Alkaline deacetylation has emerged as a promising chemistry for pretreatments performed prior to enzymatic saccharification of lignocellulosic biomass. This process avoids complex pressurized reactors and opens new opportunities for lignin covalorization. In this work, we evaluate the chemical and morphological response of sugar cane bagasse and straw submitted to alkaline treatments. Alkaline solutions for deacetylation (0.4% w/w NaOH, 70 degrees C, 3 h) as well as proximal conditions (0.1-0.7% NaOH, 55-85 degrees C, 1-5 h) chosen by 23 experimental design were evaluated. The deacetylation treatment removes ~90% of the acetyl groups and 20-30% of the lignin from both bagasse and straw, while removal of ~20% of the xylan and glucan is observed in straw, but not in bagasse. Considering nanoscale structural alterations, neither cellulose cocrystallization (evaluated by X-ray diffraction) nor formation of lignin aggregates (evaluated by thermoporometric signature) are observed after the alkaline conditions, in contrast to observations after hydrothermal treatments. Furthermore, calorimetric thermoporometry as well as scanning and transmission electron microscopies show substantial introduction of nanoscale porosity and loosening of the tissue and cell wall structures, indicating desirable mechanical weakening and gains in enzyme accessibility. These results provide fundamental and practical knowledge for biorefineries based on alkaline deacetylation of sugar cane bagasse and straw.
Lima, Cleilton S., Rabelo, Sarita C., Ciesielski, Peter N., Roberto, Ines C., Rocha, George J. M., & Driemeier, Carlos (2018). Multiscale Alterations in Sugar Cane Bagasse and Straw Submitted to Alkaline Deacetylation. ACS Sustainable Chemistry & Engineering, 6(3). https://doi.org/10.1021/acssuschemeng.7b04158
@article{osti_1430818,
author = {Lima, Cleilton S. and Rabelo, Sarita C. and Ciesielski, Peter N. and Roberto, Ines C. and Rocha, George J. M. and Driemeier, Carlos},
title = {Multiscale Alterations in Sugar Cane Bagasse and Straw Submitted to Alkaline Deacetylation},
annote = {Alkaline deacetylation has emerged as a promising chemistry for pretreatments performed prior to enzymatic saccharification of lignocellulosic biomass. This process avoids complex pressurized reactors and opens new opportunities for lignin covalorization. In this work, we evaluate the chemical and morphological response of sugar cane bagasse and straw submitted to alkaline treatments. Alkaline solutions for deacetylation (0.4% w/w NaOH, 70 degrees C, 3 h) as well as proximal conditions (0.1-0.7% NaOH, 55-85 degrees C, 1-5 h) chosen by 23 experimental design were evaluated. The deacetylation treatment removes ~90% of the acetyl groups and 20-30% of the lignin from both bagasse and straw, while removal of ~20% of the xylan and glucan is observed in straw, but not in bagasse. Considering nanoscale structural alterations, neither cellulose cocrystallization (evaluated by X-ray diffraction) nor formation of lignin aggregates (evaluated by thermoporometric signature) are observed after the alkaline conditions, in contrast to observations after hydrothermal treatments. Furthermore, calorimetric thermoporometry as well as scanning and transmission electron microscopies show substantial introduction of nanoscale porosity and loosening of the tissue and cell wall structures, indicating desirable mechanical weakening and gains in enzyme accessibility. These results provide fundamental and practical knowledge for biorefineries based on alkaline deacetylation of sugar cane bagasse and straw.},
doi = {10.1021/acssuschemeng.7b04158},
url = {https://www.osti.gov/biblio/1430818},
journal = {ACS Sustainable Chemistry & Engineering},
issn = {ISSN 2168-0485},
number = {3},
volume = {6},
place = {United States},
publisher = {American Chemical Society (ACS)},
year = {2018},
month = {01}}
National Renewable Energy Laboratory (NREL), Golden, CO (United States); Energy Frontier Research Centers (EFRC) (United States). Center for Direct Catalytic Conversion of Biomass to Biofuels (C3Bio)
Sponsoring Organization:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Journal Article
·
Sat Dec 31 23:00:00 EST 1988
· Journal of Environmental Science and Health, Part B: Pesticides, Food Contaminants, and Agricultural Wastes; (USA)
·OSTI ID:5658367