(583cq) Hydrodeoxygenation of Fast-Pyrolysis Bio-Oil From Different Biomass Feedstocks

Pighinelli, A., USDA Agricultural Research Service
Mullen, C. A., USDA-ARS
Boateng, A. A., USDA-ARS

Fast pyrolysis is proving to be a useful method for direct conversion of biomass into oxygenated liquid hydrocarbons, the product of which resembles crude oil (i.e. “bio-oil”). One major problem hindering the direct and cost-effective use of pyrolysis bio-oil is the presence of heteroatom contaminants. In particular, oxygenated components prevent bio-oil utilization due to repolymerization of pyrolyzed matter, acid corrosion of equipment, and attraction of unwanted moisture. An efficient process which removes significant amounts of oxygen would enhance the economic feasibility of biofuels for many applications. Furthermore, few works have investigated the effects of varying the feedstock source on the behavior and products of bio-oil upgrading by hydrodeoxygenation (HDO).

To evaluate the potential of plant biomass as drop-in fuels, pyrolysis bio-oils from various feedstocks underwent hydrodeoxygenation (HDO) treatment in a pressurized batch reactor. This talk will discuss the effects of both feedstock type and HDO processing parameters on the upgraded oil composition. Carbon-supported transition-metal catalysts like platinum and ruthenium catalyze the removal of oxygen. Bio-oils studied were produced from feedstock sources including switchgrass and Eucalyptus benthamii. Also studied were partially deoxygenated bio-oils produced utilizing an HZSM-5 catalyst during the pyrolysis step. The batch reactions were typically performed isothermally at temperatures greater than 300 oC for several hours. Both the aqueous and organic phases post-HDO are characterized for their composition, water content, and acidity. The feedstock choice directly impacts the composition of bio-oil, and hence affects upgradability.