Production line for batch production of graphene magnesium-based solid hydrogen storage material

Abstract

The invention discloses a production line for batch production of a graphene magnesium-based solid hydrogen storage material, and belongs to the technical field of hydrogen energy storage and transportation. The production line comprises the following steps: S1, raw material pretreatment; s2, high-energy ball milling; s3, hydrogenation; s4, dust recovery; s5, performing granulation; the production line adopts an intelligent control production process and a'ball milling-hydrogenation-granulation 'integrated process, and solves the problems of low yield, non-uniform mixing, low hydrogen storage capacity, dust recovery and the like of a hydrogen storage material through nano precise compounding of graphene and magnesium powder and a synergistic effect of a special catalytic system. The production line realizes automatic continuous operation, the annual output of the prepared graphene magnesium-based solid hydrogen storage material is 100-10000 tons, the purity reaches 99% or above, the hydrogen storage capacity is larger than or equal to 6.5 wt%, the cycle service life exceeds 3000 times, the hydrogen absorption and desorption temperature is reduced to 160-250 DEG C, the large-scale application requirements of hydrogen energy storage and transportation, vehicle-mounted energy and other scenes can be met, and the graphene magnesium-based solid hydrogen storage material has the remarkable advantages of being safe, efficient, controllable in cost and environmentally friendly.

Description

Technical Field

[0001] This invention relates to the field of solid hydrogen storage material production technology, specifically to a large-scale production line for graphene magnesium-based solid hydrogen storage materials. Background Technology

[0002] Hydrogen energy, as a clean and efficient energy carrier, faces significant challenges in its storage and transportation, which are key bottlenecks hindering the development of the hydrogen energy industry. Among existing hydrogen storage technologies, high-pressure gaseous hydrogen storage suffers from low volumetric energy density and poor safety, while cryogenic liquefaction hydrogen storage is hampered by high energy consumption and high cost. Solid-state hydrogen storage, with its advantages of high safety and high storage density, has become the preferred solution.

[0003] Graphene-magnesium-based hydrogen storage materials have attracted much attention due to their high theoretical hydrogen storage capacity (above 15 wt%), low raw material cost, and abundant resources. However, traditional magnesium-based hydrogen storage materials suffer from problems such as high hydrogen absorption and desorption temperatures, slow kinetic rates, and poor cycle stability. Graphene, with its high specific surface area, high thermal conductivity, and high carrier mobility, can effectively improve the hydrogen storage performance of magnesium-based materials, but currently there is no solution for the large-scale mass production of graphene-magnesium-based solid-state hydrogen storage materials. Although a hundred-ton-level magnesium hydride production line has achieved continuous production, it lacks graphene modification technology, and the hydrogen storage performance of the product still has room for improvement. Therefore, there is an urgent need to develop a large-scale, automated production line for graphene-magnesium-based solid-state hydrogen storage materials. Summary of the Invention

[0004] The purpose of this invention is to provide a graphene-magnesium-based solid hydrogen storage material production line. Through integrated process design and intelligent control, it achieves precise composite of graphene and magnesium-based materials, significantly improving the hydrogen storage performance of the product, while meeting the needs of large-scale and low-cost production.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: A production line for mass production of graphene-magnesium-based solid hydrogen storage materials includes the following steps: S1. Raw material pretreatment: Magnesium powder is first ultrasonically cleaned and dried, and then weighed and fed into graphene in proportion under an argon atmosphere and mixed at high speed. S2. High-energy ball milling: In a ball milling jar under an argon atmosphere, magnesium metal materials are rapidly pulverized from the micron level to the nano level, achieving precise nano-composite bonding with graphene. S3. Dust recovery: Graphene dust generated by the screening machine is collected by an argon gas purifier, and unqualified powder is recycled by a vertical elevator. S4. Hydrogenation: The reactor is first evacuated and then argon gas is introduced to atmospheric pressure. Then hydrogen storage material is added and hydrogen gas is introduced again. Hydrogen is continuously added under high temperature and high pressure. S5. Granulation: The granulator first presses the hydrogen storage particles, then uses a vibrating screen to filter out the unformed powder, and then the powder is lifted and recycled. After the hydrogen storage particles are tested for purity, hydrogen storage capacity and hydrogen absorption and desorption kinetic parameters, they are weighed and packaged. The production process utilizes PLC programming of the intelligent control system to achieve real-time monitoring and automatic adjustment of parameters of each unit. The intelligent control system includes temperature sensors, pressure sensors, oxygen concentration sensors, and gas flow controllers. The production line operates continuously in a closed protective environment formed by inert gas, and the motors of all the machines running inside are explosion-proof motors.

