Grid-based assessment of hydrogen leakages for an offshore process to improve the design and human performance

Hydrogen is gaining global recognition as a sustainable energy source, but its combustible nature raises concerns, especially in congested offshore settings. Steam methane reforming (SMR) remains the predominant hydrogen production method; however, offshore SMR facilities exposed to harsh weather could potentially compromise safety because of leakages. This study uses the fire dynamics simulator (FDS) to carry out the first-of-its-kind CFD modeling of hydrogen leakage and its wind-influenced dispersion on an offshore SMR platform. It also provides the spatial risk that accounts for the probabilities of human errors and wind speeds. The study uses a grid-based approach with 120 monitor points (MPs) to measure locally dispersed gas concentration. At 2 m/s wind speed, only nine grids contain explosive concentrations while the rest remain safe. At 5 m/s, the flammable zones increase by 133%, affecting 21 grids. Extreme wind speeds of 12.5 m/s have limited impact, but SMR1 exhibits higher stoichiometric concentrations. MPs 43-48 record flammable concentrations at all wind speeds; however, at 12.5 m/s the explosion risk is well below the threshold of 1 x 10-4 due to the low wind occurrence probability. Overall, this research contributes to addressing the safety concerns associated with hydrogen in offshore settings and provides a foundation for future risk assessments.