Revealing G-lignin model compounds pyrolysis behavior: β-O-4 and 5-5′ dimer and trimer

It is anticipated that the insight into the formation of the pyrolysis products would contribute to a fundamental understanding of the bond cleavage mechanism. Herein, in order to have a better understanding of the lignin pyrolysis property, the lignin pyrolysis property was investigated by using multi-scale lignin model components. The TGA and Py-GC/MS data indicated that even the lignin trimer contains both of the β-O-4 and 5-5′ chemical structures can be cleaved simultaneously and multiple bond cleavage mechanisms come into play, any of which has an effect on each other. But, overall, the low pyrolysis temperature (450–550 °C) is conducive to the enrichment of guaiacols as the main bio-oil, especially for guaiacol. This evidence could provide theoretical support for the pyrolysis of softwood lignin and the guidance for industrial lignin's high-value utilization and directional conversion.