Simulation of the multicomponent distillation of spearmint essential oil by a predictive Soave-Redlich-Kwong equation of state and comparison with experiments

In this study, enrichment in major component of spearmint oil has been studied by continuous multicomponent distillation. A mathematical model was evaluated to predict the enrichment by multicomponent distillation of spearmint oil. The aim of the work was to obtain simulation data to compare with experimental data of spearmint oil enriching. The simulation model is based on bubble point method ,the Wang-Henke algorithm and predictive Soave-Redlich-Kwong (PSRK) equation. In this method, MESH equations are solved and a diagonal matrix method for solving equations is used. The model was validated by experimental data obtained from a pilot-plant system, where a continuous distillation column with trays of one to five numbers has been used. The simulation was able to predict satisfactory the experimental data. The results of simulation and experiments show that the major component of spearmint essential oil is enriched from 31% to 62.04% by the distillation column with five trays. The results show that the addition of a tray to the distillation column with a low number of trays, have more effective relative to add a tray to the distillation column with higher trays. The results indicate that increasing of reflux ratio from 2 to 3 increases separation of the major component from 62.04% to 67.04%