Title: Discrete element modeling of switchgrass particles under compression and rotational shear

Abstract

Switchgrass is a perennial herbaceous plant regarded as a biomass energy crop in the United States for its highadaptability and yield potential. Processing and handling of switchgrass particles are challenging due to the erratic mechanical and flow behavior originating from their intrinsic particulate properties. Here, we present a bonded-sphere discrete element model designed specifically for switchgrass particles. The model simultaneously captures three key particulate features, i.e., fibrous particle shapes, a wide range of particle sizes, and particle deformability. Realistic yet computationally efficient particle shape templates are created based on the image analysis data of switchgrass specimens. A fitting procedure is proposed to ensure both the particle width and length distributions are captured, a unique requirement for fibrous particles. Two full-scale numerical models, i.e., a uniaxial compression model and a Schulze ring shear model, are developed using information fromphysical experiments. The model is calibrated using experimental data of chopped-small switchgrass specimens, and then, is validated using data of chopped-large specimens in both compression and ring-shear tests. Numerical results show that the numerical models capture bulk densities accurately (with an error of 3%) while slightly underestimate the bulk friction angle. Furthermore, an extensive sensitivity analysis reveals that (1) switchgrass particles with roughermore » edges (due to different processing techniques) exhibit a higher shear strength and a lower flowability; (2) stiffer particles yield a lower bulk density (up to 21% lower) compared to more deformable particles, indicating particle deformability should be incorporated when modeling biomass flow in a preprocessing system.« less

Authors:

Guo, Yuan  ^[1];

• Search DOE PAGES for author "Guo, Yuan"
• Search DOE PAGES for ORCID "0000-0002-0006-2784"

Chen, Qiushi  ^[2];

• Search DOE PAGES for author "Chen, Qiushi"
• Search DOE PAGES for ORCID "0000-0002-0394-6710"

Xia, Yidong  ^[3];

• Search DOE PAGES for author "Xia, Yidong"
• Search DOE PAGES for ORCID "0000-0002-1955-7330"

Westover, Tyler L.  ^[3];

• Search DOE PAGES for author "Westover, Tyler L."
• Search DOE PAGES for ORCID "0000-0001-7828-8436"

Roni, Mohammad Sadekuzzaman  ^[3];

• Search DOE PAGES for author "Roni, Mohammad Sadekuzzaman"
• Search DOE PAGES for ORCID "0000-0001-7114-9820"

Eksioglu, Sandra ^[4]

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+ Show Author Affiliations

1. Clemson University, SC (United States); Idaho National Laboratory (INL), Idaho Falls, ID (United States)
2. Clemson University, SC (United States)
3. Idaho National Laboratory (INL), Idaho Falls, ID (United States)
4. University of Arkansas, Fayetteville, AR (United States)

Publication Date:

Fri Aug 21 00:00:00 EDT 2020

Research Org.:

Idaho National Laboratory (INL), Idaho Falls, ID (United States); Idaho National Lab. (INL), Idaho Falls, ID (United States)

Sponsoring Org.:

USDOE Office of Energy Efficiency and Renewable Energy (EERE), Transportation Office. Bioenergy Technologies Office; USDOE Office of Energy Efficiency and Renewable Energy (EERE), Sustainable Transportation Office. Bioenergy Technologies Office (BETO)

OSTI Identifier:

1897464

Alternate Identifier(s):

OSTI ID: 1648609; OSTI ID: 1656734

Report Number(s):

INL/JOU-19-56073
Journal ID: ISSN 0961-9534

Grant/Contract Number:  

EE0008255; AC07-05ID14517

Resource Type:

Accepted Manuscript

Journal Name:

Biomass and Bioenergy

Additional Journal Information:

Journal Volume: 141; Journal ID: ISSN 0961-9534

Publisher:

Elsevier

Country of Publication:

United States

Language:

English

Subject:

09 BIOMASS FUELS; 97 MATHEMATICS AND COMPUTING; 36 MATERIALS SCIENCE; biomass preprocessing; discrete element method; switchgrass; irregular shape; deformable particles; ring shear test; mechanical properties; 09 - BIOMASS FUELS; 97 - MATHEMATICS AND COMPUTING; 36 - MATERIALS SCIENCE