Discovering the strong attraction of the carbon surface to hydrogen gas, Dr. Nguyen Xuan Thanh and his colleagues sought to store hydrogen using carbon materials with a porous structure.
The research was conducted for 2 years while Dr. Thanh worked at the University of Queensland (Australia) under the guidance of Professor Suresh K. Bhatia - Head of the research team. Returning home to work at the Faculty of Engineering, Vietnamese-German University, he pursued research and published in Physical Review Letters, the specialized scientific journal of the American Physical Society.
TAccording to Dr. Thanh, the most difficult thing with hydrogen is storing it because it is a high-energy gas that is very difficult to liquefy. Currently, hydrogen storage often uses the liquefaction method to a temperature of 20K, which is about minus 253 degrees Celsius, a very deep cold. Therefore, hydrogen storage devices need to use materials with high thermal insulation. Therefore, the volume of hydrogen-containing materials accounts for a very large proportion of about 93% of the total volume, the remaining 7% is for hydrogen storage according to regulations of the US Department of Energy. "Storing hydrogen requires very special technology that exists in countries with high levels of science and technology," Dr. Thanh said.
Dr. Nguyen Xuan Thanh with the carbon research award awarded by Elsevier Publishing House.
The fact that carbon can store charge in batteries has been widely used. However, "the carbon pore structure helps store hydrogen easier than traditional methods," Dr. Thanh said.
According to the research process, porous charcoal is created from plants containing cellulose and lignin such as trees, bamboo, duckweed, coconut fiber, rice husks... These materials are charred in a rarefied air environment. The next step is to activate the charcoal using physical methods by heat treatment in an atmosphere of air or CO2, steam and chemical methods using a strong acid or base. The heat treatment process helps adjust the desired size, shape and pore structure, creating an optimal environment for hydrogen storage. A satisfactory activated carbon structure must contain pores with a size of less than 1nm, which will create a strong attraction for hydrogen gas, helping to increase its mass per unit volume, increasing its storage capacity. of pores.
Dr. Thanh said, these are laboratory-scale studies and only focus on the ability to store hydrogen. In fact, the pores of carbon are inherently complex and difficult to adjust because of the inherently incomplete structure of coal. Controlling the structure of porous materials based on their properties to help them have the best storage capacity requires further in-depth research. The technical solution is to effectively remove a large amount of heat generated during the process of loading hydrogen into coal to ensure the storage temperature (77K) needs to be considered in application-oriented studies.
Hydrogen is inherently green energy because when using waste water, it does not emit emissions that pollute the environment. However, applications of hydrogen in the world are not popular, because the techniques for producing and storing this energy source are very difficult and expensive. Therefore, Dr. Thanh believes that when successful in solving the above problems, the application direction of the research is very clear in creating a new hydrogen storage method with carbon, which is a readily available, easy-to-find material. and lower cost.Author: Ha An
Author: Ha An