(723b) Optimizing Catalytic Fast Pyrolysis and Hydrotreating for the Production of Biofuels

Iisa, K., National Renewable Energy Laboratory
French, R., National Renewable Energy Laboratory
Orton, K., National Renewable Energy Laboratory
Liquid transportation fuels can be produced via catalytic fast pyrolysis by upgrading biomass pyrolysis vapors prior to condensation. While it is possible to obtain a completely deoxygenated hydrocarbon product by using suitable operating conditions, including high biomass-to-catalyst mass ratios, the yield of the product oil remains low. Higher yields can be obtained at lower biomass-to-catalyst ratios but the resulting oil includes oxygenates and hydrotreating is required for the final deoxygenation. With decreasing degree of deoxygenation in the catalytic pyrolysis step, higher severity is required for hydrotreating. This research discusses the optimization of the overall carbon efficiency and cost of the process for producing oils with low oxygen contents via catalytic fast pyrolysis. Pine was pyrolyzed and upgraded over ZSM-5 catalyst in a dual 2-inch fluidized bed reactor system. The catalyst-to-biomass ratio was varied to produce oils with different oxygen contents, and the oils were subsequently hydrotreated over a sulfided CoMo catalyst.