The fuel cell is an electrochemical device that converts chemical energy directly into electricity and is more efficient than traditional power generators. In this work, we developed a mathematical model for a direct ethanol fuel cell (DEFC), which considers the flow and concentration of species dependent on time and space for the calculation of losses over potentials. In addition, the concentration of each species is modeled according to the current density of the DEFC. The finite element method is used to calculate the flow and concentration of the species in different layers of the cell (inlet and outlet channels, diffusion layer and catalyst layer). The model takes into account the losses overpotentials at the anode and at the cathode and the passage of ethanol through the membrane. The voltage and power density of the cell are calculated with different catalysts, temperatures and concentrations of ethanol. A result is shown for limiting current density for low ethanol concentrations. The results obtained compare favourably with the data found in the literature. (C) 2018 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.