Hydroprocessing of Biorenewable Thermal Deoxygenation Oils

Thermal deoxygenation (TDO) of neutralized biomass acid hydrolyzate, namely, levulinate and formate salt mixtures, is demonstrated to yield low oxygen bio-oils suitable for transportation fuels. The chemistry and upgrading potential are evaluated for TDO oils derived from calcium- and magnesium-neutralized model biomass acid hydrolyzate containing levulinate/formate salt mixtures at a 1:1 molar ratio. TDO oils were prepared using a 50 L semibatch reactor and analyzed for component chemistry and physicochemical properties. The TDO oils contain a broad distribution of monoaromatic and polyaromatic hydrocarbons with H:C ratio of ≅1:1. Crude oils were processed under hydrogen pressure in a vertical downflow tubular reactor, using a Ni/SiO2–Al2O3 catalyst. Sustained yields of 90+ wt % were achieved over 700 h operating without catalyst regeneration. Products were identified by GC-MS to contain primarily naphthenes, monoaromatics, partially saturated polyaromatics, and only trace oxygenates. Hydroprocessed oils...