Air Permitting Implications of a Biorefinery Producing Raw Bio-Oil in Comparison with Producing Gasoline and Diesel Blendstocks

The potential to emit (PTE) of regulated air pollutants for two variations of biorefinery designs, which use fast pyrolysis technology as a key biomass conversion step, were compared. The first biorefinery design produces raw bio-oil via an ex-situ upgrading of fast pyrolysis vapors. The second fast pyrolysis biorefinery converts biomass to raw bio-oil, which is then fully upgraded through multiple hydroprocessing steps to produce finished hydrocarbon biofuels. Additional emission controls to reduce regulated air pollutants, whose PTE is estimated to exceed the major source thresholds under the NSR and Title V permitting programs were analyzed. Results are expected to provide biofuel developers with insights into whether process variations might affect permitting requirements.