Synergistic and Antagonistic Effects of Catalytic Torrefaction-Pyrolysis of Woody Biomass in a Carbon Dioxide Atmosphere for Biofuel Production

Torrefaction-pyrolysis is the thermal treatment of biomass in an inert atmosphere between 105 °C and 800 °C to break carbon bonds and produce biofuels. The purpose of this study is to examine how woody biomass with different particle sizes (250 µm and 500 μm), wood types (Poplar and Fir), and catalyst types (K, Na, and Mg) responds to catalytic thermochemical conversion in a CO2 environment. Torrefaction-pyrolysis of woody biomass shows the Boudouard equilibrium responds after 780 °C for K and Na-catalysts, except in samples impregnated with Mg-catalyst. When K-catalyst material is present, the C-O-C signal regarding the glycosidic linkages from cellulose and hemicelluloses in Fir is observed to decrease the most. This is related to the fact that Fir (22.43 wt.%) has nearly twice as many hemicelluloses as Poplar (12.18 wt.%), making it less thermally stable and more vulnerable to the prolonged drying required following catalyst impregnation.