In this paper the analysis of the effects of model uncertainties on predictions is reported for a multi-component gas-solid TSA fixed-bed adsorber. Owing to the complexity of the system the study was carried out by means of a simplified method. Despite its simplicity this method allowed the evaluation of the effectiveness of predictions and the identification of the most critical aspects of the model, which require improvement in order to obtain reliable model outputs. The advantages of such an analysis are that the results can be used to improve the reliability of the model and make the model useful for good design and safety considerations.