An overview of hydrogen storage technologies

How to store hydrogen efficiently, economically and safely is one of the challenges to be overcome to make hydrogen an economic source of energy. This paper presents an overview of present hydrogen storage technologies, namely, high-pressure gas compression, liquefaction, metal hydride storage, and carbon nanotube adsorption. The energy efficiency, economic aspect, environmental and safety issues of various hydrogen storage technologies were compared. Presently, high-pressure gas compression is favorable due to its high energy efficiency as well as low capital and operation costs. Liquefaction is mainly employed in space applications because of its high volumetric and gravimetric efficiency. The disadvantages are low energy efficiency and high cost. Due to their high volumetric efficiency, metal hydride storage and carbon nanotube adsorption are promising hydrogen storage technologies and are expected to play a key role in hydrogen economy in the future.