[0006] The inert gas is argon; furthermore, the argon atmosphere pressure is 0-1000 Pa, and most preferably, the argon atmosphere pressure is 50-200 Pa to prevent external air from entering the argon environment.

[0007] Furthermore, the ultrasonic cleaning frequency is 20–40 kHz, the time is 5–30 min, and the medium is isopropanol to prevent magnesium powder from clumping and deteriorating; the drying is vacuum drying at a temperature of 50–80 °C for 2–4 h.

[0008] Furthermore, the ratio of magnesium powder to graphene is 100:1 to 30, and the particle size is 3 to 100 μm; the high-speed mixing speed is 100 to 300 r / min, and the mixing time is 1 to 5 min.

[0009] The grinding jar is made of 304 stainless steel, and the grinding balls are made of one or more of zirconium oxide, alumina, and stainless steel, with a particle size of 0.2–20 mm, a ball-to-material ratio of 3–15:1, a grinding oscillation frequency of 300–1000 r / min, and a grinding time of 6–48 h.

[0010] Furthermore, in step S2, the pulverization to the nanoscale (10-100 nm) greatly improves the activity of magnesium powder. The numerous grain boundaries and lattice defects generated during ball milling can further promote the hydrogen absorption and desorption reactions. The uniform coating of graphene can also effectively prevent the agglomeration of magnesium-based particles, thereby improving the material stability and cycle life.

[0011] Furthermore, the screening machine is a vibrating screening machine. The graphene dust generated during the vibrating screening is collected by an argon gas purifier to protect the motor of the entire system from graphene adhering to it, which could cause a short circuit due to the conductivity of graphene. At the same time, the graphene is recycled for reuse. The vertical elevator recycles the unqualified powder that is screened out, reducing losses and improving the overall utilization rate of materials.

[0012] Furthermore, in step S4, the vacuum pressure is -0.09 MPa, the high-temperature heating temperature is 150–350°C, the high-pressure pressure is 0.5–5 MPa, and hydrogenation is carried out continuously for 2–10 hours. High-temperature and high-pressure hydrogenation technology is used to reduce the activation energy of the hydrogenation reaction and achieve efficient hydrogenation. During continuous hydrogenation, the temperature is cooled to below 80°C. During the hydrogenation reaction, the pressure and temperature are dynamically adjusted by a pressure pump and a chiller, with fluctuation ranges controlled within ±0.1 MPa and ±5°C, respectively. Hydrogenation is carried out in an inert gas atmosphere to avoid material oxidation and ensure product purity.

[0013] Furthermore, the granulated particles have a particle size of 3-20 mm, and the vibrating screen has a mesh size of 10-100. When the material is pressed into granules, the specific surface area is greatly reduced. When the granules are exposed to air, an oxide film forms on the surface, preventing the internal material from oxidizing and causing combustion, thus greatly improving safety performance.

[0014] Furthermore, the sensor accuracy is ≤ ±0.1℃ (temperature) and ±0.1Pa (pressure).

[0015] By adopting the aforementioned technical solution, the beneficial effects of the present invention are as follows: 1. This production line adopts an integrated closed process of "ball milling-hydrogenation-granulation" with inert gas protection throughout the process, which effectively reduces the oxidation loss of raw materials and the product purity can reach more than 99%, solving the problems of uneven mixing and severe oxidation in traditional step-by-step production.

