Optimization of the oil extraction process by response surface methodology from Podocarpus falcatus seed as a low-grade substitute feedstock for biodiesel applications

The aim of the present study was to optimize oil extraction from Podocarpus falcatus seed (PFS). Process variables, including solvent/seed ratio 6:1-12:1 (ml/g), extraction temperature 50-70 (degrees C), and extraction time 2-6 (h), were explored to determine their influence on the soxhlet extraction process. The oil extraction process was modeled and optimized using the response surface methodology (RSM) based on a Box-Benhken design (BBD). The highest oil recovery rate was 58.93%, with a solvent/seed ratio of 12:1, an extraction temperature of 66.48 degrees C, and an extraction time of 4.45 h. The determination coefficient (R-2) reveals that the model was relevant and accurate. The NMR and FT-IR analyses of Podocarpus falcatus seed oil (PFSO) showed the presence of carboxylic acids and ester carbonyl functional groups. TGA analysis revealed that PFSO is thermal stable up to 375 degrees C. Furthermore, the physicochemical properties of PFSO, such as flash point (258 degrees C), iodine value (147.10 gI(2)/100 g oil), calorific value (39.47 MJ/kg), cetane number (42.06), and copper strip corrosion (1a), were determined according to ASTMD6751 specifications. This work can pave the way for the scientific community to focus more on biodiesel production for future applications.