Sustainable regeneration of deactivated hydrochar-supported Ni catalyst for enhancing low-temperature tar reforming performance

Catalytic tar reforming using biochar-supported nanoparticle catalyst has emerged as a prominent approach for efficient biomass gasification. However, the widespread issue of catalyst deactivation significantly impedes their industrial application. Recent studies have successfully elucidated the deactivation and regeneration behaviors of pyrochar-based catalysts during high temperature (700-900 degrees C) tar reforming. In contrast, the deactivation and regeneration mechanisms of hydrochar-based catalysts for low temperature (e.g., 600 degrees C) biomass tar reforming remain unclear. In this study, we report a simple and cost-effective approach for the regeneration deactivated hydrochar-supported nickel catalyst (Ni0.1/HC). A straightforward N2 regeneration treatment (800 degrees C, 30 mL/ min for 30 min) restored the Ni0.1/HC catalyst to its highest tar reforming efficiency (71 %), H2 selectivity (38 %), H2 yield (758 mL/g) and highest LHVg (8.59 MJ/Nm3). We attribute this promising regeneration performance, which significantly outperforms previously reported regeneration atmospheres (such as CO2, O2, and air), to the suppression of Ni sintering that achieved by limiting oxidation of the coke/hydrochar support. This work advances our understanding of the deactivation and regeneration mechanisms of the hydrochar-based tar reforming catalysts and could facilitate the practical application of biochar-supported catalysts in biomass conversion.