosphite aqueous solution with a concentration of 0.1-0.8 mol / L, wherein Zn x Cd 1-x The mass volume ratio of the S material to the sodium hypophosphite aqueous solution is 50-500 mg:80 mL; the ZCS / PO material in step 8) is dispersed into a mixed aqueous solution of sodium hypophosphite with a concentration of 0.2-1.5 mmol / L and a mixed aqueous solution of ferric nitrate, cobalt nitrate, nickel sulfate, and manganese sulfate with a concentration of 0.01-0.050 mmol / L; wherein the mass volume ratio of the ZCS / PO material to the mixed aqueous solution of ferric nitrate, cobalt nitrate, nickel sulfate, and manganese sulfate is 50-200 mg:80 mL.

[0026] Furthermore, the mixed metal salt is a mixture of Zn(OAc)2 and Cd(OAc)2, and the molar ratio of Zn(OAc)2 and Cd(OAc)2 is x:1-x, wherein 0≤x≤1.

[0027] Furthermore, the mixed solvent is a mixed solution of diethylenetriamine and deionized water, and the volume ratio between the two solvents is x:1-x, wherein 0≤x≤1.

[0028] Furthermore, the mixed sulfur source is a mixture of L-cysteine ​​and thioacetamide, and the molar ratio of the two sulfur sources is x:1-x, wherein 0≤x≤1.

[0029] Furthermore, the molar volume ratio of the mixed metal salt to the mixed solvent is 1 mmol: 2-3 mL.

[0030] Furthermore, the mixed metal salt and the mixed sulfur source are mixed in a molar ratio of 1:1 to 3.

[0031] Furthermore, in the process of hydrogen production in the photocatalytic reactor, an aqueous solution of L-ascorbic acid is used as a sacrificial agent.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] In the present invention, acrylic glass is used as the main material to design a commercial photocatalytic hydrogen production reaction system for separating and storing hydrogen. The system can perform photocatalytic hydrogen production reactions under different working modes. Furthermore, the present invention proposes two different types of catalyst materials: the ZCS / PO / Ni3Pi2 catalyst can decompose pure water into hydrogen and hydrogen peroxide; the ZCS / PO / FCNPi-MnO catalyst can decompose pure water into hydrogen and oxygen. Therefore, for different types of photocatalyst materials, different photocatalytic reaction accessories can be used on the basis of the photocatalytic reactor to achieve an efficient photocatalytic hydrogen production process. When matched with the homemade piezoelectric reaction accessories, the hydrogen production rate of the ZCS / PO / Ni3Pi2 catalyst in the reactor reached the highest 558.432mmol·h -1 ·g -1 . And under this working condition, the quantum yield (AQY) and light-to-hydrogen (STH) energy conversion efficiency of the catalyst reached 86.15% and 5.09% respectively. After cost conversion, it can be seen that the total cost of catalyst materials, equipment and electricity consumed to produce each kilogram of hydrogen is at most 8.6 yuan, which has a high commercial promotion value. The oxygen separation purifier can exchange the oxygen produced by the ZCS / PO / FCNPi-MnO catalyst in real time, thereby purifying the hydrogen produced in the system. After further matching the hydrogen storage device, it opens up the "hydrogen production-separation-hydrogen storage" and other links, which has good innovation and certain practicality. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 Figure A is a schematic diagram of the photocatalytic reactor structure, and Figure B is a top view of the photocatalytic reactor;

[0035] Figure 2 TEM and EDX-Mapping images of ZCS / PO / Ni3Pi2 catalyst;

[0036] Figure 3 Schematic diagram of the ZCS / PO / Ni3Pi2 catalyst working in the "photocatalytic hydrogen production-storage" reaction system in simplified working mode;

[0037] Figure 4 Schematic diagram of the ZCS / PO / Ni3Pi2 catalyst working in the "photocatalytic hydrogen production-storage" reaction system under stirring working mode;

[0038] Figure 5 Schematic diagram of the working process of ZCS / PO / Ni3Pi2 catalyst in the "photocatalytic hydrogen production-storage" reaction system under piezoelectric working mode;

[0039] Figure 6 Schematic diagram of piezoelectric response accessories;

[0040] Figure 7 TEM and EDX-Mapping images of ZCS / PO / FCNPi-MnO catalyst;

[0041] Figure 8 Schematic diagram of the ZCS / PO / FCNPi-MnO catalyst working in the "photocatalytic hydrogen production-separation-storage" reaction system under stirring mode;

[0042] Figure 9 Schematic diagram of an oxygen separation purifier. DETAILED DESCRIPTION

[0043] The present invention will be further described in detail below with reference to the accompanying drawings.

