Abstract

Fast pyrolysis of Radiata pine bark was carried out in pursuit of a renewable source of high-value chemicals. Bench-scale experiments of pine bark were performed in a fluidized bed reactor between 450–650 °C to provide information related to yield of liquid, solid and gas, respectively. The higher yield of pyrolysis-oil was achieved at 550 °C. The obtained pyrolysis-oil was characterized through gas chromatography coupled to mass spectrometry establishing that the principal compounds were catechols, phenols, triterpenes, resin acids and fatty acids. However, the polarity and the chemical function of these compounds is in some cases antagonist. Therefore, the pyrolysis-oil becomes unsteady due to the simultaneous oxidation reactions. This stand to reason to assess a simple fractionation method for pyrolysis-oil which allows a higher stability and reproducibility for its posterior use in any application. The solvent fractionation was studied using a methanol/hexane mixture. Two fractions were obtained: A, with phenolic nature and brown color; B, with the higher molecular weight compounds (less polar) and light yellow color. The aim of this work was evaluate the optimal separation of pyrolysis-oil through solvent extractions. Afterwards, these fractions obtained (A and B) were evaluated in bioactive assays such as antioxidant capacity and control of fungus growing. Finally, the role of fraction A (higher antioxidant ability) was tested in photo-protection UV over wood in a range of 250 hours. It was found that with only 1% of fraction A dissolved in ethanol it is possible decrease the damage by UV radiation almost in a 45%. Even, with more effectiveness than some commercial varnishes. On the other hand, the rot fungus growth study over wood showed that adding a 3% of pyrolysisoil is enough for not allow the growing during 8 weeks, against the samples with lesser or null pyrolysis-oil content which showed clear rot damage.