Energy consumption of biomass bulk densification

Corn Stover and switchgrass were used for a bulk compression study to determine their compressibility and energy consumption associated with different levels of volume reduction. Each of these crops was compressed in three sizes of chambers. The bottom areas of these chambers were 10.5 in X 12 in, 8 in X 8 in, and 5.5 in X 6 in, respectively. These dimensions are to simulate 1/2, 1/4, and 1/8 of the bottom area of a standard small square bale. And the heights of chamber are 8in, 11 in, 16in respectively. The chamber size, particle size, and harvest time were considered as factors, which may impact the compression energy consumption. Suggested volume reduction of compressing bales was 60%. If volume reduction is greater than 60%, the increasing rate of specific energy consumption would be much greater than the increase in bulk density.