[0044] Example 1. Photocatalytic reactor design

[0045] First, considering the outdoor application requirements of the reactor, this embodiment places the top incident light port 11 of the photocatalytic reactor at the top ( Figure 1 ); Considering that a vacuum environment needs to be provided during the test, the present embodiment abandons the mechanical stirring mode, and places a magnetic stirrer at the bottom of the photocatalytic reactor to provide stirring force; considering that the system temperature rises due to the influence of light during the test, the present embodiment introduces circulating water into the outer cylinder for cooling, so as to maintain a constant temperature environment for the inner cylinder test system; considering that the photocatalytic reactor is large in size and cannot be placed in an ultrasonic oscillator, the present embodiment designs a piezoelectric reaction accessory 19, which is placed in a wheeled bracket 18 at the bottom of the photocatalytic reactor and fits tightly to the bottom of the photocatalytic reactor to provide an external ultrasonic environment; considering that the floor space needs to be reduced as much as possible for outdoor applications, the present embodiment places a wheeled bracket 18 at the bottom of the photocatalytic reactor, which can accommodate components such as a stirrer, a piezoelectric reaction accessory 19, a self-priming pump, and a hydrogen storage tank 3; considering that different catalysts The decomposition products of the chemical agent are different. If water is decomposed into hydrogen and oxygen, the purity of the hydrogen will be affected. In this embodiment, an oxygen separation purifier 2 is designed. The oxygen separation purifier 2 is connected to the gas sampling port 13, and a dissolved oxygen exchange membrane is placed at the lower opening and placed in an aqueous solution. Two openings are opened at the upper narrow end, one of which is for introducing inert gas to ensure an anaerobic environment inside the separator. Based on the huge difference in molecular weight and water solubility between hydrogen and oxygen, the dissolved oxygen exchange membrane is used to exchange and separate the dissolved oxygen generated by the system in real time and discharge it into the atmosphere from the other opening at the upper end, thereby obtaining high-purity hydrogen. Considering that the current photocatalytic reactor only considers the hydrogen production process, this embodiment adds hydrogen detection and separation and hydrogen storage links, thereby developing a "photocatalytic hydrogen production-separation-hydrogen storage" reaction system.

[0046] Example 2. Application of ZCS / PO / Ni3Pi2 catalyst in the “photocatalytic hydrogen production-storage” reaction system under streamlined working mode

[0047] This embodiment designs a ZCS / PO / Ni3Pi2 catalyst ( Figure 2 ), TEM and EDX-Mapping characterization revealed that the catalyst exhibited a micron-spherical morphology ( Figure 2 A, E), and Zn, Cd, and S elements are uniformly and tightly filled inside the material ( Figure 2 B, C, D), indicating that the microsphere is indeed Zn x Cd 1-x S material (abbreviated as ZCS); In addition, it was found that Ni, P, and O elements were uniformly and orderly distributed on the surface of the microspheres ( Figure 2 F, G, H), indicating that the PO protective layer and the Ni3Pi2 co-catalyst are respectively wrapped or loaded on the surface of the ZCS material. These results confirm the successful preparation of the ZCS / PO / Ni3Pi2 catalyst. Moreover, since there is no matching oxygen-producing co-catalyst, the ZCS / PO / Ni3Pi2 catalyst can produce hydrogen and hydrogen peroxide during the photocatalytic decomposition of pure water. Therefore, in this embodiment, 10g of the catalyst is weighed, and 25L of deionized water is measured, and they are put into the photocatalytic reaction system together. In the case of unmatched piezoelectric reaction accessories 19, agitators, and oxygen separation purifiers 2, a "photocatalytic hydrogen production-hydrogen storage" test is carried out. The study found that: in this working mode, the ZCS / PO / Ni3Pi2 catalyst put into the photocatalytic reactor will gradually settle to the bottom ( Figure 3 ), limited by the low efficiency of sunlight collection, the hydrogen production rate of the catalyst by decomposing pure water is 1.464mmol·h -1 ·g -1 .

