40. Safety Rules and Measures to Be Taken Where Hydrogen Gas Is Stored

Hydrogen is much safer than other energy sources. Hydrogen is nontoxic, not easily flammable and the products of oxygen water released during energy production are harmless to the natural environment. For pressurized tanks, the higher the pressure of the gas is, the smaller the tank volume needed, and the higher the operating cost. Safety regulations on high-pressure gas storage (including the compression process), utility, and transportation are strict, and complying with the regulations costs more than the hydrogen generators and storage equipment. Cryogenically cooling hydrogen into a liquid state is a well-established technology and considered the comparative benchmark for storing hydrogen. But the technology requires substantial energy to liquify the hydrogen, including continual “boil off” of hydrogen during storage and it requires very costly storage tanks and handling. Chemical or physically combined storage of hydrogen in other materials has potential advantages over other storage methods. Intensive research has been done on metal hydrides recently for improvement of hydrogenation properties. Metal-hydride–based chemical hydride and rechargeable hydride technologies offer storage efficiency and storage safety while providing the cost-saving advantage of being able to use the existing fossil fuel infrastructure to deliver and store a pumpable and nonexplosive hydride slurry as future hydrogen fuels. In this study we compare hydrogen storage methods, and show their advantages and disadvantages.