Based on a model of a porous electrode, we make a detailed numerical simulation on molten carbonate fuel cell (MCFC) performance by using the lattice Boltzmann method (LBM). We apply Brinkman-Forchheimer-extended Darcy equations (generalized momentum equation) together with a reaction-diffusion equation with several reasonable assumptions and, to simulate more realistic physical conditions, we consider a curved boundary lying between the nodes of equal lattice space. As an attempt to assess the validity and efficiency of our model, two benchmark problems are investigated, including (i) the calculation of the dependence of generated current density on averaged gas velocity and the comparison between the result obtained by the LBM and by some other analytical solutions; (ii) the comparison between the result by the LBM calculation and the one by measuring experimentally the current density of test series in an overall range of H-2 concentration. An excellent agreement is found between the results from the LBM calculation and those from the experiment. In addition, the dependence of CO2 removal rate on current density, the contributions of CO2 concentration and O-2 concentration on cell performance, and the relations of cell voltage and power density with current density (load) are also studied. (c) 2006 The Electrochemical Society.