[0016] 2. Combining graphene modification and high-temperature and high-pressure hydrogenation technology, the product has a hydrogen storage capacity of ≥6.5wt%, a hydrogen absorption and desorption temperature of 160-250℃, and a cycle life of over 3000 cycles. Compared with traditional magnesium-based hydrogen storage materials, the performance is significantly improved, meeting the needs of high-end hydrogen energy applications.

[0017] 3. The production line achieves fully automated control throughout the entire process, and the process parameters can be flexibly adjusted according to product requirements. It has high production efficiency, with an annual production capacity of 100 to 10,000 tons per line. It also has low energy consumption, is environmentally friendly and pollution-free, and meets the requirements of large-scale industrial development.

[0018] 4. The modular design of each stage facilitates equipment maintenance and capacity expansion, adapts to the production of graphene magnesium-based hydrogen storage materials of different specifications, has a wide range of applications, and can promote the large-scale application of hydrogen energy in fields such as vehicles, energy storage, and aerospace. Attached Figure Description

[0019] Figure 1 This is a process flow diagram of the mass production of graphene magnesium-based solid hydrogen storage materials in this embodiment of the invention. Detailed Implementation Example 1

[0020] refer to Figure 1The production line of this invention is used to mass-produce graphene-magnesium-based solid hydrogen storage materials. The specific steps are as follows: (1) Raw material pretreatment Magnesium powder is first ultrasonically cleaned at 20kHz and 700W for 15 minutes and then vacuum dried at 80℃ for 3 hours. Graphene and magnesium powder are then mixed in a mixer at a mass ratio of 15:100. The mixture is then conveyed into a ball mill jar via a screw conveyor. (2) High-energy ball milling During the ball milling process, zirconium oxide beads were added as balls, with a ball-to-material ratio of 5:1. The ball milling was carried out at 500 r / min for 24 h under an argon atmosphere. After ball milling, the zirconium beads and powder were separated by a sieve. (3) Dust recovery The argon gas purifier is started to recover the powder. The powder is collected by the vertical elevator and sent into the screw conveyor for use in the reactor. (4) Hydrogenation The reactor was first evacuated to -0.08 MPa, then hydrogen gas was introduced to 4 MPa, and heated to 280°C. Hydrogen was added continuously for 3 hours. (5) Granulation The hydrogen storage material is granulated using a granulator and then sieved through a 20-mesh vibrating screen. The unformed powder is then lifted and reused. The finished product has a purity of 99.5% and a hydrogen storage capacity of 6.5 wt%. It is then vacuum-sealed in an environment with an oxygen content of 25 ppm to obtain the final product. Example 2

[0021] The raw material ratio was adjusted to 20:100, the rotation speed was 2200 r / min, the high-energy ball milling time was 48 h, the hydrogen addition pressure was 4.5 MPa, and the temperature was 300 °C. Other parameters were the same as in Example 1. The final product had a purity of 99.3%, a hydrogen storage capacity of 7.3 wt%, and hydrogen absorption and desorption rates at 280 °C of 1.8 wt% / min and 1.5 wt% / min, respectively. After 1200 cycles, the hydrogen storage capacity retention rate was 92%.

[0022] This invention's production line, through process integration and technological innovation, has achieved large-scale, high-performance production of graphene-magnesium-based solid hydrogen storage materials, providing key support for the industrialization of hydrogen energy storage and transportation technology, and possessing significant economic value and social benefits.

[0023] Although the invention has been specifically shown and described in conjunction with preferred embodiments, those skilled in the art will understand that various changes in form and detail may be made to the invention without departing from the spirit and scope of the invention as defined in the appended claims, all of which shall be within the scope of protection of the invention.

