A systematic review of ammonia fuel supply chain readiness for maritime decarbonisation

Decarbonisation in international shipping has accelerated in recent years, with ammonia increasingly recognised as a promising zero-carbon marine fuel. However, ammonia's large-scale adoption remains constrained by uncertainties across the fuel supply chain. This study aims to provide a systematic assessment of ammonia's adoption in maritime transport. Drawing on a PRISMA-based review of 125 selected publications between 2010 and 2025, this study conducts a supply-chain-oriented analysis of the ammonia fuel supply chain, covering production, transport, storage, bunkering, and onboard usage. The findings show that successful adoption of ammonia depends on coordinated progress across all supply-chain stages. Critical gaps remain in scaling green ammonia production, developing harmonised safety and emissions standards, upgrading port and bunkering infrastructure, maintaining consistent policy support, and advancing fuel-handling and engine technologies. The review further identifies four priority research areas: dynamic risk assessment, supply-chain disruption evaluation, optimisation of fuel-supply-chain management, and the design of risk-mitigation strategies. Overall, this review offers a comprehensive and multi-dimensional readiness assessment that extends beyond previous technology or safety focused reviews by integrating regulatory and industry drivers with a fuel-supply-chain-oriented perspective. The findings provide stakeholders with a strengthened evidence base for planning actionable transition pathways toward zero-carbon maritime transport. • Systematic readiness assessment of maritime ammonia fuel supply chain across production, transport, storage, bunkering, and onboard use. • The evolving regulatory environments and market signals are incorporated into the evaluation of ammonia fuel supply chain. • Key challenges across the ammonia supply chain are identified with targeted mitigation strategies. • Recommendations for future research and policy are outlined, including system modelling, risk-mitigation pathways, and supply chain optimisation.