Key challenges in CFD modeling of biomass gasification in fluidized-bed reactors: A review

Biomass gasification in fluidized-bed reactors is an important process for producing carbon-neutral producer gas that can be used for power generation or as source of hydrogen-rich chemical feedstocks. Significant research has focused on studying biomass gasification using computational fluid dynamics (CFD) modeling tools. This review provides a comprehensive overview of CFD modeling techniques that have been employed to simulate gas-solid particulate behavior, including the Two-Fluid Model (TFM), Discrete Element Method (DEM), and Multiphase Particle-in-Cell (MP-PIC) method, as well as turbulence and drag models. The MP-PIC approach is recommended for simulating biomass gasification in large-scale fluidized-bed reactors without the need for high-resolution grids, making it computationally efficient. Additionally, the review critically analyzes thermochemical sub-models, including drying, pyrolysis, char gasification, and gas-phase reactions, along with the corresponding reaction mechanisms, rate expressions, and reacting particle models. This review focuses on key challenges in CFD modeling of fluidized-bed biomass gasifiers, including the lack of reliable kinetic parameters and stoichiometry for diverse biomass feedstocks. Finally, this review outlines recommendations for future research aimed at improving the accuracy for CFD models of biomass gasification in fluidized beds. • Biomass gasification produces carbon-neutral syngas for power generation. • Fluidized-bed gasifiers have excellent heat and mass transfer characteristics. • CFD models are crucial for understanding the hydrodynamics of biomass gasification. • MP-PIC method is suitable for simulating gasification in large-scale reactors. • Improved CFD models require pyrolysis and gasification kinetics from experiments.