Sustainable Chemistry for the Environment, Journal Year: 2024, Volume and Issue: 6, P. 100107 - 100107

Published: May 12, 2024

Lignin, an abundant renewable biopolymer found in plant cell walls, is enriched phenolic units within its complex molecular structure. Unlocking potential as alternative feedstock (bio)refining has posed a long-standing challenge, even though it holds immense promise for replacing fossil-derived and aromatic compounds. This study focuses on fast pyrolysis effective thermochemical depolymerization method of lignin, coupled with the situ catalytic upgrading aiming to produce valuable bio-oil dealkoxylated (alkyl)phenolic Lignin was isolated via organosolv process from beechwood sawdust (hardwood biomass). Various acidic aluminosilicate catalysts (e.g., zeolites, such ZSM-5, Beta USY, amorphous silica alumina) were applied, having different Si/Al ratio, porous properties. Fast experiments conducted fixed-bed bench-scale reactor at two distinct temperatures (500 600 °C), employing contact times lignin-to-catalyst ratios. Non-catalytic revealed that higher temperature, significantly influences bio-oil's composition yield, resulting conversion initially formed alkoxy-phenols alkyl-phenolic compounds, reaching 47% relative concentration oC, while also yielding high amount up 43 wt.%. Among tested, zeolite ZSM-5 (Si/Al=40) proved be most efficient, shifting chemical profile (mainly BTX) 57%, owing unique microporous structure acidity. Depending catalyst type, balance between BTX monomer aromatics naphthalenes observed. well obtained products (bio-oil, non-condensable gases, char/coke-on-catalyst) thoroughly characterized using various analytical techniques. The results associated physicochemical properties catalysts, providing insights into underlying reaction mechanisms.

Language: Английский