Physical characteristics of ground switchgrass related to bulk solids flow

Switchgrass has potential as an energy crop, but problems with handling and flowability hinders its utilization. The primary objective of this study was to investigate the fundamental flow-related physical characteristics of switchgrass particles ground through three hammermill screen sizes of 6.4, 3.2 and 1.6 mm. Physical properties were determined through sieve analysis, density testing, image analysis, angle of repose and fractal analysis. The geometric mean diameter and geometric standard deviation of the ground material decreased with size reduc-tion. Particle size significantly influenced particle and bulk density. Similar conclusions were made for angle of repose; values decreased with size reduction. Shape and surface parameters from image and fractal analyses were not significantly different among particle sizes. Non-spherical, needle-shaped particles were maintained through size reduction. Particle size reduction may slightly improve the flow of ground switchgrass bulk, but will always experience some degree of flow problems in regular storage silos and hoppers. (c) 2021 Elsevier B.V. All rights reserved.

Automated summary

This study investigated the physical properties of switchgrass particles of different sizes, and found that particle size significantly influenced density, angle of repose, as well as shape and surface parameters.