Lignin, which is one of main components in biomass and important component of bio-oil, has an important application in industry. In this work, the pyrolysis processes of lignin at high temperature were studied with the aid of DFT methods. B3LYP method was used in order to estimate the theoretical pathways and equilibrium composition of the reaction products of biomass thermochemical conversion processes (pyrolysis). The results of our calculations show that the Cα—Cβ and β-O-4 pathways are the main cleavage modes.

Key words: lignin dimer, bio-oil, pyrolysis, density functional theory