Safety Assessment of the Ammonia Bunkering Process in the Maritime Sector: A Review

Abstract

One of the main goals of the shipping industry is to decarbonize the fuels used in maritime transportation. Ammonia is thought to be a potential alternative for hydrogen storage in the future, allowing for CO2-free energy systems. Ammonia’s beneficial characteristics with regard to hydrogen storage include its high volumetric hydrogen density, low storage pressure, and long-term stability. However, ammonia is characterized by toxicity, flammability, and corrosiveness, making safety a challenge compared to other alternative fuels. In specific circumstances, leakage from ammonia bunkering can cause risks, dispersion, and unsafe areas due to its flammability and toxicity. Based on an analysis of 118 research papers and 50 regulations and guidelines, this review report evaluates various aspects of the hazards associated with the ammonia bunkering processes, considering both current and future implications. This report also includes the latest advancements and potential developments related to the safety of ammonia as a marine fuel. Several related regulations and standards for ammonia supply systems are discussed. This paper examines experiments and numerical investigations conducted using different methods of ammonia bunkering, such as terminal-to-ship, ship-to-ship, and truck-to-ship transfers. This review shows that the toxicity of ammonia is more relevant to the topics of vapor cloud dispersion and ammonia bunkering than its flammability. Finally, the main challenges and recommendations for the implementation of ammonia bunkering and further development of ammonia as a marine fuel are proposed. This review suggests new directions to overcome the disadvantages and research gaps associated with the leakage of ammonia during bunkering periods.