Oxidative Depolymerization of Kraft Lignin for Microbial Conversion
Abdelaziz, Omar Y. LU ; Ravi, Krithika LU ; Mittermeier, Fabian ; Meier, Sebastian ; Riisager, Anders ; Lidén, Gunnar LU and Hulteberg, Christian P. LU
(2019)
In ACS Sustainable Chemistry and Engineering
7(13).
p.11640-11652
- Abstract
The valorization of lignin is being increasingly recognized as crucial to improve the economic viability of integrated biorefineries. Because of its inherent heterogeneity and recalcitrance, lignin has been treated as a waste product in the pulp and paper industry, but new technologies are now being explored to transform lignin into a sustainable resource and enhance its value chain. In the present study, alkaline oxidative depolymerization was investigated as a potential form of pretreatment to enable further biological conversion of LignoBoost kraft lignin (LB). LB lignin oxidation reactions were studied at various temperatures (120-200 °C) and O2 partial pressures (3-15 bar) to identify the optimal conditions for obtaining... (More)
The valorization of lignin is being increasingly recognized as crucial to improve the economic viability of integrated biorefineries. Because of its inherent heterogeneity and recalcitrance, lignin has been treated as a waste product in the pulp and paper industry, but new technologies are now being explored to transform lignin into a sustainable resource and enhance its value chain. In the present study, alkaline oxidative depolymerization was investigated as a potential form of pretreatment to enable further biological conversion of LignoBoost kraft lignin (LB). LB lignin oxidation reactions were studied at various temperatures (120-200 °C) and O2 partial pressures (3-15 bar) to identify the optimal conditions for obtaining a biocompatible, oxidatively depolymerized lignin (ODLB) stream. The low molecular weight compounds resulting from this treatment consisted mainly of aromatic monomers and carboxylic acids. The highest yield of aromatic monomers, 3 wt %, was obtained at 160 °C and 3 bar O2. The yield of carboxylic acids increased with both increasing temperature and O2 pressure, exceeding 13% under the harshest conditions investigated. The growth of four aromatic-catabolizing bacterial strains was examined on reaction product mixtures, all of which showed growth on agar plates utilizing ODLB as the sole source of carbon and energy. Rhodococcus opacus and Sphingobium sp. SYK-6 were found to consume most of the aromatic monomers present in the ODLB (e.g., vanillin, vanillate, acetovanillone, and guaiacol). The findings of this study indicate that pretreatment by oxidative depolymerization has potential in the biological valorization of technical lignin streams, for the production of valuable chemicals and materials.
(Less)
- author
- Abdelaziz, Omar Y.
LU
; Ravi, Krithika
LU
; Mittermeier, Fabian
; Meier, Sebastian
; Riisager, Anders
; Lidén, Gunnar
LU
and Hulteberg, Christian P.
LU
- organization
- publishing date
- 2019
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Alkaline oxidation, Aromatic monomers, Bacterial conversion, Lignin valorization, LignoBoost, Softwood, Sustainable resources
- in
- ACS Sustainable Chemistry and Engineering
- volume
- 7
- issue
- 13
- pages
- 13 pages
- publisher
- The American Chemical Society (ACS)
- external identifiers
-
- scopus:85067959986
- ISSN
- 2168-0485
- DOI
- 10.1021/acssuschemeng.9b01605
- language
- English
- LU publication?
- yes
- id
- c75c17a1-f8a6-47af-b28e-19c9e3b7524c
- date added to LUP
- 2019-07-11 09:18:40
- date last changed
- 2024-01-16 07:00:32
@article{c75c17a1-f8a6-47af-b28e-19c9e3b7524c,
abstract = {{<p>The valorization of lignin is being increasingly recognized as crucial to improve the economic viability of integrated biorefineries. Because of its inherent heterogeneity and recalcitrance, lignin has been treated as a waste product in the pulp and paper industry, but new technologies are now being explored to transform lignin into a sustainable resource and enhance its value chain. In the present study, alkaline oxidative depolymerization was investigated as a potential form of pretreatment to enable further biological conversion of LignoBoost kraft lignin (LB). LB lignin oxidation reactions were studied at various temperatures (120-200 °C) and O<sub>2</sub> partial pressures (3-15 bar) to identify the optimal conditions for obtaining a biocompatible, oxidatively depolymerized lignin (ODLB) stream. The low molecular weight compounds resulting from this treatment consisted mainly of aromatic monomers and carboxylic acids. The highest yield of aromatic monomers, 3 wt %, was obtained at 160 °C and 3 bar O<sub>2</sub>. The yield of carboxylic acids increased with both increasing temperature and O<sub>2</sub> pressure, exceeding 13% under the harshest conditions investigated. The growth of four aromatic-catabolizing bacterial strains was examined on reaction product mixtures, all of which showed growth on agar plates utilizing ODLB as the sole source of carbon and energy. Rhodococcus opacus and Sphingobium sp. SYK-6 were found to consume most of the aromatic monomers present in the ODLB (e.g., vanillin, vanillate, acetovanillone, and guaiacol). The findings of this study indicate that pretreatment by oxidative depolymerization has potential in the biological valorization of technical lignin streams, for the production of valuable chemicals and materials.</p>}},
author = {{Abdelaziz, Omar Y. and Ravi, Krithika and Mittermeier, Fabian and Meier, Sebastian and Riisager, Anders and Lidén, Gunnar and Hulteberg, Christian P.}},
issn = {{2168-0485}},
keywords = {{Alkaline oxidation; Aromatic monomers; Bacterial conversion; Lignin valorization; LignoBoost; Softwood; Sustainable resources}},
language = {{eng}},
number = {{13}},
pages = {{11640--11652}},
publisher = {{The American Chemical Society (ACS)}},
series = {{ACS Sustainable Chemistry and Engineering}},
title = {{Oxidative Depolymerization of Kraft Lignin for Microbial Conversion}},
url = {{http://dx.doi.org/10.1021/acssuschemeng.9b01605}},
doi = {{10.1021/acssuschemeng.9b01605}},
volume = {{7}},
year = {{2019}},
}