Nyamplung Oil-Based Biodiesel as a Strategic Pathway for Renewable Energy Diversification in Indonesia

Abstract

Indonesia’s continued dependence on fossil fuels has intensified the need for renewable energy sources that are technically feasible, environmentally sustainable, and based on locally available biological resources. Nyamplung oil (Calophyllum inophyllum) represents a promising non-edible feedstock for biodiesel production because of its high seed oil content, which ranges from 40% to 74%, and its limited competition with food supply chains. This review critically evaluates the potential, conversion pathways, catalyst systems, and fuel-quality characteristics of biodiesel derived from nyamplung oil. The conversion process generally involves esterification pretreatment followed by transesterification, particularly because crude nyamplung oil contains high free fatty acid levels that may reduce conversion efficiency when alkaline catalysts are used directly. The reviewed studies indicate that biodiesel yield is strongly influenced by catalyst type, methanol-to-oil molar ratio, reaction temperature, and reaction time. Heterogeneous catalysts, particularly those derived from natural or waste-based materials, show strong potential due to their reusability, lower wastewater generation, and improved environmental performance. Optimized production systems have achieved biodiesel yields of up to 98.15%. The resulting biodiesel generally complies with national and international standards, including SNI 7182:2015, ASTM D6751, and EN 14214, based on viscosity, density, cetane number, acid value, and flash point. Overall, nyamplung oil-based biodiesel offers a strategic pathway for renewable energy diversification in Indonesia while supporting sustainable resource utilization and reduced dependence on fossil fuels.