Skip to main content
ARS Home » Southeast Area » Auburn, Alabama » Soil Dynamics Research » Research » Publications at this Location » Publication #431999
Research Project: Sustaining Productivity and Ecosystem Services of Agricultural and Horticultural Systems in the Southeastern United States

Location: Soil Dynamics Research

Title: Fast pyrolysis oil upgrading using NiMo-based catalysts under solvent-free conditions

Author
item HONGLOI, F - Auburn University
item FEYZBAR-KHALKHALI-NE, F - Auburn University
item ADHIKARI, S - Auburn University
item Torbert Iii, Henry

Submitted to: Biomass and Bioenergy
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/22/2026
Publication Date: 3/27/2026
Citation: Hongloi, F., Feyzbar-Khalkhali-Ne, F., Adhikari, S., Torbert III, H.A. 2026. Fast pyrolysis oil upgrading using NiMo-based catalysts under solvent-free conditions. Biomass and Bioenergy. 212:109328. https://doi.org/10.1016/j.biombioe.2026.109328.
DOI: https://doi.org/10.1016/j.biombioe.2026.109328

Interpretive Summary: Catalytic hydrotreatment is a key strategy for improving the quality of biomass-derived pyrolysis oil by reducing oxygen content, enhancing stability, and increasing energy density. In this study, one-step upgrading was conducted using noble metal mono- and bi-metallic catalysts in the presence of hydrogen at 350 °C. Catalyst screening revealed that CoMo catalysts were ineffective, resulting primarily in coke due to uncontrolled polymerization. By contrast, Ni- and NiMo-based catalysts produced upgraded oils with distinct differences in yield, composition, and hydrogen utilization.

Technical Abstract: Catalytic hydrotreatment is a key strategy for improving the quality of biomass-derived pyrolysis oil by reducing oxygen content, enhancing stability, and increasing energy density. In this study, one-step upgrading was conducted using noble metal mono- and bi-metallic catalysts (nickel-Ni, nickel molybdenum-NiMo, and cobalt molybdenum-CoMo) in the presence of hydrogen at 350 °C. Catalyst screening revealed that CoMo catalysts were ineffective, resulting primarily in coke due to uncontrolled polymerization. By contrast, Ni- and NiMo-based catalysts produced upgraded oils with distinct differences in yield, composition, and hydrogen utilization. Nickel supported on silica-alumina (Ni/SiO2-Al2O3) achieved the highest energy recovery (80.1%) due to lower hydrogen consumption, while retaining a higher oxygen content. NiMo catalysts, supported on zirconia, provided superior deoxygenation (oxygen removal >84.9%) and the highest higher heating value (34.6 MJ/kg), while suppressing coke. Extending reaction time from 2 to 3 h enhanced oxygen removal and shifted product distribution toward cycloketones and heavier distillate fractions, although at the cost of lower liquid yield and increased gas formation. Gas analysis, thermogravimetric analysis, Van Krevelen trends, and simulation distillation profiles highlight the mechanistic balance between hydrogenation, cracking, and condensation over NiMo-based catalysts.