Abstract

In this work we show that catalytic oxidation of aqueous phase bio-oil with molecular oxygen and a Keggin-type polyoxometalate (H 5 PV 2 Mo 10 O 40) produces formic acid with high selectivity. Bio-oil was obtained from sawdust (pinus radiata, size of 1-3 mm, moisture content of 9.1% on dry-basis), in a fast pyrolysis pilot plant using a fluidized bed of quartz sand at 530°C. The main aqueous-soluble compounds detected in 100 g of bio-oil were: 5.98 g of glycolaldehyde, 3.58 g of levoglucosan, 2.26 g of acetol, 1.39 g of acetic acid and 1.06 g of formic acid. The catalytic oxidation of the aqueous phase bio-oil was conducted at 90°C under 30 bar O 2 for 7h and produced 13.27 g of formic acid per 100 g of bio-oil. The process uses air or molecular oxygen as a cheap and green oxidant. The enriched product in formic acid will be used as H-donor for bio-oil hydrodeoxygenation at mild conditions.