Catalytic Microwave Pyrolysis of Douglas Fir Pellets with Carbon Catalysts Derived from Corn Stover

This study investigated catalytic microwave pyrolysis of Douglas fir sawdust pellets using carbon catalysts produced from corn stover. The effects of catalyst to biomass ratio on the bio-oil, syngas, and biochar yields were determined. Functional groups (carbonyls, phenolics, lactones, carboxyls) of carbon catalysts and GC/MS analysis were used to study the catalytic pyrolysis of Douglas fir sawdust pellets. Surface functional groups of carbon catalysts were quantified by titration with bases of different ionization potential before and after catalytic pyrolysis. GC/MS analysis results showed that the phenols and hydrocarbons in bio-oil increased with the increase of the carbon catalyst loading while the guaiacol decreased. Comparison between the carbon catalyst from before and after microwave catalytic pyrolysis showed that the variation in the amount of carbonyl group has a close relationship with the upgrading bio-oils. The carbon catalyst might be served as a costcompetitive catalyst in biomass conversion and bio-oil upgrading.