Safety evaluation on ammonia-fueled ship: Gas dispersion analysis through vent mast

The maritime industry is exploring ammonia as an alternative fuel to reduce greenhouse gas emissions. However, the high toxicity of ammonia poses significant safety challenges for onboard handling and storage. This study investigates ammonia dispersion and toxicity levels from vent mast releases on ships, aiming to enhance safety measures for future ammonia-fueled vessels. Using CFD analysis on a 31,000-dwt general cargo ship model, the research examines various release scenarios, considering regulatory requirements, vent mast design, and environmental conditions. Results show that direct ammonia release from the vent mast poses fatal risks to the crew in the accommodation area and on adjacent ships, regardless of current regulatory stipulations. The study recommends installing an ammonia-catching system to reduce concentrations to safe levels of 30 ppm before release. These findings offer crucial insights for improving the safety of using ammonia as marine fuel through risk assessment and management. • Provides key safety recommendations for the toxic release of ammonia from the ships. • Critically examines existing regulatory gaps related to ammonia release via vent mast. • Investigates dispersion scenarios considering different environmental conditions, vent mast designs, and release rates. • Regardless of vent mast location and height, direct ammonia release poses a fatal threat to humans onboard the ship. • Recommends the installation of an ammonia catch system before releasing ammonia into the atmosphere.