The industrial development which has provided a significant progress in the improvement of the life quality has also brought some problems to the environment. In this context, the mobility industry has generated several types of pollutants. Among these pollutants stands out the ammonia gas, that can be generated in a direct or indirect way, through fuel burning of several types of vehicles or through responsible industrial processes for the production of components and input to this industry. For being an extremely toxicant gas, it is of great importance to develop techniques that facilitate reutilize and to avoid the discard of that gas discards in the atmosphere. This way, this work had as its main objective to study the purification of the ammonia gas through the adsorption in activated coal, in which the influences of the temperature and mass of the bed in the process of adsorption were appraised.