Characterization of oat husk soda lignin from a Finnish biorefinery process
Year: 2025
Type: article
Abstract: Oat husks, a by-product of oat processing for food production, serve as a valuable source of lignin due to their high lignin content (~25%). Despite the abundance, detailed insights into the fundamental chemical structure remain limited. This study investigated the structure and properties of lignin derived from a Finnish biorefinery process utilizing BIOFORSENSE® technology. This technology produces lignin in high yield and with a molecular weight of approximately 5500 g/mol. NMR analyses revealed that the lignin extracted from the oat husk (OHLN) black liquor contained guaiacyl-syringyl (GS)-type units along with H units, comprising 48%, 36%, and 15% of the total monolignols, respectively. Analysis of inter-unit linkages indicated a relatively low β-O-4 content (8.6 per 100 aromatic units). Phenolic hydroxyl content was 4.83 mmol/g. Additionally, a more comprehensive study by ¹³C NMR, combined with HSQC, DEPT-135 and DEPTQ, provided a more accurate measurement of S, G, and H units as well as the degree of condensation, comparable to those obtained via ³¹P NMR. Further characterization by thermogravimetric analysis (TGA) displayed a significant weight loss occurring above 200°C. Overall, this study provided valuable insights into the structural and chemical properties of oat husk lignin, highlighting its potential as a sustainable raw material for various applications.
Source: Biomass and Bioenergy
Institution: Åbo Akademi University
Language: English
Topic: Lignin and Wood Chemistry
Subfield: Biomedical Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $4,270
Funders: Tekes, Business Finland
Award: G7246118595
OpenAlex ID: W4415478611