Soybean oil extraction using ethyl acetate and 1-butanol: From solvent selection to thermodynamic assessment

Abstract

Soybean oil extraction using two green solvents was investigated from solvent selection to thermodynamics: ethyl acetate and 1-butanol. The screening of the solvents was performed using the Hansen parameters and Infinite Dilution Activity Coefficient (IDAC) obtained through the COnductor-like Screening MOdels – Segment Activity Coefficient (COSMO-SAC) theory. The solvent selection was performed on ethyl acetate and 1-butanol in comparison with ethanol, a well-studied green solvent, and hexane, a non-renewable and industrially used solvent. The effects of temperature and solvent/solid ratio on the yield of soybean oil extraction were investigated through response surface methodology (RSM). The RSM obtained satisfactory statistical results, with Radj2 of 0.9958 for ethyl acetate and 0.9729 for 1-butanol. The kinetic of the extractions were evaluated using two different models: mass transfer kinetic and So and Macdonald. The last one obtained the best correlation to the data (R2 > 0.9964). The thermodynamic assessment showed endothermic, and spontaneous processes for both solvents. 1-Butanol, ethyl acetate, and hexane have a better performance on the yield of soybean oil extraction than using ethanol; however, ethyl acetate is the best candidate to replace the industrial use of hexane due to its highest rate of soybean oil extraction at the process beginning.