Flash distillation extracts essential oils from eucalyptus

UN/DICYT By means of a instant distillation process UNal-Palmira researchers efficiently and economically extracted essential oils from eucalyptus.

Flash distillation, also known as instant vaporization is an agro-industrial process that allows separating mixtures through only one balancing stage. Therefore the liquid mixture partially vaporizes, establishing a relation between vapor and liquid.

This is a very efficient method to extract essential oils from different natural products. Taking into consideration that they have a multi-component mixture that reduces energy consumption, the resulting process is optimal.

A group of UNal-Palmira researchers carried out a research project to discover the appropriate conditions to obtain essential oils from eucalyptus (Eucalytus globulus Labill). In the proposal they distilled one of the main components for extraction: 1,8 cineole or eucalyptol, used in the perfume industry, medicine and mineral flotation.

Agroindustrial Engineering Professor and Project Coordinator Hugo Martínez Correa says that “the main goal of this project was to perform flash distillation simulation studies on 1,8 cineole ethanolic extracts using balanced models and different operation conditions with the purpose of discovering optimal conditions”.

For the project, the researchers suggested separating 1,8 cineole from an ethanol mixture. They studied the effect of temperature, pressure and supply variations by means of a parametric study.

The results helped them determine that the most convenient model for identifying thermodynamic properties of the mixtures was the UNIFAC method, a universal predictive method based on group contribution, turning into a valuable alternative when experimental information is scarce.

“The best condition to obtain the greatest compound of interest is at a temperature of 71.82 ºC (161.27 ºF), with respect to others assessed, as it has a better recovery percentage and greater compound separation,” said Correa.

Then the simulation study concluded that the best 1,8 cineole and ethanol distillation mixture (with the time, pressure, temperature conditions previously worked) will always produce greater eucalyptus extract in bottom products and not in the distillate.

“This is because ethanol is much more volatile and therefore it evaporates quicker. For this reason the distillate product will have a greater percentage of ethanol,” said.

Agroindustrial Engineering students Daisy Agudelo, Lexy Díaz, Mayra Gómez and Gina Melo participated in the research project.