Tracing Sweetgum Lignin's Molecular Properties through Biorefinery Processing
Xiao Jiang1, Robert H Narron1, Qiang Han1
1Department of Forest Biomaterials, North Carolina State University, Campus Box 8005, Raleigh, NC, 27695, USA.
Chemsuschem
|May 27, 2020
Summary
Biorefinery processing of sweetgum lignin causes both degradation and condensation. Soluble lignin fractions show low molecular weight and increased phenolic hydroxyl groups, aiding lignin utilization.
Area of Science:
- Biomass Conversion
- Green Chemistry
- Wood Chemistry
Background:
- Lignin valorization is key to biorefinery economic viability.
- Understanding lignin's molecular changes during processing is crucial for its effective utilization.
Purpose of the Study:
- To investigate the molecular alterations of lignin during a hydrothermal pretreatment-based biorefinery process.
- To characterize different lignin fractions obtained from sweetgum wood.
Main Methods:
- Hydrothermal pretreatment of sweetgum wood.
- Isolation and characterization of three lignin fractions: XADL, HTCELp, and HTRELp.
- Quantitative Nuclear Magnetic Resonance (qNMR) spectroscopy analysis.
Main Results:
- Lignin undergoes both degradation and condensation during hydrothermal processing.
- Soluble fractions (XADL, HTCELp) are low-molecular-weight products rich in phenolic hydroxyl groups.
- Cleavage of approximately 28% of β-O-4' substructures and identification of Hibbert's ketones indicate acidolysis.
Conclusions:
- Hydrothermal biorefinery processing significantly modifies lignin's molecular structure.
- The characterization of lignin fractions provides insights into degradation and condensation pathways.
- Findings facilitate improved lignin utilization for enhanced biorefinery economics.
