Dissertação
Extração de óleo de soja utilizando solventes verdes: cinética, termodinâmica e transferência de massa
Fecha
2022-09-02Autor
Gasparetto, Henrique
Institución
Resumen
This dissertation focuses on the kinetic, thermodynamic, and mass transfer study on applying
green solvents in soybean oil extraction. The first work discusses ethyl acetate and 1-butanol
solvents application. Temperature and solvent-to-solid mass ratio variables were optimized
using the response surface methodology. The So and Macdonald and the mass transfer kinetic
models were applied for modeling extraction kinetics. This study shows that ethyl acetate is
the best candidate for directly replacing hexane at an industrial level, even though 1-butanol is
better for the solubilization of the triacylglycerols. However, both solvents did not present
better results than n-hexane. The second study evaluated the application of p-cymene in
soybean oil extraction. Temperature and solvent-to-solid mass ratio variables were also
optimized, and an in-depth statistical approach was used to compare kinetic models to
describe vegetable oil extraction. So and Macdonald's kinetic model was considered the best
in describing the extraction process, which was further associated with bootstrap resampling
to reduce the bias of the estimators. P-cymene resulted in better extraction yields than nhexane at 55°C. The COSMO-SAC theory could predict the behavior of the solvents
mentioned above through the activity coefficient at infinite dilution compared to the Hansen
solubility parameters. The last work used experimental data from the literature and those
obtained experimentally for ethyl acetate, 1-butanol, and p-cymene, to evaluate the
application of a generalized fractional derivative power order model. Better statistical results
were obtained compared to the integer order derivative model through the analysis of the
coefficient of determination, root-mean-square error, chi-square distribution, Akaike
information criterion, and Fisher's exact test. For all solvents, the thermodynamic assessment
indicated endothermic, irreversible, and spontaneous processes; the extracted oil's fatty acid
profile and infrared spectrum agree with what the literature present.