The angle of repose of bulk corn stover particles

Lignocellulosic biomass feedstock such as corn stover, the residues left on the field after corn grain harvest, has been studied as one of the renewable feedstocks to be used for fuel ethanol conversion in the near future. The primary objective of this work was to determine the angle of repose (AoR) of bulk corn stover particles prepared to four particle sizes (chopped and particles screened through 6.4, 3.2 and 1.6 mm) at two moisture contents (dry, < 10% and wet, > 20%). The results show that particles size and feedstock moisture content were important variables that affected the angle of repose for all three angle of repose methods (piling AoR loose-base, piling AoR fixed-base and sliding AoR) investigated. In general, increasing moisture content and particle size increased the piling AoR (loose-base), piling AoR (fixed-base) and sliding angle of repose. Characterization of the flow behavior of bulk corn stover particles using the piling AoR (loose-base) and comparison with three granular bulk solids of biological origin (corn, soybean and distillers dried grains with solubles, DDGS) indicated that dry and wet stover particles of the particle size ranges tested in this study have a poor flow behavior.