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Single stage hydroprocessing of pyrolysis oil in a continuous packed-bed reactor


  • Presented at the Tcbiomass2013 conference; September 3–6, 2013, at Chicago, Illinois.


Raw bio-oil cannot be combusted as transportation fuel directly because of its high acidity, high water content, lower heating value, and variable viscosity over time. Therefore, bio-oil should be chemically converted to a more stable liquid product before subjecting it to hydrodeoxygenation (HDO) conditions. This research article focuses on catalytic hydroprocessing of pretreated bio-oil (PTBO) in a single stage reaction using various catalyst compositions in a packed-bed reactor. Four catalysts, a conventional hydrotreating catalyst (CoMo/γ-Al2O3), an Fe-Cr based mixed oxide catalyst, an FeW/Si-Al catalyst, and a 1:2 mixture of Ru/γ-Al2O3 and Ni/Si-Al catalyst, were tested for conversion of the PTBO to mixed liquid hydrocarbons at 350–400°C, 1500 psig hydrogen pressure, and at a liquid hourly space velocity (LHSV) of 0.2–0.3 h−1. Liquid products produced from the HDO treatments were analyzed for properties such as acid value, heating value, elemental analysis, water content, and chemical characterization. The conventional hydrotreating catalyst, CoMo/γ-Al2O3, performed the best among the four catalysts employed to reduced the acid value to 2 mg KOH/g and oxygen content to 0.1% while improving the heating value to 43 MJ/kg of the liquid product. The detailed hydrocarbon analysis of the reduced CoMo/γ-Al2O3 upgraded hydrocarbon mixture showed the presence of olefins, iso-paraffins, followed by naphthenes and aromatics. Simulated distillation results indicated that the liquid fuel had a boiling point range of 69–304°C, indicating the presence of petroleum equivalents of 50% gasoline (38–170°C), 30% jet fuel (170–250°C), and 20% diesel (250–304°C) range hydrocarbons. © 2014 American Institute of Chemical Engineers Environ Prog, 33: 726–731, 2014