Pilot-Scaled Fast-Pyrolysis Conversion of Eucalyptus Wood Fines into Products: Discussion Toward Possible Applications in Biofuels, Materials, and Precursors

Based on a circular bioeconomy strategy, eucalypt wood fines rejected from a Kraft pulp line were used as starting material in a pilot-scaled fast-pyrolysis process. The bio-oil and its coproducts were characterized regarding their physical, chemical, and thermal aspects. We put in perspective their properties to bring forward considerations for applications on biofuels, materials, and precursors. The yields of the pilot-scaled fast-pyrolysis process reached interesting values even if compared with optimized laboratory conditions. The results indicated the highest heating values (22-27 MJ/kg) for bio-oil, char, and crust material. The higher water content of aqueous extract had a negative effect for its application as fuel. The lignin/carbohydrate ratio for the bio-oil (2.82) and aqueous extract (0.53) identified a higher concentration of lignin-derived compounds in the first, mainly syringyl units. Bio-oil and aqueous extract presented chemical compounds with many functionalities, such as syringaldehyde and levoglucosan, expanding their potential application for higher value-added products besides energy.