Claims

1. A production line for mass production of graphene-magnesium-based solid hydrogen storage materials, characterized in that, Includes the following steps: S1. Raw material pretreatment: Magnesium powder is first ultrasonically cleaned and dried, and then weighed and fed into graphene in proportion under an argon atmosphere and mixed at high speed. S2. High-energy ball milling: In a ball milling jar under an argon atmosphere, magnesium metal materials are rapidly pulverized from the micron level to the nano level, achieving precise nano-composite bonding with graphene. S3. Dust recovery: Graphene dust generated by the screening machine is collected by an argon gas purifier, and unqualified powder is recycled by a vertical elevator. S4. Hydrogenation: The reactor is first evacuated and then argon gas is introduced to atmospheric pressure. Then hydrogen storage material is added and hydrogen gas is introduced again. Hydrogen is continuously added under high temperature and high pressure. S5. Granulation: The granulator first presses the hydrogen storage particles, then uses a vibrating screen to filter out the unformed powder, and then the powder is lifted and recycled. After the hydrogen storage particles are tested for purity, hydrogen storage capacity and hydrogen absorption and desorption kinetic parameters, they are weighed and packaged. The production process utilizes PLC programming of the intelligent control system to achieve real-time monitoring and automatic adjustment of the parameters of each unit; the production line operates continuously in a closed protective environment formed by inert gas, and the motors of the machines running inside are all explosion-proof motors.

2. The production line for mass production of graphene-magnesium-based solid hydrogen storage materials according to claim 1, characterized in that, The magnesium powder to graphene mixture has a ratio of 100:1 to 30, with both magnesium powder and graphene having a particle size of 3 to 100 μm. Crucially, the raw materials enter the closed production system through a specially designed vacuum chamber. The high-speed mixing speed is 100 to 300 r / min, and the mixing time is 1 to 5 min. Finally, the mixture is conveyed to the ball mill jar via a screw conveyor.

3. The production line for mass production of graphene-magnesium-based solid hydrogen storage materials according to claim 1, characterized in that, The high-energy ball mill uses a 304 stainless steel ball mill jar, and the grinding balls are made of one or more of zirconium oxide, alumina and stainless steel, with a particle size of 0.2 to 20 mm, a ball-to-material ratio of 3 to 15:1, a ball mill oscillation frequency of 300 to 1000 r / min, and a ball milling time of 6 to 48 h.

4. The production line for mass production of graphene-magnesium-based solid hydrogen storage materials according to claim 1, characterized in that, The screening machine is a vibrating screen that separates solid hydrogen storage materials from grinding balls and other foreign matter. The materials are then reused via vertical elevator A. Difficult-to-settle dust is recovered using a specially designed argon gas purifier and then reused via vertical elevator B.

5. The production line for mass production of graphene-magnesium-based solid hydrogen storage materials according to claim 1, characterized in that, The hydrogenation process includes a vacuum reactor, a temperature and pressure control system, and a hydrogen delivery channel. The process involves evacuating to a pressure of -0.09 MPa, heating to a high temperature of 150–350°C, applying a high pressure of 0.5–5 MPa, continuously adding hydrogen for 2–10 hours, and then cooling to below 80°C under continuous hydrogenation. During the hydrogenation reaction, the pressure and temperature are dynamically adjusted using a pressurizing pump and a chiller, with fluctuations controlled within ±0.1 MPa and ±5°C, respectively.

6. The production line for mass production of graphene-magnesium-based solid hydrogen storage materials according to claim 1, characterized in that, The granulation process includes a granulator, sieving, powder lifting, weighing, and canning; the granulated particles are 3–20 mm in size, and the vibrating screen is 10–100 mesh.

7. The production line for mass production of graphene-magnesium-based solid hydrogen storage materials according to claim 1, characterized in that, The intelligent control system includes a temperature sensor, a pressure sensor, an oxygen concentration sensor, and a gas flow controller. The accuracy of the sensors is ≤ ±0.1℃ (temperature) and ±0.1Pa (pressure).

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