A group of students from Da Nang used metal hydride materials and heating techniques to carry out the hydrogen charging and discharging process, creating a device that can store more than 20g of gaseous hydrogen.
The research was conducted by Vo Du Dinh, Le Anh Van, Lam Dao Nhon, Nguyen Hung Tam and Mai Duc Hung, Department of Automotive Mechanics, Faculty of Mechanical Engineering, University of Technical Education - University of Danang from October 2023. The product focuses on solid hydrogen energy storage technology, applied in energy management systems and green transportation.
The product is designed with two main parts: a hydrogen tank with auxiliary components and an intelligent control system. The operating principle of the tank is based on the reaction between magnesium metal in the tank and hydrogen to create Magnesium Hydride (MgH₂) compound. When heated at 250-350°C, hydrogen charging occurs under pressure conditions above 1 bar. Conversely, hydrogen release occurs when the pressure is below 1 bar.
With an intelligent system including microcontrollers and sensors that monitor and control temperature and pressure. This ensures the system operates efficiently and safely during the phase transition of the hydrogen storage compound.
According to team leader Vo Du Dinh, there are currently three hydrogen storage technologies in the form of compressed gas, liquefied gas and solid. In the form of compressed gas, hydrogen is stored in high-pressure tanks, from 350 to 700 bar (5,000-10,000 psi). In the form of liquid hydrogen is cooled to -253°C to turn into a liquid state, then stored in insulated tanks. In the form of solid, hydrogen is stored in metal hydride compounds or other absorbent materials such as metal organic frameworks (MOFs), carbon nanotubes, etc.
According to Dinh, each storage method has different advantages and disadvantages. Therefore, the choice of technology depends on the purpose of use such as transportation, static storage or mobile applications... in which cost, performance and safety factors are taken into account.
The assessment team said the challenge of hydrogen storage requires complex, high-cost technologies to ensure safety and efficiency. The lack of supporting infrastructure and low economic efficiency are major barriers to the widespread application of hydrogen as a clean energy source.
In the team's research, members wanted to create a solid hydrogen storage device because this technology is safe and less likely to explode. This technology allows for easier storage because it does not require extremely high pressures or extremely low temperatures like gas or liquefied gas storage.
Theoretically, the group's product can store materials, and after the reaction, it will produce a maximum output of 20.74g of gaseous hydrogen. According to Dinh, this is an estimated number due to the limited research facilities and lack of specialized equipment, so the actual volume has not yet been determined.
The group designs specialized tanks according to Vietnamese standards and regulations on pressure vessels. When unexpected incidents occur while the device is operating, the indirect heating system will cut off all heat sources and return to normal to ensure safety.
Dr. Bui Van Hung, Lecturer of the Faculty of Mechanical Engineering, University of Technical Education - University of Da Nang, assessed that the group's research is only at the stage of finding suitable storage materials that can absorb and release hydrogen. The group also built a simulation model of the ability and conditions to store this fuel.
He assessed that the amount of hydrogen in the group's product is estimated at about 20 grams, equivalent to about 0.66 kWh, which is quite low. This energy level is suitable for small devices or experiments, but not enough to operate vehicles such as cars or industrial equipment for a long time.
To increase the amount of hydrogen stored, Dr. Hung suggested that the team should find alloys or materials that can absorb more hydrogen without increasing the mass of the material too much. However, some materials with high hydrogen storage density require conditions and environments that make the phase transition between charging and discharging more difficult to occur. He said that, based on this research, the team needs to conduct more tests on materials that are difficult to phase transition in the future.
According to Intellectual Property and Innovation
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