Measurement and comparison of mechanical properties of ground corn stover, switchgrass, and willow and their pellet qualities

Apoorva Karamchandani, Hojae Yi, Virendra Puri

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

Corn stover, switchgrass, and willow are promising bioenergy crops, which are found in abundance in the Northeast region of the U.S. In this study, mechanical properties of ground corn stover, switchgrass, and willow are measured and compared in addition to the quality of pellets formed. Size reduction was performed with two different screen sizes (3.175 mm and 6.35 mm) and conditioned to obtain biomass at two different moisture contents (17.5% and 20% on wet basis). Physical properties included bulk density, particle density, and particle size distribution. Ground switchgrass has the smallest D50, whereas, willow has the highest D50, when size reduced with the same screen size. Hydrostatic triaxial compression (HTC) tests were performed using the Cubical Triaxial Tester (CTT) to determine the various mechanical properties. Bulk modulus for the three materials at four conditions at specific unloading pressures (20, 45, 70, and 95 kPa) was determined. Durability, pellet density, axial compressive strength, and diametral tensile strength were the indicators of pellet quality. Willow, size-reduced with 3.175 mm screen size at 17.5% w.b., has the highest bulk modulus among different conditions of all three biomass. The diametral tensile strength is 4-5.8 MPa for corn stover, 0.9-3.8 MPa for switchgrass and 0.8-5.7 MPa for willow pellets, respectively. Axial compressive strength is 8-11.5 MPa for corn stover, 0.8-5.7 MPa for switchgrass and 1.5-8.5 MPa for willow pellets, respectively. Corn stover pellets formed with 3.175 mm screen size at 20% w.b. has the highest diametral tensile and axial compressive strengths among different conditions for all three biomass. Pellet durability for all three materials is more than 80%.

Original languageEnglish (US)
Title of host publicationAmerican Society of Agricultural and Biological Engineers Annual International Meeting 2014, ASABE 2014
PublisherAmerican Society of Agricultural and Biological Engineers
Pages727-731
Number of pages5
ISBN (Electronic)9781632668455
StatePublished - Jan 1 2014
EventAmerican Society of Agricultural and Biological Engineers Annual International Meeting 2014, ASABE 2014 - Montreal, Canada
Duration: Jul 13 2014Jul 16 2014

Publication series

NameAmerican Society of Agricultural and Biological Engineers Annual International Meeting 2014, ASABE 2014
Volume1

Other

OtherAmerican Society of Agricultural and Biological Engineers Annual International Meeting 2014, ASABE 2014
CountryCanada
CityMontreal
Period7/13/147/16/14

All Science Journal Classification (ASJC) codes

  • Agricultural and Biological Sciences(all)
  • Mechanical Engineering

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