OPTIMIZATION OF PROCESS VARIABLES FOR THE PRODUCTION OF FATTY ACID METHYL ESTERS FROM BIGPOD SESBANIA SEED OIL

<p>This study explores the potential of <em>Bigpod Sesbania</em> seed oil as feedstock for production of biodiesel. The extracted oil was transformed to biodiesel via transesterification reaction using potassium hydroxide as catalyst. The process variables methanol-to-oil molar ratio (4:1–8:1), catalyst concentration (0.1–0.5 wt%), reaction time (30–90 min), and temperature (45–65 °C) were optimized using the Box–Behnken design of the Response Surface Methodology (RSM). The highest biodiesel yield of 96% was obtained at 8:1 methanol-to-oil ratio, 0.5 wt% catalyst, 60 min reaction time, and 55 °C. The physicochemical properties of the biodiesel conformed to ASTM D6751 and EN 14214 standards, with a specific gravity of 0.8491, viscosity of 4.39 cP, acid value of 0.32 mg KOH/g, ash content of 0.01%, flash point of 166 °C, and pour point of 4.2 °C, indicating high purity and stability. FTIR spectra confirmed the successful conversion of triglycerides to fatty acid methyl esters. GC-MS analysis revealed eight major fatty acid methyl esters (FAMEs), with methyl hexadeca-7,10,13-trienoate (29.80%), methyl (9E,12E)-octadeca-9,12-dienoate (15.97%), and carbonic acid octadecyl prop-1-en-2-yl ester (19.30%) as the dominant components. These unsaturated FAMEs accounted for 99.12% of the total composition, indicating high unsaturation favorable for cold-flow properties. These compounds accounted for over 90% of the total composition, indicating a high level of unsaturation responsible for good ignition quality. <em>Bigpod Sesbania</em> seed oil is validated as a promising non-edible feedstock for high-yield, high-quality biodiesel production with favorable physicochemical and combustion characteristics.</p>