The adsorption experiments were carried out under dynamic conditions for the removal of trace sulfur-dioxide (SO2) in nitrogen by 5A zeolites. The experiments were conducted to characterize the breakthrough characteristics of SO2 in a fixed bed under different operating conditions including temperature, pellet size, concentration levels, and gas flowrate. At a reaction temperature of 70 degreesC, the breakthrough time was found to be maximum. The adsorption isotherm was found to be linear over the gas concentration range from 1000 to 10000 ppm. The exothermic heat of adsorption assuming Arrehenius type of temperature dependence of the equilibrium constant was determined to be 9.8 kc/mol. The mathematical model was developed to predict the breakthrough profiles of SO2 during adsorption over the biporous zeolites (containing both macro and micro-pores). The model incorporates all resistances to mass transfer, namely: diffusion in the gas film around pellets in the bed, diffusion in the binder-phase of zeolites and within the crystals, and adsorption/desorption at the interface of binder-phase and crystals. The model was successfully validated with the observed experimental breakthrough data. The study showed potential application of 5A zeolites in controlling SO2 emissions at trace levels. (C) 2003 Elsevier Science B.V. All rights reserved.