Carbon-coated ceramic monoliths have been studied for the dynamic adsorption of low-concentration n-butane. They exhibit a very sharp breakthrough performance., especially in the low-concentration regime, that illustrates the better breakthrough performance of monoliths with respect to shallow carbon packed beds. The low pressure drop of the monolithic system and its excellent performance under discontinuous flow conditions make it an attractive option for gas mask canister applications. A simulation model is presented, including terms of adsorption, diffusion and mass transfer. A parametric analysis has been carried out to study the influence of different variables on the breakthrough profile. The breakthrough performance is best described by considering a gas velocity distribution over the monolith cross-section. Stacking of the monolithic pieces, increasing cell density, and gas redistribution between pieces reduced this distribution and improved the breakthrough performance. (C) 2004 Elsevier Ltd. All rights reserved.