Chemicals from lignin: an interplay of lignocellulose fractionation, depolymerisation, and upgrading

Area of Science:

• Biorefining and Biomass Valorisation
• Sustainable Chemistry
• Catalysis and Chemical Engineering

Background:

• Lignin valorisation is essential for developing competitive and sustainable biorefineries.
• Exploiting lignin as a resource for chemicals presents a significant opportunity.
• Three core technological aspects underpin successful lignin-to-chemicals valorisation: fractionation, depolymerisation, and upgrading.

Purpose of the Study:

• To provide a comprehensive summary and perspective on research in lignin valorisation.
• To delineate distinct strategies and innovations in lignocellulose fractionation, lignin depolymerisation, and chemical upgrading.
• To identify conceptual principles guiding future research for expanding lignin-based chemical production.

Main Methods:

• Review of established and innovative techniques in lignocellulose fractionation.
• Analysis of depolymerisation strategies to minimise lignin condensation.
• Exploration of upgrading approaches, including 'funneling' via chemocatalytic and biological methods.

Main Results:

• Minimising lignin condensation during fractionation and depolymerisation is critical for chemical production.
• Fractionation strategies include preserving native lignin or preventing condensation of reactive intermediates.
• Depolymerisation can be enhanced by increasing lignin reactivity, while upgrading raw mixtures uses convergent transformations like funneling.

Conclusions:

• Successful lignin-to-chemicals valorisation relies on integrated strategies across fractionation, depolymerisation, and upgrading.
• Minimising condensation and employing funneling approaches are key to efficient chemical production from lignin.
• This review provides a framework for future research to advance lignin valorisation technologies.