PourKhiabani - Chemical and Petroleum Eng. Dep., Sharif University Of Technology, Tehran, Iran
Farhadi - Chemical and Petroleum Eng. Dep., Sharif University Of Technology, Tehran, Iran
Razavi - Chemical and Petroleum Eng. Dep., Sharif University Of Technology, Tehran, Iran

Supercritical Fluid Extraction (SFE) has unique advantages over other methods of extracting essential oils. An important step of SFE with CO2 is separation of output mixture of extractor. If extraction is performed from fresh raw materials, product would have natural smell and taste but also water might be present in the extract. For a better quality of the product and for recycling carbon dioxide, water and carbon dioxide should be separated from essential oils. One of the methods for separating essential oils from CO2 and water is decreasing the pressure lower than supercritical state. In the separation process carbon dioxide should be separated as in vapor state, essential oils as light liquid phase and water as heavy liquid phase. In this study VLL-3 phase separation process for mixtures of caraway essential oil+CO2+water and orange peel essential oil+CO2+water are investigated. Simulation of the separation process is performed by PRSV, PR and modified PR. Binary coefficients of PR equation of state based on experimental data for CO2+D-Limonene and CO2+Carvone are found to be -0.05 and -0.1 respectively. Simulation results with the three equations of state are similar. Finally, optimized separation temperature and pressure based on modified PR EOS are proposed in the range of 15-25 °C and 45-60 bar respectively.

Essential oil, Supercritical Fluid Extraction, Carbon dioxide, Process Simulation, Equilibrium data