Online Electrochemical Upgrading of Furfural as a Model Compound for Biomass Pyrolysis Vapours Via Solid Oxide Electrolysis Cell

Abstract

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 °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 new concept of integrated online electrochemical hydrogenation-saturation and deoxygenation, utilizing SOEC to achieve the online electrochemical upgrading of furfural, a crucial product of biomass pyrolysis. 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 °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 °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.

Keywords: Solid oxide electrolysis cell, Electrocatalytic hydrogenation, furfural, pyrolysis, Biomass energy conversion