Integrated data-driven and fuzzy logic-based failure mode and effects analysis (FMEA) for biodiesel risk quantification in maritime systems

The increasing emphasis on reducing ship emissions has accelerated the global maritime industry’s search for cleaner alternative fuels. Biodiesel, due to its renewable nature and partial compatibility with existing diesel engines, has emerged as a promising candidate. Nevertheless, applying biodiesel in marine diesel engines entails operational and environmental uncertainties that require rigorous and systematic evaluation. This study addresses this gap by combining experimental engine test data and fuzzy logic with Failure Mode and Effects Analysis (FMEA) to establish a robust risk prioritization framework for biodiesel use in maritime applications. For this purpose, biodiesel derived from the most popular vegetable oils in the literature was produced, and engine performance and emissions tests were conducted on the produced biodiesel. Biodiesel has a viscosity of 57.6 % higher than diesel, and its energy content is 10.8 % lower. Biodiesel and diesel fuel were tested in a diesel engine at a constant speed of 3000 rpm at six different loads, ranging from 0.5 kW to 3 kW. The biodiesel test fuel had 34 % and 18 % fewer CO and HC emissions than diesel fuel, while NO x and CO 2 were 80 % and 42 % higher, respectively. Fuel consumption increased by 20 % and efficiency decreased by 2 %, respectively, with the biodiesel test fuel compared to diesel. The study identified 34 critical failure modes in four main areas: fuel production and supply, storage and fuel quality, engine performance, and emissions, and evaluated them according to severity, occurrence, and detectability criteria. The fuzzy inference model generated fuzzy risk priority numbers (FRPNs). The results show that the highest risk intensity was due to engine performance-related problems (5.70), followed by fuel degradation risks during storage in the primary category (5.61). In the secondary category, the four highest FRPN values were observed for sustainability (6.41), NOₓ emissions (6.37), hygroscopic nature (6.12), and low energy content (6.07). • A hybrid data-driven and fuzzy FMEA was applied to assess biodiesel risks in shipping. • 34 biodiesel-related failure modes were identified and prioritized using FRPN scores. • Engine performance and fuel degradation risks showed the highest risk concentrations. • Key risks include NOₓ emissions, low energy content, and oxidative fuel degradation. • The study supports safer biodiesel integration into maritime systems via empirical insights.