Lignins Isolated via Catalyst-Free Organosolv Pulping from Miscanthus x giganteus, M. sinensis, M. robustus and M. nagara: A Comparative Study
- As a low-input crop, Miscanthus offers numerous advantages that, in addition to agricultural applications, permits its exploitation for energy, fuel, and material production. Depending on the Miscanthus genotype, season, and harvest time as well as plant component (leaf versus stem), correlations between structure and properties of the corresponding isolated lignins differ. Here, a comparative study is presented between lignins isolated from M. x giganteus, M. sinensis, M. robustus and M. nagara using a catalyst-free organosolv pulping process. The lignins from different plant constituents are also compared regarding their similarities and differences regarding monolignol ratio and important linkages. Results showed that the plant genotype has the weakest influence on monolignol content and interunit linkages. In contrast, structural differences are more significant among lignins of different harvest time and/or season. Analyses were performed using fast and simple methods such as nuclear magnetic resonance (NMR) spectroscopy. Data was assigned to four different linkages (A: β-O-4 linkage, B: phenylcoumaran, C: resinol, D: β-unsaturated ester). In conclusion, A content is particularly high in leaf-derived lignins at just under 70% and significantly lower in stem and mixture lignins at around 60% and almost 65%. The second most common linkage pattern is D in all isolated lignins, the proportion of which is also strongly dependent on the crop portion. Both stem and mixture lignins, have a relatively high share of approximately 20% or more (maximum is M. sinensis Sin2 with over 30%). In the leaf-derived lignins, the proportions are significantly lower on average. Stem samples should be chosen if the highest possible lignin content is desired, specifically from the M. x giganteus genotype, which revealed lignin contents up to 27%. Due to the better frost resistance and higher stem stability, M. nagara offers some advantages compared to M. x giganteus. Miscanthus crops are shown to be very attractive lignocellulose feedstock (LCF) for second generation biorefineries and lignin generation in Europe.
Document Type: | Article |
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Language: | English |
Author: | Michel Bergs, Yulia Monakhova, Bernd W. Diehl, Christopher Konow, Georg Völkering, Ralf Pude, Margit Schulze |
Parent Title (English): | Molecules |
Volume: | 26 |
Issue: | 4 |
Article Number: | 842 |
Number of pages: | 21 |
ISSN: | 1420-3049 |
URN: | urn:nbn:de:hbz:1044-opus-53259 |
DOI: | https://doi.org/10.3390/molecules26040842 |
PMID: | https://pubmed.ncbi.nlm.nih.gov/33562747 |
Publisher: | MDPI |
Place of publication: | Basel |
Publishing Institution: | Hochschule Bonn-Rhein-Sieg |
Date of first publication: | 2021/02/05 |
Copyright: | © 2021 by the authors. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license. |
Funding: | Funding: This project was funded by the BMBF program “IngenieurNachwuchs” project “LignoBau” (03FH013IX4) and BioSC project “Miscanthus Cascade Utilization” (NRW state ministry for research). |
Keyword: | Lignin; Miscanthus nagara; Miscanthus robustus; Miscanthus sinensis; Miscanthus x giganteus; low-input crops; monolignol ratio |
Departments, institutes and facilities: | Fachbereich Angewandte Naturwissenschaften |
Projects: | LignoBau - IngenieurNachwuchs 2014: Lignin-basierte Polymere für bauchemische Anwendungen (DE/BMBF/03FH013IX4,13FH013IX4) |
Dewey Decimal Classification (DDC): | 5 Naturwissenschaften und Mathematik / 57 Biowissenschaften; Biologie / 570 Biowissenschaften; Biologie |
Entry in this database: | 2021/02/09 |
Licence (German): | Creative Commons - CC BY - Namensnennung 4.0 International |