Catalytic Reforming Strategies for Tar Reduction and Hydrogen Enhancement in Biomass Gasification

Catalytic biomass gasification is considered a promising route for the production of hydrogen-rich syngas. However, the impact of catalytic enhancement on gas composition is a complex phenomenon, as experimental outcomes are often strongly dependent on reactor configurations and kinetic effects. To address these challenges, a thermodynamic equilibrium-based modeling approach was developed to theoretically investigate the influence of catalytic enhancement in biomass steam gasification. The gasification process was modeled using Gibbs free energy minimization, focusing on the elemental composition of biomass and the equilibrium distribution among the major gaseous species, namely H2, CO, CO2, CH4, and H2O. The effects of the different catalyst types, including dolomite, Ni/olivine, and iron-based catalysts, were examined through catalyst-dependent activity coefficients. Simulations were carried out under steam gasification conditions at atmospheric pressure, with particular emphasis on the influence of temperature, steam-to-biomass ratio, and catalyst activity on syngas composition. The results showed that increasing catalyst activity enhanced hydrogen production while suppressing methane formation, primarily through intensified tar reforming and water–gas shift reactions. The model successfully reproduced widely accepted thermodynamic trends reported in the literature. Overall, the proposed framework can provide a flexible and computationally efficient screening-level tool for the theoretical assessment of catalytic effects in biomass gasification, offering valuable insights for preliminary catalyst selection and conceptual process design.