Physical properties of pellets made from sorghum stalk, corn stover, wheat straw, and big bluestem

▶ Biomass densification can increase bulk density, improve storability and ease of biomass handling. ▶ This study determined the physical properties of pellets made from corn stover, sorghum stalk, wheat straw and big bluestem. ▶ The effect of biomass moisture content, hammer mill screen size, and die thickness on bulk density, true density, and durability of the pellets were determined. ▶ The increase in moisture level, hammer mill screen size, and die thickness all resulted in increases of bulk density and true density of pellets. ▶ Durability of pellets made from corn stover, wheat straw, and big bluestem initially increased with an increase in moisture content, reached a maximum value of about 96.8%, and decreased afterwards. Hammer mill screen size and die thickness had positive effects on pellet durability.