A Further Study of the Kinetics and Optimization of the Essential Oil Hydrodistillation from Lavender Flowers

Hydrodistillation has commonly been used to recover essential oil from various plant materials, including lavender (Lavandula officinalis) flowers. The main objectives of the present study were to model the kinetics of the lavender essential oil (LEO) hydrodistillation using a phenomenological model, to evaluate the statistical significance of the hydromodule and hydrodistillation time on LEO yield combining a 42 full factorial design with the response surface methodology, to model statistically LEO yield by multiple non-linear regression and to determine the optimal process conditions that provided the maximum LEO yield. The fast-essential oil distillation (washing stage) in the initial period and the slow diffusion stage until the saturation occurring simultaneously were observed, justifying the use of the phenomenological model. With increasing the hydromodule, the saturation LEO yield and the washable fraction of the LEO decreased while the washing and diffusion rate constants increased. Knowledge of the LEO oil yield and the hydrodistillation kinetics is important from the techno-economical point of view.