Safety of compressed hydrogen fuel tanks: Leakage from stationary vehicles

Compressed gas is one of the options for on-board storage of hydrogen in hydrogen-fueled vehicles. An assessment of the hazard posed by this method of storage is presented in this paper. Compressed hydrogen fuel tanks will operate under high (5000-10,000 psi) pressure and will be subject to potential failures associated with pressure vessels. In the event of a failure, hydrogen will leak through the cracks developed in these vessels, triggering an increase in the temperature, due to the negative value of the Joule-Thompson coefficient of hydrogen. The net effect of a leakage in a confined space, such as that from a vehicle parked in a garage, will be the creation of a hazardous situation, which may cause severe damage to property and human health. The potential for such hazards (from stationary vehicles) must be considered and quantified to the greatest possible extent when evaluating the various on-board hydrogen storage alternatives.