HEGEL Pablo Ezequiel
congresos y reuniones científicas
SOLUBILITY OF ORANGE PEEL OIL COMPONENTS IN SUPERCRITICAL CO2+ETHANE AZEOTROPIC MIXTURE
FORTUNATTI MONTOYA, MARIANA; GRANONE, LUIS I.; HEGEL, PABLO; PEREDA, SELVA
Conferencia; 20th International Symposium on Solubility Phenomena and Related Equilibrium Processes; 2022
Polytechnic Institute of Bragança
Supercritical technologies have become attractive and economically viable alternatives for the processing of natural products during the last few years. CO2 is the most used supercritical fluid because it is inexpensive, non-flammable, non-hazardous at low exposure levels, and it is readily available at high purity . According to several authors [1,2], the fractionation of orange peel oil by supercritical CO2 (SCCO2) is technically feasible at pressures between 88 bar and 110 bar and temperature between 303 K and 333 K. On the other hand, ethane has also been proposed as an alternative solvent for the deterpenation of citrus fruit essential oils [3-5]. According to previous studies, the use of ethane rather than CO2 enables obtaining five-fold and ten-fold oils at lower pressure (ca. 60 bar) and with substantially lower solvent consumption. The main drawback of using ethane as solvent is its flammability, however, mixtures of CO2+ethane can be design as non-flammable solvent for the deterpenation of citrus oils. Particularly, this is the case of the azeotropic CO2+ethane mixture, with the additional advantage that it can be recycled minimizing changes in the solvent composition, which is key for achieving a stable operation.In this work, we research the solubility of orange peel oil in CO2, in ethane and in the azeotropic mixture CO2+ethane (66 mol% CO2) in a dynamic cell of 50 ml at 333 K in a range of pressure between 60 bar and 110 bar according to the solvent. Also, we compare the selectivity of the three solvents to extract limonene and raffinate the oxygenated compounds in the peel oil The solubility values of orange peel oil in pure CO2 and ethane agree with previous experimental data reported in the literature. Regarding the solubility in the azeotropic ethane/CO2 mixture, it is worth highlighting that it varies significantly with the operating pressure between 4 mg extract/g solvent at 60 bar to 27 mg extract/g solvent at 110 bar. Finally, the selectivity of the fractionation process, defined as mg limonene per mg of linalool extracted, switches between 228 and 244.Previous studies carried out with the GCA-EOS (Group Contribution with Association Equation of State) show that the model can predict the phase equilibria of orange peel oil with CO2 mixtures as well as with ethane. Thus, in this work we also challenge GCA-EOS predictive capacity to model the experimental cumulative extraction curves obtained under equilibrium conditions. The results show that the GCA-EOS is a robust tool to design and optimize the supercritical deterpenation process using the azeotropic mixture.