Recent advances of lignin valorization techniques toward sustainable aromatics and potential benchmarks to fossil refinery products

Aromatic compounds are important fuels and key chemical precursors for organic synthesis, however the current aromatics market are mainly relying on fossil resources which will eventually contribute to carbon emissions. Lignin has been recognized as a drop-in substitution to conventional aromatics, with its values gradually realized after tremendous research efforts in the recent five years. To facilitate the development of a possible lignin economics, this study overviewed the recent advances of various biorefinery techniques and the remaining challenging for lignin valorization. Starting with recent discovery of unexplored lignin structures, the potential functions of lignin related chemical structures were emphasized. The important breakthrough of lignin-first pretreatment, catalytic lignin depolymerization, and the high value products with possible benchmark with modern aromatics were reviewed with possible future targets. Possible retrofit of conventional petroleum refinery for lignin products were also introduced and hopefully paving a way to progressively migrate the industry towards carbon neutrality.

Automated summary

This article provides an overview of the recent advances and challenges in the utilization of lignin as a substitute for conventional aromatics. It highlights the discovery of unexplored lignin structures and their potential functionalities. The breakthroughs in lignin-first pretreatment, catalytic lignin depolymerization, and the production of high-value products comparable to modern aromatics are reviewed, along with the possibility of retrofitting conventional petroleum refineries for lignin products.