Optimization of Solvent Extraction of African Pea Seed Oil Using Ethanol and Petroleum Ether for Bioaviation Fuel Feedstock

Abstract

Extraction of oil from African pea seeds for jet fuel sustainability is vital in promoting renewable energy. This work focuses on extracting oil from African pea seeds by optimizing the extraction process parameters using response surface methodology (RSM). Solvent extraction method was used with ethanol and petroleum ether as solvents. Three independent extraction parameters; particle sizes (0.15, 0.3, 0.45 mm), temperature (40, 60, 80 °C) and time (30, 60, 90 min) were considered. The highest oil yield was 6% and 18.4% for ethanol petroleum ether respectively. The optimal conditions: particle size, temperature and extraction time, were recorded  at 0.3 mm, 60 ^oC and 123.9 min respectively for ethanol and 0.45 mm, 40 ^oC and 120 min respectively for petroleum ether. Quadratic model is suggested for both solvents as the best fit with adjusted R² of 0.9143 and 0.8571 and predicted R² of 0.7452 and 0.7822 respectively, indicating good agreement between the two (predicted and observed). Temperature (B), time (C), and interaction terms (AB, AC, BC) are significant for petroleum ether with temperature and particle size having the most significant effect on oil yield, while Particle size (A), time (C), and squared terms (B² and C²) are significant in affecting ethanol. Time (C) has the most substantial effect (F-value of 27.38), meaning the longer the extraction time, the higher the yield for ethanol as solvent. Consequently, the results showed that Petroleum ether gave a better yield compared to ethanol.