HIGH-PRESSURE EXTRACTION USING SUPERCRITICAL CO2

Supercritical CO2 extraction of oil from lavender inflorescence was performed on a laboratory apparatus. A two-stage separation procedure was added to extraction to induce the fractional separation of the extracts by selective supersaturation and precipitation of the undesidered compounds. Detailed GC-MS analysis of the products was performed to assess the best extraction and the best separation conditions. The best overall performance of the process resulted from the extraction performed at 90 bar and 50°C and from the separation conducted at 90 bar, 0°C in the first separator and 15 bar, 5°C in the second separator, respectively. The lavender oil produced by supercritical CO2 extraction and fractionation was compared to the oil obtained by classical hydrodistillation. The major difference between the two products resulted in the linalyl acetate content. This compound was found to be 31.82 % of the oil produced by supercritical fluid extraction and as 16.05 % of the hydrodistilled oil. The difference can be ascribed to the hydrolysis of part of the compound during hydrodistillation. The oil yield of the extraction process was measured at various extraction lengths