In this study, trans-esterification of rice bran oil employing a heterogeneous catalyst like CaO has been conducted in a batch reactor with ethanol. The optimal set of various critical reaction parameters are found to be temperature of 70°C, reactant molar ratio 9:1, agitation speed of 600 rpm, catalyst mount of 3 wt % to maximize the biodiesel yield. For the heterogeneous system possibly influenced by reaction and pore diffusion, the controlling regime has been found based on the experimental data and well established theoretical estimations. The kinetic model along with the relevant parameters viz., reaction order, rate constants and Arrhenius parameters have been estimated.