Understanding deactivation pathways in bio-oil upgrading with the use of in situ NMR and EPR techniques

Biomass is the most readily available renewable source of liquid transportation fuel. According to DOE, fast pyrolysis followed by catalytic upgrading is projected to be the most cost effective among the different thermochemical routes in the mid-term time frame. However, this proposed system has challenges that still need to be overcome, including: (1) polymerization (aging) reactions that occur in pyrolysis oil during storage; (2) reaction pathways of competing thermal reactions that cause catalyst deactivation through extended time on stream or that produce plugs that necessitate operation shutdowns. Extended catalyst lifetimes are necessary to improve the cost-effectiveness of this process.
This proposal will use in situ NMR (nuclear magnetic resonance) and EPR (electron paramagnetic resonance) spectroscopy techniques to monitor bio-oil reactions to gain better understanding of the mechanistic pathways involved in: (1) aging of bio-oil during storage and its proposed mitigation; and, (2) catalytic bio-oil pre-stabilization. Surface analysis techniques such as IR, SEM and XPS will be used to characterize the catalysts. It is expected that information on the optimal characteristics of a stable bio-oil as well as insight in designing more robust catalysts will be determined by these techniques.