WITHDRAWN: Solvent recovery from systems containing crude sesame seed oil and short-chain alcohols at different temperatures and local pressure

Abstract Apart from advantages regarding safety, short-chain alcohols used as substitutes for hexane in vegetable oil extraction can be partially recovered from the extract only by cooling due to their partial miscibility with oil. Therefore, the circumstances under which this separation is possible were studied from the determination of liquid-liquid equilibrium data of systems containing crude sesame seed oil and short-chain alcohols (crude sesame seed oil + ethanol + water, and crude sesame seed oil + isopropanol + water) with different hydration levels, in temperatures from (283.2 ± 0.1) to (333.2 ± 0.1) K. Adjusted NRTL model temperature-dependent parameters adequately described the phase compositions, with low global deviation values (0.24-0.63%). Results of the predicted alcohol amount that could be separated from extracts revealed that azeotropic ethanol is the most advantageous since approximately 100% of recovering was reached for temperatures between 283.2 and 288.2 K and for extracts with oil contents of up to 20 mass%. In addition to high recoveries, systems containing azeotropic ethanol showed the lowest amounts of residual alcohol to be evaporated from the oil-rich phases (approximately 8%). Finally, partition coefficients for free fatty acids close to or higher than 1 indicating greater migration of these components to the alcohol-rich phase, which corresponds to the possibility that the partial desolventization and deacidification processes are performed simultaneously.