(635d) Effects of Feedstock, Collected Condensate Fraction, and Filtration on Pyrolysis Oil Stability

The physical and chemical properties of pyrolysis oil have been shown to be dependent on the feedstock composition. Accelerated aging tests were performed to understand the effects of feedstock, condenser fraction collected, and filtration on the stability of pyrolysis oil. In this study, properties critical for upgrading were measured and compared for pyrolysis oils produced using different feedstock weight ratios of pine clear wood and pine bark. These pyrolysis oil samples were produced using an auger reactor with multiple condensers. For each feedstock composition, three different fractions were collected by selectively collecting sample from one or multiple condensers.  Post-condensation filtration of pyrolysis oil was evaluated using both lab-scale and pilot plant-scale centrifugal filtration with several operation parameters evaluated, including temperature.  The pilot-plant centrifuge can be used as a three-phase separator [light liquid-heavy liquid-solids] or a two-phase clarifier [liquid-solid]. Since pyrolysis oil is an oil-water micro-emulsion, separation is difficult, and emulsion destabilization studies were performed in concert with centrifugation. Physical properties—such as water content, pH, density, viscosity, and solids content, and chemical composition were monitored to determine the impact on the production and processing parameters on the ultimate properties critical for application in fuel and specialty chemicals production.