Pine bio-oil based biorefinery procedure for the production of antioxidants, acids, and sugars

In this study, a wood-based biorefinery with Pinus halepensis biomass was developed to obtain acids, sugars, and antioxidants with high recovery yields. Pine wood residues from sustainable forest management are transformed into bio-oil (BO) and separated into value-added chemicals with an integrated and innovative methodology. First, biomass is thoroughly characterized and the optimum operational parameters to produce BO are determined, the maximum yield being obtained at 450 °C. Second, BO is processed using a novel approach that integrates adsorption chromatography, vacuum distillation, liquid-liquid extraction, and precipitation, all of which are mature techniques at an industrial scale. This methodology offers a step forward to a more integrated strategy than current studies in the literature, allowing the simultaneous recovery of multiple chemicals rather than focusing only on the separation of a single family of compounds. The BO was divided into three fractions: (1) an acid-rich fraction, containing polar compounds with low boiling points such as acetic acid, formic acid, acetol, and furfural; (2) a sugar-rich fraction, containing polar compounds with higher boiling points like levoglucosan, 5-hydroxymethylfurfural (5HMF), and methyl cyclopentenolone, and (3) an antioxidant fraction, containing phenolic species with antioxidant properties such as phenol, guaiacol, catechol and vanillin. Elevated recovery yields were obtained: 69 wt% of the initial acetic acid with a value of 18 g·kg biomass, 92 wt% of the initial levoglucosan with a value of 10 g·kg biomass, and 65 wt% of the initial phenol with a value of 0.7 g·kg biomass. This represents a step forward in the development of biorefineries and the integrated production of chemicals for the pharmaceutical, nutraceutical, and chemical industries from a renewable feedstock: wood.