[0048] Example 3. Application of ZCS / PO / Ni3Pi2 catalyst in the “photocatalytic hydrogen production-storage” reaction system under stirring working mode

[0049] Weigh 10g of ZCS / PO / Ni3Pi2 catalyst and 25L of deionized water and put them into the photocatalytic reaction system. Place a magnetic stirrer in the wheeled bracket 18 below the photocatalytic reactor to provide stirring force, but do not match the piezoelectric reaction accessories 19 and the oxygen separation purifier 2 to conduct the "photocatalytic hydrogen production-hydrogen storage" test. The study found that: in this working mode, the ZCS / PO / Ni3Pi2 catalyst put into the photocatalytic reactor will be suspended in the entire reaction solution ( Figure 4 ), efficiently capturing incident light, thereby increasing the photocatalytic hydrogen production rate to 4.449 mmol·h -1 ·g -1 .

[0050] Example 4. Application of ZCS / PO / Ni3Pi2 catalyst in the “photocatalytic hydrogen production-storage” reaction system under piezoelectric working mode

[0051] Weigh 10g of ZCS / PO / Ni3Pi2 catalyst and 25L of deionized water, and put them into the photocatalytic reaction system. Place the piezoelectric reaction accessory 19 in the bracket below the reactor to provide ultrasonic pressure for the reaction system, and conduct the "photocatalytic hydrogen production-hydrogen storage" test ( Figure 5 The study found that: in this working mode, the ZCS / PO / Ni3Pi2 catalyst put into the photocatalytic reactor will be suspended in the entire reaction system, efficiently capture the incident light, and be affected by the piezoelectric accessories ( Figure 6 ) induces ultrasonic waves, which generates a piezoelectric effect inside the catalyst, thereby efficiently increasing the hydrogen production rate of the catalyst to 8.478 mmol·h -1 ·g -1 .

[0052] In addition, this example uses L-ascorbic acid aqueous solution as a sacrificial agent to assist the ZCS / PO / Ni3Pi2 catalyst in hydrogen production properties testing under this piezoelectric mode. It is found that due to the piezoelectric effect, the photogenerated carriers inside the catalyst are efficiently separated. The presence of the sacrificial agent further efficiently captures the separated photogenerated holes, thereby greatly improving the hydrogen production performance of the ZCS / PO / Ni3Pi2 catalyst, and the hydrogen production rate is further increased to 558.432 mmol·h -1 ·g -1 In addition, under this mode, the quantum yield (AQY) of the ZCS / PO / Ni3Pi2 catalyst is about 86.15% (N e : the total number of electrons transferred in the reaction; N p : number of incident photons; v, mol·s -1 : Photocatalytic hydrogen production rate. In this experimental device, 10g of catalyst was added during the test. Due to the excitation of 420nm monochromatic light, the hydrogen production rate dropped sharply to 342.88mmol·h -1 ·g -1 , the hydrogen production rate is converted to 342.88 mmol·h -1 ·g -1 =3428.77mmol·h -1 =9.524×10 -4 mol·s -1 ; N A :Avogadro constant (6.02×10 23 mol -1 ); K: number of electrons transferred in the reaction, which is 2; h: Planck constant (6.62×10 -34 J·s); c: speed of light (3.0×10 8 m·s -1 ); I: Light power density (measured using a radiometer: 0.0175 W cm-2 A: incident light area (the incident light port on the top of the all-in-one device is a 19cm×19cm circular window with an area of ​​361cm 2 ); λ: wavelength of incident light (420nm monochromatic light is used as incident light in this experiment), the calculation formula is:

[0053]

[0054] In this mode, the light-to-hydrogen (STH) energy conversion efficiency of the ZCS / PO / Ni3Pi2 catalyst is about 5.09% (R H2 , mmol·s -1 : Photocatalytic hydrogen production rate. In this experimental device, 5g of catalyst was added during the test, and the hydrogen production rate was converted to 558.432mmol·h -1 ·g -1 =2792.16mmol·h -1 =0.7756mmol·s -1 ;ΔG r θ , J.mol -1 :The standard molar reaction Gibbs free energy of water decomposition reaction (237×10 3 J.mol -1 );P sun :AM1.5G standard solar spectrum light power density (100mW·cm -2 ); S: illumination area (the incident port on the top of the all-in-one device of this experimental device is a circular window of 19 cm × 19 cm, with an area of ​​361 cm 2 ), the calculation formula is:

