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Title: The effect of biomass densification on structural sugar release and yield in biofuel feedstock and feedstock blends

In this work, we examined the behavior of feedstock blends and the effect of a specific feedstock densification strategy (pelleting) on the release and yield of structural carbohydrates in a laboratory-scale dilute acid pretreatment (PT) and enzymatic hydrolysis (EH) assay. We report overall carbohydrate release and yield from the two-stage PT-EH assay for five single feedstocks (two corn stovers, miscanthus, switchgrass, and hybrid poplar) and three feedstock blends (corn stover-switchgrass, corn stover-switchgrass-miscanthus, and corn stover-switchgrass-hybrid poplar). We first examined the experimental results over time to establish the robustness of the PT-EH assay, which limits the precision of the experimental results. The use of two different control samples in the assay enabled us to identify (and correct for) a small bias in the EH portion of the combined assay for some runs. We then examined the effect of variable pretreatment reaction conditions (residence time, acid loading, and reactor temperature) on the conversion of a single feedstock (single-pass corn stover, CS-SP) in order to establish the range of pretreatment reaction conditions likely to provide optimal conversion data. Finally, we applied the assay to the 16 materials (8 feedstocks in 2 formats, loose and pelleted) over a more limited range of pretreatment experimentalmore » conditions. The four herbaceous feedstocks behaved similarly, while the hybrid poplar feedstock required higher pretreatment temperatures for optimal results. As expected, the yield data for three blended feedstocks were the average of the yield data for the individual feedstocks. As a result, the pelleting process appears to provide a slightly positive effect on overall total sugar yield.« less
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  1. National Renewable Energy Lab. (NREL), Golden, CO (United States)
  2. Idaho National Lab. (INL), Idaho Falls, ID (United States)
Publication Date:
Report Number(s):
NREL/JA-5100-67906; INL/JOU-16-39719
Journal ID: ISSN 1939-1234
Grant/Contract Number:
AC36-08GO28308; AC07-05ID14517
Published Article
Journal Name:
BioEnergy Research
Additional Journal Information:
Journal Volume: 10; Journal Issue: 2; Journal ID: ISSN 1939-1234
Research Org:
National Renewable Energy Lab. (NREL), Golden, CO (United States); Idaho National Lab. (INL), Idaho Falls, ID (United States)
Sponsoring Org:
USDOE Office of Energy Efficiency and Renewable Energy (EERE), Bioenergy Technologies Office (EE-3B)
Country of Publication:
United States
09 BIOMASS FUELS; biomass feedstocks; pelleting; densification; recalcitrance; pretreatment; enzymatic hydrolysis; response surface
OSTI Identifier:
Alternate Identifier(s):
OSTI ID: 1356882; OSTI ID: 1367540