Performance of three delignifying pretreatments on hardwoods [electronic resource] : hydrolysis yields, comprehensive mass balances, and lignin properties.
<p>Background: </p><p>In this work, three pretreatments under investigation at the DOE Bioenergy Research Centers (BRCs) were subjected to a side-by-side comparison to assess their performance on model bioenergy hardwoods (a eucalyptus and a hybrid poplar). These include co-solven...
Saved in:
| Online Access: |
Full Text (via OSTI) |
|---|---|
| Corporate Author: | |
| Format: | Electronic eBook |
| Language: | English |
| Published: |
Berkeley, Calif. : Oak Ridge, Tenn. :
Lawrence Berkeley National Laboratory ; Distributed by the Office of Scientific and Technical Information, U.S. Department of Energy,
2019.
|
| Subjects: |
| Summary: | <p>Background: </p><p>In this work, three pretreatments under investigation at the DOE Bioenergy Research Centers (BRCs) were subjected to a side-by-side comparison to assess their performance on model bioenergy hardwoods (a eucalyptus and a hybrid poplar). These include co-solvent-enhanced lignocellulosic fractionation (CELF), pretreatment with an ionic liquid using potentially biomass-derived components (cholinium lysinate or [Ch][Lys]), and two-stage Cu-catalyzed alkaline hydrogen peroxide pretreatment (Cu-AHP). For each of the feedstocks, the pretreatments were assessed for their impact on lignin and xylan solubilization and enzymatic hydrolysis yields as a function of enzyme loading. Lignins recovered from the pretreatments were characterized for polysaccharide content, molar mass distributions, ?-aryl ether content, and response to depolymerization by thioacidolysis. </p><p> Results: </p><p>All three pretreatments resulted in significant solubilization of lignin and xylan, with the CELF pretreatment solubilizing the majority of both biopolymer categories. Enzymatic hydrolysis yields were shown to exhibit a strong, positive correlation with the lignin solubilized for the low enzyme loadings. The pretreatment-derived solubles in the [Ch][Lys]-pretreated biomass were presumed to contribute to inhibition of enzymatic hydrolysis in the eucalyptus as a substantial fraction of the pretreatment liquor was carried forward into hydrolysis for this pretreatment. The pretreatment-solubilized lignins exhibited significant differences in polysaccharide content, molar mass distributions, aromatic monomer yield by thioacidolysis, and ?-aryl ether content. Key trends include a substantially higher polysaccharide content in the lignins recovered from the [Ch][Lys] pretreatment and high ?-aryl ether contents and aromatic monomer yields from the Cu-AHP pretreatment. For all lignins, the <sup>13</sup>C NMR-determined ?-aryl ether content was shown to be correlated with the monomer yield with a second-order functionality. </p><p>Conclusions: </p><p>Overall, it was demonstrated that the three pretreatments highlighted in this study demonstrated uniquely different functionalities in reducing biomass recalcitrance and achieving higher enzymatic hydrolysis yields for the hybrid poplar while yielding a lignin-rich stream that may be suitable for valorization. Furthermore, modification of lignin during pretreatment, particularly cleavage of ?-aryl ether bonds, is shown to be detrimental to subsequent depolymerization.</p> |
|---|---|
| Item Description: | Published through Scitech Connect. 09/09/2019. "Journal ID: ISSN 1754-6834" "Other: ark:/13030/qt4195t2c0" Bhalla, Aditya ; Cai, Charles M. ; Xu, Feng ; Singh, Sandip K. ; Bansal, Namita ; Phongpreecha, Thanaphong ; Dutta, Tanmoy ; Foster, Cliff E. ; Kumar, Rajeev ; Simmons, Blake A. ; Singh, Seema ; Wyman, Charles E. ; Hegg, Eric L. ; Hodge, David B. ; USDOE Office of Science (SC), Biological and Environmental Research (BER) (SC-23) |
| Physical Description: | Size: Article No. 213 (2019) : digital, PDF file. |