Catalytic upgrading of biomass fast pyrolysis vapors with titania and zirconia/titania based catalysts

Fast pyrolysis of poplar wood followed with catalytic upgrading of the pyrolysis vapors was performed using analytical pyrolysis–gas chromatography/mass spectrometry (Py-GC/MS). The catalysts applied in this study were three commercial meso- or macroporous catalysts (TiO2 (Rutile), TiO2 (Anatase) and ZrO2&TiO2) and their modified ones with incorporation of Ce, Ru or Pd. These catalysts displayed different catalytic effects on the pyrolytic products. The TiO2 (Rutile) based catalysts, especially the Pd/CeTiO2 (Rutile), were effective to convert the lignin-derived oligomers to monomeric phenolic compounds, with the phenols increasing from 25.6% in the non-catalytic products to 37.2% after catalyzed by the Pd/CeTiO2 (Rutile). The ZrO2&TiO2 based catalysts were the most effective to change the pyrolytic products. They significantly reduced the phenols, acids and sugars, and meanwhile, increased the hydrocarbons, linear ketones and cyclopentanones. The highest hydrocarbon content of 13.1% was obtained by the ZrO2&TiO2, compared with only 0.1% in the non-catalytic products. The catalytic effects of the TiO2 (Anatase) based catalysts were between that of the TiO2 (Rutile) and ZrO2&TiO2 based catalysts.