[0055]

[0056] Example 5. Application of ZCS / PO / FCNPi-MnO catalyst in the “photocatalytic hydrogen production-separation-storage” reaction system under stirring working mode

[0057] This embodiment designs a ZCS / PO / FCNPi-MnO catalyst ( Figure 7 ), TEM and EDX-Mapping characterization revealed that the catalyst exhibited an elliptical micron-spherical morphology ( Figure 7 A), and the Zn, Cd, and S elements are uniformly and tightly filled inside the material ( Figure 7 B, C, D), indicating that the microspheres are indeed ZCS materials; in addition, it was found that Fe, Co, Ni, P, O, and Mn elements are uniformly and orderly distributed on the surface of the microspheres ( Figure 2EH), indicating that the PO protective layer, FCNPi and MnO co-catalysts are respectively wrapped or loaded on the surface of the ZCS material. These results confirm the successful preparation of the ZCS / PO / FCNPi-MnO catalyst. Moreover, the MnO material is matched as an oxygen-producing co-catalyst. The ZCS / PO / FCNPi-MnO catalyst can produce hydrogen and oxygen during the photocatalytic decomposition of pure water. Therefore, in this embodiment, 10g of the catalyst is weighed, and 25L of deionized water is measured, and they are put into the photocatalytic reaction system together, and a magnetic stirrer ( Figure 8 ), providing stirring force; in the photocatalytic reactor gas sampling port 13 connected to the oxygen separation purifier 2 ( Figure 9 ), separate the dissolved oxygen produced by the system, and conduct a "photocatalytic hydrogen production-separation-hydrogen storage" test. The study found that under this working mode, the photocatalytic decomposition of pure water by the ZCS / PO / FCNPi-MnO catalyst in the photocatalytic reactor can produce hydrogen at a rate of 2.518mmol·h -1 ·g -1 The hydrogen production rates of the catalysts under various working modes are detailed in Table 1 below.

[0058] Table 1 Hydrogen production rate (R) under different combinations of “working mode + catalyst + reaction system” H ,mmol·h -1 ·g -1 )data

[0059]

[0060] Example 6. Analysis of emergency response plan for the “photocatalytic hydrogen production-separation-storage” reaction system

[0061] Considering that good lighting conditions are not available every day, especially when the rainy season arrives in the south, there may be no excellent outdoor light source available for several consecutive days or weeks. In order to ensure the normal operation of the photocatalytic hydrogen production plant of this embodiment, this embodiment adopts the following two emergency plan analyses.

[0062] Wind-solar hybrid "power generation and energy storage" energy supply system: This system consists of two parts: power generation and energy storage. The purchased power generation system is assembled from wind turbines and solar panels, using a wind-solar hybrid model. Each system generates approximately 9 kWh of electricity per day. This embodiment also purchased a mobile power supply, which uses large-cell lithium iron phosphate batteries and has a storage capacity of 10 kWh, fully accommodating the power generated by the wind-solar hybrid power generation system. When sunlight is insufficient, if this embodiment adds a 300W xenon lamp to the all-in-one experimental device, the total daily power consumption is only 4.8 kWh (assuming a 10-hour operation day, the xenon lamp consumes 3 kWh, and the piezoelectric reaction device consumes 1.8 kWh), fully meeting the energy needs of the "photocatalytic hydrogen production-separation-storage" reaction system. After calculation, the cost of this wind-solar hybrid "power generation-storage" energy supply system is approximately 7,000 yuan. Including the cost of the "photocatalytic hydrogen production-separation-storage" reaction system, the cost of each device is 10,000 yuan. Assume that each set of equipment is used for 10 years, with a total electricity cost of 0 yuan (assuming self-sufficiency in "power generation and energy supply"), and a total material cost of 4,000 yuan (40 quarters in total, calculated based on 3,600 days. If the material cost of 50 grams of catalyst (approximately 80 yuan), the material cost of 200 grams of L-ascorbic acid (approximately 8 yuan), and the material cost of a 25L barrel of pure water (approximately 12 yuan) are considered, and 100 yuan per quarter, the total material cost for 40 quarters is 4,000 yuan). After integration, it was found that the total cost was 14,000 yuan, and the total hydrogen production in 40 quarters was approximately 2,009.2 kilograms, so the material and electricity cost required for hydrogen production was 7.0 yuan / kg.

