Comparative risk assessment of liquefied and gaseous hydrogen refueling stations

Several countries are incentivizing the use of hydrogen (H-2) fuel cell vehicles, thereby increasing the number of H-2 refueling stations (HRSs), particularly in urban areas with high population density and heavy traffic. Therefore, it is necessary to assess the risks of gaseous H-2 refueling stations (GHRSs) and liquefied H-2 refueling stations (LHRSs). This study aimed to perform a quantitative risk assessment (QRA) of GHRSs and LHRSs. A comparative study is performed to enhance the decision-making of engineers in setting safety goals and defining design options. A systematic QRA approach is proposed to estimate the likelihood and consequences of hazardous events occurring at HRSs. Consequence analysis results indicate that catastrophic ruptures of tube trailer and liquid hydrogen storage tanks are the worst accidents, as they cause fires and explosions. An assessment of individual and societal risks indicates that LHRSs present a lower hazard risk than GHRSs. However, both station types require additional safety barrier devices for risk reduction, such as detachable couplings, hydrogen detection sensors, and automatic and manual emergency shutdown systems, which are required for risk acceptance. (C) 2021 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Automated summary

The study conducted a quantitative risk assessment of gaseous and liquid hydrogen refueling stations, showing that LHRSs present a lower hazard risk but still require additional safety devices for risk reduction. Moreover, catastrophic ruptures of tube trailers and liquid hydrogen storage tanks are identified as the worst accidents that can lead to fires and explosions.