Revealing the catalytic mechanism of Ni/Al2O3 in biomass catalytic gasification for hydrogen-rich syngas production: Integrating experimental characterization with numerical simulation

Biomass catalytic gasification is promising for hydrogen-rich syngas production. However, Ni-based catalysts suffer from coke and sintering induced deactivation, and reactor scale heat and mass transfer behavior remains unclear. This study investigates the catalytic gasification mechanism of biomass over Ni/Al 2 O 3 in a two-stage fixed-bed reactor by integrating experimental characterization with numerical simulation. Compared with NiO and γ-Al 2 O 3 , Ni/Al 2 O 3 exhibits superior catalytic activity. Under the optimal conditions, the gasification and catalytic reforming temperatures are 850 °C and 800 °C, respectively. At a steam flow rate of 0.5 mL/min and Ni loading of 20 %, the H 2 volume fraction reaches 47.46 %. After five cycles, the H 2 volume fraction remains at 39.31 %. The total syngas and H 2 yields reach maximum values of 33.11 and 22.09 mmol/g, respectively, at a steam flow rate of 1.5 mL/min. Simulation results indicate that the catalytic reforming region promotes volatile conversion and enhances H 2 volume fraction.