Abstract: Biodiesel is one of the new possible substitutes of regular fuel for engines and is produced from different vegetable oils or animal fats. The main reaction involved is the transesterification of triglycerides into esters. The employment of low quality or waste raw materials has been considered to strongly improve the economic competitiveness of this biofuel with respect to the petroleum-derived diesel. In the case of waste raw materials characterized by a high content of Free Fatty Acids (FFAs), direct esterification of the FFAs is the primary route for producing biodiesel. The novel sustainable esterification process based on catalytic Reactive Distillation Column (RDC) has been proposed to overcome the shortcomings in the conventional process. A reliable kinetic model which would be applicable in a wide range of operating conditions is an important data for the RDC design. In the present study, kinetics of heterogeneous catalyzed direct fatty acid esterification was studied with a tungstated zirconia catalyst in a stirred batch reactor to synthesis biodiesel. The waste cooking oil with high content of FFAs was simulated by mixing pure oleic acid with refined palm oil. Ethanol was used in the experiments instead of methanol because it is less toxic and safer to handle. The effects of the main variables involved in the process such as reaction temperature, amount of catalyst, amount of triglyceride and the molar ratio of alcohol/free fatty acid were analyzed. The experimental data were interpreted with a second order, pseudo homogeneous kinetic model and a good agreement between experimental data and the model is obtained.