Simulation of the Vacuum Distillation Separating Process of Citral from Litsea cubeba Oil

Using process simulation software Aspen Plus, distillation equilibrium citral separating process from Litsea cubeba oil was simulated by the Modified Group Contribution Method (UNIFAC-DMD). Based on the characteristics of L. cubeba oil components, vapor-liquid equilibrium between citral and other components was analyzed under the distillation pressure of 0.24 kPa.The two-stage distillation equilibrium separation route was established firstly; then sensitivity analysis of distillation temperature and pressure was carried out. The results showed that when the distillation pressure of the two stages was 0.24 kPa, distillation temperature of the first stage was 50 ℃, and that of the second stage was 58 ℃, the content of citral in distillation residue reached 93.35% and the total yield was 31.63%.