Py-GC/MS study of lignin pyrolysis and effect of catalysts on product distribution

Fast pyrolysis is one of the most promising methods to convert lignin into fuels and chemicals.In the present study,pyrolysis-gas chromatography/mass spectrometry(Py-GC/MS)was used to evaluate vapor phase product distribution of lignin fast pyrolysis.During the non-catalytic pyrolysis process,lignin was pyrolyzed at 400℃,500℃ and 600℃ respectively,finding that the highest yield of aromatic hydrocarbons was obtained at 600℃.Catalytic pyrolysis experiments were also conducted to investigate the effects of catalyst pore structure and acidity on the product distributions.Five different catalysts(HZSM-5,MCM-41,TiO_(2),ZrO_(2) and Mg(Al)O)were applied to lignin catalytic pyrolysis,and the catalytic performance was estimated by analyzing the pyrolytic products.The catalysts were characterized by using X-ray diffraction(XRD),BET,and NH3(CO_(2))temperature programmed desorption.Based on these characterizations,discussion was carried out to explain the formation of the produc distributions.Among the five catalysts,HZSM-5 exhibited the best performance on the formation of aromatic hydrocarbons.