Fast Pyrolysis of Pine Sawdust in a Fluidized-Bed Reactor

Pine (Pinus strobus) sawdust was pyrolyzed in a fluidized-bed reactor between the temperatures of 400 and 600 degrees C. The fixed-bed volume and residence time were optimized to maximize the liquid yield. We report the detailed physical and chemical properties of the bio-oil fraction collected during fast pyrolysis. The liquid yield was maximized at 500 degrees C, whereas increased gas formation occurred at 600 degrees C. DC NMR of the bio-oil fractions indicated a decrease in the carbohydrate fraction and an increase in the aromatic fraction when pyrolysis temperatures were increased from 500 to 600 degrees C. Over the ranges of our investigation, the effects of the fixed-bed volume and residence time were negligible on the chemical composition of the bio-oil. Toluene and ethyl acetate bio-oil extracts were analyzed by gas chromatography/mass spectrometry following chemical derivatization. At increased reaction temperatures, the process favored conversion of guaiacols to catechols.