Beyond Road Biodiesel: Qualifying Palm-Derived FAME and Hydrotreated Vegetable Oil for Marine Propulsion, Fuel-System Reliability and Well-to-Wake Decarbonization

Maritime decarbonization increasingly relies on liquid renewable fuels capable of serving existing diesel propulsion systems. Yet applying road-sector experience to vessels risks overlooking prolonged storage, moisture exposure, fuel-system architecture and operational load variation. This qualitative literature review critically compares palm-derived fatty acid methyl esters (FAME) and hydrotreated vegetable oil (HVO) through an integrated analysis of fuel chemistry, equipment compatibility, combustion performance, operational reliability and well-to-wake (WTW) greenhouse-gas accounting. The evidence indicates that FAME and HVO are not interchangeable: oxygenated FAME may require enhanced control of oxidation, moisture and cold-flow behavior, whereas paraffinic HVO can offer different stability advantages while still posing density, lubricity and injection-calibration questions. Marine trials provide evidence of feasibility for certain fuels and blends, but do not establish unrestricted applicability across fleets. Lifecycle outcomes depend decisively on feedstock provenance, land-use change, peat emissions, production energy, renewable hydrogen and allocation assumptions. The review proposes a six-gate Marine Palm-Fuel Qualification and Decarbonization Framework spanning feedstock identity, marine-fuel standards, equipment approval, voyage reliability, WTW verification and continuing surveillance. It concludes that practical marine adoption should proceed through vessel-specific, evidence-based qualification paired with transparent lifecycle and traceability audits, rather than generic biofuel mandates or claims of automatic carbon neutrality.