Online electrochemical upgrading of furfural as a model compound for biomass pyrolysis vapors via solid oxide electrolysis cell

Biomass pyrolysis produces crude bio-oil, which has drawbacks such as high oxygen content and poor stability, necessitating upgrading treatments. Conventional upgrading of crude bio-oil faces issues such as significant mass transfer resistance, slow reaction rates, and difficulties in separating the products. SOEC are high-temperature (600-1000 degrees C) all-solid-state energy conversion devices capable of generating hydrogen in situ at elevated temperatures, thereby enhancing efficiency and directly integrating with the pyrolysis process. This work proposes a novel SOEC-based vapor-phase electrochemical upgrading process that achieves integrated online hydrogenation-saturation and deoxygenation of furfural without relying on external hydrogen. The reactor design used includes air electrode (LSCF), electrolyte (8YSZ), and fuel electrode(NiO-YSZ), ensuring the high efficiency of the hydrogenation process. Increasing the applied voltage to 1.4 V at 700 degrees C significantly enhances the aromatics yield, achieving a rate of 0.279 mmol/h, a furfural conversion of 87.7 %, and a deoxygenation rate exceeding 90 %. Additionally, at 600 degrees C, the process exhibits a selectivity of over 97 % for monocyclic aromatics and effectively eliminates polymerization products. These findings demonstrate the potential of SOEC electrocatalytic hydrogenation as an effective online upgrading method for biomass-derived compounds, offering a promising route for the sustainable and high-quality production of biofuels.