In this research, combustion behavior of agricultural residues known as miscanthus, poplar wood, and rice husk was investigated using thermal analysis techniques. Differential scanning calorimeter (DSC) and thermogravimetry (TG-DTG) techniques were used. Combustion experiments were performed at five different heating rates (5, 10, 15, 25, and 50 degrees C/min). The reaction regions, ignition and burnout temperatures, heat flow rate values of biomass samples are determined. Activation energy of the biomass samples are calculated using three different iso-conversional methods. It is observed that all three agricultural residues show similar combustion characteristics. The results indicate that the reactivity of biomass fuels is due to the combustion of light compounds; however the energy release from biomass fuels is mainly due to the combustion of fixed carbon. (c) 2012 Elsevier B.V. All rights reserved.