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Various softwood and hardwood bark residues, primary sludges and softwood sawdust residues were processed by vacuum pyrolysis in a laboratory scale batch reactor. The pyrolysis oil, water, charcoal, and gas were recovered and analyzed. The pyrolysis oils were analyzed in details for their content in phenolic compounds after derivatization to their acetyl derivatives. The influence of temperature, heating rate, feedstock bed thickness, particle size and feedstock water pretreatment on the yield of phenols was investigated. The highest yield of phenols was obtained when hardwood bark was soaked in water for 48 hours and pyrolyzed at a temperature of 450°C and a heating rate of 10°C/min. Pyrolysis performance was evaluated in terms of total phenolic yield and composition.

ResolsAdhesive Synthesis Pyrolysis oil Softwood bark OSB Mechanical properties Phenol Formaldehyde Bark residues generated by the pulp and paper and wood industries represent a threat to the environment due to leaching of chemicals such as phenolics and resin acids which are being currently regulated by governments. Vacuum pyrolysis of resinous bark produces phenolic-rich oils which represent a potential raw material to replace petroleum-based phenol presently used in the formulation of wood adhesive resols.Resols with different levels of phenol replacement by phenolic pyrolysis oils, formaldehyde to phenolics molar ratios and sodium hydroxide to phenolics molar ratios were synthesized. Strandboards werepreparedandtheirmechanicalandphysicalpropertiessuchasmodulusofrupture(MOR),modulus of elasticity (MOE), dry and 2-hour boil internal bond (IB) and thickness swelling (TS) were evaluated.Homogeneous panels bonded with resins having 25 and 50% by wt of pyrolysis oils replacing phenol exhibited comparable mechanical properties to those of panels made with a commercial surface resin under the same pressing conditions. Three-layer panels made with resins having 50 % by wt phenol replacement in the surface and 25% by wt phenol replacement in the core had mechanical properties above the requirements specified by the Canadian Standards CSA O437.0-93 for OSB products.