Grinding Performance and Physical Properties of Selected Biomass

Abstract

Biomass residues such as straws, corn stover and energy crop - switchgrass were ground using a hammer mill with three different screen sizes (3.175 mm, 1.588 mm and 0.794 mm) for densification. Energy required for grinding these materials was measured at two different moisture contents. Among the four materials, switchgrass had the highest specific energy requirement to grind using a hammer mill. Corn stover used the least specific energy. Physical properties of ground samples such as moisture content, geometric mean diameter, particle size distribution, bulk and particle densities were determined. Second or third order polynomial models were developed relating bulk and particle densities of ground samples to geometric mean diameter within the range of 1.428 to 0.178 mm. Switchgrass had the highest calorific value and the lowest ash content among the materials used in the experiment.