(351c) CFD Modeling of Steam Gasification of Biomass in a Fluidized Bed

Authors: 
Agyemang, S., North Carolina Agricultural and Technical State University
Wang, L., North Carolina Agricultural and Technical State University
Shahbazi, A., North Carolina Agricultural and Technical State University



Gasification has been identified as an energy-efficient, environmentally-friendly and economically-feasible technology to partially oxidize biomass into a gaseous mixture of syngas consisting of H2, CO, CH4 and CO2.  High-quality syngas can be further used to catalytically synthesize liquid fuels and produce hydrogen. The gasification of biomass in a fluidized bed using steam can produce hydrogen-rich syngas, which is essential for the further catalytic synthesis of liquid fuel from the syngas. Biomass gasification involves complicated reaction pathways, reactive gas-particle behavior, and comminution of solid biomass particles. A computational fluid dynamics (CFD) model with a high order turbulence closure is developed to analyze the behavior of multiple-phase, reactive gas-particle flow during steam gasification of biomass in a fluidized bed gasifier. A commercial Fluent CFD software package is used as a basis for the computational model.  Advanced computer visualization techniques are used to observe the patterns of the gas-particle flow and comminution of solid biomass particles in the gasifier. The experimental data are used to validate the CFD model. The effects of gasifier configuration, temperature, steam/biomass ratio, biomass/bed material ratio, biomass loading rate and biomass particle size on the yield and composition of syngas are analyzed using the CFD model.