Extraction Modeling, Nonlinear Kinetics, and Thermodynamics of Solvent Extraction of Neem Seeds Oil

Abstract

The oil extraction modeling, nonlinear kinetics, thermodynamics, and effects of process parameters on neem seed oil (NO) extraction were investigated via soxhlet extraction using ethanol. The nonlinear kinetic models of the power law, Elovich, parabolic-diffusion, and hyperbolic models were investigated. The process variables studied comprise, the extraction time, temperature, and average particle size. The thermodynamics parameters such as enthalpy, entropy, and Gibbs free energy were determined. The results revealed that oil yield increased with increase in temperature and time and decreased with increase in particle size. The maximum oil yield of 36.7% was recorded at 74 oC, 0.1 mm, and 180 min. The best fitted kinetic models in order of performance were parabolic, power-law, elovich, and hyperbolic models. The average values of the sum of the squares of errors (SSE), root mean squared error (RMSE), coefficient of determination (R2), and adjusted-coefficient of determination (adj-R2) for parabolic-model as the best-fitted model is as follows: 4.538, 0.845, 0.971 and 0.965, respectively. The enthalpy, entropy, and Gibbs free energy values of the neem oil extraction process at 328K and 0.1mm were 28.74kJ/mol, 0.09kJ/mol, and -3.61kJ/mol, respectively, signifying irreversible, endothermic, and spontaneous-process.