Quantitative analysis of toxicity risks in the operation of ammonia-fueled tugboats

• Published in: Ocean engineering Vol. 310; p. 118759
• Main Authors: Hu, Libin, Niu, Jiaqi, Wu, Wanqing, Zhao, Zihao, Du, Min, Chen, Liang, Zheng, Qinggong, Cao, Haidong
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 15-10-2024
• Subjects: Ammonia-fueled tugboat; Multiple operational scenarios; Probability; Quantitative analysis; Toxicity risk; Probability; Multiple operational scenarios; Toxicity risk; Ammonia-fueled tugboat; Quantitative analysis
• ISSN: 0029-8018
• DOI: 10.1016/j.oceaneng.2024.118759

As efforts to conserve energy and reduce emissions in the global shipping industry intensify, people are constantly looking for new types of energy to replace traditional fuels. Ammonia is considered a novel energy source due to its potential for carbon-neutral shipping when produced from renewable energy sources and is extremely promising for the shipping industry. In this study, the fuel toxicity risk of ammonia-fueled ships under operating conditions was quantified for the first time. The assessment process adopts the traditional quantitative risk assessment (QRA) framework with accident probability calculations based on Bayesian theory, and the process of partial quantification of consequences also guides the delineation of safety zones. The results of the study suggest that ammonia-powered tugboats are at a higher risk of toxic accidents during operation than accidents at sea, but both are within the acceptable limits of current international maritime safety and environmental standards. Finally, safety measures and risk mitigation strategies are proposed based on the study results. This provides important support in safety risk analysis for the design, production and operation of subsequent ammonia fueled vessels and is of great theoretical and practical importance.
In this study, we focus on accident probability and accident consequences. Through HAZOP analysis, we identified potential hazardous scenarios and calculated accident probabilities using Bayesian principles in combination with historical data from LNG ships. For the traditional QRA model, we worked on improving the quantification of toxicity consequences. For the first time, we combined the toxic gas concentration field obtained from computational fluid dynamics calculations with dose-response modeling, and applied it to the hazard assessment work for real operating scenarios of ammonia-fueled tugboats. The research shows that both the personal and societal risks of toxic hazards when operating an ammonia-powered tugboat are within the acceptable range under current international maritime safety and environmental standards. [Display omitted]
•Quantitative analysis of toxicity risks when operating ammonia-powered tugboats.•Systematic investigation of hazard scenarios during tugboat operations.•Risk assessment of operational and marine accidents for individuals and society.•Safety measures and risk mitigation strategies for ammonia-powered tugboats.