The characteristics of lignin pyrolysis was investigated by TG at different heating rate

combined with FTIR characterization of the chars from different stages of slow pyrolysis of lignin to analyze lignin pyrolysis mechanism at slow heating rate.The results show that pyrolysis of lignin is a process involving breakage of old chemical branched chains and recombination of new branched chains.With time extending i.e.temperature rising

there are three successive stages in process of lignin pyrolysis:dewatering

breakage-recombination-volatilization of branched chains and polymerization of aromatic rings and formation of carbon.Based on the weight loss rate at different heating rates

according to the Flynn-Wall-Ozawa equation

the calculation of kinetic parameters resulted in activation energies of 64 kJ穖ol-1 and 132 kJ穖ol-1 for the latter two pyrolysis stages

respectively.This indicates further that the pyrolysis of lignin carried out in different stages and the breakage of the branded chains was easier than the polymerization of aromatic rings.