Characterization of the physicochemical and thermal properties of different forest residues

The assessment of the variability of the fuel properties is essential information to understand combustion behavior and to develop mathematical models. This work comprehensively investigates the physicochemical and thermal properties of four different forest residues (eucalyptus, pine, acacia, and olive). Each fuel is fully characterized in terms of chemical composition by proximate and ultimate analysis and its calorific value. Furthermore, this study examines the variation in terms of the thermal properties and the ash elements to evaluate the tendency for slagging and fouling. Selected samples of the solid biomasses were tested using the Hot Disk Thermal Constants Analyzer TPS 2500S to measure the thermal conductivity, which was found in the range of 0.239–0.404 W/mK. In addition, the heat capacity was evaluated within 0.855–2.442 MJ/m3K, and the thermal diffusivity was between 0.187 and 0.258 mm2/s. The ultimate and proximity analyses were carried out on the fuel samples using LECO TruSpec CHN Macro and LECO CS-200 equipment and a muffle furnace, respectively. The results revealed a higher reactivity of eucalyptus, which was around 2 times higher than the other fuels, and the propensity of acacia to produce pollutant emissions (mostly Nitrogen based) and ash deposition problems due to their chemical composition.