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

Abstract

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.