Extraction of Oil from Tetrapleura Tetraptera (Akpangbo) Seeds: A Kinetic and Thermodynamics Study

Extraction of oil from Tetrapleura Tetraptera (Akpangbo) seeds using n- hexane as solvent was carried out at a temperature range between 45°C to 65°C while time was varied from 20 - 100 minutes. The results obtained showed that the yield of oil increased with increase in time and temperature at all experimental conditions. The maximum oil yield from seeds was 40.32%. Predictive models of Power and Exponential laws were used to evaluate the kinetic order and model of the extraction process parameters using experimental data. Power law model predicted the experimental results at temperatures of 45°C to 55°C with better sum of squares of residuals (R2) maximum value of 0.99 while the sum of squares of residuals value for Exponential law model had a maximum value of 0.95. However, at a temperature range between 60°C to 65°C, exponential law model gave a better result and higher values of R2 (0.99) than the Power law model (0.98) which goes to show that lower temperature favors power law model while higher temperature favors exponential law model as seen within the context of this study. The maximum deviation of power law model from experimental yield is 2.03% while that of exponential law is 1.58%. Hence, it is inferred that exponential law model is the most suitable model for predicting the yield of oil. Thermodynamic analysis was done in order to determine the enthalpy, entropy and Gibbs free energy of the seed which shows =13.89kJ/mol, =0.0423kJ/mol and = -1.0412kJ/mol. The findings suggest that oil extraction from Tetrapleura Tetraptera seeds is enhanced by increased temperature and time, consistent with an endothermic process. Thus, this study has provided broadened knowledge on the effects of kinetics and thermodynamic parameters aimed at minimizing the loss of oil and time, amount of energy expended and cost of production during solvent extraction processes.