The kinetics of heterogeneous methanolysis of sunflower oil was studied at 60?C using mechanochemically synthesized CaO?ZnO as catalyst. Influence of agitation speed, catalyst amount and methanol to oil molar ratio on the rate of reaction was analyzed. The rate of the process depends on the two resistances - mass transfer of triglycerides to the catalyst surface and chemical reaction on the catalyst surface, which are defined as the values of the overall triglyceride volumetric mass transfer coefficient, kmt,TG, and the effective pseudo first-order reaction rate constant, k, respectively. These kinetic parameters actually determine the value of the apparent reaction rate constant, kapp, whose change with time is defined with the change of triglyceride (TG) conversion. The kinetic model was proposed and the model parameters determined.

Currently, the catalytic efficiency and reusability of the solid base catalysts cannot meet the demand of industrial biodiesel production under low temperature. The purpose of this study is to define the kinetics of heterogeneous transesterification process which might be used for the prediction of the biodiesel synthesis at high temperature and pressure. The focus in this study was paid to recently reported data obtained with different catalysts used for biodiesel synthesis in a batch reactor at high temperatures. It was shown that three kinetic models that include: a) irreversible first order reaction; b) reaction with changeable order; and c) resistances of mass transfer and chemical reaction at active sites of the catalyst could be applied for predicting the effect of high temperature of the transesterification. The apparent reaction rate constant of the irreversible first order reaction was determined, as well as the parameters of the other two, more complicated kinetic models. The best agreement was obtained with the more complicated models and the mean relative percent deviation between calculated and experimentally determined triacylglycerols conversion for these kinetic models is between 3 and 10%.