AN INTEGRATED STUDY ON BIODIESEL PRODUCTION FROM FLAMBOYANT ( DELONIX REGIA) SEED OIL: EXTRACTION, PHYSICOCHEMICAL, FUEL PROPERTIES AND ASTM COMPLIANCE ASSESSMENT

The global search for sustainable alternatives to fossil fuels has highlighted biodiesel as a promising substitute. This study investigates the production and characterization of biodiesel derived from Delonix regia seed oil—a non-edible, underutilized biomass. Soxhlet extraction using n-hexane yielded 58.67% oil, which underwent base-catalyzed transesterification to produce biodiesel (methyl esters). Biodiesel was blended with petroleum diesel at varying ratios (F10–F50) and evaluated for physicochemical and fuel properties in line with ASTM D6751 standards. The Delonix regia oil showed an acid value of 7.66 mgKOH/g, iodine value of 52.5 g I₂/100g, and saponification value of 223 mgKOH/g. Delonix regia biodiesel blends somewhat exhibits properties that are compliant with ASTM fuel quality standards. The blends have a viscosity of 4.80–5.35 mm²/s, a flash point of 52–60°C, and a calorific value of 41.25–44.68 MJ/kg. While, the cetane number is estimated at a high 58.96 and the glycerin content remains unmeasured, On account of the higher flash point, B100 fuel sample is safer to handle the B10-B50 blends. The fuel samples exhibited good ignition quality, and compatibility with compression ignition engines. These characteristics position Delonix regia seed oil as a viable and sustainable feedstock for biodiesel production, offering potential for energy diversification, rural development, and reduced environmental impact in developing nations.