Thermal characterization and pyrolysis kinetics of tropical biomass feedstocks for energy recovery

This paper aims to analyse energy related properties, thermal degradation behaviour and devolatilization kinetics of five Cameroonian biomasses namely, Palm Kernel Shells (PKS), Mesocarp Fibres (PMF), Coffee Husk (CH), Corn Cob (CC) and Peanut Shell (PNS). The thermal degradation was performed using thermogravimetric analysis (TG). Different behaviours related to the presence of chemical constituents such as cellulose, hemicellulose and lignin were obtained. Comparison of the thermal characterization shows that PMF is the most interesting feedstock with the highest heating values and reactivity due to higher volatile content. Decomposition of TG data was analysed by applying diffusion and chemical reaction kinetic models. Obtained results show that biomass pyrolysis is represented by two successive steps. The devolatilization stage characterized by high weight loss rate is well described by diffusion reaction models. In contrast, the char formation stage characterized by low weight loss rate is well described by third order chemical reaction models.