Mechanism study on the interaction between holocellulose and lignin during secondary pyrolysis of biomass: In terms of molecular model compounds

A thorough examination of the interaction between holocellulose and lignin during secondary pyrolysis of biomass is essential for the targeted management of pyrolysis products. In this work, the interaction between holocellulose and lignin model compounds was explored utilizing a self-designed micro-pyrolysis device with a U-tube reactor. The content and distribution of liquid/gaseous products were investigated to determine potential interaction reaction routes. Holocellulose-lignin interaction was discovered to enhance the formation of furan products from the ring-opened C5/C6 monomer while blocking its conversion to anhydrous pyranose. The homolysis of methoxy groups on lignin model compounds is important for their interaction with holocellulose. Although phenol is generally stable, the phenolic hydroxyl group boosts the activity of the holocellulose monomer. The holocellulose monomer significantly promotes the cracking of the branched chains of guaiacol and syringol while inhibiting eugenol cleavage. Furfural induces eugenol condensation, resulting in the formation of dimers such as naphthalene and naphthalenol. The interaction between holocellulose monomer and eugenol primarily enhances the carboxylation of eugenol vinyl groups to generate aromatic acid compounds. The finding improves knowledge of the interactions that occur during secondary pyrolysis of biomass.