Mild degradation of corncob extract 1 residue in a novel sodium metavanadate and aqueous hydrogen peroxide/acetic anhydride system for monophenolic compounds

Abstract

An efficient and environmentally benign binary mild oxidative degradation method, consisting of a novel sodium metavanadate and aqueous hydrogen peroxide/acetic anhydride (SM-AHPO/AAH) system, was used to convert corncob extraction residue (CCER) for producing monophenolic compounds (MPCs). The SM-AHPO/AAH system demonstrates excellent performance for producing MPCs in a high yield from CCER and CCER conversion to soluble portion (SP) is ca. 97.7 wt%. According to multiple analyses the SP is rich in aromatics. The SM-AHPO/AAH system is also effective for oxidatively degrading other lignin-rich raw materials to producing aromatics as the main products. In the initial step, H2O2 breaks a >C-O- bond in a peroxy chain of lignin structure to produce phenylpropanoid, followed by H2O2 attacking Cβ and Cα to producing H, G and S-type aromatics.