Impact of biomass constituent interactions on the evolution of char's chemical structure: An organic functional group perspective

An in-depth investigation of the chemical structural evolution of char throughout the pyrolysis process is critical for subsequent biochar utilization. Therefore, the interaction mechanism among biomass constituents was studied by the examination of product distribution, bio-oil and bio-gas composition, organic functional groups, and two-dimensional correlation infrared spectrum characteristic of char. Char evolution was influenced by primary interaction (at 300 or 400 degrees C) and secondary interaction (at 500 or 650 degrees C). Polymer depolymerization and phenylpropane side chain breaking were aided by the primary interaction. Due to a melting and wrapping effect, it hindered ring opening, recombination, and polymerization of D-allose/D-xylose molecules, allowing the char to preserve its original C-O-C and C-OH structure. The secondary interaction stimulated the cyclization and intramolecular dehydration of D-allose, leading pyrolysis to advance to the pyran pathway. It also encouraged the ring opening, cyclization, rearrangement, and polymerization of monomer molecules, resulting in the char's C = O, C = C, and C-OH structures with greater aromatization degree. The discovery advances the understanding of the interacting mechanism of biomass pyrolysis and char formation.

Automated summary

This study investigates the mechanism of interaction among biomass constituents during the pyrolysis process by examining product distribution, bio-oil and bio-gas composition, organic functional groups, and the two-dimensional correlation infrared spectrum characteristic of char. The primary and secondary interactions influence the evolution of char, with the former aiding depolymerization and side chain breaking, and the latter stimulating cyclization and intramolecular dehydration of specific molecules.