Comprehensive valorisation of technically relevant organosolv lignins via anodic oxidation

Abstract

Lignin represents the largest renewable feedstock of aromatic moieties in nature. However, its valorisation towards organic chemicals poses a challenging task. We herein report the selective electrochemical depolymerisation of several technically relevant organosolv lignins to aromatic fine chemicals with a simple two-electrode arrangement using caustic soda as electrolyte. Vanillin, syringaldehyde, the corresponding ketones and guaiacol were obtained with a combined maximum of 7.8 wt% isolated yield. Deeper insight in the process was provided by FT-IR, HSQC NMR and ³¹P NMR analyses of the lignins.