Optimization of Extraction Process and Kinetics of Sterculia foetida Seed Oil and Its Process Augmentation for Biodiesel Production

This article reports optimization and kinetic studies on extraction of Sterculia foetida seed oil and process optimization for biodiesel production from the same. The oil extraction follows first-order kinetics, and the yield was found to reach a maximum of 55.58 wt % for a 1:12 seed-to-hexane weight ratio. The activation energy and activation thermodynamic parameters at 338 K were determined as E a = 69.441 kJ mol –1, Δ H ‡ = 66.63 kJ mol –1, Δ S ‡ = −238.07 J mol –1 K –1, and Δ G ‡ = 147.09 kJ mol –1 . Complete physicochemical properties of the oil were analyzed using standard methods. The low acid value of 0.42 mg of KOH g –1 for fresh oil enables alkali catalytic transesterification. Different biodiesel production parameters including methanol-to-oil molar ratio, catalyst concentration, and reaction temperature were examined. An optimum yield of 95.4 wt % with a conversion of 98.91% was achieved at values of 6:1, 0.9 wt %, and 338 K, respectively. The fuel properties of the produced biodiesel were compared with the ASTM D6751 biodiesel standard.