Dynamic Domino Effect Analysis of Large-Scale Toluene Storage Tanks for Organic Hydride Hydrogen Carrier

Hydrogen is a promising energy carrier for a sustainable society, and large-scale storage tanks are crucial for its widespread utilization. However, the safe storage of hydrogen poses significant challenges due to its unique hazards including embrittlement and high flammability. Among various hydrogen storage methods, the use of methylcyclohexane (MCH) and toluene as organic chemical hydrides has practical advantages such as compatibility with existing oil storage infrastructure and the ability to store hydrogen safely under ambient conditions.

Despite these advantages, the risks associated with large-scale storage of these chemicals have not been sufficiently evaluated. One critical concern is the domino effect that an initial incident triggers secondary events in adjacent tanks leading to an escalation of the overall hazard. Given that multiple tanks are often installed in close proximity, dynamic risk analysis of a fire-induced domino effect involving both spatial and temporal dependencies is significant.

The purpose of this study was to conduct dynamic risk analysis of the domino effect in large-scale toluene storage. First, the thermal impact of a toluene pool fire was simulated using the ALOHA software to assess its consequences on neighboring tanks. Next, the spatial and temporal propagations of the fire was modeled and analyzed using a dynamic Bayesian network. Based on these analyses, we proposed and evaluated risk reduction measures to enhance the safety of large-scale toluene storage tanks.