• Journal of the Society of Naval Architects of Korea
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• v.60 no.6
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• pp.433-440
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• 2023

This study aims to establish safety zones for bunkering operations of hydrogen propulsion ships in coastal areas through risk assessment and evaluate their validity. Using a 350 kW-class ferry operating in Busan Port as the subject of analysis, with quantitative risk assessment based on accident consequence and frequency analysis, along with a social risk assessment considering population density. The results of the risk assessment indicate that all scenarios were within acceptable risk criteria and ALARP region. The most critical accident scenarios involve complete hose rupture during bunkering, resulting in jet flames (Frequency: 2.76E-06, Fatalities: 9.81) and vapor cloud explosions (Frequency: 1.33E-08, Fatalities: 14.24). For the recommended safety zone criteria in the 6% hose cross-sectional area leakage scenario, It could be appropriate criteria considering overall risk level and safety zones criteria for hydrogen vehicle refueling stations. This research contributes to establishing safety zone for bunkering operations of hydrogen propulsion ships through risk assessment and provides valuable technical guidelines.

• Transactions of the Korean hydrogen and new energy society
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• v.33 no.2
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• pp.142-147
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• 2022

Along with the global discussion on climate change prevention, regulations on hazardous substances emitted from ships were also carried out. Batteries have been regularly proposed as a solution for transportation, but lack of energy density has presented hydrogen as a final alternative. This study conducted legal issues regarding the method of providing hydrogen fuel on land and providing hydrogen fuel at sea. It is necessary to study how to institutionalize hydrogen bunkering in the legal system of the licensing system and distribution system.

• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.7
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• pp.964-970
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• 2023

As part of the International Maritime Organization ef orts to reduce greenhouse gas emissions, the maritime industry is exploring low-carbon fuels such as liquefied natural gas and methanol, as well as zero-carbon fuels such as hydrogen and ammonia, evaluating them as environmentally friendly alternatives. Particularly, ammonia has substantial operational experience as cargo on transport ships, and ammonia ship engines are expected to be available in the second half of 2024, making it relatively accessible for commercial use. However, overcoming the toxicity challenges associated with using ammonia as a fuel is imperative. Detection is possible at levels as low as 5 ppm through olfactory senses, and exposure to concentrations exceeding 300 ppm for more than 30 min can result in irreparable harm. Using the KORA program provided by the Chemical Safety Agency, an assessment of the potential risks arising from leaks during ammonia bunkering was conducted. A 1-min leak could lead to a 5 ppm impact within a radius of approximately 7.5 km, affecting key areas in Busan, a major city. Furthermore, the potentially lethal concentration of 300 ppm could have severe consequences in densely populated areas and schools near the bunkering site. Therefore, given the absence of regulations related to ammonia bunkering, the potential for widespread toxicity from even minor leaks highlights the requirement for the development of legislation. Establishing an integrated system involving local governments, fire departments, and environmental agencies is crucial for addressing the potential impacts and ensuring the safety of ammonia bunkering operations.

• Transactions of the Korean hydrogen and new energy society
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• v.33 no.3
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• pp.247-254
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• 2022

Slush hydrogen containing liquid and solid hydrogen is expected to achieve zero boil-off by suppressing boil-off gas because heat of fusion for solid absorbe the heat ingress from atmosphere. In this paper, quantitative analysis on storage cost considering specific energy consumption between 1,000 m³ class liquid hydrogen storage system with re-liquefaction and slush hydrogen storage system during equivalent zero boil off period. Even though approximately 50% of total storage capacity should be converted into solid phase during the initial cargo bunkering, total energy consumption to convert into slush hydrogen is relatively 25% less than re-liquefaction energy for boil off hydrogen during zero boil off period. That's because energy consumption of slush phase change take up only 1.8% of liquefaction energy. moreover, annual revenue requirement including CAPEX, OPEX and electric cost for slush hydrogen storage could be more reduced approximately 32.5% than those of liquid hydrogen storage and specific energy storage cost ($/kg-H₂) could also be lowered by about 41.7% compared with liquid hydrogen storage.