Alkaline oxidation of sugarcane bagasse and straw lignin to obtain aromatic aldehydes

Lignin is an amorphous phenolic macromolecular material frequently obtained as residue during technological processing of biomass. Modifications in chemical structure of lignin generate valuable products, such as aromatic aldehydes of great interest. One of the available methods for modification of industrial lignin is oxidation by hydrogen peroxide. The objective of this study was to  investigate the feasibility of producing aromatic aldehydes by extracting the lignin from sugarcane bagasse and straw with soda process and using hydrogen peroxide as oxidizing agent in three different conditions. The utilization of sugarcane bagasse and straw to obtain lignin by the method employed was satisfactory. Aiming a higher yield of aromatic aldehydes, especially vanillin, the reaction using 9.1% H₂O₂ (m/v) showed to be more appropriate when using sugarcane bagasse lignin and 6.1% H₂O₂ (m/v) when using sugarcane straw lignin, both with 90 min reaction.