Chemical interesterification of soybean oil and methyl acetate to FAME using CaO as catalyst

•CaO as catalyst was assessed in interesterificaion reaction from soybean oil.•Catalyst was complete characterized and active in reaction.•Kinetic experiments allowed to evaluate the influence of main variables.•Ester content of 62.3 wt% was obtained in the best experimental condition.•Decreasing catalytic activity was observed in reuse test. This study evaluated calcium oxide as catalyst from calcium carbonate at different calcination temperatures and the hydration-dehydration technique was used to produce a nanocrystalline catalyst. CaO samples were characterized by XRD, thermogravimetric analysis, Fourier transform infrared spectroscopy, scanning electron microscopy and nitrogen adsorption/desorption. Interesterification reaction at 275 °C, 1: 40 M ratio (soybean oil: methyl acetate) and 6 wt% catalyst concentration for 120 min was used with Tukey's test to determine the best calcination temperature, 800 °C. Selected catalyst was used in kinetic experiments to evaluate the effect of temperature, catalyst concentration and Oil:MeA molar ratio. The optimum condition was 325 °C, catalyst content of 10 wt%, and 1:40 Oil:MeA molar ratio, with a 62.3 wt% FAME content. Reuse catalyst was tested and the results showed a decreasing catalytic activity. Leaching test and FTIR analyses of the catalyst pointed out to mass loss and adsorbents at the basic sites would be contributing to CaO deactivation.