Corrosion in biodiesel storage systems: A review of mechanistic understanding, challenges, and mitigation strategies

The widespread adoption of biodiesel as a renewable alternative to fossil diesel has intensified concerns regarding the durability of storage and distribution infrastructure. Corrosion in biodiesel storage systems has emerged as a critical challenge affecting material integrity, fuel stability, and operational safety. Unlike conventional diesel, biodiesel exhibits higher hygroscopicity, lower oxidative stability, and greater susceptibility to microbial activity, resulting in a dynamically evolving storage environment. This review critically synthesizes current knowledge on the mechanisms, material susceptibility, research challenges, and mitigation strategies associated with biodiesel-induced corrosion. The discussion first examines the physicochemical characteristics of biodiesel, including fatty acid methyl ester composition, contaminants, water affinity, and aging products, and their influence on corrosivity. Key corrosion mechanisms are then analyzed, with emphasis on the synergistic interactions among electrochemical reactions, oxidation-derived species such as peroxides and organic acids, water accumulation, vapor-phase exposure, and microbiologically influenced corrosion at fuel–water–metal interfaces. Current mitigation strategies, including fuel stabilization, material and coating selection, corrosion inhibitors, and microbial control, are evaluated within a systems-level framework. Persistent knowledge gaps are highlighted, particularly the limitations of conventional corrosion indicators, insufficient long-term storage simulations, limited understanding of interfacial processes, and underrepresentation of microbial dynamics. By integrating perspectives from materials science, fuel chemistry, and microbiology, this review provides a mechanism-informed perspective on biodiesel corrosion in storage systems and highlights considerations relevant to the development of more reliable mitigation strategies for biodiesel storage infrastructure.