(684b) Effect of Lignin Content of Hybrid Poplar on the Quality of Fast Pyrolysis Bio-Oil

Fast pyrolysis of woody biomass has been identified as a potential means for the production of advanced transportation fuels. During fast pyrolysis the three main components of biomass (cellulose, hemicellulose, and lignin) thermochemically breakdown to produce bio-oil. Several studies have isolated these individual components and looked at their product distributions. However the interactions between these three main components and how variations in feedstock composition affect product distribution are not well understood. The purpose of this work is to assess the quality of bio-oil as lignin content is varied in hybrid poplar, a promising plantation-style energy suitable for cultivation in a wide range of forest settings.  The quality of bio-oil is assessed by calculating bio-oil yield relative to dry biomass and relative to char and gas, changes in relative abundance of oxygen in the bio-oil, and energy density of the bio-oil. Eight genetically different poplar samples with varying lignin content were pyrolyzed using a CDS 5200 HP micro-pyrolysis unit, which was directly connected to a ThermoFisher Trace GC coupled with a DSQII MS.  An increase of lignin concentration, by approximately 10%, increased the relative abundance of phenolic species in bio-oil by 50% and decreased the relative abundance of oxygen by 11%. It is expected that as the concentration of lignin increases, bio-oil yield will decrease (Mohan et al. 2006), but this trend has yet to be observed in our experiments to date. Overall an increase in the amount of lignin within woody biomass generates a higher quality bio-oil.