An efficient and economical process for lignin depolymerization in biomass-derived solvent tetrahydrofuran

Area of Science:

• Chemical Engineering
• Polymer Chemistry
• Green Chemistry

Background:

• Lignin, a renewable aromatic polymer, is a promising source for valuable chemicals.
• Efficient depolymerization of lignin into phenolic monomers is crucial for biofuel and biochemical production.
• Existing methods often face challenges with low yields and significant char formation.

Purpose of the Study:

• To develop an efficient base-catalyzed lignin depolymerization process.
• To utilize inexpensive industrial solid alkali MgO and biomass-derived tetrahydrofuran (THF).
• To investigate the inhibition of char formation and understand residue formation mechanisms.

Main Methods:

• Base-catalyzed depolymerization of lignin using MgO as catalyst and THF as solvent.
• Optimization of reaction conditions (temperature, time).
• Characterization of raw material, products, and residue using techniques like Py-GC-MS, FT-IR, and TG-DSC.

Main Results:

• Achieved over 13.2% yield of phenolic monomers at 250°C for 15 min.
• THF demonstrated excellent lignin dissolution and enhanced MgO catalytic activity.
• The process significantly inhibited char formation compared to conventional methods.

Conclusions:

• The MgO/THF system provides an efficient and cost-effective method for lignin depolymerization.
• Understanding residue formation due to thermal repolymerization is key to improving catalyst performance.
• This approach offers a sustainable pathway for converting renewable lignin into valuable phenolic compounds.