Supercritical Carbondioxide Extraction of Terpene Hydrocarbons from Constructed Citrus Peel Oil

Abstract

Supercritical carbondioxide (SC-CO₂) extraction was applied to a constructed citrus peel oil. The extraction conditions were as follows: extraction pressure; 75-200atm, extraction temperature; 35-60°C. (1) Under a constant temperature, the solubility of peel oil components into SC-CO₂ increased from 0.5% to 11.5% with pressure. As the temperature increased, however, the solubility was decreased from 3.4 to 1.1% 100atm, but increased from 3.5 to 11.5% above 120atm. (2) Limonene was selectively extracted under the following conditions: below 80atm at 35°C, 90atm at 40 and 50°C, and 100atm at 60°C. The solubility was less than 1.1% in all the cases. (3) BWR (Benedict-Webb-Rubin) equation of state was applied to experimental data in order to reveal PVT relation in SC-CO₂ phase. (4) At 35 and 40°C, limonene could be extracted selectively under the compressed state less than its critical molar volume, but at higher temperature, limonene was extracted selectively only under larger molar volume than the critical one.