Epoxidation reaction of vegetable oils: experimental measurement of partition coefficients in the biphasic system and NMR characterization of the epoxidized product

Abstract

The epoxidation reaction of vegetable oils typically consists of a liquid biphasic reaction system, subdivided into an aqueous and an organic phase. When the soybean oil is used as feedstock, the main product of the reaction is named epoxidized soybean oil (ESO), which presents application as a plasticizer element for polyvinyl chloride (PVC). The main advantage to use ESO in this application is the possibility to replace other substances with carcinogenic potential, named phthalates. The modeling of this reaction system includes the kinetics of the relevant reactions, heat and mass transfer effects, phase equilibrium, quantification of the interfacial area and physico-chemical properties of the substances. Most of these topics were extensively studied and can be considered well-consolidated, although some still need a deep investigation. Particularly, inserted in the phase equilibrium topic, the literature presents the estimation of partition coefficients of reagents and products in the biphasic system with SPARC calculator, as a function of temperature. In the present study, the first objective is the collection of experimental data on the partition coefficients by means of a dedicated glass equipment to be constructed and, in a subsequent phase of the research, the acquired data will be interpreted by a suitable correlation. The expected results will be particularly useful to improve the accuracy in modeling the reaction system of epoxidation of vegetable oils, with posterior application in simulations. The second object of study concerns the characterization of ESO, which typically is performed by standardized titration methods. The nuclear magnetic resonance (NMR) spectroscopic method will be evaluated as an alternative of the titration methods. The alternative may be particularly useful for the ESO characterization after tests that produce a reduced amount of sample in short periods (ex. microreactors). (AU)