Effect of pelletization on biomass thermal degradation in combustion: A case study of peanut shell and wood sawdust using macro-TGA

Abstract

Pelletization reduces storage and transportation costs and improves the thermal efficiency, making it a key technology for the efficient utilization of biomass energy. However, there are few comparative investigations on how pelletization affects biomass thermal degradation in the combustion process. In this study, five types of fuels with different mixing ratios of wood sawdust and peanut shells were prepared. Powder and pellet samples were combusted using a custom-designed macro-TGA. The combustion characteristics, kinetics, and thermodynamic parameters were discussed. The results show that pelletization increases the ignition difficulty and prolongs combustion time. Compared with that of the powder sample, the weight loss peak of the pellet sample moved towards a higher temperature. The apparent activation energy for pellet samples was 20–38 % lower than that of powder samples. The results prove that biomass pellets have better combustion performances than biomass powders in the macro-TGA.