[0063] Mains power supply system: If there are many days of rainy weather, the wind-solar complementary "power generation-storage" energy supply system of this embodiment will also face the problem of insufficient production capacity. Then this embodiment will convert the supplied energy into mains power. Even if all energy supplies are converted to mains power, it only increases the power consumption of a set of xenon lamps (3 kWh). If calculated at 0.6 yuan per kWh, the increased electricity cost per day is 1.8 yuan. The piezoelectric reaction accessories consume electricity at a cost of 1.08 yuan per day, and the total electricity cost for a quarter is 259.2 yuan. If you consider the material cost of 50 grams of catalyst (about 80 yuan), the material cost of 200 grams of L-ascorbic acid (about 8 yuan), and the material cost of a 25L barrel of pure water (about 12 yuan). If we assume that each set of experimental device all-in-one machine is used for 10 years (a total of 40 quarters, calculated based on 3,600 days, and if the equipment is not damaged, and four devices are placed per square meter at a total cost of 12,000 yuan, then the cost of each device is 3,000 yuan), and the total electricity cost for 40 quarters is 10,368 yuan, and the total material cost is 4,000 yuan. After integration, it is found that: all total costs are 17,368 yuan, and the total hydrogen production in 40 quarters is about 2,009.2 kilograms. Therefore, the material and electricity cost required for hydrogen production is 8.6 yuan / kg. The tentative hydrogen selling price of this embodiment is 30 yuan / kg, which can achieve a profit of 21.4 yuan / kg, which still has a rich profit return. For the specific hydrogen production cost conversion, please see Table 2 below.

[0064] Table 2 Hydrogen production rate (R) under different combinations of “working mode + catalyst + reaction system” H ,mmol·h -1 ·g -1 )data

[0065]

[0066]

[0067] Note: Assuming that the service life of each set of equipment is 10 years; the service life of various materials in each integrated experimental device is 3 months, then the materials need to be replaced 40 times in 10 years.

Claims

1. A photocatalytic hydrogen production reaction system capable of separating and storing hydrogen, characterized in that: The reaction system comprises a photocatalytic reactor, an oxygen separation purifier (2) and a hydrogen storage tank (3); The photocatalytic reactor comprises a top light incident port (11), a pressure gauge head (12), a gas sampling port (13), a reactor outer tube circulating water inlet (14), a reactor outer tube circulating water outlet (15), a reactor inner tube gas inlet (16), a reactor inner tube liquid inlet (17), a pulley bracket (18) and a piezoelectric reaction accessory (19); The photocatalytic reactor is a double-layer cylinder consisting of an inner cylinder and an outer cylinder. The reactor inner cylinder gas inlet (16) is connected to the photocatalytic reactor inner cylinder and is connected to the hydrogen storage tank (3) through a pipeline; the reactor inner cylinder liquid inlet (17) is connected to the photocatalytic reactor inner cylinder, and the reactor outer cylinder circulating water inlet (14) is connected to the outer cylinder of the photocatalytic reactor; the top of the photocatalytic reactor inner cylinder is provided with a top incident light port (11), the pressure gauge head (12) and the gas sampling port (13) are respectively provided on the top of the photocatalytic reactor inner cylinder, and the photocatalytic reactor and the hydrogen storage tank (3) are both provided on a pulley bracket (18); the piezoelectric reaction accessory (19) is provided at the bottom of the photocatalytic reactor; the oxygen separation purifier (2) is respectively connected to the gas sampling port (13) and the hydrogen storage tank (3); the piezoelectric reaction accessory (1 9) consists of an acrylic glass plate (191), 6 ultrasonic vibrators (192), 4 brackets (193), a piezoelectric ceramic circuit board (194) and a power switch (195); the 4 brackets (193) are respectively arranged at the four corners of the bottom of the photocatalytic reactor; the 6 ultrasonic vibrators (192) are arranged at the bottom of the acrylic glass plate (191); the piezoelectric ceramic circuit board (194) and the power switch (195) are electrically connected; the leads on the piezoelectric ceramic circuit board (194) are respectively electrically connected to the 6 ultrasonic vibrators (192); the oxygen separation purifier (2) is connected to the gas sampling port (13); a dissolved oxygen exchange membrane is placed at the lower opening of the oxygen separation purifier (2) and is placed inside the aqueous solution, and an inert gas inlet and an exhaust port are opened at the upper narrow end of the oxygen separation purifier (2).

