A new insight of lignin pyrolysis mechanism based on functional group evolutions of solid char

To elucidate the mechanism of biomass lignin pyrolysis, the functional group evolution in lignin chars derived at 200-600 degrees C was investigated using two-dimensional perturbation correlation infrared spectroscopy, associated with the properties of the volatile products. Results from 2D-PCIS pointed that the change in the alcohol groups C-OH occurs earlier than that in the carbonyl groups C=O before 250 degrees C, corresponding to the reaction of keto-enol tautomerization: C-OH -> C=O, and the cleavage of bonds and remodeling reactions of the side chains of the benzene rings are synchronous. Besides, the formation of simple substituted benzene structures was earlier than complex substituted benzene structures. Decarbonylation, dehydrogenation and dealkylation were intensified during polycondensation of benzene rings. These findings are significant for achieving an in-depth understanding of lignin pyrolysis.

Automated summary

The study on the mechanism of biomass lignin pyrolysis revealed that the change in alcohol groups occurs earlier than that in carbonyl groups, and the cleavage and remodeling reactions of benzene rings' side chains are synchronous. Additionally, the formation of simple substituted benzene structures precedes the complex ones. Furthermore, decarbonylation, dehydrogenation and dealkylation processes are intensified during the polycondensation of benzene rings.