NOVELTY - Creating significantly deoxygenated bio-oils from biomass involves providing a feedstock; associating the feedstock with an alkali formate to form a treated feedstock; dewatering the treated feedstock; heating the dewatered treated feedstock to form a vapor product; and condensing the vapor product to form pyrolysis oil, where the pyrolysis oil contains less than 30 wt.% oxygen.    USE - The method is useful for creating significantly deoxygenated bio-oils from biomass (claimed).    ADVANTAGE - Improved methods for thermally converting biomass, including woody biomass, and spent pulping/fractionation liquors, into highly deoxygenated fuels and chemicals are provided. Associating a feedstock with an alkali formate, formate salt or formic acid prior to a pyrolysis reaction can lead to formation of significantly deoxygenated products without the need for addition of either exogenous hydrogen or precious metal catalysts during the pyrolysis reaction. Addition of an alkali formate, formate salt or formic acid allows for biomass to be converted to deoxygenated products at lower pressures including atmospheric pressure or even below atmospheric pressure.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is a method involving providing a feedstock; associating the feedstock with an oxidant to form an oxidized feedstock; associating the oxidized feedstock with an alkali formate to form an oxidized treated feedstock; dewatering the oxidized treated feedstock; heating the dewatered treated feedstock to form a vapor product; and condensing the vapor product to form a pyrolysis oil, where the pyrolysis oil contains less than 30 wt.% oxygen; or a method involving providing a feedstock; associating the feedstock with an alkali formate in the presence of an oxidant to form an oxidized treated feedstock; dewatering the oxidized treated feedstock; heating the dewatered treated feedstock to form a vapor product; and condensing the vapor product to form a pyrolysis oil; where the pyrolysis oil contains less than 30 wt.% oxygen.