Subcritical butane extraction of acer truncatum seed oil: Kinetics, thermodynamics, and optimization

In this study, the kinetics, thermodynamics, and optimization of the subcritical butane extraction of Acer truncatum seed oil were investigated. The effects of experimental parameters on the extraction yield and efficiency was studied and optimized by response surface methodology, with the optimum time, temperature, and liquid/solid ratio (mL/g) of 44 min, 52 °C, and 3.4, respectively. The extraction efficiency could reach up to 94.50 % after twice extraction under optimized conditions. The extraction kinetics was determined by a modified Fick’s law model and the activation energy of the effective diffusion coefficient was obtained as 23.26 kJ/mol. The enthalpy change and the entropy change were both positive with values of 20.06 kJ/mol and 70.02 J/(mol·K), respectively, while The Gibbs free energy change was negative in the temperature range. Finally, the comparisons of extraction efficiency, fatty acid composition , and properties were made for subcritical extraction and other three methods.