(675e) Hydrodeoxygenation of Oxidized Low-Water Bio-Oil Produces Higher Hydrocarbon Yield

Fast pyrolysis bio-oil has a high oxygen content of 40-45% in the form of oxygenates and approximately 30 vol. % water content; both lead to numerous negative properties. Bio-oil needs to be upgraded  for use as liquid transportation fuel. Hydrodeoxygenation is one of the most effective methods to remove oxygen. However, catalysts usually employed have been rapidly deactivated because of high water content and coking resulting from charring of the highly reactive oxygenates. In this study, we tested lower water content bio-oil for hydrodeoxygenation as means to reduce coking and enhance hydrocarbon yields. Distilled bio-oil and oxidized distilled bio-oil were hytrotreated and hydrocracked with nickel/silica-alumina catalysts. Raw bio-oil and oxidized raw bio-oil had the same hydroprocessing treatments applied. All four hydrocracked products contained a water content of nearly zero, a higher heating value of 44-45 MJ/Kg and an oxygen content near zero.The oxidized bio-oils had higher hydrocarbon yields than did non-oxidized bio-oils. Gas chromatography/mass spectrometry characterization showed that 58-64% of aromatic hydrocarbons and 36-42% of alkyl hydrocarbons were the main products for both distilled bio-oil and raw bio-oil while 63-70% of alkyl hydrocarbons and 30-37% of aromatic hydrocarbons were the main products for both oxidized bio-oils.