Phase equilibrium measurements of Brazil nut (Bertholletia excelsa) oil in supercritical carbon dioxide

Brazil nut is one of the most important species from Amazon region with thousands of tons exported each year. With high content of oil, Brazil nut can be used for different applications. In this work the phase equilibrium of Brazil nut oil in supercritical carbon dioxide were measured, by static method, at pressures between 15 and 30 MPa and temperatures of 323.15 and 343.15 K. The experimental data were correlated using the Peng-Robinson and the Soave-Redlich-Kwong EOS with four different mixing rules: the van der Waals mixing rule for two binary interaction parameters, the Panagiotopoulos-Reid, Stryjek-Vera and Adachi-Sugie for three binary interaction parameters. For all isotherms studied the solubility of Brazil nut oil in the gaseous phase and that of carbon dioxide in the liquid phase increased, as the system pressure increases. For all mixing rules the Peng-Robinson and Soave-Redlich-Kwong EOS described very well the pseudo-binary system Brazil nut oil/carbon dioxide phase equilibrium data. (c) 2004 Elsevier B.V. All rights reserved.