assessment of technical and environmental standards for methanol and ethanol marine fuels in iran

The international maritime organization (imo)’s decarbonization strategy has intensified global efforts to adopt low-carbon marine fuels. this study evaluates the technical and environmental standardization of methanol and ethanol for iran’s maritime fleet, addressing the lack of localized standards compatible with national operational and climatic conditions. a framework for adapting imo and iso regulations, including marpol annex vi, igf code, iso 8217, and msc.1/circ.1621, is proposed to ensure safe, efficient, and environmentally compliant fuel utilization. comprehensive analyses encompass fuel physicochemical properties, life-cycle environmental assessment (well-to-wake), and engine compatibility and integration. results indicate that bio-methanol, produced from biomass or carbon-recycled feedstocks, can achieve up to 70% co₂ reduction compared to conventional heavy fuel oil, with additional benefits in soₓ, noₓ, and particulate matter reduction. critical technical challenges, including material corrosion, flash-point management, and dual-fuel system calibration, are identified and evaluated through comparison with international case studies and empirical fleet data. the findings establish a technical and regulatory foundation for developing national alcohol-based marine fuel standards in iran. implementing these standards enables alignment with imo 2050 greenhouse gas reduction targets, supports safe and efficient fleet operation, and provides a practical pathway toward sustainable, low-carbon maritime propulsion.