Abstract
Lignin is an abundant biopolymer and a promising source of feedstock for high-value chemicals and materials. This study aims to characterize the lignin-rich endocarp biomass and identify features of this unique feedstock that are relevant to feedstock preprocessing and logistics. The chemical composition and cellular structure of walnut and peach endocarps were characterized using HPLC and scanning electron microscopy (SEM) imaging. Mechanical properties of the endocarps were investigated using nanoindentation. Mechanical tests revealed hardness values of up to 0.48 and 0.40 GPa for walnut and peach endocarps, respectively. With screen sizes of 1 and 2 mm, the specific energy consumption was 9.21 and 1.86 MJ kg-1 for walnut and 12.6 and 2.72 MJ kg-1 for peach, respectively, as determined using a knife mill. Milling energy consumption was correlated to screen size, lignin content, bulk density, and mechanical properties. This study provides critical information on feedstock supply logistics necessary to implement a novel feedstock in biorefineries and evaluate the economic feasibility for coproduction of biofuels and lignin-derived products.
Original language | English |
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Pages (from-to) | 67-74 |
Number of pages | 8 |
Journal | Journal of the ASABE |
Volume | 65 |
Issue number | 1 |
DOIs | |
State | Published - 2022 |
Externally published | Yes |
Funding
This work was supported by the USDA National Institute of Food and Agriculture (NIFA) Sustainability Challenge Area Grant and Multistate Grant S1075 under Accession Nos. 1015068 and 1018315, respectively. We thank Ryan Hill and Dr. Dingying Dang of the Department of Chemical and Materials Engineering at the University of Kentucky for their technical assistance with the nanoindentation measurements.
Keywords
- Biomass feedstock
- Lignin
- Mechanical properties
- Nanoindentation
- Size reduction