Optimization of Eucalyptus essential oil extraction by applying response surface methodology in traditional distillation and its adaption to solar thermal process

Abstract

This work reports the utilization of solar thermal energy to generate Eucalyptus essential oil, reducing the dependence on conventional energy and minimizing the environmental impact. The study optimized oil extraction by traditional steam distillation using response surface methodology and applied the results to a Scheffler concentrator-driven solar steam distillation setup. The optimum factors included leaf size (0.02 m), extraction temperature (97.76 ℃), solid/solvent ratio (0.61), and extraction time (206 min), with temperature being crucial. The major oil components were 1–8 cineole (57.53–78.45%) and α-Pinene (15.27–27.83%). The outdoor experiments achieved an efficiency of 27% and produced 2 kg/h steam at an average solar insolation of 700 W/m2. Despite consistent processing temperatures favouring conventional steam distillation, the solar extraction process offers an eco-friendly alternative. In line with the sustainable development goals, this initiative is well-suited for sunny regions and small businesses targeting niche markets.