Vegetable cuticular waxes have to be separated from the more valuable essential oils in extraction processes carried out with supercritical fluids (namely CO2), allowing a solvent selectivity by modification of temperature and pressure. The solubility of these waxes in supercritical CO2 can be adequately represented by that of solid n-octacosane. The present work shows that isothermal investigations, carried out with a differential flux calorimeter with adequate cells, allow the solubility and solubilization enthalpy of n-octacosane to be determined. The results concern investigations either at constant pressure and variable supercritical CO2 flow-rate, or at zero flow-rate and increasing pressure. The latter conditions allow the solubility-pressure trend to be obtained, in satisfactory agreement with literature data derived from standard dynamic methods.
|Titolo:||SOLUBILITY OF VEGETABLE CUTICULAR WAXES IN SUPERCRITICAL CO2 ISOTHERMAL CALORIMETRY INVESTIGATIONS|
SCHIRALDI, ALBERTO (Primo)
|Parole Chiave:||SUPERCRITICAL FLUIDS; EXTRACTION|
|Settore Scientifico Disciplinare:||Settore CHIM/02 - Chimica Fisica|
|Data di pubblicazione:||1994|
|Digital Object Identifier (DOI):||10.1016/0040-6031(94)80106-1|
|Appare nelle tipologie:||01 - Articolo su periodico|