(401bb) Chemical Separations for Improved Catalytic Upgrading of Fast Pyrolysis Bio-Oils

Chemical Separations for Improved Catalytic Upgrading of Fast Pyrolysis Bio-oils

Mi (Aimee) Lu and Michael Z. Hu

Oak Ridge National Laboratory, Oak Ridge, TN 37831

Selective removal of target component(s) from streams of thermochemical conversion pathways for bio-oil liquids or vapors was investigated by selective separations and reactive conversions to enhance bio-refinery processing economics through catalyst preservation and process intensification strategies. In one task on pre-processing of condensed bio-oil liquids, we develop molecular removal technology to address two major barriers: (1) Mitigation of catalyst deactivation by highly reactive and thermally unstable foulants, such as carbonyl molecules (e.g., carboxylic acid and aldehydes), to enhance the stability of bio-oils and thereby enhance the lifetime of downstream upgrading catalysts. (2) Improvement of carbon and hydrogen efficiency by removing low-molecular-weight C1-C4 oxygenates from raw bio-oils to prevent the H₂-consuming conversion of these small molecules into low-value hydrocarbon gasses. The recovered carbonyls are considered for production of high-value chemicals. The effectiveness of adsorption and membrane technologies are experimentally and economically evaluated for their separation performance and impacts on bio-oil stability, hydrotreatment catalyst lifetime, carbon and hydrogen efficiency, and cost reduction in both materials and operational maintenance. In another task on in-situ chemistry tailoring of hot pyrolysis vapors, we develop catalytic hot gas filter to process (deoxygenate) vapors before they are condensed into liquid and upgraded to hydrocarbon fuels. Besides the filtration removal of inorganic mineral (alkali/alkaline metals), catalyst-loaded filters are being developed to enable selective target conversions (such as carboxylic acids to ketones or alcohols), producing low-carbonyl bio-oils for better performance and lifetime of upgrading catalysts.