Modelling the kinetics of transesterification reaction of sunflower oil with ethanol in microreactors

Transesterification reaction of vegetable oil with ethanol leads to ethyl esters, used to date for applications principally in food and cosmetic industry. To open the application field to biofuels (to substitute current fuels resulting from fossil resources), the process efficiency has to be developed to be economically profitable. In this work, the sunflower oil ethanolysis was performed in a micro-scaled continuous device, inducing better control for heat and mass transfer in comparison with batch processes. Moreover, this device ensures kinetic data acquisition at the first seconds of the reaction, which was not feasible in a conventional batch process. These data were used to model occurring phenomena and to determine kinetic constants and mass transfer coefficients. A single set of these parameters is able to represent the evolution of the reaction media composition function of time for five ethanol to oil molar ratios (6.0, 9.0, 16.2, 22.7 and 45.4). The model was validated in reaction and diffusion mode. Finally, it was subsequently used to simulate reactions with other operational conditions and to propose other process implementation.

► The biodiesel produced from sunflower oil and ethanol is of 100% renewable origin.
► The transesterification reaction was carried out in continuous microreactors.
► Kinetic data were acquired from the first seconds of the reaction.
► Reaction kinetics and mass transfer parameters were identified.
► The model was used to simulate other operating conditions (glycerol removal).