2. The reaction system according to claim 1, characterized in that The double-layer cylinder of the photocatalytic reactor is cylindrical, with a height of 40-60 cm, an inner cylinder diameter of 20-30 cm, and an outer cylinder diameter of 25-35 cm.

3. The reaction system according to claim 1, characterized in that When the top incident light port (11) receives sunlight, a circular condenser is placed at the incident light port, with a diameter of 5-20 cm.

4. The reaction system according to claim 1, characterized in that The output power of the piezoelectric reaction accessories is 250-320W.

5. The reaction system according to claim 1, characterized in that The oxygen separation purifier (2) is in the shape of a thin tube at the upper end and a three-headed shape at the lower end.

6. The reaction system according to claim 1, characterized in that The catalyst used in the hydrogen production process of the photocatalytic reactor is a ZCS / PO / Ni3Pi2 catalyst or a ZCS / PO / FCNPi-MnO catalyst.

7. The reaction system according to claim 6, characterized in that The preparation method of the ZCS / PO / Ni3Pi2 catalyst or the ZCS / PO / FCNPi-MnO catalyst comprises the following steps: 1) dissolving the mixed metal salt in a mixed solvent to form a suspension; 2) adding the mixed sulfur source to the above suspension, stirring after ultrasonication until the solution is transparent; 3) transferring the clear solution into a polytetrafluoroethylene-lined stainless steel autoclave for reaction; 4) The precipitate after the reaction was recovered by centrifugation using deionized water and anhydrous ethanol respectively, and then the precipitate was vacuum dried to obtain Zn x Cd 1-x S material; 5) Zn x Cd 1-x The S material is put into an aqueous solution containing sodium hypophosphite and ultrasonically stirred under argon to form a suspension; 6) transferring the suspension obtained in step 5) into a photocatalytic reactor, sealing the container, evacuating the entire reaction system with a vacuum pump, irradiating the reactor with a visible light source, and maintaining room temperature with continuous stirring; 7) After the photochemical modification reaction is completed, the reactor is opened, the supernatant is removed, the precipitate is recovered by centrifugation, and the ZCS / PO is recovered after drying; 8) A ZCS / PO sample is dispersed in a mixed aqueous solution of nickel sulfate and sodium hypophosphite or a mixed aqueous solution containing ferric nitrate, cobalt nitrate, nickel sulfate, manganese sulfate, and sodium hypophosphite, and ultrasonically treated under the protection of an inert gas. The sample is then transferred to a photocatalytic reactor, the container is sealed, and the entire reaction system is evacuated with a vacuum pump. The reactor is irradiated with a visible light source and maintained at room temperature with continuous stirring. After the photochemical modification reaction is completed, the reactor is opened, the supernatant is removed, and the precipitate is recovered by centrifugation and oven-dried to obtain the ZCS / PO / Ni3Pi2 catalyst or ZCS / PO / FCNPi-MnO catalyst.

8. The reaction system according to claim 7, characterized in that Zn in step 5) x Cd 1-x S material is dispersed in a sodium hypophosphite aqueous solution with a concentration of 0.1-0.8 mol / L, wherein Zn x Cd 1-x The mass volume ratio of the S material to the sodium hypophosphite aqueous solution is 50-500 mg:80 mL; the ZCS / PO material in step 8) is dispersed into a mixed aqueous solution of sodium hypophosphite with a concentration of 0.2-1.5 mmol / L and a mixed aqueous solution of ferric nitrate, cobalt nitrate, nickel sulfate, and manganese sulfate with a concentration of 0.01-0.050 mmol / L; wherein the mass volume ratio of the ZCS / PO material to the mixed aqueous solution of ferric nitrate, cobalt nitrate, nickel sulfate, and manganese sulfate is 50-200 mg:80 mL.

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