Simulation of air-biomass gasification in a bubbling fluidized bed using CPFD model

Abstract

Biomass is a renewable energy source. Biomass gasification process produces producer gas, which can be further used for power generation or as raw materials for the production of secondary fuels. Experiment on the air gasification of biomass in a bubbling fluidized bed reactor was performed in a pilot-scale reactor located at the University of South-Eastern Norway (USN). A kinetics-based simulation model was developed based on MultiPhase Particle-In-Cell MPPIC approach, using commercial software Barracuda®, and the results were compared with the experimental data. The average volume percentage of carbon monoxide, hydrogen, methane and nitrogen were found to be around 20%, 10%, 7% and 38% respectively in the experiment. The simulation results agree well for carbon monoxide, hydrogen and methane, but there is a difference in nitrogen volume percentage compared to the experimental results. The oxygen concentration during the experiment was around 1% suggesting a good performance of the gasifier. The char partial oxidation is less significant compared to the homogenous phase reactions. This shows that devolatilization reaction and the homogenous phase reactions dominate the char gasification reaction.