Kinetics of Ethyl Ester Production from Soybean and Sunflower Oils Catalyzed by Sodium Ethoxide

Abstract

The present paper reports the kinetics of soybean and sunflower oils’ ethanolysis. The transesterification reaction was carried out using a molar ratio of ethanol to oil of 9:1 and 1.0 wt% of sodium ethoxide as catalyst under stirring of 400 rpm. The reactions were performed in a stirred batch reactor at three different temperatures (308.15, 323.15 and 338.15 K) over a period of 120 min. The concentration of compounds was analyzed by High-Performance Size Exclusion Chromatography (HPSEC). The kinetic model assumed that ethanolysis occurs in a sequence of three reversible steps with the production of di- and monoacylglycerols as intermediate components. Based on the modeling approach it was possible to determine the rate constants of reaction and activation energies for the transesterification process of soybean and sunflower oils. Despite the phase splitting, no mass transfer control was observed and the proposed mathematical model fitted well the experimental data