TY - JOUR
T1 - Energy requirement for comminution of biomass in relation to particle physical properties
AU - Miao, Z.
AU - Grift, T. E.
AU - Hansen, A. C.
AU - Ting, K. C.
N1 - Funding Information:
This study was funded by BP p.l.c. through the Energy Biosciences Institute (EBI) within a program titled “Engineering Solutions for Biomass Feedstock Production”. The authors would like to thank Professors Poo Chow, Vijay Singh, and Mr. Steve Ford for providing grinding machines and setting up the energy measurement equipment. The authors are grateful to Mr. Tim Mies, Mr. Chris Rudisill, Dr. Scott Bretthauer and Dr. Tom Voigt for providing Miscanthus, switchgrass, willow and energy cane samples. Thanks are due to students Ethan Ford, Jesse J Woodruff and Sebastian Witkowski for conducting size reduction experiments.
PY - 2011/3
Y1 - 2011/3
N2 - The energy requirement for biomass comminution and the resulting particle physical properties are important factors to study logistic components, select equipment, and assess the overall efficiency of feedstock supply-conversion chain. In this study, mechanical size reduction of Miscanthus (Miscanthus giganteus), switchgrass (Panicum virgatum), willow (Salix babylonica), and energy cane (Saccharum spp.) was carried out using a commercial-scale hammer mill, a bench-scale Retsch SM2000 knife mill and a Retsch SK100 hammer mill. The results showed that the specific energy consumption of biomass comminution and the aperture sizes of the milling screens were related in power-law forms. Biomass moisture significantly influenced comminution energy consumption, especially for finer size reduction. Given a specific milling screen, the Retsch SK100 hammer mill was found more energy efficient than the SM2000 knife mill. This was mainly attributed to the higher motor speed and axial feeding mechanism of the hammer mill. The particle sizes after comminution were found inversely proportional to the bulk densities of all four energy crops used in experiments. In addition, the comminution ratio, being the ratio of the final mean particle size and the original mean particle size, was proportional to energy consumption for all four energy crops. The bulk densities for 4-mm and smaller Miscanthus and switchgrass particles were higher than those of the original bale. Particle size and surface area estimates using commonly used ANSI/ASAE Standards S424.1 and 319.4 were highly sensitive to particle size distributions and shapes. Further studies on standardization of particle size and surface area estimates are needed.
AB - The energy requirement for biomass comminution and the resulting particle physical properties are important factors to study logistic components, select equipment, and assess the overall efficiency of feedstock supply-conversion chain. In this study, mechanical size reduction of Miscanthus (Miscanthus giganteus), switchgrass (Panicum virgatum), willow (Salix babylonica), and energy cane (Saccharum spp.) was carried out using a commercial-scale hammer mill, a bench-scale Retsch SM2000 knife mill and a Retsch SK100 hammer mill. The results showed that the specific energy consumption of biomass comminution and the aperture sizes of the milling screens were related in power-law forms. Biomass moisture significantly influenced comminution energy consumption, especially for finer size reduction. Given a specific milling screen, the Retsch SK100 hammer mill was found more energy efficient than the SM2000 knife mill. This was mainly attributed to the higher motor speed and axial feeding mechanism of the hammer mill. The particle sizes after comminution were found inversely proportional to the bulk densities of all four energy crops used in experiments. In addition, the comminution ratio, being the ratio of the final mean particle size and the original mean particle size, was proportional to energy consumption for all four energy crops. The bulk densities for 4-mm and smaller Miscanthus and switchgrass particles were higher than those of the original bale. Particle size and surface area estimates using commonly used ANSI/ASAE Standards S424.1 and 319.4 were highly sensitive to particle size distributions and shapes. Further studies on standardization of particle size and surface area estimates are needed.
KW - Bioenergy
KW - Energy crops
KW - Mechanical size reduction
KW - Specific energy consumption
UR - http://www.scopus.com/inward/record.url?scp=78651481938&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=78651481938&partnerID=8YFLogxK
U2 - 10.1016/j.indcrop.2010.12.016
DO - 10.1016/j.indcrop.2010.12.016
M3 - Article
AN - SCOPUS:78651481938
SN - 0926-6690
VL - 33
SP - 504
EP - 513
JO - Industrial Crops and Products
JF - Industrial Crops and Products
IS - 2
ER -