Kinetic study of the esterification of free fatty acid and ethanol in the presence of triglycerides using solid resins as catalyst

Abstract

Biodiesel production is gaining more and more relevance due to its environmental advantages and because of the world situation of petroleum: decreases of reserves, augmentation of prices etc. Biodiesel is produced by transesterification of triglycerides; however, it can also be generated by the esterification of fatty acid, normally considered as an impurity. The evolution of the reaction when using oleic acid (diluted in triglycerides) and ethanol, in the presence of a heterogeneous catalyst, has been studied. Kinetics expression for the esterification reaction as well as for the esterification and transesterification taking place simultaneously have been developed and fit with the experimental data. It is shown that, when both reactions are being taking into account, the kinetics fits the experimental data better since it does consider the interaction between all the compounds involved. The kinetics expression obtained represented satisfactorily the experimental information for several operations conditions.