Biomass Recalcitrance in Willow Under Two Biological Conversion Paradigms: Enzymatic Hydrolysis and Anaerobic Digestion

Journal Article · 07 December 2019 · BioEnergy Research

DOI: https://doi.org/10.1007/s12155-019-10079-6 · OSTI ID:1659772

Ware, Anne ^[1]; Ohlsson, Jonas A. ^[2]; Sandgren, Mats ^[2]; Schnurer, Anna ^[2]

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1. National Renewable Energy Lab. (NREL), Golden, CO (United States). Biosciences Center, Center for Bioenergy Innovation
2. Swedish Univ. of Agricultural Sciences, Uppsala (Sweden)

Biomass recalcitrance, the inherent resistance of plants towards deconstruction, negatively affects the viability of biorefineries. This trait is not only dictated by the properties of the biomass but also by the conversion system used and its interactions with specific features of the biomass. Here, biomass recalcitrance to anaerobic digestion (AD) was assessed using a biomethanation potential (BMP) assay. Plant material (n = 94) was selected from a large population of natural Salix viminalis accessions, previously evaluated for biomass recalcitrance using hydrothermal pretreatment-enzymatic hydrolysis. Correlations between yields from the two biological conversion systems were evaluated, as well as the influence of biomass compositional features, analyzed by pyrolysis-molecular beam mass spectrometry (py-MBMS), and other biomass physical properties on conversion performance. BMP values averaged 198.0 Nml CH₄/g biomass after 94 days, ranging from 28.6 to 245.9. S lignin and carbohydrate-derived spectral features were positively correlated with performance under both systems, whereas G lignin, p-coumaric acid, and ferulic acid-derived ions were negatively correlated with yields and rates. Most spectral features were more strongly correlated with enzymatic hydrolysis yields compared to methane production. For early-stage methane production and rate, recalcitrance factors were similar compared to enzymatic hydrolysis, with weaker correlations observed at later timepoints. The results suggest that although variation in methane potential was considerably lower than enzymatic hydrolysis yields, a reduced recalcitrance under this system will still be of importance to improve early conversion rates. Spectral features of low methane-producing samples indicate the presence of inhibitory substances, warranting further study.

• Research Organization: National Renewable Energy Laboratory (NREL), Golden, CO (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Biological and Environmental Research (BER); Swedish Research Council (SRC)
• Grant/Contract Number: AC36-08GO28308
• OSTI ID: 1659772
• Report Number(s): NREL/JA-2700-74548; MainId:19430; UUID:97c1f8f4-4db9-e911-9c24-ac162d87dfe5; MainAdminID:7908
• Journal Information: BioEnergy Research, Vol. 13; ISSN 1939-1234
• Publisher: SpringerCopyright Statement
• Country of Publication: United States
• Language: English