This paper reports a theoretical study of thermal convection in a fluid-saturated porous medium generated by a surface reaction. The convective phenomena driven by temperature gradients, via heat release from an nth-order irreversible reaction, are modeled by the Brinkman-Forschheimer equation including the Boussinesq-Oberbeck approximations together with the energy and species equations. Solutions are obtained by a Fourier spectral element method in conjunction with a semi-implicit method combining the second-order Adams-Bashforth and first-order backward Euler schemes for advancing the solution in time. Numerical results indicate a strong influence of natural convection on the physicochemical process. Effects due to non-Darcy flow are significant for Rayleigh number on the order of 10(6) and that symmetry about theta = pi persists even for anisotropic materials unless the off-diagonal entry of the thermal conductivity tensor is nonzero.