Due to an increasing environmental awareness renewable fuels such as biomass become an attractive source of energy because they offer a reduction of net production of carbon dioxide (CO2) and better management of agricultural waste. However, thermal conversion of biomass leads to emission of undesirable secondary products, such as components of alkali, chlorine or sulphur, and may increase the corrosion rate of boilers. Therefore, the objective of the present contribution is to evaluate the kinetics of formation of both potassium chloride (KCl) and sulphur dioxide (SO2) during combustion of switchgrass. The kinetics were determined through experimental time-dependent data for the combustion of switchgrass, carried out by the National Renewable Energy Institute in Colorado (US). In order to describe numerically the combustion process of switchgrass with sufficient accuracy the Discrete Particle Method (DPM) was employed. It predicts all major processes such as heating-up, pyrolysis and combustion of switchgrass. The reaction rates of the emission species were approximated by an Arrhenius-like expression including a pre-exponential factor and an activation energy. The latter were determined by a least square method so that the deviation between the measured data and the predictions was minimised. The kinetic data determined yielded good agreement between experimental data and predictions and was applied to predict the emission behaviour of switchgrass blades. (C) 2012 Elsevier Ltd. All rights reserved.