The essential oil of Achyrocline satureioides was obtained by steam distillation in four operating conditions (1.0, 1.5, 2.0 and 2.5 bar) and the aromatic profile of these essential oils was evaluated by gas chromatography/olfactometry (CG/O). It was observed that the relation between the aromatic intensities and the compounds concentration is not directly proportional, except for the α-pinene, which presented a high concentration and aromatic intensity. The essential oil compounds were identified by gas chromatography/mass spectrometry and a principal component analysis (PCA) was used to evaluate the pressure effect on the essential oil composition. Through the PCA, similarity of composition was observed between pressures of 2.0 and 2.5 bar. Furthermore, a mathematical modeling of extraction process and an essential oil theoretical fractionation process study by batch distillation of the major compounds were performed. In order to enhance its aromatic activity, the simulation methodology applied to fractionate the A. satureioides essential oil presented a high-purity (99.10%) α-pinene fraction. [ABSTRACT FROM AUTHOR]