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Switchgrass and poultry litter are feedstocks that can be developed in the state of Alabama for bioenergy applications. Both feedstocks are however, lightly dense and therefore not economical to transport them from the site of production to places where they can be effectively utilized, hence the need to densify them by pelleting. In order to develop the optimal pelletization method for these feedstocks, fundamental studies were carried out on the effect of process parameters (moisture content, temperature and die size) on pellet formation quantified by pellet density and specific energy required to make the pellets in a single die system. Pellets were manufactured by attaching a single die to a universal testing machine operated at constant speed.

Results obtained showed that at compaction forces of 350 and 400 kg, the density of the switchgrass and poultry litter pellets increased with die sizes of 4.8mm to 7.9mm. Density also increased with increasing temperature from 60 to 90C. Density was also affected by the moisture content of the feed material. There was no significant effect of temperature on the specific energy used to make switchgrass pellets. The density of the switchgrass pellets varied from 850 kg/m3 to 1250 kg/m3 and 1350 kg/m3 to 1500 kg/m3 for poultry litter pellets. The specific energy needed for switchgrass pellets varied from 19 kJ/kg to 90kJ/kg.