High Pressure Phase Equilibrium: Prediction of Essential Oil Solubility

Abstract

This work describes a method to predict the solubility of essential oils in supercritical carbon dioxide. The method is based on the formulation proposed in 1979 by Asselineau, Bogdanic and Vidal. The Peng-Robinson and Soave-Redlich-Kwong cubic equations of state were used with the van der Waals mixing rules with two interaction parameters. Method validation was accomplished calculating orange essential oil solubility in pressurized carbon dioxide. The solubility of orange essential oil in carbon dioxide calculated at 308.15 K for pressures of 50 to 70 bar varied from 1.7<FONT FACE="Symbol">±</font> 0.1 to 3.6<FONT FACE="Symbol">±</font> 0.1 mg/g. For same the range of conditions, experimental solubility varied from 1.7<FONT FACE="Symbol">±</font> 0.1 to 3.6<FONT FACE="Symbol">±</font> 0.1 mg/g. Predicted values were not very sensitive to initial oil composition.<br>Este trabalho descreve uma metodologia para o cálculo da solubilidade de óleos essenciais em dióxido de carbono a altas pressões baseada na formulação proposta em 1979 por Asselineau, Bogdanic e Vidal. Foram utilizadas as equações cúbicas de estado de Peng-Robinson e Soave-Redlich-Kwong com regras de mistura de van der Waals com dois parâmetros de interação. O cálculo da solubilidade do óleo essencial de laranja em dióxido de carbono pressurizado foi usado para validação do método. A solubilidade calculada a 308,15 K para pressões entre 50 e 70 bar variou entre 1,5 e 4,1 mg/g. Valores experimentais para as mesmas condições variam entre 1,7<FONT FACE="Symbol">±</font> 0.1 a 3,6<FONT FACE="Symbol">±</font> 0.1 mg/g. Os valores preditos não são muito sensíveis à composição inicial do óleo essencial

Simulation modeling of the phase behavior of palm oil‐supercritical carbon dioxide

“…The results show that the separation factors predicted by the RKA model are in good agreement with the experimental data. The average deviation was 15.81% over a wide range of temperatures (313-373 K) and pressures (20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30). This confirms that the model is a reliable alternative for predicting the distribution of palm oil components in supercritical CO 2 at various extraction conditions.…”

“…Nevertheless, satisfactory results have been reported in the literature from predicting the phase equilibrium of a complex oil mixture based on only supercritical solvent-solute interactions while neglecting the solute-solute interactions. Some examples include the prediction of phase equilibrium for a CO 2 -soybean oil deodorizer condensates system by Araújo et al (5), a CO 2 -orange oil system by Cardozo-Filho et al (30), and a CO 2 -essential oil system by Sovová et al (31).…”

Phase Equilibrium Measurements for the System Fennel (Foeniculum vulgare) Extract + CO2

“…Due to the variety and complexity of the chemical functional groups that form a natural extract, such as volatile oils, oleoresins, and the like, the phase equilibria of these systems generally is not trivial. [5][6][7][8][9] Nonetheless, the Peng-Robinson 10 equation of state (PR EOS) was capable of quantitatively describing the phase behavior of such systems as demonstrated by Souza et al 9 for clove oil + CO 2 : The clove oil obtained by SFE was treated as a pseudo-pure compound; its thermophysical properties were estimated by the Kay's 11 rule using the pure components properties estimated using the method of Constantinou and Gani; 12 the acentric factor was calculated with the Lee and Kesler method. 11 The purposes of the present work were to measure the phase equilibrium for the system formed by CO 2 + fennel extract, to model the experimental data using the PR EOS coupled to the phase stability analysis, and to compare the phase equilibrium behavior predicted using the estimated parameters for a pseudo-binary system formed by CO 2 + SFE fennel extract; three pseudo-pure compounds denoted as FE 1 , FE 2 , and FE 3 were considered based on the compositions of fennel extracts published in the literature.…”

“…Relevant data on phase equilibria of several binary and ternary systems of interest have been published in the literature. − The use of phase equilibria data for real systems, such as the mixture that forms fennel extract, is more appropriate for process design; nonetheless, this type of data is still scarcely available. Due to the variety and complexity of the chemical functional groups that form a natural extract, such as volatile oils, oleoresins, and the like, the phase equilibria of these systems generally is not trivial. − Nonetheless, the Peng−Robinson equation of state (PR EOS) was capable of quantitatively describing the phase behavior of such systems as demonstrated by Souza et al for clove oil + CO 2 : The clove oil obtained by SFE was treated as a pseudo-pure compound; its thermophysical properties were estimated by the Kay's rule using the pure components properties estimated using the method of Constantinou and Gani; the acentric factor was calculated with the Lee and Kesler method…”

Análise fitoquímica e atividade antiproliferativa de espécies nativas de Croton L. (Euphorbiaceae)

“…Óleos voláteis Extrato foliar: 1,8 cineol, 1,10-di-epi-cubenol, sabineno, α-pineno Extrato caulinar: germacreno D, β-cariofileno, elixeno 1,8 cineol -anestésico, antibronquite, antisséptico, bactericida, expectorante, herbicida e insetífugo (Cardozo-Filho et al, 1997) Extrato caulinar: atividade moderada contra OVCAR-3 e K562 Flavonoides Extrato foliar: rutina, apigenina di-hexosídeo, quecetina hexose-pentose, derivado de quercetina 1 e 2 Extrato caulinar: tilirosídeo, quercetina p-cumaroil glucosídeo, flavonol p-cumaroil glicosídeo, derivado de luteolina rutina -anti-inflamatória (Guardia et al, 2001), antioxidante (Metodiewa et al, 1997), anticoagulante (Navarro-Núñez et al, 2008) C. erythroxyloides…”